rosy apple aphid, dysaphis plantaginea (passerini), with worldwide distribution is an important pest of apple orchards. host plant resistance is an essential component of integrated management of this insect pest. we investigated the resistance of seven apple cultivars, malus domestica (borkhausen), namely granny smith, starkrimson, golden smoothee, red delicious, golden delicious, boshghabi, a...

Ostriches farmed in Canada often have particular behavioral problems that are brought about by periods of extreme confinement during winter months. Although they still perform normal species specific behaviors such as twirling, kanteling, and kicking, abnormal behaviors become prominent when excessively confined. They include for all age groups of ostriches, feather-picking, behavioral stargazi...

The animal immune system provides defence against microbial infection, and the evolution of certain animal-microbial symbioses is predicted to involve adaptive changes in the host immune system to accommodate the microbial partner. For example, the reduced humoral immune system in the pea aphid Acyrthosiphon pisum, including an apparently non-functional immune deficiency (IMD) signalling pathwa...

The drive towards a more sustainable and integrated approach to pest management has engendered a renewed interest in conservation biological control, the role of natural enemy communities and their interactions with prey. Monoclonal antibodies have provided significant advances in enhancing our knowledge of trophic interactions and can be employed to help quantify predation on target species. T...

Aphids are pests on many crops and depend on plant phloem sap as their food source. In an attempt to find factors improving plant resistance against aphids, we studied the effects of overexpression and down-regulation of the lipoxygenase gene LOX2.2 in barley (Hordeum vulgare L.) on the performance of two aphid species. A specialist, bird cherry-oat aphid (Rhopalosiphum padi L.) and a generalis...

BACKGROUND Defensive medicine is prevalent among US neurosurgeons due to the high risk of malpractice claims. This study provides national estimates of US neurosurgeons' defensive behaviors and perceptions. OBJECTIVE To examine the relationship of defensive medicine-both "assurance" behaviors and "avoidance" behaviors-to the liability environment. METHODS A 51-question online survey was sen...

Plants show considerable within-species variation in their resistance to insect herbivores. In the case of Zea mays (cultivated maize), Rhopalosiphum maidis (corn leaf aphids) produce approximately twenty times more progeny on inbred line B73 than on inbred line Mo17. Genetic mapping of this difference in maize aphid resistance identified quantitative trait loci (QTL) on chromosomes 4 and 6, wi...

Terrestrial arthropods are often infected with heritable bacterial symbionts, which may themselves be infected by bacteriophages. However, what role, if any, bacteriophages play in the regulation and maintenance of insect-bacteria symbioses is largely unknown. Infection of the aphid Acyrthosiphon pisum by the bacterial symbiont Hamiltonella defensa confers protection against parasitoid wasps, b...

Parasites and hosts live in communities consisting of many interacting species, but few studies have examined how communities affect parasite virulence and transmission. We studied a food web consisting of two species of milkweed, two milkweed herbivores (monarch butterfly and oleander aphid) and a monarch butterfly-specific parasite. We found that the presence of aphids increased the virulence...