Question: Host races of phytophagous insects originate when a population adapts to a novel resource (host) while other populations remain resident on their ancestral host. The derived and ancestral host race populations will be subject to unequal selection intensity and genetic drift. Is this asymmetry responsible for asymmetric reproductive isolation observed in some populations? Hypothesis: U...

Two new species of the Stenochinus amplus species-group are described, S. apiciconcavus sp. n. (CHINA: Shaanxi) and S. xinyicus sp. n. (CHINA: Guangdong). Also, some new distribution data are provided for S. cylindricus (Gebien, 1914), and a key to the seven species of the S. amplus species-group from China is given.

The spectra of Tribolium castaneum and T. confusum larval digestive peptidases were characterized with respect to the spatial organization of protein digestion in the midgut. The pH of midgut contents in both species increased from 5.6-6.0 in the anterior to 7.0-7.5 in the posterior midgut. However, the pH optimum of the total proteolytic activity of the gut extract from either insect was pH 4....

Approximately 50% of total harvested cereal grains are lost during the post-harvest handling and storage, insects main cause for both quantity (reductions in weight) quality. In present study effect microwave radiation was studied on one stored product pest, flour beetle Tribolium castaneum (Hersbt). Adult were obtained from infested products at stores specialized selling Sakaka. Insects with i...

The relationship between number of holes in a grain probe trap body and capture of stored-grain pests was determined in laboratory tests using adults of the rice weevil, Sitophilus oryzae (L.), the sawtoothed grain beetle, Oryzaephilus surinamensis (L.), and the red flour beetle, Tribolium castaneum (Herbst). Polyvinylchloride (PVC) probe bodies were attached to electronic sensor heads, and ins...

Individuals of both dispersal and non-dispersal types (disperser and non-disperser) are found in a population, suggesting that each type has both costs and benefits for fitness. However, few studies have examined the trade-off between the costs and benefits for the types. Here, we artificially selected for walking distance, i.e., an indicator of dispersal ability, in the red flour beetle Tribol...

Human-dominated landscapes often feature patches that fluctuate in suitability through space and time, but there is little experimental evidence relating the consequences of dynamic patches for species persistence. We used a spatially and temporally dynamic metapopulation model to assess and compare metapopulation capacity and persistence for red flour beetles (Tribolium castaneum) in experimen...