Publications by authors named "Jiří Skuhrovec"

44 Publications

Effect of host switching simulation on the fitness of the gregarious parasitoid Anaphes flavipes from a novel two-generation approach.

Sci Rep 2021 Sep 30;11(1):19473. Epub 2021 Sep 30.

Crop Research Institute, Drnovská 507, 161 06, Praha 6-Ruzyně, Czech Republic.

Herbivorous insects can escape the strong pressure of parasitoids by switching to feeding on new host plants. Parasitoids can adapt to this change but at the cost of changing their preferences and performance. For gregarious parasitoids, fitness changes are not always observable in the F1 generation but only in the F2 generation. Here, with the model species and gregarious parasitoid Anaphes flavipes, we examined fitness changes in the F1 generation under pressure from the simulation of host switching, and by a new two-generation approach, we determined the impact of these changes on fitness in the F2 generation. We showed that the parasitoid preference for host plants depends on hatched or oviposited learning in relation to the possibility of parasitoid decisions between different host plants. Interestingly, we showed that after simulation of parasitoids following host switching, in the new environment of a fictitious host plant, parasitoids reduced the fictitious host. At the same time, parasitoids also reduced fertility because in fictitious hosts, they are not able to complete larval development. However, from a two-generation approach, the distribution of parasitoid offspring into both native and fictitious hosts caused lower parasitoid clutch size in native hosts and higher individual offspring fertility in the F2 generation.
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http://dx.doi.org/10.1038/s41598-021-98393-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8484349PMC
September 2021

On the Affinities and Systematic Position of Schoenherr and Germar in the Tribe Lixini (Coleoptera: Curculionidae: Lixinae) Based on the Morphological Characters of the Immature Stages.

Insects 2021 May 24;12(6). Epub 2021 May 24.

Administration of Podyji National Park, Na Vyhlídce 5, CZ-669 02 Znojmo, Czech Republic.

Mature larvae and pupae of Schoenherr, 1826 and Gültekin, Diotti and Caldara, 2019 and pupae of (Frölich, 1792), belonging to the Lixini (Curculionidae: Lixinae), are morphologically described for the first time. They possess all the characters considered distinctive in the immature stages of this tribe and are distinguishable from all the related genera by a combination of some characters (e.g., presence of endocarina, shape of premental sclerite; the number of on the abdominal segments; size and presence of urogomphi). It is emphasized that the controversial tribe Rhinocyllini is not supported by the characters of the larvae and pupae of and that the two subgenera of this genus, s. str. and , are separable from each other not only by characters of the adult but also distinctive characters of the larvae and pupae. These results confirm that the morphology of the immature stages, which is usually overlooked, can be very important for the purpose of identifying new characters that are useful for clarifying taxonomical and phylogenetic complex situations based only on the study of the imagoes.
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http://dx.doi.org/10.3390/insects12060489DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8225078PMC
May 2021

Diversification, selective sweep, and body size in the invasive Palearctic alfalfa weevil infected with Wolbachia.

Sci Rep 2021 05 6;11(1):9664. Epub 2021 May 6.

Nata-Danchi, Fukuoka, Japan.

The alfalfa weevil Hypera postica, native to the Western Palearctic, is an invasive legume pest with two divergent mitochondrial clades in its invading regions, the Western clade and the Eastern/Egyptian clade. However, knowledge regarding the native populations is limited. The Western clade is infected with the endosymbiotic bacteria Wolbachia that cause cytoplasmic incompatibility in host weevils. Our aim was to elucidate the spatial genetic structure of this insect and the effect of Wolbachia on its population diversity. We analyzed two mitochondrial and two nuclear genes of the weevil from its native ranges. The Western clade was distributed in western/central Europe, whereas the Eastern/Egyptian clade was distributed from the Mediterranean basin to central Asia. Intermediate mitotypes were found from the Balkans to central Asia. Most Western clade individuals in western Europe were infected with an identical Wolbachia strain. Mitochondrial genetic diversity of the infected individuals was minimal. The infected clades demonstrated a higher nonsynonymous/synonymous substitution rate ratio than the uninfected clades, suggesting a higher fixation of nonsynonymous mutations due to a selective sweep by Wolbachia. Trans-Mediterranean and within-European dispersal routes were supported. We suggest that the ancestral populations diversified by geographic isolation due to glaciations and that the diversity was reduced in the west by a recent Wolbachia-driven sweep(s). The intermediate clade exhibited a body size and host plant that differed from the other clades. Pros and cons of the possible use of infected-clade males to control uninfected populations are discussed.
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http://dx.doi.org/10.1038/s41598-021-88770-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8102540PMC
May 2021

Direct and Knock-on Effects of Water Stress on the Nutrient Contents of Triticum aestivum (Poales: Poaceae) and Population Growth of Rhopalosiphum padi (Hemiptera: Aphididae).

J Econ Entomol 2021 Aug;114(4):1496-1508

Department of Entomology, National Chung Hsing University, Taichung, Taiwan, Republic of China.

To ascertain the direct effects of water stress upon wheat plants (Triticum aestivum L.) and how these effects, in turn, influence the population growth of the bird cherry-oat aphid (Rhopalosiphum padi L.), we conducted a physiological analysis of wheat seedlings grown under three different watering regimes and subsequently determined the population parameters of the aphid using the age-stage, two-sex life table. A significantly higher content of free amino acids and soluble sugars were observed in wheat seedlings exposed to drought stress compared to seedlings that were well-watered and those that were grown under waterlogged conditions. Extended phloem salivation and stylet penetration with shorter duration of sustained ingestion from phloem was observed in an electrical penetration graph (EPG) of R. padi on drought-stressed wheat seedlings. This suggested that the aphid's feeding activity, as well as nutrient intake, were impeded. The significantly higher percentage of essential amino acids found in wheat seedlings grown under waterlogged conditions promoted significantly higher fecundity and intrinsic rate of increase in R. padi populations compared to aphids fed on drought-treated or well-watered wheat seedlings. Our findings suggest that wheat seedling responses to water stress involve changes in sap composition that are responsible for altering the aphids' nutrient intake and consequently affect their population growth. From a grower's perspective, extending wheat cultivation in a rice-wheat rotation paddy field during the winter season may not be economically profitable if the fields are chronically waterlogged, since this may potentially lead to a higher infestation of cereal aphids.
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http://dx.doi.org/10.1093/jee/toab069DOI Listing
August 2021

Antibiosis to Metopolophium dirhodum (Homoptera: Aphididae) in Spring Wheat and Emmer Cultivars.

