Alan Cork

Bio: Alan Cork is an academic researcher from University of Greenwich. The author has contributed to research in topics: Sex pheromone & Mating disruption. The author has an hindex of 24, co-authored 57 publications receiving 2290 citations.

Sex pheromones and their impact on pest management.

Abstract: The idea of using species-specific behavior-modifying chemicals for the management of noxious insects in agriculture, horticulture, forestry, stored products, and for insect vectors of diseases has been a driving ambition through five decades of pheromone research. Hundreds of pheromones and other semiochemicals have been discovered that are used to monitor the presence and abundance of insects and to protect plants and animals against insects. The estimated annual production of lures for monitoring and mass trapping is on the order of tens of millions, covering at least 10 million hectares. Insect populations are controlled by air permeation and attract-and-kill techniques on at least 1 million hectares. Here, we review the most important and widespread practical applications. Pheromones are increasingly efficient at low population densities, they do not adversely affect natural enemies, and they can, therefore, bring about a long-term reduction in insect populations that cannot be accomplished with conventional insecticides. A changing climate with higher growing season temperatures and altered rainfall patterns makes control of native and invasive insects an increasingly urgent challenge. Intensified insecticide use will not provide a solution, but pheromones and other semiochemicals instead can be implemented for sustainable area-wide management and will thus improve food security for a growing population. Given the scale of the challenges we face to mitigate the impacts of climate change, the time is right to intensify goal-oriented interdisciplinary research on semiochemicals, involving chemists, entomologists, and plant protection experts, in order to provide the urgently needed, and cost-effective technical solutions for sustainable insect management worldwide.

1-octen-3-ol: a potent olfactory stimulant and attractant for tsetse isolated from cattle odours.

Abstract: Recording of electroantennographic (EAG) responses from tsetse, Glossina pallidipes and G. morsitans morsitans (Diptera: Glossinidae) has been used to detect olfactory stimulants in volatiles from cattle. The most potent stimulant in cattle odours collected on Porapak resin has been identifiedas 1-octen-3-ol by gas chromatographic retention data and mass spectrometry. The rate of production of 1-octen-3-ol by a normal ox was estimated to be 0.043 mghr−1, and the natural material was shown to be predominantly the (R)-(−)enantiomer. No 1-octen-3-ol was collected under the conditions used in the absence of an ox. EAG dose-response curves to 1-octen-3-ol showed it to be about 106 times more potent than acetone, a known attractant for tsetse, with the maximum response of about 1 mV occurring to approx. 1 ng at source. 1-octen-3-ol caused increased upwind flight by tsetse in a wind tunnel bioassay, and in the field it was attractive to tsetse by itself and also increased the attractiveness of both ox odour and of mixtures ofcarbon dioxide and acetone.

Identification of components of cattle urine attractive to tsetse flies, Glossina spp. (Diptera: Glossinidae)

Abstract: The attractiveness of cattle urine to Glossina morsitans morsitans Westwood and G. pallidipes Austen was shown to be entirely attributable to the phenolic components which it contains. Four of the eight naturally occurring phenol derivatives (3- and 4-methylphenol, 3-ethylphenol and 3-n-propylphenol) were electroantennographically active, induced upwind flight in wind-tunnel bioassays and increased trap catches in field tests in Zimbabwe. One of the minor components, 2-methoxyphenol, had little antennographic activity but induced upwind flight in the wind-tunnel and appeared to be repellent in field tests.

Electrophysiological and behavioral responses of female Helicoverpa armigera to compounds identified in flowers of African marigold, Tagetes erecta.

Abstract: Seven electrophysiologically active compounds were detected in air-entrained headspace samples of live flowers of Tagetes erectaanalyzed by gas chromatography (GC) linked to a female Helicoverpa armigeraelectroantennograph (EAG) using polar and nonpolar capillary columns. These compounds were subsequently identified using GC linked to mass spectrometry as benzaldehyde, (S)-(−)-limonene, (R,S)-(±)-linalool, (E)-myroxide, (Z)-β-ocimene, phenylacetaldehyde, and (R)-(−)-piperitone. Electrophysiological activity was confirmed by EAG with a 1-μg dose of each compound on filter paper eliciting EAG responses that were significantly greater than the solvent control response from female moths. Wind-tunnel bioassays with T. erectaheadspace samples, equivalent to 0.4 flower/hr emission from a live flower, elicited a significant increase in the number of upwind approaches from female H. armigerarelative to a solvent control. Similarly, a seven-component synthetic blend of EAG-active compounds identified from T. erectapresented in the same ratio (1.0 : 1.6 : 0.7 : 1.4 : 0.4 : 5.0 : 2.7, respectively) and concentration (7.2 μg) as found in the natural sample elicited a significant increase in the number of upwind approaches relative to a solvent control during a 12-min bioassay that was equivalent to that elicited by the natural T. erectafloral volatiles.

