the pea aphid, acyrthosiphon pisum (harris) is one of the most important pests of pea throughout the world.host stage preference under choice and no-choice tests and age-specific functional response of praon volucre (haliday) parasitizing a. pisum were investigated. the experiments were carried out under laboratory conditions at 25 ± 1 °c, 60 ± 5% rh and a photoperiod of 14: 10 h (l: d). functi...

in this research, host stage preference of parasitoid wasp, aphidius matricariae haliday in choice and no-choice tests and functional response of the parasitoid were investigated on common wheat aphid, schizaphis graminum rondani on the alvand cultivar in laboratory conditions at 20, 25 and 30 °c, rh 70 ±10 % and a photoperiod of 16 h l : 8 h d. the maximum mean parasitisms in choice and no-cho...

understanding of parameters that influence parasitoids fitness is necessary for mass rearing and effective use of parasitoids. host quality is an intrinsic feature that is determined by quantitative and qualitative differences in hosts. these differences can change nutritional resources available and consequently affect life history traits of parasitoid. in this study, parasitoid wasps lysiphle...

Many insects harbour facultative symbiotic bacteria, some of which have been shown to provide resistance against natural enemies. One of the best-known protective symbionts is Hamiltonella defensa, which in pea aphid (Acyrthosiphon pisum) confers resistance against attack by parasitoid wasps in the genus Aphidius (Braconidae).We asked (i) whether this symbiont also confers protection against a ...

Insects use endogenous mechanisms and infection with protective symbionts to thwart attacks from natural enemies. Defenses that target specific enemies, however, potentially mediate competition between rivals and thereby impact community composition. Following its introduction to North America to control pea aphids (Acyrthosiphon pisum), the parasitoid Aphidius ervi competitively displaced othe...

The role of volatile stimuli in the host-searching behaviour of the two parasitoid species Lysiphlebus testaceipes Cresson and Aphidius colemani Viereck (Hymenoptera: Braconidae) was studied in relation to the host Aphis gossypii Glover (Homoptera: Aphididae) on cucumber plants, Cucumis sativa L. (Cucurbitaceae). Experiments were carried out in the laboratory in a wind tunnel, exposing individu...

Host-parasite interactions are a key paradigm for understanding the process of coevolution. Central to coevolution is how genetic variation in interacting species allows parasites to evolve manipulative strategies. However, genetic variation in the parasite may also be associated with host phenotype changes, thereby changing the selection on both species. For instance, parasites often induce ch...

Specialization is a central concept in ecology and one of the fundamental properties of parasitoids. Highly specialized parasitoids tend to be more efficient in host-use compared to generalized parasitoids, presumably owing to the trade-off between host range and host-use efficiency. However, it remains unknown how parasitoid host specificity and host-use depends on host traits related to susce...