J Econ Entomol 2020 12;113(6):2979-2985

Functional Diversity Group, Crop Research Institute, Drnovská, Praha - Ruzyně, Czech Republic.

Yield losses caused by pests, including aphids, can be substantial in cereals. Breeding for resistance against aphids is therefore desirable for enhancing the economic and environmental sustainability of cereal production. The aim of our study was to reveal the degree of antibiosis against Metopolophium dirhodum (Walker) (Homoptera: Aphididae), in four cultivars of spring wheat, Triticum aestivum L. ('Alicia', 'Odeta', 'Libertina', 'Astrid'), and two cultivars of emmer, Triticum turgidum ssp. dicoccum (Schrank ex Schübler) Thell. ('Rudico', 'Tapiruz') (both Poales: Poaceae) under controlled laboratory conditions. Using age-stage, two-sex life table, we quantified responses of M. dirhodum to each cultivar and to project population growth. The spring wheat and emmer cultivars varied in their suitability to M. dirhodum. The cultivar most susceptible to M. dirhodum was the emmer cultivar 'Rudico'; the projected population size of M. dirhodum on this cultivar was one order of magnitude larger than those on other cultivars. The most resistant cultivar was the spring wheat cultivar 'Libertina'. Since emmer is commonly used as a gene source for breeding T. aestivum, we advocate that care be taken to avoid the transmission of genes responsible for suitability to aphids from emmer to T. aestivum.
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http://dx.doi.org/10.1093/jee/toaa234DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7792919PMC
December 2020

Data on Herbivore Performance and Plant Herbivore Damage Identify the Same Plant Traits as the Key Drivers of Plant-Herbivore Interaction.

Insects 2020 Dec 4;11(12). Epub 2020 Dec 4.

Crop Research Institute, 161 06 Prague, Czech Republic.

Data on plant herbivore damage as well as on herbivore performance have been previously used to identify key plant traits driving plant-herbivore interactions. The extent to which the two approaches lead to similar conclusions remains to be explored. We determined the effect of a free-living leaf-chewing generalist caterpillar, (Lepidoptera: Noctuidae), on leaf damage of 24 closely related plant species from the Carduoideae subfamily and the effect of these plant species on caterpillar growth. We used a wide range of physical defense leaf traits and leaf nutrient contents as the plant traits. Herbivore performance and leaf damage were affected by similar plant traits. Traits related to higher caterpillar mortality (higher leaf dissection, number, length and toughness of spines and lower trichome density) also led to higher leaf damage. This fits with the fact that each caterpillar was feeding on a single plant and, thus, had to consume more biomass of the less suitable plants to obtain the same amount of nutrients. The key plant traits driving plant-herbivore interactions identified based on data on herbivore performance largely corresponded to the traits identified as important based on data on leaf damage. This suggests that both types of data may be used to identify the key plant traits determining plant-herbivore interactions. It is, however, important to carefully distinguish whether the data on leaf damage were obtained in the field or in a controlled feeding experiment, as the patterns expected in the two environments may go in opposite directions.
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http://dx.doi.org/10.3390/insects11120865DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7762045PMC
December 2020

Description and biological notes of the larva of Rosenschoeld, 1838 (Coleoptera, Curculionidae), with a comparison with other species of the tribe Cionini.

Zookeys 2020 20;976:131-145. Epub 2020 Oct 20.

Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China Chinese Academy of Sciences Beijing China.

The mature larva of Rosenschoeld, 1838 is described and illustrated in detail for the first time. It is compared with those known from the same genus and other genera in the tribe Cionini and with those of the hypothesized sister tribe Mecinini in the Curculioninae. The larvae of have three distinctive diagnostic features: the reduced number of setae on the epicranium (only two or three and one or two ) and on the epipharyngeal lining (only two , two , and no ); i.e., distinctly fewer than the most frequent number of setae in weevils, and mandibles dentate or angulate internally near the base. If considered together with Suffrian, 1854, the other genus of Cionini with larvae studied in detail, it is preliminarily suggested that mature larvae of this tribe might be characterized by six main diagnostic features: (1) labial palpi one-segmented, (2) labral rods absent, (3) pedal areas swollen to form large lobes or prolegs, (4) mandible with sharp apical teeth, (5) reduced number of on frons, only one or two , and (6) reduced number of epipharyngeal setae (two or three and two or three , but no ). It was noticed that Reitter, 1904 from Japan, a very distinct species in the genus for some characters of the adult, also possesses distinctive characters in the larva which are uncommon among known cionines. New biological data on with the discovery of its host plant, (Scrophulariaceae), in central Asia are also reported.
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http://dx.doi.org/10.3897/zookeys.976.53930DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7591547PMC
October 2020

The resilience of weed seedbank regulation by carabid beetles, at continental scales, to alternative prey.

Sci Rep 2020 11 9;10(1):19315. Epub 2020 Nov 9.

Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne Franche-Comté, 17 rue Sully, BP 86510, 21065, Dijon Cedex, France.

