Entomologia Experimentalis et Applicata (2015) 155, 18-27

Mey Jerbi-Elayed, Kaouthar Lebdi-Grissa, Vincent Foray, Frédéric Muratori and Thierry Hance (2015)
Using multiple traits to estimate the effects of heat shock on the fitness of Aphidius colemani
Entomologia Experimentalis et Applicata 155 (1), 18-27
Abstract: Extreme temperature events are a great challenge for most ectotherms, particularly for the immature stages of parasitoids, as they do not possess the ability to behaviourally thermoregulate. In this study, we measured the effect of an acute heat shock, combined with desiccation stress (34 °C and 35% r.h. during 10 h) during the mummy stage on several fitness-related traits of emerging adults of the aphid parasitoid Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae). Our results showed that the emergence rate was strongly affected by the heat shock (63 ± 2.3 vs. 96.1 ± 0.7% for stress vs. control conditions, respectively), and the resulting population was male biased. Heat stress reduced the lifespan of emerged parasitoids but had no effect on fat reserves and female size. Egg load at emergence and parasitism rate were also reduced by heat treatment. The antennal symmetry was disturbed by the heat treatment, and stressed individuals had reduced mating success compared to control parasitoids. Specifically, time before wing fanning, a typical male courtship behaviour, was significantly longer in parasitoid pairs involving females that had emerged from heat-treated mummies. Additionally, olfactometry tests on experimental females indicated that their response to host odour was similar to that of control individuals, but they required a longer time for perception. These results highlight that exposure to high temperatures during the mummy stage has cumulative detrimental effects that may strongly impact parasitoid populations under natural conditions and hinder the success of biological control programs.
(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): Mey Jerbi-Elayed, Thierry Hance, Frédéric Muratori

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Aphidius colemani (parasitoid)