We investigate the effect of parasitoid phenology on host-parasitoid population cycles. Recent experimental research has shown that parasitized hosts can continue to interact with their unparasitized counterparts through competition. Parasitoid phenology, in particular the timing of emergence from the host, determines the duration of this competition. We construct a discrete-time host-parasitoi...

Animal medication is a behavioral strategy to resist enemies based on the use of substances from the environment. While it has been observed in several animals, whether invasive species can use medication to resist new enemies during its expansion is unknown. Here, we show that the worldwide invasive pest Drosophila suzukii performs trans-generational prophylactic medication by adapting its ovi...

Natural enemies respond to herbivore-induced plant volatiles (HIPVs), but an often overlooked aspect is that there may be genotypic variation in these 'indirect' plant defence traits within plant species. We found that egg deposition by stemborer moths (Chilo partellus) on maize landrace varieties caused emission of HIPVs that attract parasitic wasps. Notably, however, the oviposition-induced r...

How global warming will affect insect parasitoids and their role as natural enemies of insect pests is difficult to assess within a short period of time. Considering that elevation gradients can be used as analogues for global warming, we carried out meta-analyses of 27 correlations between parasitoid richness and elevation and 140 correlations between parasitism rate and elevation in natural a...

Predaceous and parasitic arthropods can play an important role in the regulation of herbivore populations. However, the majority of predators and parasitoids also use plant-derived foods as a source of nutrients. This vegetarian side of the menu may include various plant-provided substrates, such as nectar, pollen, fruits or foods indirectly derived from plants (e.g., honeydew or pycnial fluid ...

A theoretical analysis of the feasibility of controlling tick populations (Ixodidae) by the release of reared Ixodiphagus parasitoids in tick ecosystems yielded promising results. The analysis suggested that if reasonable progress could be made in mass-rearing the parasitoids, it would be possible to control the blacklegged tick, Ixodes scapularis (Say), the vector of Lyme disease, by this biol...

Egg parasitoids of the corn leafhopper, Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), were surveyed exposing sentinel eggs of the leafhopper along a latitudinal transect of 600 km in Argentina, the southernmost area of its distribution range. Four parasitoid species were obtained: the mymarids Anagrus breviphragma Soyka (Hymenoptera: Mymaridae), Anagrus flaveolus Waterhouse, a...

Van Alphen and Vet (1986) refer to the work of Arthur E. Weis (1983) on a torymid wasp that attacks a gall midge on goldenrod. This system seems to be quite well-studied, particularly, but not exclusively, by Weis. Van Alphen and Vet point out that the parasitoids tend to attack about the same proportion of hosts in patches (galls) with varying numbers of hosts. This has implications for the fo...

The accurate measurement of parasitoid impact on diamondback moth, Plutella xylostella (L.) populations is important to both the evaluation of exotic parasitoids for introduction, and to the integration of parasitoids with other cropping practices, particularly pesticides. Parasitoid impact is usually measured by samples for percent parasitism. Problems with the accuracy of this approach, and i...