Papers by Simon Springate
New records of ash whitefly Siphoninus phillyreae(Halliday) (Hemiptera: Aleyrodidae) in Kent
British journal of entomology and natural history, 2012
The whitefly records for Kent were recently summarised by Malumphy & Badmin (2012). A total o... more The whitefly records for Kent were recently summarised by Malumphy & Badmin (2012). A total of thirteen species are currently known from VCs 15 and 16, though several have not been recorded for many years. Ash whitefly Siphoninus phillyreae (Halliday) (Plate 15, Fig. 4) is a typical example with just two records, from Beckenham, West Kent dating from 1950 (C. B. Williams) to as recently as 1988 (J. H. Martin). Searches this year have revealed that ash whitefly is more widespread in the county than previously understood.
Journal for Nature Conservation, Jun 1, 2021
Strategies to achieve agricultural production and biodiversity conservation fall into two categor... more Strategies to achieve agricultural production and biodiversity conservation fall into two categories, land-sparing or land-sharing. Plant species richness under organic arable (land sharing) versus conventional arable with land set-aside for conservation (land sparing) was evaluated on adjacent farms to compare these strategies. Sampled plant species richness was significantly higher under organic than conventional arable, as expected, but very similar to set-aside. Nevertheless, the Chao1 estimator of total plant species richness indicated that the larger area available to plants under organic arable may sustain more scarce species leading to a higher species richness. It appears that the conservation value of sparing versus sharing depends on the relative species richness of the portion of land spared (set-aside) compared to the larger area of shared land (organic), and not with the species richness on conventionally cropped land. Furthermore, in theory the land-shared use will have greater capacity to sustain populations of scarce low-density species simply due 100% of the land area being available to these species. These are important principals for assessing land sparing versus sharing strategies seeking to balance production and biodiversity conservation not just for arable land but all agricultural land uses.
Pyrethroid insecticide resistance in British populations of the cabbage whitefly, <i>Aleyrodes proletella</i>
Pest Management Science, Jul 28, 2011
The cabbage whitefly, Aleyrodes proletella L., is emerging as a significant pest of field brassic... more The cabbage whitefly, Aleyrodes proletella L., is emerging as a significant pest of field brassica crops in certain regions of the United Kingdom. In order to investigate the contribution of pesticide resistance to this phenomenon, A. proletella populations were sampled from five different areas in England in 2008 and 2009. Adult residual leaf-dip bioassays were carried out using pyrethroid and neonicotinoid insecticides. Significant resistance to pyrethroids was found in multiple samples collected from two areas. No evidence of cross-resistance to neonicotinoids was found in a subset of the pyrethroid-resistant populations. While the patterns of resistance to different pyrethroids were broadly correlated, the magnitude of resistance factors differed substantially. Survival of strains at a putative diagnostic concentration of lambda-cyhalothrin was found to provide a guide to their LC50. Significant differences in LC50 were found when different brassica crops were used in the bioassay, although the resistance patterns between strains were maintained. Reduced susceptibility to multiple pyrethroid insecticides exists in populations of A. proletella in the United Kingdom, corresponding to recent major outbreaks. The mechanism(s) of resistance are yet to be determined, but molecular structural differences in pyrethroids probably influence the magnitude of cross-resistance within this group of insecticides.
Glucosylation prevents plant defense activation in phloem-feeding insects
Nature Chemical Biology, Sep 28, 2020
The metabolic adaptations by which phloem-feeding insects counteract plant defense compounds are ... more The metabolic adaptations by which phloem-feeding insects counteract plant defense compounds are poorly known. Two-component plant defenses, such as glucosinolates, consist of a glucosylated protoxin that is activated by a glycoside hydrolase upon plant damage. Phloem-feeding herbivores are not generally believed to be negatively impacted by two-component defenses due to their slender piercing-sucking mouthparts, which minimize plant damage. However, here we document that glucosinolates are indeed activated during feeding by the whitefly Bemisia tabaci. This phloem feeder was also found to detoxify the majority of the glucosinolates it ingests by the stereoselective addition of glucose moieties, which prevents hydrolytic activation of these defense compounds. Glucosylation of glucosinolates in B. tabaci was accomplished via a transglucosidation mechanism, and two glycoside hydrolase family 13 (GH13) enzymes were shown to catalyze these reactions. This detoxification reaction was also found in a range of other phloem-feeding herbivores. The whitefly Bemisia tabaci defends against plant glucosinolate toxins by serial addition of glucose moieties catalyzed by a pair of glycoside hydrolases, preventing toxin activation during feeding on the plant tissue.
