Publications by authors named "Andrew G S Cuthbertson"

36 Publications

Characterization and Toxicity of Crude Toxins Produced by against (Gennadius) and (Koch).

Toxins (Basel) 2021 03 18;13(3). Epub 2021 Mar 18.

Key Laboratory of Bio-Pesticide Innovation and Application, Guangzhou 510642, China.

, an insect pathogenic fungus, produces different toxins/secondary metabolites which can act as pest control agents. This study reports the extraction and characterization of crude mycelial extracts of isolate SP502 along with their bio-efficacy against and . Fourier transform infrared spectroscopy, liquid chromatography, mass spectrometery and nuclear magnetic resonance analysis of isolate SP502 extracts showed the presence of five major compounds-Trichodermin, 5-Methylmellein, Brevianamide F, Enniatin and Beauvericin-which all may potentially be involved in insecticidal activity. The HPLC analysis of mycelial extracts and Beauvericin standard showed similar chromatographic peaks, with the content of Beauvericin in the crude toxin being calculated as 0.66 mg/ml. The median lethal concentrations of mycelial extracts towards first, second, third and fourth instar nymphs of were 46.35, 54.55, 68.94, and 81.92 µg/mL, respectively. The median lethal concentrations of mycelial extracts towards first, second, third and fourth instar nymphs of were 62.67, 72.84, 77.40, and 94.40 µg/mL, respectively. Our results demonstrate that bioactive compounds produced by isolate SP502 have insecticidal properties and could, therefore, be developed into biopesticides for the management of and .
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http://dx.doi.org/10.3390/toxins13030220DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8003032PMC
March 2021

Toxicity and Biological Effects of Fe Nanoparticles against (Fabricius).

Insects 2020 Dec 21;11(12). Epub 2020 Dec 21.

Key Laboratory of Bio-Pesticide Innovation and Application, Guangzhou 510642, China.

Nanotechnology has clear potential in the development of innovative insecticidal products for the biorational management of major insect pests. Metal-based nanoparticles of different microbial pest control agents have been effective against several pests. Synthesis of based Fe nanoparticles (FeNPs) and their bio-efficacy against was observed during this study. conidia were coated with FeNPs and characterized by applying a selection of different analytical techniques. Ultraviolet (UV) spectroscopy showed the characteristic band of surface plasmon at 430 nm; Scanning electron microscopy (SEM) images showed spherical shaped nanoparticles with a size ranging between 0.41 to 0.80 µm; Energy-dispersive X-ray (EDX) spectral analysis revealed characteristic Fe peaks at 6.5 and 7.1 Kev; the X-ray diffractogram showed three strong peaks at 2 values of 45.72°, 64.47°, and 84.05°. The bioassay studies demonstrated that mortality of 2nd instar larvae following FeNPs treatment increased with increasing concentrations of FeNPs at different time intervals. The median lethal concentration (LC) values of FeNPs against after seven days of fungal treatment was 59 ppm, whereas median survival time (LT) values for 200 and 500 ppm concentrations of FeNPs against seven days post-treatment were 5.1 and 2.29 days, respectively. -FeNPs caused significant reductions in feeding and growth parameters (relative growth rate, relative consumption rate, and efficiency of conversion of ingested food) of . FeNPs induced reduction in glutathione-S-transferase activities throughout the infection period whereas activities of antioxidant enzymes decreased during later periods of infection. These findings suggest that FeNPs can potentially be used in biorational management programs.
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http://dx.doi.org/10.3390/insects11120895DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7767332PMC
December 2020

Biological Impact and Enzyme Activities of (Lepidoptera: Noctuidae) in Response to Synergistic Action of Matrine and .

Front Physiol 2020 2;11:584405. Epub 2020 Nov 2.

Key Laboratory of Bio-Pesticide Innovation and Application, Engineering Research Centre of Biological Control, South China Agricultural University, Guangzhou, China.

Matrine, a naturally occurring heterocyclic compound, has been shown to enhance the pathogenicity of the entomopathogenic fungus against . In the current study, the biological impacts and synergism activities of these two agents on nutritional efficiency and antioxidant enzymes in were explored. Our results showed a high antifeedant activity of and matrine on . The larvae were unable to pupate and emerge when treated with combinations of matrine and . Following on, we measured the activities of five important antioxidant enzymes [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), acetylcholinesterase (AChE), and glutathione-S-transferase (GST)] when treated with SB010 (1 × 10 spores/ml), matrine (0.5 mg/ml), and SB010 (1 × 10 spores/ml) + matrine (0.5 mg/ml). The results indicated the detoxification activity of the five enzymes in the fat body and hemolymph of when facing a combined and matrine challenge. The activities of the enzymes were significantly lower than that of the control group 7 days post-treatment, indicating the inhibitory effect of the two xenobiotics. Matrine had better inhibition effects than in a majority of the trials. The improved detoxification activity of the five enzymes may be the internal mechanism of synergism of matrine on .
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http://dx.doi.org/10.3389/fphys.2020.584405DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7667252PMC
November 2020

Special Issue: Integrated Pest Management in Arable and Open Field Horticultural Crops.

Insects 2020 Jan 23;11(2). Epub 2020 Jan 23.

Independent Science Advisor, York YO10 5AQ, UK.

