BACKGROUND Tree-killing bark beetles (Coleoptera, Scolytinae) are among the most economically and ecologically important forest pests in the northern hemisphere. Induction of terpenoid-based oleoresin has long been considered important in conifer defense against bark beetles, but it has been difficult to demonstrate a direct correlation between terpene levels and resistance to bark beetle colon...

Spruce beetle (Dendroctonus rufipennis) outbreaks are rapidly spreading throughout subalpine forests of the Rocky Mountains, raising concerns that altered fuel structures may increase the ecological severity of wildfires. Although many recent studies have found no conclusive link between beetle outbreaks and increased fire size or canopy mortality, few studies have addressed whether these combi...

Drought and mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks have affected millions of hectares of high-elevation conifer forests in the Northern Rocky Mountains during the past century. Little research has examined the distinction between mountain pine beetle outbreaks and climatic influence on radial growth in endangered whitebark pine (Pinus albicaulis Engelm.) ecosystems. We...

The larger black flour beetle, Cynaeus angustus (LeConte) (Coleoptera: Tenebrionidae), is an agricultural and home nuisance pest in North America. In the Southern High Plains of Texas, the larger black flour beetle is associated with cotton gin trash, by-products of cotton ginning that are field stored in large piles for economic reasons. Larger black flour beetle overwinter in gin trash piles ...

A dramatic forest decline due to the bark beetle outbreak, which occurs in the Norway spruce stands in the Western Beskidy (southern Poland) since 2003, was started after severe physiological drought during winter time. An analysis describing some spatio-temporal characteristics of this process, with special regard to the patterns of bark beetle occurrence related to root fungal diseases, is pr...

A vigor-structured model for mountain pine beetle outbreak dynamics within a forest stand is proposed and analyzed. This model explicitly tracks the changing vigor structure in the stand. All model parameters, other than beetle vigor preference, were determined by fitting model components to empirical data. An abrupt threshold for tree mortality to beetle densities allows for model simplificati...

Biological control agents may have unintended effects on native biota, particularly species that are closely related to the target invader. Here, we explored how Chrysolina quadrigemina, a beetle introduced to control the invasive weed Hypericum perforatum, impacts native H. punctatum in Tompkins County, New York, USA. Using a suite of complementary field surveys and experimental manipulations,...

rove beetle dermatitis produced by the family staphylinidae genus paederus has world- wide distribution some one hundred species of paederus have been found, but it is believed that only 30 of these produce dermatitis. up to 1976 three species of paederus have been found in iran as: p. fusciped curtis; p. pietschmanni bershaner , and p. spectabilis kraatz . observations on the biology of paeder...

the seed beetle, stafor limbatus (horn) (col.: bruchidae), collected from bushehr and yazd provinces, iran, on acasia sp. and prosopis farcta, is newly recorded from iran. it is native to southwestern united states but distributed in various parts of the world. the beetle was identified by delobel from france.

Larval and adult life stages are described for Contortylenchus brevicomi (Massey) Rühm parasitizing a Mississippi population of Dendroctonus frontalis, the southern pine beetle. Fourth-stage larvae and free-living adult females of this species are identified and described for the first time. The life cycle of C. brevicomi can be reconstructed from this study. The adult female nematode lays eggs...