Carabids are generalist predators that contribute to the agricultural ecosystem service of seedbank regulation via weed seed predation. To facilitate adoption of this ecosystem services by farmers, knowledge of weed seed predation and the resilience of seedbank regulation with co-varying availability of alternative prey is crucial. Using assessments of the seedbank and predation on seed cards in 57 cereal fields across Europe, we demonstrate a regulatory effect on the soil seedbank, at a continental scale, by groups formed of omnivore, seed-eating (granivore + omnivore) and all species of carabids just prior to the crop-harvest. Regulation was associated with a positive relationship between the activity-density of carabids and seed predation, as measured on seed cards. We found that per capita seed consumption on the cards co-varied negatively with the biomass of alternative prey, i.e. Aphididae, Collembola and total alternative prey biomass. Our results underline the importance of weed seedbank regulation by carabids, across geographically significant scales, and indicate that the effectiveness of this biocontrol may depend on the availability of alternative prey that disrupt the weed seed predation.
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http://dx.doi.org/10.1038/s41598-020-76305-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7652833PMC
November 2020

A new, peculiar genus of Cossoninae (Coleoptera, Curculionidae) from Oman with description of a new species, larva and notes on biology.

Zootaxa 2020 Apr 30;4768(1):zootaxa.4768.1.8. Epub 2020 Apr 30.

Department of Entomology, National Museum, Natural History Museum, Cirkusová 1740, CZ-193 00 Praha 9 - Horní Počernice, The Czech.

A new genus and species of the subfamily Cossoninae, Omanocossonus sabulosus gen. et sp. nov. is described from Oman. All specimens including larvae were found on sand dunes on the seashore in roots of Calotropis procera (Aiton) W.T. Aiton. The crucial features, including male and female terminalia, are illustrated, and the taxonomic position of the new genus within Cossoninae is briefly discussed. The generic status of Lindbergius Roudier, 1957 is resurrected. The mature larva of the new species is described, larval morphology is discussed and the current state of knowledge about immature stages of Cossoninae is summarized.
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http://dx.doi.org/10.11646/zootaxa.4768.1.8DOI Listing
April 2020

Immature stages of Palearctic species (Coleoptera, Curculionidae, Curculioninae): morphological characters diagnostic at genus and species levels.

Zookeys 2020 9;939:87-165. Epub 2020 Jun 9.

CABI, Rue des Grillons 1, 2800 Delémont, Switzerland Institute for Plant Protection and Environment Zemun Serbia.

The immature stages of ten species are described for the first time and those of two other species are redescribed, adding important chaetotaxy characters that were missing from previous descriptions. These species belong to six of the nine assemblages of species previously established according to a phylogenetic analysis. All these groupings are confirmed on the basis of several characters of mature larvae and pupae. Moreover, all the species show several characters that are useful for distinguishing them from each other, including cryptic species that previously had few differential characters. Some characters that may be useful for separating from other genera in the tribe are suggested. To confirm the taxonomic identification of some larvae, the mtCOII gene was obtained and compared with sequences from identified adult specimens. The most important characters for separating the immature stages of the genera and species groups in are the number of palpomeres of the labial palpi (1 or 2), the number of air tubes of the thoracic and abdominal spiracles (unicameral or bicameral), and the number of epipharyngeal setae. The species studied herein were compared with those known from other genera in the tribe Mecinini. Two keys, one to the described larvae and the other to the pupae, are provided. Detailed biological data, several of which are new, on some species are reported.
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http://dx.doi.org/10.3897/zookeys.939.50612DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7297811PMC
June 2020

Host Specificity of the Parasitic Wasp (Hymenoptera: Mymaridae) and a New Defence in Its Hosts (Coleoptera: Chrysomelidae: spp.).

Insects 2020 Mar 10;11(3). Epub 2020 Mar 10.

Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 43 Prague 2, Czech Republic.

The parasitic wasp (Förster, 1841) (Hymenoptera: Mymaridae) is an important egg parasitoid of cereal leaf beetles. Some species of cereal leaf beetle co-occur in the same localities, but the host specificity of the wasp to these crop pests has not yet been examined in detail. A lack of knowledge of host specificity can have a negative effect on the use of this wasps in biological control programs addressed to specific pest species or genus. In this study, laboratory experiments were conducted to assess the host specificity of for three species of cereal leaf beetles ( Redtenbacher, 1874, Heyden, 1879 and Linnaeus, 1758) in central Europe. For the first time, a new host defence against egg parasitoids occurring in from localities in the Czech Republic, a strong dark sticky layer on the egg surface, was found and described. The host specificity of was studied in the locality with the presence of this defence on eggs (the dark sticky layer) (Czech Republic) and in a control locality (Germany), where no such host defence was observed. Contrary to the idea that a host defence mechanism can change the host specificity of parasitoids, the wasps from these two localities did not display any differences in that. Respectively, even though it has been observed that eggs with sticky dark layer can prevent parasitization, the overall rate of parasitization of the three species of cereal beetles has not been affected. However, in our view, new host defence can influence the effects of biological control, as eggs of all spp. in the locality are protected against parasitization from the wasps stuck on the sticky layer of the host eggs of .
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http://dx.doi.org/10.3390/insects11030175DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7143892PMC
March 2020

Two new genera of Trachyphloeini with a key to the genera of small terricolous South African Trachyphloeini and Embrithini (Coleoptera: Curculionidae: Entiminae).

Zootaxa 2019 Nov 12;4695(5):zootaxa.4695.5.3. Epub 2019 Nov 12.

Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Department of Forest Protection and Entomology, Kamýcká 1176, CZ-165 21 Praha 6-Suchdol, Czech Republic..