Invertebrate pest control within both agricultural and horticultural production systems continues to present many challenges. Over the past decades the commonly used method for pest control has been the direct application of chemical products. However, in response to environmental, economic, and other problems associated with the over-reliance on chemical insecticides there has been an increasing drive towards the development of Integrated Pest Management (IPM) approaches. Many IPM strategies are now well developed under protected environments. However, within the open field in many situations targeted success is yet to be achieved. This special issue will seek to showcase original articles and reviews by leading research entomologists and associated experts. Articles presented will focus on the development and implementation of IPM strategies against various major arable and horticultural invertebrate pests (both indigenous and invasive species).
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http://dx.doi.org/10.3390/insects11020082DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7073958PMC
January 2020

Behaviour is Influenced by Volatiles from Both Plants and Nymphs.

Insects 2019 May 16;10(5). Epub 2019 May 16.

Key Laboratory of Bio-Pesticide Innovation and Application, Department of Entomology, South China Agricultural University, Guangzhou 510640, China.

(Waterston) is an important ectoparasitoid of the Asian citrus psyllid, Kuwayama, a globally destructive pest of citrus. In the present study, a Y-tube olfactometer was employed to investigate whether the parasitoid is capable of utilizing the odour source emitted by both plants and insect hosts during its foraging. The odour sources included (L.) shoots, 1st, 2nd, 3rd, 4th, and 5th instar nymphs, both individually and in combinations. Moreover, nymph-stage choice for parasitism, including 3rd, 4th, and 5th instar nymphs, was carried out. The results indicated that female were only significantly attracted to volatiles emitted by shoots, 3rd, 4th, and 5th instar nymphs of , but could not distinguish between them. males were not attracted by odours sourced from any instar nymphs. Female adults exhibited a significant preference to later instar nymphal stages of for oviposition. The results from this study can be used to guide further investigations on the searching behaviour of this parasitoid and its utilization in biocontrol.
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http://dx.doi.org/10.3390/insects10050141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6572530PMC
May 2019

The Impact of Mulsant (Coleoptera: Coccinellidae) on Control of Beardsley (Hemiptera: Pseudococcidae).

Insects 2019 May 6;10(5). Epub 2019 May 6.

Independent Science Advisor, York YO10 5AQ, UK.

(Coleoptera: Coccinellidae) is an important predator of the mealybug (Hemiptera: Pseudococcidae), a major pest of in China. Limited reports on the efficacy of against are available. This study reports the predatory efficacy and functional response of against under laboratory conditions. The prey consumption rate per day of 4th instar larvae of feeding on 1st instar nymphs (241.3 mealybugs) was the highest among the different larval life stages of the beetle. For , the prey consumption per day of adult females (19.8 mealybugs) was significantly higher compared to males (15.2 mealybugs) when feeding on 3rd instar nymphs. The functional responses of on 1st and 2nd instar nymphs were determined as Holling type II. The search rates of 4th instar larvae towards the 1st and 2nd instar nymphs of were higher than those of the other beetle life stages. In addition, the handling times of 4th instar larvae were shorter than those of the other beetle life stages. The results from this study indicate that can be used as a predator of and, therefore, it should be evaluated further for use as a biocontrol agent in management programs.
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http://dx.doi.org/10.3390/insects10050131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6572104PMC
May 2019

Isaria fumosorosea-based zero-valent iron nanoparticles affect the growth and survival of sweet potato whitefly, Bemisia tabaci (Gennadius).

Pest Manag Sci 2019 Aug 10;75(8):2174-2181. Epub 2019 Mar 10.

Key Laboratory of Bio-Pesticide Innovation and Application, Engineering Research Centre of Biological Control, South China Agricultural University, Guangzhou, P.R. China.

Background: Nanoparticles can be used for effective pest management as a combined formulation of metal and some other material that has proven efficacy against a given pest. This study reports the synthesis, characterization and efficacy of Isaria fumosorosea-based zero-valent iron (ZVI) nanoparticles against sweet potato whitefly Bemisia tabaci (Gennadius).

Results: The I. fumosorosea-ZVI nanoparticles showed a characteristic surface plasmon absorption band at 470 nm during UV-visible spectroscopy. The scanning electron micrographs of nanoparticles showed spherical shaped nanoparticles with sizes ranging between 1.71 and 3.0 µm. The EDX analysis showed the characteristic peak of iron at 0.6 and 6.8 KeV. The XRD analysis showed characteristic peaks at 44.72°, 65.070°, 82.339° and 82.65°. The bioassay results indicated that the percentage of larval mortality of B. tabaci challenged with I. fumosorosea ZVI nanoparticles was both concentration and age dependent. Isaria fumosorosea ZVI nanoparticles showed high pathogenicity against second and third instar nymphs, and pupae with LC values of 19.17, 26.10 and 37.71 ppm, respectively. The LT was lowest for second instar nymphs (3.15 days) and highest for pupae (4.22 days) when inoculated with a concentration of 50 ppm.

Conclusion: Isaria fumosorosea ZVI nanoparticles can be an eco-friendly tool for effective B. tabaci management. © 2019 Society of Chemical Industry.
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http://dx.doi.org/10.1002/ps.5340DOI Listing
August 2019

Monitoring the Attack Incidences and Damage Caused by the Almond Bark Beetle, Scolytus amygdali, in Almond Orchards.

Insects 2018 Jan 1;9(1). Epub 2018 Jan 1.

Deparment of Olive Tree Physiology, Institute of the Olive Tree Station of Sousse, 40 Street Ibn Khouldoun, Sousse 4061, Tunisia.

