Newly molted last (5th) instar of the desert locust, Schistocerca gregaria (Forsk.), was treated through fresh plant food with 2 concentrations: high (1000.0 ppm) or low (62.5 ppm) of 3 IGRs: pyriproxyfen, tebufenozide, and lufenuron. Carbohydrate content was determined in the hemolymph and in the fat body of the early-aged, mid-aged, and late-aged 5th instar, as well as of 1and 4-d old adult f...

The within-plant distribution of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), in cotton, Gossypium hirsutum L., was determined during June through the 1st week in August in 1992 and 1993 at Stoneville, MS. Locations of adults and nymphs in cotton were determined weekly using visual searches of whole plants or plant sections (mainstem terminals, upper and lower plant halves b...

The Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Psyllidae) is the primary vector of the bacterium causing citrus huanglongbing (citrus greening), the most serious disease of citrus worldwide. Psyllids and other hemipterans produce large amounts of honeydew, which has been used previously as an indicator of phloem sap composition and insect feeding or metabolism. Behavioral, ultrast...

Animal behavior can have profound effects on pathogen transmission and disease incidence. We studied the questing (= host-seeking) behavior of blacklegged tick (Ixodes scapularis) nymphs, which are the primary vectors of Lyme disease in the eastern United States. Lyme disease is common in northern but not in southern regions, and prior ecological studies have found that standard methods used to...

Populations of Homalodisca coagulata (Say) were sampled from citrus orchards in southern California, USA to characterize and quantify seasonal occurrences of nymphs and adults with the goal of identifying management opportunities through well-timed treatments and/or natural enemy releases. Higher densities of H. coagulata in 2001 contributed to a complete seasonal profile that began in early sp...

In parasitic associations, the evolutionary interest of a symbiont contradicts that of a host, which sometimes causes the phenomena so-called 'parasite manipulation' wherein symbiont infection alters host behaviour to facilitate its vertical/horizontal transmission. In mutualistic associations, meanwhile, symbiont-induced alteration of host behaviour that enhances its transmission has been litt...

Development, longevity, survivorship and fecundity of the alate and apterous forms of the turnip aphid, Lipaphis erysimi (Kaltenbach), were studied on cabbage under constant temperatures in the laboratory. The developmental durations for alate nymphs were 15.8, 9.5, 8.0 and 5.4 d at 15, 20, 25 and 30 ° C, respectively, and those for apterous nymphs were 13.9, 6.8, 6.1 and 5.0 d. Alate nymphs de...

The photo-responsiveness of 2 groups of interneurons responding to light in the protocerebrum was investigated at 2 developmental stages, the last instar nymphs and adults, in the cricket Gryllus bimaculatus. The cricket is diurnally active during the nymphal stage but becomes nocturnal as an adult. In both adults and nymphs, light-induced responses of optic lobe light-responding interneurons t...

Rain and dew droplets can dislodge or drown small insects and may be important factors that drive adaptations for avoidance and escape. Studying the microstructure of small insects and insect behaviour can help understand these adaptations. We quantified avoidance behaviour and entrapment of nymphs and adults of the tea green leafhopper (Empoasca onukii) using simulated rainfall onto host plant...

In aphids there is a fecundity-dispersal trade-off between wingless and winged morphs. Recent research on the molecular mechanism of wing morphs associated with dispersal reveals that insulin receptors in the insulin signaling (IS) pathway regulate alternation of wing morphs in planthoppers. However, little is known about whether genes in the IS pathway are involved in developmental regulation ...