Two new genera, Barclayanthus Borovec Skuhrovec, gen. nov. and  Janakius Borovec Skuhrovec, gen. nov., assigned to the tribe Trachyphloeini Lacordaire, 1863, are described for three South African species of weevil: Barclayanthus micros Borovec Skuhrovec, sp. nov., B. cooteri Borovec Skuhrovec, sp. nov. and Janakius sylvaticus Borovec Skuhrovec, sp. nov. All species are illustrated and keyed. The taxonomic status of each of the new genera is discussed, and compared with similar genera of Trachyphloeini and Embrithini Marshall, 1942. A key to known small terricolous South African genera of both Trachyphloeini and Embrithini is included.
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http://dx.doi.org/10.11646/zootaxa.4695.5.3DOI Listing
November 2019

The mature larva and pupa of Tychius subsulcatus Tournier, 1847 (Coleoptera, Curculionidae), with comments on its biology and phylogenetic relationships.

Zootaxa 2019 Mar 19;4568(1):zootaxa.4568.1.10. Epub 2019 Mar 19.

Department of Environmental Ecology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, SK-842 15 Bratislava, Slovakia..

The larva and the pupa of the Palaearctic weevil species Tychius subsulcatus Tournier, 1847 are described and illustrated for the first time. The characters of larva and pupa of T. subsulcatus completely fit the described differential diagnosis of the subtribe Tychiina, genus Tychius, and also Tychius intrusus group. Astragalus onobrychis Linnaeus is confirmed as its host plant. The biology of T. subsulcatus in south Slovakia (Cerová vrchovina Mts.) is described.
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http://dx.doi.org/10.11646/zootaxa.4568.1.10DOI Listing
March 2019

A taxonomic study of the South African terricolous weevil genus Pentatrachyphloeus Voss (Coleoptera: Curculionidae: Entiminae: Trachyphloeini).

Zootaxa 2019 Mar 29;4574(1):zootaxa.4574.1.1. Epub 2019 Mar 29.

Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Department of Forest Protection and Entomology, Kamýcká 1176, CZ-165 21 Praha 6-Suchdol, Czech Republic..

The genus Pentatrachyphloeus Voss, 1974, with two known species, is redefined and compared with related genera. An additional thirty seven new species are described here: P. andersoni sp. nov. (South Africa, Mpumalanga); P. baumi sp. nov. (South Africa, Gauteng); P. brevithorax sp. nov. (South Africa, KwaZulu-Natal); P. bufo sp. nov. (South Africa, Mpumalanga); P. endroedyi sp. nov. (South Africa, Mpumalanga); P. exiguus sp. nov. (South Africa, Mpumalanga); P. frici sp. nov. (South Africa, Limpopo); P. grobbelaarae sp. nov. (South Africa, KwaZulu-Natal); P. hanzelkai sp. nov. (South Africa, KwaZulu-Natal); P. holubi sp. nov. (South Africa, Mpumalanga); P. howdenae sp. nov. (South Africa, Mpumalanga); P. hystrix sp. nov. (South Africa, Mpumalanga); P. insignicornis sp. nov. (South Africa, KwaZulu-Natal); P. kalalovae sp. nov. (South Africa, Gauteng); P. kuscheli sp. nov. (South Africa, KwaZulu-Natal); P. laevis sp. nov. (South Africa, Mpumalanga); P. lajumensis sp. nov. (South Africa, Limpopo); P. leleupi sp. nov. (Zimbabwe, Manica); P. lesothoensis sp. nov. (Lesotho, Qacha's Nek); P. machulkai sp. nov. (South Africa, Free State); P. marshalli sp. nov. (South Africa, KwaZulu-Natal); P. muellerae sp. nov. (South Africa, Mpumalanga); P. musili sp. nov. (South Africa, Limpopo); P. ntinini sp. nov. (South Africa, KwaZulu-Natal); P. oberprieleri sp. nov. (South Africa, Gauteng, North West); P. pavlicai sp. nov. (South Africa, Free State); P. rudyardi sp. nov. (South Africa, Limpopo); P. schoemani sp. nov. (South Africa, Limpopo); P. soutpansbergensis sp. nov. (South Africa, Limpopo); P. spinimanus sp. nov. (South Africa, Mpumalanga); P. stingli sp. nov. (South Africa, Limpopo); P. tenuicollis sp. nov. (South Africa, Mpumalanga); P. tuberculatus sp. nov. (South Africa, Mpumalanga); P. vavrai sp. nov. (South Africa, Eastern Cape); P. vossi sp. nov. (South Africa, Mpumalanga); P. vrazi sp. nov. (South Africa, Limpopo) and P. zikmundi sp. nov. (South Africa, Free State). All of the species are keyed and illustrated; ecological information is presented only where available. All species seem to be very localised, being known only from one or only a very limited number of localities. Immature stages or host plants are not known for any of the species. The species are distributed as follows: South Africa: Mpumalanga (13), Limpopo (8), KwaZulu-Natal (7), Free State (3), Gauteng (3), Eastern Cape (3), North West (1); Lesotho: Qacha's Nek (1) and Zimbabwe: Manica (1).
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http://dx.doi.org/10.11646/zootaxa.4574.1.1DOI Listing
March 2019

Insecticidal and Behavioral Effect of Microparticles of Pimpinella anisum Essential Oil on Larvae of Leptinotarsa decemlineata (Coleoptera: Chrysomelidae).

J Econ Entomol 2020 02;113(1):255-262

Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamýcká 129, 165 00 Prague 6 - Suchdol, Czech Republic.

