The effects of varying photophase conditions on biological parameters of Mahanarva fimbriolata (Stal) (Hemiptera: Cercopidae), nymphs and adults were evaluated. Eggs of a late developmental stage were placed near sugarcane roots (cultivar RB739735) maintained in a greenhouse (21 ± 7 °C, 90 ± 10% RH). Nymphs and adults were exposed to the following photophase conditions: (a) 13:11 L:D as nymphs ...

The pink bollworm, Pectinophora gossypiella (Saunders), remains a signiÞcant pest of cotton (Gossypium spp.) in the southwestern United States, but is not known to be established in the primary cotton production areas of the southeastern United States. Absence of P. gossypiellamay be the result of federal regulatory action (e.g., monitoring, quarantine, and eradication), climate, or other ecolo...

An insect's cold hardiness affects its potential to overwinter and outbreak in different geographic regions. In this study, we characterized the response of Helicoverpa zea (Boddie) pupae to low temperatures by using controlled laboratory measurements of supercooling point (SCP), lower lethal temperature (LT(50)), and lower lethal time (LLTime). The impact of diapause, acclimation, and sex on t...

In the present study the temporal changes in the volume of the corpus allatum in three experimental groups of adult males (macropterous, reproductive brachypterous and diapausing brachypterous) of the flightless bug Pyrrhocoris apterus were determined and related to the size of male accessory glands. The results revealed wing morphand age-dependent differences in the corpus allatum volume in ma...

hippodamia variegata is an efficient and most abundant predatory coccinellids in many countries. understanding the ability of long-term low temperature survival in beneficial insects can be used to make better predictions about subsequent abundance and hence the biological control potential in the next spring and summer. so in this study, effects of long-term temperatures were investigated on m...

The objective of this research was to identify a reliable biochemical indicator for diapause (dormancy) in the boll weevil, Anthonomus grandis. Hemolymph polypeptides from reproductive and diapausing weevils were compared using denaturing sodium dodecyl sulpfate (SDS)-polyacrylamide gel electrophoresis (PAGE). A 77-kDa protein, which proved to be a hexamerin (AgSP-1), strongly correlated with m...

BACKGROUND Diapause, a condition of developmental arrest and metabolic depression exhibited by a wide range of animals is accompanied by complex physiological and biochemical changes that generally enhance environmental stress tolerance and synchronize reproduction. Even though some aspects of diapause have been well characterized, very little is known about the full range of molecular and bioc...

Heat treatments have been suggested as alternatives to chemical fumigants for control of postharvest insects in dried fruits and nuts. Conventional forced hot air treatments heat product too slowly to be practical, but radio frequency treatments are capable of more rapid product heating. While developing radio frequency heat treatments for dried fruits and nuts, the heat tolerance of nondiapaus...

effect of controlled atmospheres (cas) at various concentrations of co2, n2 and o2 on the lethal times of tribolium castaneum and trogoderma granarium was investigated at 20 and 30 ºc. experiments were performed using a recirculatory multi-flask apparatus. the results revealed that, the shortest times (0.1, 0.3 and 0.9 day for adults, larvae and pupae, respectively) required to obtain 50% morta...

Industry concerns over insect resistance, regulatory action, and the needs of organic processors have renewed interest in nonchemical alternative postharvest treatments to fumigants used for California tree nuts. The development of inexpensive polyvinyl chloride containers capable of holding low pressures has increased the practicality of vacuum treatments for durable commodities such as tree n...