The almond bark beetle, Geurin-Meneville, is responsible for significant loss of fruit production in almond orchards throughout the world. Here, we studied the damage and the incidences of attack on two different scales: (1) at the level of a single tree; and (2) in an entire orchard. Our results revealed no differences in attack level among four orientations (east, west, south and north sides) for the whole tree. However, the bark that was facing west side in the direction of the prevailing wind was found to be the most suitable for females to initiate attack in Stratum S2. Attack distribution remains the same among different strata (strata is vertical divisions of the tree from the ground to the uppermost twigs with ~40 cm intervals). More than 50% of attack was observed in the trunk of the tree and upper strata. However, multiplication rate (number of emerged adults/maternal gallery) varies significantly between strata. In addition, we studied attack intensity (holes produced by beetle per tree) comparing it to tree morphology (flowers, leaves and circumferences) and gum deposit. Our results revealed a positive correlation between attack intensity and gum deposits, and a negative correlation between attack intensity and tree morphology. This revealed that gum on the tree was an indicator for attack intensity. A positive correlation between attack intensity and the circumference of the tree revealed that older trees were more susceptible to attack. These results, while preliminary, aim to help in the monitoring of populations before deciding to apply any control measures.
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http://dx.doi.org/10.3390/insects9010001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5872266PMC
January 2018

RNAi knock-down of the Bemisia tabaci Toll gene (BtToll) increases mortality after challenge with destruxin A.

Mol Immunol 2017 08 22;88:164-173. Epub 2017 Jun 22.

Department of Entomology, South China Agricultural University, Guangzhou 510640, China; Key Laboratory of Bio-Pesticide Innovation and Application, Engineering Technology Research Center of Agricultural Pest Biocontrol of Guangdong Province, Guangzhou 510640, China. Electronic address:

Bemisia tabaci (Gennadius) Middle East-Asia Minor 1 (MEAM1) is a well known invasive insect species. Little information is available on immune system of B. tabaci to date. In this study, one of the Toll-like receptors (TLR; namely BtToll) was cloned in MEAM1 B. tabaci which contains an open reading frame of 3153bp, encoding putative 1050 amino acids. Phylogenetic analysis indicated that BtToll is highly identitical with other members of the TLR family. Transcripts of BtToll detected through qRT-PCR were expressed in all developmental stages of B. tabaci and the highest expression level was observed in the 3rd nymphal instar. BtToll was highly expressed in response to immune challenge. RNA interference was used to knockdown the BtToll expression in adults through the oral route which resulted in significant reduction of BtToll transcript. When the adults were challenged with a mycotoxin from entomogenous fungi - destruxin A (DA) and RNAi, the median lethal concentration (LC) decreased by 70.67% compared to DA treatment only. Our results suggest that BtToll is an important component of the B. tabaci immune system. RNAi technology using dsToll combined with general control methods (using toxin only) can be used as a potential strategy in integrated B. tabaci management programs.
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http://dx.doi.org/10.1016/j.molimm.2017.06.031DOI Listing
August 2017

Invasion dynamics of Asian hornet, (Hymenoptera: Vespidae): a case study of a commune in south-west France.

Appl Entomol Zool 2017 17;52(2):221-229. Epub 2017 Mar 17.

ZEEMAN Institute: SBIDER, University of Warwick, Coventry, CV4 7AL UK.

Asian hornet, Lepeletier nests were discovered in 2007 in Andernos-les-Bains on the south-west coast of France, 3 years after the first reported sightings in France. The number of nests increased in the commune over the following 7 years, despite local authorities enacting a destruction policy. The nests existed in close proximity to one another leading to a high density of over 10 nests per square kilometre in urban areas. New information on the chosen habitat for nests is presented, and the differences between primary and secondary locations are evident, with primary nests mostly occupying buildings and man-made structures, while secondary nests were found on trees. Using Bayesian inference methods, we fit a basic model to the observational data, which allows us to estimate key demographic parameters. This model fit is highly informative for predicting spread and colonisation of other at-risk regions, and suggests that local control has a limited impact on the spread of once established within a region.
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http://dx.doi.org/10.1007/s13355-016-0470-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5409922PMC
March 2017

Toxicological and biochemical basis of synergism between the entomopathogenic fungus Lecanicillium muscarium and the insecticide matrine against Bemisia tabaci (Gennadius).

Sci Rep 2017 04 20;7:46558. Epub 2017 Apr 20.

Key Laboratory of Bio-Pesticide Innovation and Application, Engineering Research Center of Biological Control, South China Agricultural University, Guangzhou, 510640, P.R. China.

The sweetpotato whitefly Bemisia tabaci (Gennadius) was challenged with different combinations of matrine (insecticide) and Lecanicillium muscarium (entomopathogenic fungus). Our results revealed a synergistic relationship between matrine and L. muscarium on mortality and enzyme activities of B. tabaci. To illustrate the biochemical mechanisms involved in detoxification and immune responses of B. tabaci against both control agents, activities of different detoxifying and antioxidant enzymes were quantified. After combined application of matrine and L. muscarium, activities of carboxylestrease (CarE), glutathione-s-transferase (GSTs) and chitinase (CHI) decreased during the initial infection period. Acetylcholinestrase (AChE) activities increased during the entire experimental period, whereas those of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased during the later infection period. The increased mortality and suppression of enzymatic response of B. tabaci following matrine and L. muscarium application suggests a strong synergistic effect between both agents. The strong synergistic effect is possibly related to the disturbance of acetylcholine balance and changes in AchE activities of the whitefly as both matrine and L. muscarium target insect acetylcholine (Ach) receptors which in turn effects AchE production. Therefore, our results have revealed the complex biochemical processes involved in the synergistic action of matrine and L. muscarium against B. tabaci.
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http://dx.doi.org/10.1038/srep46558DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5397844PMC
April 2017

Wolbachia Has Two Different Localization Patterns in Whitefly Bemisia tabaci AsiaII7 Species.