The Colorado potato beetle ranks as one of the most important potato pests, mainly due to its high feeding rate during all developmental stages, particularly third and fourth larval instar, and high fecundity. The effect of essential oil (EO) from anise (Pimpinella anisum L. [Apiales: Apiaceae]) prepared as conventional and encapsulated (EN) formulations on the mortality and antifeedant responses of young larvae of Colorado potato beetles was studied to evaluate the insecticidal and antifeedant effects of five concentrations of this EO and to assess the persistence of both formulations on potato plants. The EN formulation had a significantly higher residual amount compared with that of the conventionally formulated EO. Significantly different values of LC50 and LC90 (ppm) were established for the EO (LC50 = 1,700 and LC90 = 9500) and EN (LC50 = 3,100 and LC90 = 14,300) formulations. The effects of both P. anisum formulations (EO and EN) applied topically to Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) larvae were distinctly different from those observed with the contact treatment. At the highest concentration of 20,000 ppm, the mortality of the second instars of the L. decemlineata larvae did not exceed 25%. On the other hand, both tested formulations of P. anisum were highly effective when administered orally. The encapsulated EO formulation achieved a distinctly higher biological activity. Our results confirm that the EO from P. anisum, especially the encapsulated formulation, has high insecticidal properties that may lead to the development of new organic products for the control of Colorado potato beetles.
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http://dx.doi.org/10.1093/jee/toz279DOI Listing
February 2020

(Scopoli, 1763) (Coleoptera: Curculionidae: Lixinae): Morphological Re-Description of the Immature Stages, Keys, Tribal Comparisons and Biology.

Insects 2019 Sep 30;10(10). Epub 2019 Sep 30.

Department of Ecology & Environmental Sciences, Faculty of Science, Palacký University Olomouc, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.

Mature larvae and pupae of (Scopoli, 1763) (Curculionidae: Lixinae: Cleonini) are morphologically described in detail for the first time and compared with known larvae and pupae of other Cleonini species. The results of measurements and characteristics most typical for larvae and pupae of Cleonini are newly extracted and critically discussed, along with some records given previously. Keys for the determination of selected Cleonini species based on their larval and pupal characteristics are attached. Dyar's law was used for the estimation of a number of larval instars of Descriptions of habitats, adult behavior, host plants, life cycle, and biotic interactions are reported here. Adults and larvae feed on plants from the Asteraceae family only (genera , , , and ). Oviposition occurs on the base of the plant stem or the root neck. In the process of larval development, a fusiform gall forms. and can coexist in the same locality. In open habitats, the weevils become the prey of carnivorous animals.
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http://dx.doi.org/10.3390/insects10100325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6836170PMC
September 2019

Host population density and presence of predators as key factors influencing the number of gregarious parasitoid Anaphes flavipes offspring.

Sci Rep 2019 04 15;9(1):6081. Epub 2019 Apr 15.

Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 43, Praha 2, Czech Republic.

The number of parasitoids developed per host is one of the major factors that influences future adult body size and reproductive success. Here, we examined four external factors (host species, heritability, host population density, and presence of predators) that can affect the number of the gregarious parasitoid Anaphes flavipes (Förster, 1841) (Hymenoptera: Mymaridae) wasps developing in one host. The effect of host population density on the number of parasitoid offspring developed per host was confirmed, and for the first time, we also showed that the number of offspring per host is influenced by the presence of predators. Low host density and presence of predators increases the number of wasps developed in one host egg. However, a higher number of A. flavipes in one host reduces A. flavipes body size and hence its future individual fertility and fitness. Our results highlighted the importance of some external factors that distinctly affect the number of wasp offspring. Therefore, in this context, we suggest that in comparison to solitary parasitoids, the gregarious parasitoid A. flavipes can better respond to various external factors and can more flexibly change its population density.
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http://dx.doi.org/10.1038/s41598-019-42503-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6465251PMC
April 2019

Morphological characters of immature stages of Palaearctic species of and and their systematic value in Mecinini (Coleoptera, Curculionidae, Curculioninae).

Zookeys 2018 18(808):23-92. Epub 2018 Dec 18.

University of Life Sciences in Lublin, ul. Akademicka 13, 20-950 Lublin, Poland University of Life Sciences in Lublin Lublin Poland.

The relationship between the genera and of Mecinini (Curculionidae, Curculioninae) was tested on the basis of morphological characters from the immature stages. The mature larvae of five species ( (Boheman, 1845), (Gyllenhal, 1813), (Gyllenhal, 1838), (Desbrochers des Loges, 1893), and (H. Brisout de Barneville, 1863)), three species ( Solari, 1947, (Herbst, 1795), and (Linnaeus, 1767)), and the pupae of four species (, , , and ) and two species ( and ) are described in detail for the first time. To confirm the taxonomic identification of some larvae, DNA COI barcode was obtained and compared with those of adults. The immature stages of the species herein studied were compared with those known from other genera in tribe Mecinini. It is suggested that and may be monophyletic based on several shared distinctive characters. Larvae of have a characteristic maxillary mala with six finger-like of two sizes (one or two very long and the rest of medium length), this feature being apparently unique among weevils. Other genus-specific character states are observed in the pupae, such as the length of setae on the head, rostrum and pronotum, including the number of on the rostrum, on pronotum, and finally the shape of the urogomphi. A key to the described larvae and pupae were respectively presented. New biological and distributional data on some species are reported.
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http://dx.doi.org/10.3897/zookeys.808.28172DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6305772PMC
December 2018

Differences in the Phenology of Harmonia axyridis (Coleoptera: Coccinellidae) and Native Coccinellids in Central Europe.

Environ Entomol 2019 02;48(1):80-87

Department of Nonlinear Modeling, Institute of Computer Science AS CR, Prague, Czech Republic.

