Hyperparasitism is a normal behavior of parasitoids, which often happens among species. Conspecific hyperparasitism, such as some kinds of heteronomous hyperparasitic behaviors, has been only reported in some species belonging to Aphelinidae. In this article, the conspecific hyperparasitism of Pachycrepoideus vindemmiae (Pteromalidae) is reported, with Drosophila puparia as hosts. Hosts were ex...

The influence of parasites on host reproduction has been widely studied in natural and experimental conditions. Most studies, however, have evaluated the parasite impact on female hosts only, neglecting the contribution of males for host reproduction. This omission is unfortunate as sex-dependent infection may have important implications for host-parasite associations. Here, we evaluate for the...

Honey bee (Apis mellifera) gene expression related to immunity for hymenoptaecin (AmHym) and defensin-1 (AmDef-1), longevity for vitellogenin (AmVit2) and stem cell proliferation for poly U binding factor 68 kDa (AmPuf68) was compared following Varroa destructor parasitism, buffer injection and injection of V. destructor compounds in its homogenate. In adults, V. destructor parasitism decreased...

Laboratory, greenhouse and field studies were conducted on Oomyzus sokolowskii Kurdjumov, a parasite of diamondback moth, Plutella xylostella (L.), to judge its suitability for introduction in the field to control the plutellid. Oomyzus sokolowskii preferred the third and fourth instar diamondback moth larvae over fresh pupae for parasitization. It is thus a larval parasite. Within the range of...

Many parasites affect the development and survival of offspring. Because passerines exhibit determinate growth, parasites may have lasting effects on phenotypes. The life-history consequences of parasite-induced developmental modifications have rarely been analyzed, and require long-term experimental studies. Here we present the results of a four-year experimental study on the effects of a hema...

Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel; Coleoptera: Curculionidae) by Microctonus hyperodae Loan (Hymenoptera: Braconidae) are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian Lolium multiflorum, diploid...

Bird populations in North America's grasslands have declined sharply in recent decades. These declines are traceable, in large part, to habitat loss, but management of tallgrass prairie also has an impact. An indirect source of decline potentially associated with management is brood parasitism by the Brown-headed Cowbird (Molothrus ater), which has had substantial negative impacts on many passe...

A field study was conducted in forested plots near Lansing, Michigan in 2008 and 2009 to evaluate the newly introduced egg parasitoid Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) for control of the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). To measure parasitism by O. agrili, laboratory-reared ‘‘sentinel EAB eggs’’ were deployed under b...

Hosts may use two different strategies to ameliorate negative effects of a given parasite burden: resistance or tolerance. Although both resistance and tolerance of parasitism should evolve as a consequence of selection pressures owing to parasitism, the study of evolutionary patterns of tolerance has traditionally been neglected by animal biologists. Here, we explore geographical covariation b...

4 Allee effects and parasitism are common biological phenomena observed in nature, which are believed to have significant impacts in ecological conservation programs. In this article, we investigate the population dynamics of host-parasitoid systems with Allee effects induced by predation satiation in host to study the effects of Allee effects and parasitism as well as the timing of parasite’s ...