The suitability of kale and tatsoi as hosts for Aleyrodes proletella in rearing and bioassays was... more The suitability of kale and tatsoi as hosts for Aleyrodes proletella in rearing and bioassays was assessed at 20°C and 25°C. Development was significantly faster at 25°C than at 20°C on both hosts and slower on tatsoi than kale at 20°C but not at 25°C. Survival was greater on kale than on tatsoi. A number of small scale trials were carried out to identify a repeatable adult bioassay method with low control mortality for A. proletella on brassica leaves. Beginning with the standard cut leaf disc method used for whitefly insecticide bioassays, various modifications and alternatives were attempted with available materials to solve problems such as leaf waxiness and static. A cut leaf petiole method involving the use of clip cages was identified as suitable, with dipping of leaves in a 0.1% concentration of the surfactant Activator 90 in deionised water found to provide an acceptable compromise between leaf wetting and phytotoxicity. Despite less even leaf wetting compared to kale at this concentration, tatsoi was adopted for adult bioassays for practical reasons with kale used for nymphal bioassays on whole plants, due to the longer time to leaf senescence and proven better survival of whiteflies to eclosion.
Ecological Entomology, Dec 1, 2005
1. The thermal biology of the meadow grasshopper, Chorthippus parallelus, a common, habitat gener... more 1. The thermal biology of the meadow grasshopper, Chorthippus parallelus, a common, habitat generalist acridid species found in the U.K., was characterised and the influence of thermoregulatory behaviour for resistance against a temperate (Beauveria bassiana) and tropical (Metarhizium anisopliae var. acridum) fungal pathogen was determined. 2. Chorthippus parallelus was found to be an active behavioural thermoregulator, with a preferred temperature range of 32-35 C. 3. Both pathogens proved lethal to fifth instar and adult grasshoppers. No evidence of behavioural fever in response to infection by either pathogen was found, but normal thermoregulation was found to reduce virulence and spore production of B. bassiana. Normal thermoregulation did not appear to affect M. anisopliae var. acridum. 4. These results suggest that the effects of temperature on host resistance depend on the thermal sensitivity of the pathogen and, in this case, derive from direct effects of temperature on pathogen growth rather than indirect effects mediated by host immune response. 5. The implications for possible risks of exotic pathogens and influence of climate change are discussed.
Assemblages of Social Wasps in Forests and Open Land Across Europe – an ALARM-FSN Study
New records of ash whitefly Siphoninus phillyreae (Halliday)(Hemiptera: Aleyrodidae) in Kent
The whitefly records for Kent were recently summarised by Malumphy & Badmin (2012). A total o... more The whitefly records for Kent were recently summarised by Malumphy & Badmin (2012). A total of thirteen species are currently known from VCs 15 and 16, though several have not been recorded for many years. Ash whitefly Siphoninus phillyreae (Halliday) (Plate 15, Fig. 4) is a typical example with just two records, from Beckenham, West Kent dating from 1950 (C. B. Williams) to as recently as 1988 (J. H. Martin). Searches this year have revealed that ash whitefly is more widespread in the county than previously understood.
New vice-county records of Clitostethus arcuatus (Rossi)(Col.: Coccinellidae) and a new association with wild cabbage
Parasites & Vectors, 2015
Background: As part of efforts to more fully understand the potential risks posed by West Nile vi... more Background: As part of efforts to more fully understand the potential risks posed by West Nile virus (WNV) and Usutu virus (USUV) in the UK, and following on from previous reports of a potential bridge vector Culex modestus for these viruses, at wetland sites in North Kent, mosquito surveillance was undertaken more widely across the Isle of Sheppey, the Hoo Peninsula and the Kent mainland. Methods: Larval surveys were conducted and Mosquito Magnet® adult traps were used to collect adult mosquitoes. Pools of female mosquitoes were tested for the presence of WNV using real-time reverse transcriptase polymerase chain reaction. A subset of samples was tested for USUV. Results: Culex modestus was found in both the pre-imaginal and imago stage at all five locations surveyed, accounting for 90% of adult mosquitoes collected. WNV or USUV were not detected in any sample. Conclusions: Although no mosquitoes have been shown to be virus positive, the field survey data from this study demonstrated the dominance of an important bridge vector species for WNV in this region. Its wide geographical distribution highlights the need to update risk assessments on WNV introduction, and to maintain vigilance for WNV in the South East of England.