PLoS One 2016 9;11(9):e0162558. Epub 2016 Sep 9.

Department of Entomology, South China Agricultural University, Guangzhou, China.

The whitefly Bemisia tabaci is a cosmopolitan insect species complex that harbors the obligate primary symbiont Portiera aleyrodidarum and several facultative secondary symbionts including Wolbachia, which have diverse influences on the host biology. Here, for the first time, we revealed two different localization patterns of Wolbachia present in the immature and adult stages of B. tabaci AsiaII7 cryptic species. In the confined pattern, Wolbachia was restricted to the bacteriocytes, while in the scattered pattern Wolbachia localized in the bacteriocytes, haemolymph and other organs simultaneously. Our results further indicated that, the proportion of B. tabaci AsiaII7 individuals with scattered Wolbachia were significantly lower than that of confined Wolbachia, and the distribution patterns of Wolbachia were not associated with the developmental stage or sex of whitefly host. This study will provide a new insight into the various transmission routes of Wolbachia in different whitefly species.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0162558PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5017708PMC
August 2017

Further Screening of Entomopathogenic Fungi and Nematodes as Control Agents for Drosophila suzukii.

Insects 2016 Jun 9;7(2). Epub 2016 Jun 9.

Fera, Sand Hutton, York YO41 1LZ, UK.

Drosophila suzukii populations remain low in the UK. To date, there have been no reports of widespread damage. Previous research demonstrated that various species of entomopathogenic fungi and nematodes could potentially suppress D. suzukii population development under laboratory trials. However, none of the given species was concluded to be specifically efficient in suppressing D. suzukii. Therefore, there is a need to screen further species to determine their efficacy. The following entomopathogenic agents were evaluated for their potential to act as control agents for D. suzukii: Metarhizium anisopliae; Isaria fumosorosea; a non-commercial coded fungal product (Coded B); Steinernema feltiae, S. carpocapsae, S. kraussei and Heterorhabditis bacteriophora. The fungi were screened for efficacy against the fly on fruit while the nematodes were evaluated for the potential to be applied as soil drenches targeting larvae and pupal life-stages. All three fungi species screened reduced D. suzukii populations developing from infested berries. Isaria fumosorosea significantly (p < 0.001) reduced population development of D. suzukii from infested berries. All nematodes significantly reduced adult emergence from pupal cases compared to the water control. Larvae proved more susceptible to nematode infection. Heterorhabditis bacteriophora proved the best from the four nematodes investigated; readily emerging from punctured larvae and causing 95% mortality. The potential of the entomopathogens to suppress D. suzukii populations is discussed.
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http://dx.doi.org/10.3390/insects7020024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931436PMC
June 2016

The Importance of Maintaining Protected Zone Status against Bemisia tabaci.

Insects 2015 May 11;6(2):432-41. Epub 2015 May 11.

Natural Resources Institute Finland, Tietotie 2C, Jokioinen FI-31600, Finland.

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of economically important crops worldwide. Both the United Kingdom (UK) and Finland hold Protected Zone status against this invasive pest. As a result B. tabaci entering these countries on plants and plant produce is subjected to a policy of eradication. The impact of B. tabaci entering, and becoming established, is that it is an effective vector of many plant viruses that are not currently found in the protected zones. The Mediterranean species is the most commonly intercepted species of B. tabaci entering both the UK and Finland. The implications of maintaining Protected Zone status are discussed.
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http://dx.doi.org/10.3390/insects6020432DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553489PMC
May 2015

Tri-Tek (Petroleum Horticultural Oil) and Beauveria bassiana: Use in Eradication Strategies for Bemisia tabaci Mediterranean Species in UK Glasshouses.

Insects 2015 Feb 12;6(1):133-40. Epub 2015 Feb 12.

The Food and Environment Research Agency, Sand Hutton, York YO41 1LZ, UK.

The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest of global importance on both outdoor and glasshouse crops. To date, B. tabaci has not become established in the UK. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Mediterranean species is now the most prevalent Bemisia species entering the UK. Increasing neonicotinoid resistance is becoming increasingly widespread and problematic with this species. As a result, this continues to pose problems for eradication strategies. The current study investigates the efficacy of Tri-Tek (a petroleum horticultural oil awaiting UK registration) and the fungus Beauveria bassiana to act as control agents against Mediterranean species in UK glasshouses. Tri-Tek provided 100% egg mortality compared to 74% for B. bassiana. When tested against second instar larvae, mortalities of 69% and 65% respectively were achieved. Both products can be successfully "tank-mixed". A tank-mix application provided 95.5% mortality of second instar larvae under glasshouse conditions. The potential integration of both products into current Bemisia eradication strategies in UK glasshouses is discussed.
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http://dx.doi.org/10.3390/insects6010133DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553534PMC
February 2015

Status of insecticide resistance and selection for imidacloprid resistance in the ladybird beetle Propylaea japonica (Thunberg).

Pestic Biochem Physiol 2015 Sep 26;123:87-92. Epub 2015 Mar 26.

