The southern pine beetle (Dendroctonus frontalis Zimmermann) kills all pines within its range and is among the most important forest pest species in the US. Using a specialized mycangium surrounded by gland cells in the pronotum, adult females culture, transport, and inoculate two fungi into beetle galleries during oviposition. These fungal symbionts, to varying degrees, exclude antagonistic fu...

Tree mortality caused by bark beetle infestation has significant effects on the ecology and value of both natural and commercial forests. Therefore, prediction of bark beetle infestations is critical in forest management. Existing predictive models, however, rarely consider the influence of long-term stressors on forest susceptibility to bark beetle infestation. In this study we introduce pre-d...

topping stage of tobacco is a key time for development of agriculture measures to promote the quality of leaves. in order to investigating influence of topping timing and suckericide content on tobacco leaf, a factorial experiment on the basis of rcb design with 3 replications was conducted in 2011 at the tobacco research farm of isfahan. treatments were including topping time (t1: topping at e...

Surveys for mountain pine beetle are undertaken across a range of scales to provide forest managers with up-to-date information regarding the location, extent, and numbers of infested trees. Remote sensing provides new opportunities to detect and map mountain pine beetle damage to inform management and mitigation decisions. The key to using remotely sensed data is to identify how this new infor...

Regurgitant from leaf-feeding beetles (Cerotoma trifurcata, Epilachna varivestis and Diabrotica undecimpunctata) contains RNase activity equivalent to 0.1 to 1 mg/ml pancreatic RNase. When mixtures of pancreatic RNase at 0-1 to 1-0 mg/ml and viruses that are or are not transmissible by beetles, were inoculated to plants using the gross wounding technique, those containing viruses not transmissi...

Background: To define underlying predictors of tobacco smoking among Iranian Teenagers in a generalized structural equation model. Materials and Methods: In this cross-sectional study, a Generalized Structural Equation Model based on planned behavioral theory was used to explain the relationship among different factors such as demographic factors, subjective norms, and the intention to tobacco ...

Population cycles occur frequently in forest insects. Time-series analysis of fluctuations in one such insect, the southern pine beetle (Dendroctonus frontalis), suggests that beetle dynamics are dominated by an ecological process acting in a delayed density-dependent manner. The hypothesis that delayed density dependence in this insect results from its interaction with predators was tested wit...

Topping stage of tobacco is a key time for development of agriculture measures to promote the quality of leaves. In order to investigating influence of topping timing and suckericide content on tobacco leaf, a factorial experiment on the basis of RCB design with 3 replications was conducted in 2011 at the Tobacco Research Farm of Isfahan. Treatments were including topping time (T1: t...