Sex pheromones and their impact on pest management.

Abstract: The idea of using species-specific behavior-modifying chemicals for the management of noxious insects in agriculture, horticulture, forestry, stored products, and for insect vectors of diseases has been a driving ambition through five decades of pheromone research. Hundreds of pheromones and other semiochemicals have been discovered that are used to monitor the presence and abundance of insects and to protect plants and animals against insects. The estimated annual production of lures for monitoring and mass trapping is on the order of tens of millions, covering at least 10 million hectares. Insect populations are controlled by air permeation and attract-and-kill techniques on at least 1 million hectares. Here, we review the most important and widespread practical applications. Pheromones are increasingly efficient at low population densities, they do not adversely affect natural enemies, and they can, therefore, bring about a long-term reduction in insect populations that cannot be accomplished with conventional insecticides. A changing climate with higher growing season temperatures and altered rainfall patterns makes control of native and invasive insects an increasingly urgent challenge. Intensified insecticide use will not provide a solution, but pheromones and other semiochemicals instead can be implemented for sustainable area-wide management and will thus improve food security for a growing population. Given the scale of the challenges we face to mitigate the impacts of climate change, the time is right to intensify goal-oriented interdisciplinary research on semiochemicals, involving chemists, entomologists, and plant protection experts, in order to provide the urgently needed, and cost-effective technical solutions for sustainable insect management worldwide.

Biological invasion of European tomato crops by Tuta absoluta: ecology, geographic expansion and prospects for biological control

Abstract: The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a devastating pest of tomato originating from South America. After its initial detection in eastern Spain in 2006, it rapidly invaded various other European countries and spread throughout the Mediterranean basin. If no control measures are taken, then the pest can cause up to 80–100% yield losses in tomato crops in recently invaded areas and may pose a threat to both greenhouse and open-field tomato production. The exceptional speed and extent of T. absoluta invasion have called for studies documenting its biology and ecology, while indicating an urgent need for efficient and sustainable management methods. The development of approaches to manage T. absoluta would be facilitated through a detailed revision of information on this pest in its area of origin. This review combines information on the invasion by T. absoluta, its ecology, and potential management strategies, including data that may help the implementation of efficient biological control programs. These programs, together with a variety of other management tactics, may allow efficient integrated pest management of T. absoluta in Europe and Mediterranean Basin countries.

Biology of Blood-Sucking Insects

Abstract: Part 1 The importance of blood-sucking insects. Part 2 The evolution of the blood-sucking habit: prolonged close association with vertebrates morphological pre-adaptation for piercing. Part 3 Feeding preferences of blood-sucking insects: host choice host choice and species complexes. Part 4 Location of the host: the behavioural framework of host location appetitive searching activation and orientation attraction movement between hosts. Part 5 Ingestion of the blood meal: vertebrate haemostasis insect anti-haemostatic factors probing stimulants phagostimulants mouthparts blood intake. Part 6 Managing the blood meal: midgut anatomy the blood meal gonotrophic concordance nutrition host hormones in the blood meal partitioning of resources from the blood meal autogeny. Part 7 Host - insect interactions: insect distribution on the surface of the host morphological specializations for life on the host host immune responses to insect salivary secretions behavioural defences of the host density dependent effects on feeding success. Part 8 Transmission of parasites by blood-sucking insects: transmission routes specificity in vector-parasite relationships origin of vector parasite relationships.

Odor-mediated behavior of afrotropical malaria mosquitoes

Abstract: The African mosquito species Anopheles gambiae sensu lato s.l. and Anopheles funestus rank among the world's most efficient vectors of human malaria. Their unique bionomics, particularly their anthropophilic, endophagic and endophilic characters, guarantee a strong mosquito-host interaction, favorable to malaria transmission. Olfactory cues govern the various behaviors of female mosquitoes and here we review the role of semiochemicals in the life history of African malaria vectors. Recent evidence points towards the existence of human-specific kairomones affecting host-seeking A. gambiae s.l., and efforts are under way to identify the volatiles mediating this behavior. Based on examples from other Culicidae spp., it is argued that there is good reason to assume that mating, sugar feeding, and oviposition behavior in Afrotropical malaria vectors may also be mediated by semiochemicals. It is foreseen that increased knowledge of odor-mediated behaviors will be applied in the development of novel sampling techniques and possibly alternative methods of intervention to control malaria.