Engineering Research Center of Biological Control, Ministry of Education, South China Agricultural University, Guangzhou 510642, China. Electronic address:

Field populations or strains of Propylaea japonica collected from four places in southern China (Guangzhou, Nanning, Guilin, and Yuxi) were tested for susceptibility to four insecticides (abamectin, imidacloprid, beta-cypermethrin, and chlorpyrifos) by the Petri-dish Potter tower method and compared with an insecticide-susceptible strain. Concentrations that proved lethal for 50% of the tested individuals (LC50) were estimated by probit analysis, and resistance factors (RF) were calculated at the LC50 level, which ranged from 1.6 to 10.1, depending on the insecticide. In addition, the Guangzhou strain formed the original population for imidacloprid resistance selection. After selection for 20 generations, the resistance had increased 39.3-fold. Fitness analysis in terms of such traits as fecundity, days to maturity, and survival showed that although both resistant and susceptible populations developed at comparable rates, the resistant strain was less fecund (it laid fewer eggs and a smaller proportion of those eggs hatched and resulted in adults), attaining a fitness score of only 0.56 relative to the susceptible strain. These observations suggest that it is possible to detect strains of P. japonica highly resistant to insecticides under laboratory conditions, and that resistance to imidacloprid carries considerable fitness costs to P. japonica. The study served to expand our understanding of the impact of imidacloprid resistance on biological parameters of P. japonica in more detail and to facilitate the deployment of natural enemies resistant to insecticides in integrated pest management.
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http://dx.doi.org/10.1016/j.pestbp.2015.03.008DOI Listing
September 2015

RNAi-mediated knockdown of serine protease inhibitor genes increases the mortality of Plutella xylostella challenged by destruxin A.

PLoS One 2014 16;9(5):e97863. Epub 2014 May 16.

Engineering Research Center of Biological Control, Ministry of Education, South China Agricultural University, Guangzhou, China.

Destruxin A is a mycotoxin that is secreted by entomopathogenic fungi which has a broad-spectrum insecticidal effect. Previous transcript and protein profiling analysis showed that destruxin A has significant effects on the expression of serine protease inhibitor genes (serpin-2, 4, 5) in the larvae of Plutella xylostella. In the current study, we aimed to understand the role of serpins under application of destruxin A. We obtained two full-length cDNA sequences of P. xylostella serpins, named serpin-4 and serpin-5, and cloned the serpin-2 gene whose full-length has already been published. Phylogenetic analysis indicated that these two serpin genes were highly clustered with other serpins associated with the immune response in other insects. The temporal and spatial expression of serpin-2, serpin-4 and serpin-5 were determined to be the highest in the fat body and hemolymph of 4th larval stage using qRT-PCR and western blot detection techniques. RNA interference (RNAi) mediated knockdown of P. xylostella serpin genes was carried out by microinjection of double-stranded RNA (dsRNA). The expression levels of serpins decreased significantly after RNAi. Results showed that the depletion of serpins induced cecropins expression, increased phenoloxidase (PO) activity, body melanization and mortality in the larvae of P. xylostella under the same lethal concentration of destruxin A. The superimposed effects of serpins RNAi were similar with the destruxin A treatment upon mortality of P. xylostella larvae. We discovered for the first time that serpins play indispensable role in P. xylostella when challenged by destruxin A and deduced the possible function mechanism of destruxin A. Our findings are conducive to fully understanding the potential insecticidal mechanism of destruxin A and constitute a well-defined potential molecular target for novel insecticides.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0097863PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4023956PMC
August 2015

Efficiency of plant induced volatiles in attracting Encarsia formosa and Serangium japonicum, two dominant natural enemies of whitefly Bemisia tabaci in China.

Pest Manag Sci 2014 Oct 19;70(10):1604-10. Epub 2014 Mar 19.

Department of Entomology, South China Agricultural University, Guangzhou, China.

Background: Whitefly Bemisia tabaci is a globally distributed and most destructive pest to agriculture. Owing to increasing chemical resistance, a long-lasting strategy to manage this pest must involve biological control. Herbivore-induced plant volatiles (HIPVs) usually play a profoundly important role in the foraging behaviour of natural enemies. Here, the effects of HIPVs from Chinese broccoli on the foraging behaviour of two dominant natural enemy species of B. tabaci in China, Encarsia formosa and Serangium japonicum, were investigated using a four-arm olfactometer, and exogenous jasmonic acid (JA) was used to induce plant volatiles to mimic the damage of the herbivore pest.

Results: The parasitoid E. formosa was found to be more attracted by the volatiles from JA-induced broccoli than those from control plants. The residence times of E. formosa in the final-choice areas closed to volatiles from shoot JA (SJA)- and root JA (RJA)-induced plants were 119.8 ± 35.2 s and 99.8 ± 34.7 s respectively in the dual-choice experiments, and 123.8 ± 32.0 s and 102.3 ± 28.7 s respectively in the three-choice experiment. All are significantly longer than those spent in the final-choice area closed to volatiles from control plants (CON). JA-induced volatiles were also only a little more attractive to the predator S. japonicum. However, there was no significant difference between each of the two natural enemies in residence time spent in the final-choice areas closed to SJA, RJA or CON volatiles in both the dual- and three-choice experiments. Furthermore, the number of times that the parasitoid or predator entered the SJA, RJA and CON final-choice areas was not significantly different in any of the experiments.

