In many ecosystems the effects of disturbance can be cryptic and disturbance may vary in subtle spatiotemporal ways. For instance, we know that bark beetle outbreaks are more frequent in temperate forests during droughts; however, we have little idea about why they occur in some locations and not others. Understanding biotic and abiotic factors promoting bark beetle outbreaks can be critical to...

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in the current study some information is presented about the distribution and associations between alfalfa aphids and their parasitoids in different regions in 11 provinces of iran, as well as an identification key to the parasitoids. the main aphids were therioaphis trifolii maculata (buckton) and acyrthosiphon pisum (harris) followed by aphis craccivora koch and acyrthosiphon kondoi shinji. t...

Numerous species in the Old World army ant genus Dorylus have been described based on a single sex or caste. Our analysis of mitochondrial cytochrome oxidase II gene sequences of specimens from the same population reveals that D. gribodoi Emery males are conspecific with D. gerstaeckeri Emery workers, rendering D. gerstaeckeri a junior synonym of D. gribodoi. Dorylus gribodoi var. insularis San...

The present work constitutes the first ultrastructural analysis of the spermatozoon in the Pleurogenidae, with the study of three species belonging to three of the 16 genera included in this family, namely Pleurogenes claviger, Pleurogenoides medians and Prosotocus confusus. The mature spermatozoa of these pleurogenids present two axonemes of the 9+"1" trepaxonematan pattern, a nucleus, two mit...

Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus import...

Mites are among the most common associates of bark beetles and they can influence ecology microbial composition within beetle-colonized trees. The pinyon pine engraver, Ips confusus is a beetle in trees southwestern United States, but mite associated with this has been little studied. In study, we quantify abundance, diversity, attachment locations phoretic mites on that emerge from naturally i...