Harmonia axyridis (Pallas), an invasive non-native species in central Europe, can outcompete other aphidophagous species. The distribution and abundance of H. axyridis vary depending on different host plants, and its effects on native coccinellid communities may change accordingly. The distribution and abundance of coccinellids in central Europe (50°N, 14°E) were investigated from 2010 to 2016. Coccinellids were counted at regular intervals on cereals (Avena, Hordeum, and Triticum), herbaceous plants (Matricaria and Urtica) and trees (Acer, Betula, and Tilia). Additionally, the occurrence over time of each species on these plants was assessed and used as an index of persistence. Across all years, the adults and larvae of H. axyridis were the dominant species of coccinellid on trees. However, H. axyridis was less abundant on herbaceous plants and cereals than on trees. Populations of native coccinellids and H. axyridis co-occurred on trees and persisted for the same length of time, while native coccinellids persisted longer than H. axyridis on herbaceous plants and cereals. Compared to 1976-1986, in the 2010s, the abundance of native species decreased on all plants by 50-70%. The presence of H. axyridis could be considered as a factor driving changes in the assemblages of native coccinellids.
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http://dx.doi.org/10.1093/ee/nvy173DOI Listing
February 2019

Conotrachelus dimidiatus Champion, 1904 (Coleoptera: Curculionidae: Molytinae): morphological re-description of the immature stages, keys, tribal comparisons and biology.

Zootaxa 2018 Jun 11;4433(1):127-140. Epub 2018 Jun 11.

Centro de Agroecología, Instituto de Ciencias, Universidad Autónoma de Puebla, Mexico, Edif. VAL 1, km 1.7 Carretera San Baltazar Tetela, CP 72960, San Pedro Zacachimalpa..

The mature larva and pupa of Conotrachelus dimidiatus Champion, 1904 (Curculionidae: Molytinae) are morphologically re-described, keyed and, for the first time, compared with known larvae and pupae of other Conotrachelus species. The chaetotaxy of the larval and pupal body in the genus Conotrachelus is probably strictly uniform. The immature stages of described species are also compared with available data on the immature stages of genera from several tribes in the subfamily Molytinae. All larvae of Conotrachelus have a distinct endocranial line of a different size and a frons with only three setae. The states of these two distinct characteristics in larvae of the eight known Conotrachelus species are constant and unique compared to other tribes in the subfamily Molytinae. In Central Mexico, overwintering Conotrachelus beetles emerge in July and then feed and mate on host plants. Larvae are endophagous within the fruits. In September and October, the larvae pupate in the soil. This new information will be very useful in the application of pesticides to the fight against this well-known pest in Mexico.
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http://dx.doi.org/10.11646/zootaxa.4433.1.7DOI Listing
June 2018

Revision of the species related to Lalagetes subfasciatus Boheman and transfer of remaining Lalagetes species to other genera of Embrithini (Coleoptera: Curculionidae: Entiminae).

Zootaxa 2018 Jan 17;4374(1):71-90. Epub 2018 Jan 17.

Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Department of Forest Protection and Entomology, Kamýcká 1176, CZ-165 21 Praha 6-Suchdol, Czech Republic..

The genus Lalagetes Schoenherr, 1842 is redefined, compared with related genera and all known species placed among three genera. Four new species from South Africa are described: L. andersoni sp. nov. (Mpumalanga), L. howdenorum sp. nov. (Limpopo), L. sarkae sp. nov. (KwaZulu-Natal) and L. zitae sp. nov. (KwaZulu-Natal). Lectotypes of Lalagetes seminulum Fåhraeus, 1871 and L. subfasciatus Boheman, 1842 are designated here, and both species redescribed. All of the following species are keyed and illustrated. The following new combinations are proposed: Glyptosomus edax (Marshall, 1939), G. inaequalis (Marshall, 1941), G. leurops (Marshall, 1931), G. setosus (Boheman, 1845), G. squamulatus (Boheman, 1842), G. subfrenatus (Marshall, 1947b), G. variegatus (Boheman, 1845), Phaylomerinthus hispidus (Hartmann, 1906), P. nanus (Marshall, 1947a), P. pallipes (Fåhraeus, 1871), P. parcus (Marshall, 1947a), P. rudis (Marshall, 1958), P. signatus (Hartmann, 1906) and P. viridulus (Fåhraeus, 1871).
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http://dx.doi.org/10.11646/zootaxa.4374.1.4DOI Listing
January 2018

Systematic position of the Afrotropical species described in Trachyphloeini (Coleoptera: Curculionidae: Entiminae).

Zootaxa 2017 Nov 8;4344(3):522-540. Epub 2017 Nov 8.

Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Department of Forest Protection and Entomology, Kamýcká 1176, CZ-165 21 Praha 6-Suchdol, Czech Republic. E-mail:.

The Afrotropical species described as Trachyphloeini Lacordaire, 1863 were examined and their taxonomic status is revised. Atrachyphloeus Voss, 1962 is proposed as a junior synonym of Phaylomerinthus Schoenherr, 1842, Cathormiocerus africanus Hoffmann, 1965 as a junior synonym of Tapinomorphus sylvicola Voss, 1962 and Trachyphloeus pustulifer Voss, 1959 as a junior synonym of Platycopes tuberculatus Marshall, 1906. Atrachyphloeus convergens Voss, 1962 is transferred to the genus Phaylomerinthus Schoenherr, 1842, Trachyphloeus hardenbergi Marshall, 1923 and T. notulatus Boheman, 1842 to Glyptosomus Schoenherr, 1847, Trachyphloeus nanus Fåhraeus, 1871 to Pentatrachyphloeus Voss, 1974, Trachyphloeus pustulifer Voss, 1959 to Platycopes Schoenherr, 1823 and Trachyphloeus setiger Fåhraeus, 1871 to Phaylomerinthus Schoenherr, 1842. "Trachyphloeosoma" brevicolle Voss, 1974, "Trachyphloeus" brevis Boheman, 1842, "T". nodifrons Hoffmann, 1968 and "T". squalidus Boheman, 1842 are provisionally left in their current genera, but new genera for them will be described in future papers. The genus Phaylomerinthus Schoenherr, 1842 has been redefined and redescribed. Lectotypes for the following species are designated (current names added in brackets where different): Cathormiocerus africanus Hoffmann, 1965 (Tapinomorphus sylvicola Voss, 1962), Trachyphloeus hardenbergi Marshall, 1923 (Glyptosomus hardenbergi (Marshall, 1923)), Trachyphloeus nanus Fåhraeus, 1871 (Pentatrachyphloeus nanus (Fåhraeus, 1871)), Trachyphloeus notulatus Boheman, 1842 (Glyptosomus notulatus (Boheman, 1842)), Trachyphloeus pustulifer Voss, 1959 (Platycopes tuberculatus (Marshall, 1906)), Trachyphloeus setiger Fåhraeus, 1871 (Phaylomerinthus setiger (Fåhraeus, 1871)), "Trachyphloeus" brevis Boheman in Schoenherr, 1842 and "Trachyphloeus" squalidus Boheman in Schoenherr, 1842. Two paralectotypes of Cathormiocerus africanus Hoffmann, 1965 from Tanzania are described as a new species, Tapinomorphus franzi sp. n. All type specimens are illustrated.
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http://dx.doi.org/10.11646/zootaxa.4344.3.5DOI Listing
November 2017