Conclusion: The present results indicate that RJA- and SJA-induced plant volatiles have higher efficiencies in attracting the natural enemies of whitefly B. tabaci. The attractive efficiencies varied according to the plant volatiles that JA induced, and also depended on the natural enemy species. The parasitoid E. formosa seems to be more sensitive to and attracted by the induced volatiles than the predator S. japonicum.
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http://dx.doi.org/10.1002/ps.3749DOI Listing
October 2014

Efficacy of Commercially Available Invertebrate Predators against Drosophila suzukii.

Insects 2014 Nov 28;5(4):952-60. Epub 2014 Nov 28.

The Food and Environment Research Agency, Sand Hutton, York YO41 1LZ, UK.

Drosophila suzukii has been recorded in the UK since the end of 2012. To date, reports of serious damage have been rare. Previous research has demonstrated that there are chemicals available within the UK that are efficient in dealing with D. suzukii. However, few effective chemicals for use by the organic sector have been identified; equally the addition of "new" insecticides into previously stable ecosystems can have negative impacts upon natural enemies and so disrupt control strategies that have developed over a period of time. Therefore, there is a need also to screen for potential biological control agents for D. suzukii. The following commercially available predatory species were evaluated for their potential to act as control agents for D. suzukii: Orius majusculus, Orius laevigatus, Atheta coriaria, Hypoaspis miles and Anthocoris nemoralis. This set of natural enemies could potentially target several life stages of D. suzukii (larvae, pupae and adults). All species, except H. miles, fed on D. suzukii life stages to some extent. Hypoaspis miles displayed no impact upon D. suzukii populations. Anthocoris nemoralis displayed a tendency to feed upon more male than female adult D. suzukii and caused 45% mortality after five days. None of the natural enemies trialed were able to control D. suzukii individually. However, these and other non-commercially produced species will all play a role within a given ecosystem in controlling D. suzukii populations.
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http://dx.doi.org/10.3390/insects5040952DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592616PMC
November 2014

Anystis baccarum: An Important Generalist Predatory Mite to be Considered in Apple Orchard Pest Management Strategies.

Insects 2014 Jul 24;5(3):615-28. Epub 2014 Jul 24.

The Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK.

The increasing concern over the continued use of pesticides is pressurising apple growers to look for alternatives to chemical pest control. The re-discovery, and subsequent conservation, of the beneficial predatory mite, Anystis baccarum (Linnaeus) (Acari: Anystidae), in Bramley apple orchards in Northern Ireland offers a potential alternative control component for incorporation into integrated pest management strategies. Anystis baccarum readily feeds upon economically important invertebrate pest species including European fruit tree red spider mite, Panonychus ulmi (Koch) (Acari: Tetranychidae) and show a level of compatibility with chemical pesticides. Recent mis-identification by apple growers of this beneficial mite species had resulted in unnecessary pesticide applications being applied within Northern Irish apple orchards. However, dissemination of information to the apple growers and promotion of the benefits this mite offers in apple orchards has helped to conserve its populations. Apple growers, across the United Kingdom, must be encouraged to be aware of A. baccarum, and indeed all predatory fauna, within their orchards and seek to conserve populations. In doing so, it will ensure that the British apple market remains an environmentally sustainable production system.
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http://dx.doi.org/10.3390/insects5030615DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592577PMC
July 2014

The Feeding Rate of Predatory Mites on Life Stages of Bemisia tabaci Mediterranean Species.

Insects 2014 Jul 22;5(3):609-14. Epub 2014 Jul 22.

The Food and Environment Research Agency, Sand Hutton, York YO41 1LZ, UK.

The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. There has recently been a shift from Middle East-Asia Minor 1 to the more chemical resistant Mediterranean species entering the UK. Predatory mites (Amblyseius swirskii, Transeius montdorensis and Typhlodromalus limonicus) were screened for their impact upon various lifestages of B. tabaci Mediterranean species. Approximately 30% of eggs were fed upon by A. swirskii following a 5 day period. Feeding rates slightly decreased for all mite species when feeding on first instar life-stages (27%, 24%, 16% respectively) and significantly decreased when feeding on second instars (8.5%, 8.5%, 8.7% respectively). Combining the two mite species (A. swirskii and T. montdorensis) increased mortality of Bemisia eggs to 36%. The potential of incorporating the mites into existing control strategies for B. tabaci is discussed.
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http://dx.doi.org/10.3390/insects5030609DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592588PMC
July 2014

Preliminary Screening of Potential Control Products against Drosophila suzukii.

Insects 2014 Jun 20;5(2):488-98. Epub 2014 Jun 20.

The Food and Environment Research Agency, Sand Hutton, York YO41 1LZ, UK.

The first recording of Drosophila suzukii in the UK occurred in the south of England during August 2012. Since then sticky traps have continued to record the presence of individuals. Several products (both chemical and biological) were investigated for their efficacy against different life-stages of the pest. Both direct and indirect exposure to control products was assessed. Spinosad, chlorantraniliprole and the experimental product, TA2674, showed excellent potential as control agents when used as either a pre- or post-dipping treatment for blueberries with mortalities of 100%, 93% and 98% mortality, respectively, being achieved following pre-treatment. Direct spray application of all products tested had limited impact upon adult flies. Highest mortality (68%) was achieved following direct application of TA2674. Entomopathogenic agents (nematodes and fungi) tested appeared to reduce fly population development (ranges of 34-44% mortality obtained) but would seem unable to eradicate outbreaks. The potential of the tested products to control D. suzukii is discussed.
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http://dx.doi.org/10.3390/insects5020488DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592600PMC
June 2014

Update on the Status of Bemisia tabaci in the UK and the Use of Entomopathogenic Fungi within Eradication Programmes.

