Landscape change has great, yet infrequently measured, potential to influence the susceptibility of natural systems to invasive species impacts. We quantified attack by an invasive biological control weevil (Rhinocyllus conicus) on native thistles in relation to two types of landscape change: agricultural intensification and invasion by an exotic thistle, Carduus nutans, the original target of ...

The grain weevil (Sitophilus granarius) caused symptoms of allergic rhinitis and asthma in two laboratory workers, one after exposure to weevil dust for only six months and the other after three years. The former worker also noticed sneezing when she was cooking with National Flour. Skin testing with extracts of the grain weevil faecal dust gave positive skin responses. The antibodies were succ...

Silicon soil amendment has been shown to enhance plant defenses against insect pests. Rice is a silicon-accumulating graminaceous plant. In the southern United States, the rice water weevil and stem borers are important pests of rice. Current management tactics for these pests rely heavily on the use of insecticides. This study evaluated the effects of silicon amendment when combined with curre...

In laboratory, greenhouse and field tests, we determined the effects of combining full rates of the defoliants tribufos and thidiazuron and the herbicide thifensulfuron-methyl with half rates of the insecticides lambda-cyhalothrin or azinphos-methyl, and the combination of tribufos and thidiazuron, both in half rates, on mortality of the boll weevil, Anthonomus grandis grandis Boheman and on th...

Plants that have potential as alternative food source (floral nectar, pollen and plant tissues) to the boll weevil during the intercropping season were evaluated considering the prevalent conditions of Cerrado in the Central Brazil. Initially, we tested the nutritional adequacy for the survival of the insect of flower resource (pollen and nectar) provided by eight plant species (fennel, mexican...

We study false vacuum decays catalysed by magnetic monopoles which act as tunnelling sites with exponentially enhanced decay rates. The field profiles describing the do not have typically assumed $O(3)/O(4)$ symmetry, thus requiring an extension of usual rate calculation. To numerically determine saddle point solutions describe process we use a new algorithm based on mountain pass theorem. This...