ABSTRACT We used the red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), to compare three feeding bioassay techniques using flour disks. The area (scanner or digital photographs) and mass (sensitive balance) of the same flour disks were measured daily for 1 or 2 wk to assess feeding by insects. The loss in mass and area over 4 h was measured, as some variation over time wa...

Sitophilus oryzae (L.), S. granarius (L.), Tribolium castaneum (Hbst.), Oryzaephilus surinamensis (L.), Rhyzopertha dominica (F.), Tenebroides mauritanicus (L.), and Cryptolestes pusillus (Schon.) transmitted Salmonella montevideo from wheat contaminated with 10(6) organisms/g to clean wheat. The insects were fed on the contaminated grain for 21 days and were then transferred to clean grain and...

A total of 154 enterococcal isolates from 95 stored-product insects collected from a feed mill, a grain storage silo, and a retail store were isolated and identified to the species level using PCR. Enterococcus casseliflavus represented 51% of the total isolates, followed by Enterococcus gallinarum (24%), Enterococcus faecium (14%), Enterococcus faecalis (7%), and Enterococcus hirae (5%). Many ...

Twenty naturally occurring monoterpenoids were evaluated in a preliminary fumigation screening test on some important stored-product pest insects, including the rice weevil, Sitoplzilus oryzae, the red flour beetle, Tribolium castaneum, the sawtoothed grain beetle, 0rj)zaephilus surinamensis, the house fly, Musca dornestica, and the German cockroach, Blattella germanica. Cineole, 1-fenchone, an...

essential oil extracted from the leaves of lemon verbena, lippia citriodora kunth (verbenaceae) was tested for fumigant toxicity in the laboratory against two stored-product insects tribolium confusum jacquelin du val and callosobruchus maculatus (f.). the chemical composition of the isolated oil was examined by gc-ms. the major compounds were citral (11.3%), limonene (10.6%), neral (7.9%), 4-p...

Abstract In the present study we examined effect of presence wheat bugs ( Eurygaster spp. and Aelia spp.) on mortality, progeny production infestation patterns three stored product insects, Trogoderma granarium Everts, Sitophilus oryzae (L.) Rhyzopertha dominica (F.). The bioassays were carried out under laboratory conditions (25 ± 1 °C, 60 5% relative humidity (r.h.) continuous darkness), 20 a...

762 between the tracheoles and the internal tissues. In resistant insects phosphine slowly reacts with some component of the membrane which retards its entry but may slowly oxidize it to hypophosphite. Since this site is not the toxic lesion no harm is done. In susceptible insects phosphine is transported unchanged into the internal tissues where it disrupts sensitive redox systems thus generat...

Persistence of stored-product insects in hidden refugia and their subsequent movement into stored commodities resulting in product infestation contributes to their pest status and represents a potential target for biological control agents. Entomopathogenic nematodes have not been previously tested against stored-product insects in environments such as empty grain bins or food processing and wa...

Behavior of extinct organisms can be inferred only indirectly, but occasionally rare fossils document particular behaviors directly. Brood care, a remarkable behavior promoting the survival of the next generation, has evolved independently numerous times among animals including insects. However, fossil evidence of such a complex behavior is exceptionally scarce. Here, we report an ensign scale ...