Insects 2013 May 16;4(2):198-205. Epub 2013 May 16.

The Food and Environment Research Agency, Sand Hutton, York YO41 1LZ, UK.

The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Both B and Q Bemisia biotypes are now regularly intercepted entering the UK. With increasing reports of neonicotinoid resistance in both these biotypes, it is becoming more problematic to control/eradicate. Therefore, alternative means of control are necessary. Entomopathogenic fungi (Lecanicilllium muscarium and Beauveria bassiana) offer much potential as control agents of B. tabaci within eradication programmes in the UK.
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http://dx.doi.org/10.3390/insects4020198DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553518PMC
May 2013

Population Development of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) under Simulated UK Glasshouse Conditions.

Insects 2013 May 15;4(2):185-97. Epub 2013 May 15.

The Food and Environment Research Agency, Sand Hutton, York, YO41 1LZ, UK.

Tomato leafminer Tuta absoluta (Meyrick) is a major pest of tomato plants in South America. It was first recorded in the UK in 2009 where it has been subjected to eradication policies. The current work outlines T. absoluta development under various UK glasshouse temperatures. The optimum temperature for Tuta development ranged from 19-23 °C. At 19 °C, there was 52% survival of T. absoluta from egg to adult. As temperature increased (23 °C and above) development time of the moth would appear to decrease. Population development ceases between 7 and 10 °C. Only 17% of eggs hatched at 10 °C but no larvae developed through to adult moths. No eggs hatched when maintained at 7 °C. Under laboratory conditions the total lifespan of the moth was longest (72 days) at 13 °C and shortest (35 days) at both 23 and 25 °C. Development from egg to adult took 58 days at 13 °C; 37 days at 19 °C and 23 days at 25 °C. High mortality of larvae occurred under all temperatures tested. First instar larvae were exposed on the leaf surface for approximately 82 minutes before fully tunnelling into the leaf. Adult longevity was longest at 10 °C with moths living for 40 days and shortest at 19 °C where they survived for 16 days. Generally more males than females were produced. The potential of Tuta absoluta to establish populations within UK protected horticulture is discussed.
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http://dx.doi.org/10.3390/insects4020185DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553517PMC
May 2013

Evaluation of the predatory mite Amblyseius hainanensis (Acari: Phytoseiidae) and artificial rainfall for the management of Brevipalpus obovatus (Acari: Tenuipalpidae).

Exp Appl Acarol 2012 Oct 21;58(2):121-31. Epub 2012 Apr 21.

State Key Laboratory for Biocontrol and Institute of Entomology, Sun Yat-Sen University, Guangzhou 510275, China.

Brevipalpus obovatus Donnadieu is an important pest mite on tea plants in South China. In the current study, predatory mites of B. obovatus in the tea gardens of Guangzhou were extensively surveyed. In total, 13 species of predatory mites (four families with seven genera) were recorded. The population proportion of Amblyseius hainanensis Wu et Qian was the highest (68.6 %), followed by that of Anystis baccarum (L.) (8.4 %) and A. theae Wu (6.3 %). The effects of starvation time, habitat size and pest population density on the predatory efficiency of the most dominant species, A. hainanensis, feeding on B. obovatus were assessed. In addition, the effectiveness of artificial rainfall in reducing B. obovatus populations was evaluated. After starvation for 48 h, the predatory efficiency of A. hainanensis was significantly higher than those that had been starved for 24 or 72 h when 30-50 B. obovatus eggs were made available. The predation of A. hainanensis on B. obovatus also increased with increasing prey density. The number of prey attacked by A. hainanensis in a 3.2 cm(2) habitat was significantly higher than in a 6.3 cm(2) habitat. The average predation of A. hainanensis was 31.7 eggs per day when offered 100 B. obovatus eggs on a tea leaf. This decreased to 17.8 eggs per day when four A. hainanensis shared 100 B. obovatus eggs. B. obovatus populations can be reduced by artificial rainfall, with the reduction affected by rainfall intensity. With an intensity of 40 mm in 15 min, 90.2 % mortality of B. obovatus occurred; lower mortalities were recorded (13.3 and 29.8 %) when the intensity was 2 or 4 mm in 15 min. Combination of the predatory mite A. hainanensis and artificial rainfall for the integrated pest management of B. obovatus is discussed.
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http://dx.doi.org/10.1007/s10493-012-9555-8DOI Listing
October 2012

Prey consumption rates and compatibility with pesticides of four predatory mites from the family Phytoseiidae attacking Thrips palmi Karny (Thysanoptera: Thripidae).

Pest Manag Sci 2012 Sep 19;68(9):1289-95. Epub 2012 Apr 19.

The Food and Environment Research Agency, Sand Hutton, York, UK.

Background: Predatory mites (Amblyseius swirskii Athias-Henriot, Typhlodromips montdorensis Schicha, Neoseiulus cucumeris (Oudemans) and Iphiseius degenerans Berlese) were investigated for their potential to act as control agents for Thrips palmi Karny. Prey consumption rates and compatibility with pesticides were assessed.