Estimating Prey Consumption in Natural Populations of Harmonia axyridis (Coleoptera: Coccinellidae) Using Production of Feces.

J Econ Entomol 2017 12;110(6):2406-2412

Crop Research Institute, Group Functional Diversity of Invertebrates and Plants in Agro-Ecosystems, Czech Republic.

Production of feces (PF) is a useful proxy indicating quantity of ingested food. Although influenced by many uncontrolled factors PF provides insight into food consumption under natural conditions. In Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) variation in PF was investigated in populations of various hostplants at localities of central Bohemia (50N, 14E), throughout the season of 2016. The adults collected from these hostplants were starved for 48 h at standard conditions, and dry mass of feces produced during this period was measured. Despite enormous differences in PF among individuals, significant variation over the season occurred in average PF of both males and females. PF increased with abundance of aphids and was significantly greater in females than males. Gravidity, as manifested through oviposition within 48 h after capture, was associated with increased PF, while hostplant and color morph did not affect variation in PF among individuals. From PF as measured in this study, it can be estimated that at sites hosting abundant aphid populations H. axyridis (as an adult male or female) may consume 19 (male) to 45 (female) aphids per day (assumed body length 1mm). In the absence of aphids, adults may consume one to nine individuals of alternative prey per day (body length 1-2 mm).
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http://dx.doi.org/10.1093/jee/tox294DOI Listing
December 2017

Revision of the genus , with the description of a new species (Coleoptera, Curculionidae, Hyperini).

Zookeys 2017 18(709):71-85. Epub 2017 Oct 18.

Depto. de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC). José Gutiérrez Abascal, 2. E-28006, Madrid, Spain.

The new species, is described, keyed, and illustrated. This enigmatic new species has seven desmomeres as other Hyperini-species, but according to shape of elytra and aedeagus, which are typical for representatives of , it is treated in this genus. The actualised key and check-list of is presented. The taxonomical position and status of the genus within the tribe Hyperini is also discussed here.
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http://dx.doi.org/10.3897/zookeys.709.14877DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5674169PMC
October 2017

Description of the immature stages of and notes on its biology (Coleoptera, Curculionidae, Lixinae).

Zookeys 2017 12(679):107-137. Epub 2017 Jun 12.

Department of Zoology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.

Mature larva and pupa of (Olivier, 1807) (Curculionidae: Lixinae: Lixini) are morphologically described for the first time and compared with known larvae and pupae of other species. Very high counts of larval body setae (pronotum with more than 25 setae and postdorsum on meso- and metathorax and also on abdominal segments I-VII with more than 12 setae) are characteristic features of the nominotypical subgenus Larinus. The biology of the species was studied in Ukraine. and were identified as host plants of both larvae and adults of this weevil based on the present research in Ukraine, which shows probably oligophagous. Overwintering beetles emerged at the end of May or earlier, then feeding and mating on the host plants. The highest level of adult activity was observed at the end of June. Larvae were endophagous within the flower heads. In July and August, the larvae pupated within inflorescences in a pupation cell. Adults exited the cells at the end of August and did not hibernate on the host plants. Sometimes, larvae and imagines of a new generation were found outside the flower heads in chambers constructed on the stems.
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http://dx.doi.org/10.3897/zookeys.679.12560DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5523399PMC
June 2017

Spatial and temporal changes in the abundance and compostion of ladybird (Coleoptera: Coccinellidae) communities.

Curr Opin Insect Sci 2017 04 10;20:61-67. Epub 2017 Apr 10.

Group Function of Invertebrate and Plant Biodiversity in Agro-ecosystems, Crop Research Institute, 16106 Prague 6-Ruzyně, Czech Republic.

Because of their services to agriculture most ladybirds (Coleoptera: Coccinellidae) are intensively studied predators of mainly phytophagous pests. The study of the long-term variation in the composition of their communities was stimulated by recent dramatic changes in the abundance of some species. We review and evaluate possible effects of the main causes cited in the literature. Agricultural and habitat changes (particularly urbanization) affect coccinellid abundance, both negatively and positively. In the temperate zone dominant species occur most frequently associated with abundant prey populations on crops, weeds and planted stands of trees resulting from human activity. Invasive non-native species of coccinellids may endanger native species through intraguild predation or competition for resources, but their supposed serious negative effects on native species can differ considerably. Climatic change may influence coccinellid species in several ways, including indirect effects through lower trophic levels and desynchronisation of the phenologies of host plants, prey and coccinellid populations. In the near future we do not expect climate warming to have important effects on ladybird diversity globally, but local changes in the composition of coccinellid communities and abundance of particular species could occur.
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http://dx.doi.org/10.1016/j.cois.2017.04.001DOI Listing
April 2017

Treating Prey With Glyphosate Does Not Alter the Demographic Parameters and Predation of the Harmonia axyridis (Coleoptera: Coccinellidae).

