Oögenesis in Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae)

Abstract

Synopsis An account is given of the development of the oöcyte in Nasonia vitripennis. The probable functions of the trophocytes, the accessory nuclei and the annulate lamellae are discussed.

Exposure of a single host (Chrysomya megacephala) (Calliphoridae) to different quantities of female parasitoids (Nasonia vitripennis) (Pteromalidae)

“…Thus, it was possible to observe that the duration of the development period was potentially influenced by the proportion of wasp/ host, since the other factors that could have influenced the development were controlled, such as environmental conditions. According to King & Rafai (1970) the discrimination of parasitized host does not occur during the first 60 h, then, as seen in this study, the parasitism was during 48h when the females possibly could not detect the parasitized host. Within a column means followed by same capital letters and/or within a line means followed by same tiny letters, do not differ significantly at the 5% level according to Tukey's HSD.…”

“…The parasitism success of these parasitoids is usually divided in hierarchic stages, which consist of locating the habitat and the host, evaluation and physiological regulation of the host (Brodeur & Boivin 2004). Female parasitoids cannot distinguish newly parasitized hosts from unparasitized ones, but after 60h of parasitization, the parasitized puparium are rejected as oviposition sites (King & Rafai 1970). This discrimination between the parasitized and unparasitized is only possible after the ovipositor had drilled through the puparium and made contact with the pupa within (King & Rafai 1970, King & Ellison 2006.…”

“…Female parasitoids cannot distinguish newly parasitized hosts from unparasitized ones, but after 60h of parasitization, the parasitized puparium are rejected as oviposition sites (King & Rafai 1970). This discrimination between the parasitized and unparasitized is only possible after the ovipositor had drilled through the puparium and made contact with the pupa within (King & Rafai 1970, King & Ellison 2006. The value of this discrimination to the parasitoid is perhaps to prevent the second clutch being eaten or being unable to feed because the host has been rendered unsuitable in some way by the first clutch (King & Rafai 1970).…”

“…It may occur because the chances of successive ovipositions in the same host is higher when there is an increase of the number of females per host and also because the discrimination cannot occur during the first 60 h according to King & Rafai (1970).…”

Early Detection of Prospective Mates by Males of the Parasitoid Wasp <I>Pimpla disparis</I> Viereck (Hymenoptera: Ichneumonidae)

“…Other chemical changes could stem from the hatching and developing parasitoid larva (Hofsvang 1990). The parasitoid N. vitripennis induces persistent changes in the hostÕs hemolymph that deter superparasitism (King and Rafai 1970).…”