Results: Second-instar larvae were the preferred life stage. Typhlodromips montdorensis consumed the most larvae (2.8) and also an average of 1.2 adult T. palmi per 5 day period. Both 24 and 48 h assessments following application of abamectin, spinosad and imazalil demonstrated mortality of predatory mites (across all species), which was significantly higher than with the other treatments (P < 0.001). Spraying with pymetrozine did not provide any increased mortality when compared with the water control. Application of thiacloprid proved detrimental only to I. degenerans. Following indirect exposure of predatory mites to pymetrozine and imazalil, no significant differences in mite mortality were obtained. Indirect exposure to spinosad was identified as the most detrimental treatment (P < 0.001) to all mites. Abamectin also proved detrimental, with only T. montdorensis showing any potential tolerance.

Conclusion: All predatory mites investigated offer potential for controlling T. palmi. Compatibility with chemicals varied between the mites. The potential of incorporating the mites into eradication strategies for T. palmi is discussed.
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http://dx.doi.org/10.1002/ps.3296DOI Listing
September 2012

Screening Commercially Available Entomopathogenic Biocontrol Agents for the Control of Aethina tumida (Coleoptera: Nitidulidae) in the UK.

Insects 2012 Aug 9;3(3):719-26. Epub 2012 Aug 9.

The Food and Environment Research Agency, National Bee Unit, Sand Hutton, York YO41 1LZ, UK.

The Small hive beetle, Aethina tumida, is an invasive pest of honey bees. Indigenous to sub-Saharan Africa, it has now become established in North America and Australia. It represents a serious threat to European honey bees. Commercially available entomopathogenic agents were screened for their potential to control beetle larvae. Entomopathogenic fungi investigated had minimal impact. The nematodes Steinernema kraussei and S. carpocapsae provided excellent control with 100% mortality of larvae being obtained. Sequential applications of the nematodes following larvae entering sand to pupate also provided excellent control for up to 3 weeks. The information gained supports the development of contingency plans to deal with A. tumida should it occur in the UK, and is relevant to the management of Small hive beetle where it is already present.
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http://dx.doi.org/10.3390/insects3030719DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553586PMC
August 2012

The occurrence of Melissococcus plutonius in healthy colonies of Apis mellifera and the efficacy of European foulbrood control measures.

J Invertebr Pathol 2010 Oct 19;105(2):164-70. Epub 2010 Jun 19.

The Food and Environment Research Agency, Sand Hutton, York, YO41 1LZ, UK.

European foulbrood (EFB) persists in England and Wales despite current treatment methods, all of which include feeding honey bee colonies with the antibiotic oxytetracycline (OTC). A large-scale field experiment was conducted to monitor a husbandry-based method, using comb replacement (known as Shook swarm), as a drug free EFB control option. The understanding of EFB epidemiology is limited, with little information on the presence of Melissococcus plutonius in disease free colonies. Additional samples were collected from diseased and disease free apiaries to identify symptomless infection. EFB reoccurrence was not significantly different between OTC and husbandry methods and real-time PCR data demonstrated that fewer Shook swarm treated colonies contained M. plutonius carryover to the Spring following treatment. Asymptomatic colonies from diseased apiaries showed an increased risk of testing positive for M. plutonius compared to asymptomatic colonies from disease free apiaries. The probability of a sample being symptomatic increased when a greater quantity of M. plutonius was detected in adult bees and larvae. The possibility of treating EFB as an apiary disease rather than a colony disease and the implications of a control strategy without antibiotics are discussed.
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http://dx.doi.org/10.1016/j.jip.2010.06.004DOI Listing
October 2010

First molecular detection of a viral pathogen in Ugandan honey bees.

J Invertebr Pathol 2010 Jun 26;104(2):153-6. Epub 2010 Feb 26.

National Agricultural Research Organisation, National Livestock Resources Research Institute, Tororo, Uganda.

Ugandan honey bees (Apis mellifera L.) produce honey, and are key pollinators within commercial crops and natural ecosystems. Real-time RT-PCR was used to screen immature and adult bees collected from 63 beekeeping sites across Uganda for seven viral pathogens. No samples tested positive for Chronic bee paralysis virus, Sacbrood virus, Deformed wing virus, Acute bee paralysis virus, Apis iridescent virus or Israeli acute paralysis virus. However, Black queen cell virus (BQCV) was found in 35.6% of samples. It occurred in adults and larvae, and was most prevalent in the Western highlands, accounting for over 40% of positive results nationally.
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http://dx.doi.org/10.1016/j.jip.2010.02.007DOI Listing
June 2010

The incidence of honey bee pests and diseases in England and Wales.

Pest Manag Sci 2007 Nov;63(11):1062-8

Central Science Laboratory, National Bee Unit, Sand Hutton, York, UK.

The Central Science Laboratory (CSL) National Bee Unit (NBU) has been responsible for maintaining the Integrated Bee Health Programme in England and Wales since the early 1990s. The role of the Bee Health Programme is to protect the honey bee, a major pollinator of agricultural and horticultural crops and wild flora, and to provide up-to-date technical support to beekeepers. The Bee Health Programme is funded in England by the Department for Environment, Food and Rural Affairs (Defra) and in Wales by the Welsh Assembly Government (WAG). The work includes inspection of honey bee colonies, disease and pest diagnosis, development of contingency plans for emerging threats, minimising the risk of introduction of potentially serious exotic pests and diseases through importation by import risk analysis and related extension work and consultancy services to both government and industry. There is also an underpinning programme of research and development.
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http://dx.doi.org/10.1002/ps.1461DOI Listing
November 2007