Journal of Chemical Ecology (2013) 39, 591-601

Eline C. Susset, Felipe Ramon-Portugal, Jean-Louis Hemptinne, Sarah Y. Dewhirst, Michael A. Birkett and Alexandra Magro (2013)
The role of semiochemicals in short-range location of aggregation sites in Adalia bipunctata (Coleoptera, Coccinellidae)
Journal of Chemical Ecology 39 (5), 591-601
Abstract: To survive unfavorable periods, ladybird beetles form conspicuous aggregations in specific microsites, with these locations remaining the same year after year. This constancy of location leads to the hypothesis that semiochemicals are involved in the attraction and aggregation of ladybirds to the microsite. In this study, we identified two types of semiochemicals that could play key roles in the attraction and aggregation formation of the two-spotted ladybird, Adalia bipunctata. We first isolated and identified three alkylmethoxypyrazines from A. bipunctata and tested the behavioral responses of diapausing ladybirds to these chemicals in a four-way olfactometer. This revealed that 2-isobutyl-3-methoxypyrazine, on its own or as part of a two-component mixture with 2-isopropyl-3-methoxypyrazine, elicited a positive behavioral response, causing arrestment of diapausing A. bipunctata. As ladybirds are in contact with each other in aggregations, we investigated the role of cuticular hydrocarbons (CHCs) in driving the cohesion and maintenance of aggregation. When an extract of CHCs from diapausing ladybirds was deposited near an alkylmethoxypyrazine source, ladybirds spent more time in the vicinity of the source. We identified a set of CHCs specific to diapausing A. bipunctata. Alkylmethoxyyrazines and CHCs thus deliver information to diapausing ladybirds searching for an aggregation site, as well as mediating several other behaviors throughout the ladybird's life cycle. Chemical parsimony is discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Sarah Y. Dewhirst, Alexandra Magro, Michael A. Birkett, Jean-Louis Hemptinne

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
population dynamics/epizootiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Adalia bipunctata (predator)