Ecological Entomology, 2005
1. The thermal biology of the meadow grasshopper, Chorthippus parallelus, a common, habitat gener... more 1. The thermal biology of the meadow grasshopper, Chorthippus parallelus, a common, habitat generalist acridid species found in the U.K., was characterised and the influence of thermoregulatory behaviour for resistance against a temperate (Beauveria bassiana) and tropical (Metarhizium anisopliae var. acridum) fungal pathogen was determined. 2. Chorthippus parallelus was found to be an active behavioural thermoregulator, with a preferred temperature range of 32-35 C. 3. Both pathogens proved lethal to fifth instar and adult grasshoppers. No evidence of behavioural fever in response to infection by either pathogen was found, but normal thermoregulation was found to reduce virulence and spore production of B. bassiana. Normal thermoregulation did not appear to affect M. anisopliae var. acridum. 4. These results suggest that the effects of temperature on host resistance depend on the thermal sensitivity of the pathogen and, in this case, derive from direct effects of temperature on pathogen growth rather than indirect effects mediated by host immune response. 5. The implications for possible risks of exotic pathogens and influence of climate change are discussed.
Does farm management influence ground predator abundance and diversity in the Kent North Downs?
The cabbage whitefly, Aleyrodes proletella, has in recent years become a primary pest of several ... more The cabbage whitefly, Aleyrodes proletella, has in recent years become a primary pest of several brassica crops in Europe. In the UK, its greatest impact has been on kale, where nymphs, wax deposits and sooty mould caused by honeydew excretion reduce the marketable portion of the crop, particularly later in the year. In order to test the contribution of insecticide resistance to these outbreaks, a leaf-dip bioassay method was developed. Resistance to several pyrethroids was found in multiple populations in Lincolnshire and Kent, with similar patterns between compounds but differing magnitudes of resistance. This resistance was expressed to a similar degree by both adults and nymphs. The host plant used in bioassays influenced lethal concentrations but not resistance factors. A diagnostic concentration of lambda-cyhalothrin was identified and used to screen further populations over successive years. No cross-resistance to neonicotinoid insecticides was evident in highly pyrethroid-re...
Land sparing or sharing: Strategies for conservation of arable plant diversity
Journal for Nature Conservation
Glucosylation prevents plant defense activation in phloem-feeding insects
Nature Chemical Biology
The cabbage whitefly Aleyrodes proletella and its natural enemies on wild cabbage Brassica oleracea on the Kent coast.
Transactions of the Kent Field Club, 2017
New records of ash whitefly Siphoninus phillyreae (Halliday) (Hemiptera: Aleyrodidae) in Kent
British Journal of Entomology and Natural History
Parasites & Vectors, 2015
Background: As part of efforts to more fully understand the potential risks posed by West Nile vi... more Background: As part of efforts to more fully understand the potential risks posed by West Nile virus (WNV) and Usutu virus (USUV) in the UK, and following on from previous reports of a potential bridge vector Culex modestus for these viruses, at wetland sites in North Kent, mosquito surveillance was undertaken more widely across the Isle of Sheppey, the Hoo Peninsula and the Kent mainland. Methods: Larval surveys were conducted and Mosquito Magnet® adult traps were used to collect adult mosquitoes. Pools of female mosquitoes were tested for the presence of WNV using real-time reverse transcriptase polymerase chain reaction. A subset of samples was tested for USUV.
British Journal of Entomology and Natural History, 2012
Pyrethroid insecticide resistance in British populations of the cabbage whitefly, Aleyrodes proletella
Pest management science, 2012
BACKGROUND: The cabbage whitefly, Aleyrodes proletella L., is emerging as a significant pest of f... more BACKGROUND: The cabbage whitefly, Aleyrodes proletella L., is emerging as a significant pest of field brassica crops in certain regions of the United Kingdom. In order to investigate the contribution of pesticide resistance to this phenomenon, A. proletella populations were sampled from five different areas in England in 2008 and 2009. Adult residual leaf-dip bioassays were carried out using pyrethroid and neonicotinoid insecticides.RESULTS: Significant resistance to pyrethroids was found in multiple samples collected from two areas. No evidence of cross-resistance to neonicotinoids was found in a subset of the pyrethroid-resistant populations. While the patterns of resistance to different pyrethroids were broadly correlated, the magnitude of resistance factors differed substantially. Survival of strains at a putative diagnostic concentration of lambda-cyhalothrin was found to provide a guide to their LC50. Significant differences in LC50 were found when different brassica crops were used in the bioassay, although the resistance patterns between strains were maintained.CONCLUSION: Reduced susceptibility to multiple pyrethroid insecticides exists in populations of A. proletella in the United Kingdom, corresponding to recent major outbreaks. The mechanism(s) of resistance are yet to be determined, but molecular structural differences in pyrethroids probably influence the magnitude of cross-resistance within this group of insecticides. Copyright © 2011 Society of Chemical Industry
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Papers by Simon Springate