J Econ Entomol 2017 Apr;110(2):392-399

Crop Research Institute, Group Functional Diversity of Invertebrates and Plants in Agro-Ecosystems, Drnovská 507, Prague 6 - Ruzyne, 161 06 Czech Republic

Glyphosate is an herbicide that is used worldwide with potential environmental risks to nontarget organisms. We applied an age-stage, two-sex life table approach to assess the sublethal effects of short-term oral exposure to a glyphosate-based herbicide on the life table parameters and biocontrol potential of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). Aphids (Metopolophium dirhodum (Walker) (Sternorrhyncha: Aphididae)) treated with herbicide (an isopropylamine-salt of glyphosate) at low recommended, maximum recommended, and double the maximum recommended concentration for agricultural situations, and untreated controls were offered to the fourth instar of H. axyridis for 24 h. Development, consumption, and fecundity were measured daily until death. We detected minor differences in the hatching rate and mean generation time, whereas the longevity, fecundity, net reproductive rate, intrinsic rate of increase, finite rate of increase, and consumption were unaffected across treatments. We conclude that biocontrol potential of H. axyridis was not affected by acute oral intoxication by a glyphosate-based herbicide during the larval stage for 24 h under the study design.
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http://dx.doi.org/10.1093/jee/tow325DOI Listing
April 2017

Velcro-Like System Used to Fix a Protective Faecal Shield on Weevil Larvae.

PLoS One 2017 26;12(1):e0170800. Epub 2017 Jan 26.

Department of Science, University Roma Tre, Rome, Italy.

The last instar larva and pupa of Eucoeliodes mirabilis (A. Villa & G. B. Villa, 1835) (Curculionidae: Ceutorhynchini) are described using drawings and SEM images and are compared and keyed with already described larvae of 58 other ceutorhynchinae taxa. The larval body has an effective combination of morphological adaptations that assist a unique biological defensive strategy. All larval stages of E. mirabilis feed ectophytically on leaves of Euonymus europaeus L. (Celastraceae), and the larval body is covered with a thick faecal shield. The fixation of this protective shield on the larval back is performed by a peculiar dorsal microsculpture composed of a dense carpet of microtrichia on the thorax and abdomen, which serves effectively as a velcro system. Because of this strategy, macrosetae on the larval and pupal body of E. mirabilis are completely reduced. Larvae of E. mirabilis also have distinct morphological adaptations for protecting the spiracles against intrusion of faeces and avoiding occlusion of the tracheal system: a) microtrichia around spiracles are slightly shorter, distinctly stronger and are arranged with high-density and in clusters and b) spiracles are protected by an external safety valve. This strategy of E. mirabilis larvae is unique, although somewhat similar to that of Criocerinae and Blepharida-group leave beetles (Galerucinae) (both Coleoptera: Chrysomelidae), but with distinctly different morphological adaptations.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0170800PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5268442PMC
August 2017

Contrasting effects of ploidy level on seed production in a diploid tetraploid system.

AoB Plants 2016 Dec 23. Epub 2016 Dec 23.

Group Function of Invertebrate and Plant Biodiversity in Agro-ecosystems, Crop Research Institute, Prague, Czech Republic.

Previous studies demonstrated the effects of polyploidy on various aspects of plant life. It is, however, difficult to determine which plant characteristics are responsible for fitness differences between cytotypes. We assessed the relationship between polyploidy and seed production. To separate the effects of flowering phenology, flower head size and herbivores from other possible causes, we collected data on these characteristics in single flower heads of diploid and tetraploid Centaurea phrygia in an experimental garden. We used structural equation modelling to identify the main pathways determining seed production. The results showed that the relationship between polyploidy and seed production is mediated by most of the studied factors. The different factors acted in opposing directions. Wider flower heads displayed higher above the ground suggested higher seed production in diploids. In contrast, earlier flowering and a lower abundance of herbivores suggested higher seed production in tetraploids. However, because phenology was the strongest driver of seed production in this system, the sum of all the pathways suggested greater seed production in tetraploids than in diploids. The pathway linking ploidy level directly to seed production, representing unstudied factors, was not significant. This suggests that the factors studied likely are drivers of the between-cytotype differences. Overall, this study demonstrated that tetraploids possess overall higher fitness estimated as seed production. Regardless of the patterns observed here, strong between year fluctuations in the composition and diversity of insect communities have been observed. The direction of the selection may thus vary between years. Consequently, understanding the structure of the interactions is more important for understanding the system than the overall effects of cytotype on a fitness trait in a specific year. Such knowledge can be used to model the evolution of species traits and plant-herbivore and plant-pollinator interactions in diploid-polyploid systems.
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http://dx.doi.org/10.1093/aobpla/plw077DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5499820PMC
December 2016

A new species of the genus Corimalia Gozis, 1885 (Coleoptera: Brentidae: Nanophyinae) from the Caucasus.

Zootaxa 2016 Sep 21;4169(3):571-578. Epub 2016 Sep 21.

Group Function of Invertebrate and Plant Biodiversity in Agrosystems, Crop Research Institute, Drnovská 507, CZ-161 06 Praha 6 - Ruzyně, Czech Republic.; Email:

Corimalia strejceki Schön& Skuhrovec,sp. nov. is described and illustrated from the Caucasus, Russia. The new species is compared with the allopatric C. aliena (Faust, 1890) differing in size, shape of scales, scale patch close to the scutellum, size of mucrones on the meso- and metatibiae, and also shape of the apex of the penis. Controversy over the number of segments in the antennae in the genus Corimalia is summarized. An annotated catalogue and key of all Corimaliini species in the Caucasus is provided.
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http://dx.doi.org/10.11646/zootaxa.4169.3.9DOI Listing
September 2016
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