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...

In 1990 and 1991, populations of the cabbage aphid, Brevicoryne brassicae, and the green peach aphid, Myzus persicae, were monitored on broccoli interplanted with three leguminous cover crops (the living mulches) and compared with broccoli without cover crop (clean cultivation). The cover crops used were white clover ( Trifolium repens L.), strawberry clover (Trifolium fragiferum L.) and a mixt...

Pieris napi oleracea Harris is a native pierid butterfly that has suffered a range reduction in New England that began after the invasion of its range by the non-native congener Pieris rapae L. and one of its braconid parasitoids, Cotesia glomerata (L.). P. napi has nearly disappeared from Massachusetts, but remains common in northern Vermont. We investigated food plant abundance and Cotesia sp...

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 ...

Interactions between avian hosts and brood parasites can provide a model for how animals adapt to a changing world. Reed warbler (Acrocephalus scirpaceus) hosts employ costly defenses to combat parasitism by common cuckoos (Cuculus canorus). During the past three decades cuckoos have declined markedly across England, reducing parasitism at our study site (Wicken Fen) from 24% of reed warbler ne...

Neosilba perezi (romero & ruppel) is known as the cassava shoot fly or shoot fly, because, unlike other species of its genus, its larvae feed exclusively on shoots of cassava (Manihot esculenta crantz). these larvae kill the affected cassava shoots. natural parasitism by a braconid, phaenocarpa neosilba arouca & Penteado-Dias, 2006, on shoot fly larvae was studied at 3 locations in the southwes...

Vertically transmitted micro-organisms can increase in frequency in host populations by providing net benefits to hosts. While laboratory studies have identified diverse beneficial effects conferred by inherited symbionts of insects, they have not explicitly examined the population dynamics of mutualist symbiont infection within populations. In the pea aphid, Acyrthosiphon pisum, the inherited ...

Generalist parasites exploit multiple host species at the population level, but the individual parasite's strategy may be either itself a generalist or a specialist pattern of host species use. Here, we studied the relationship between host availability and host use in the individual parasitism patterns of the Shiny Cowbird Molothrus bonariensis, a generalist avian obligate brood parasite that ...

High levels of conspecific brood parasitism are found in a communally breeding bird, with implications for the evolutionary links between brood parasitism and communal breeding. It also uncovers a novel egg recognition mechanism hosts use to foil brood parasites.