Circadian pacemaker neurons in the Drosophila brain control daily rhythms in locomotor activity. These pacemaker neurons can be subdivided into early or late groups depending on whether rhythms in period (per) and timeless (tim) expression are initiated at the first instar (L1) larval stage or during metamorphosis, respectively. Because CLOCK-CYCLE (CLK-CYC) heterodimers initiate circadian osci...

Midgut tissue undergoes remodeling during metamorphosis in insects belonging to orders Lepidoptera and Diptera. We investigated the developmental and hormonal regulation of these remodeling events in lepidopteran insect, Heliothis virescens. In H. virescens, programmed cell death (PCD) of larval midgut cells as well as proliferation and differentiation of imaginal cells began at 108 h after ecd...

Stream grazers have a major impact on food web structure and the productivity of stream ecosystems; however, studies on the longitudinal (upstream versus downstream) and temporal changes in their drift dynamics and resulting distributions remain limited. Here, we investigated the longitudinal and temporal distributions and drift propensity of a trichopteran grazer, the caddisfly, Micrasema quad...

Blow flies of the genus Hypopygiopsis are considered forensically important. In Thailand, four Hypopygiopsis species coexist, i.e., Hypopygiopsis fumipennis, Hypopygiopsis infumata, Hypopygiopsis violacea and Hypopygiopsis tumrasvini. In this study, the ontogeny and developmental rate of H. tumrasvini eggs, larvae and pupae were determined in the laboratory chamber reared at 25.0±2.0°C and 80.0...

The functional relationship between cardioacceleratory peptide 2 (CAP2) and hindgut activity during wandering behaviour was investigated in fifth-instar larvae of the tobacco hawkmoth Manduca sexta. Inspection of the alimentary canal on the day prior to wandering showed that the gut, in preparation for metamorphosis, was voided of all contents by 18:00 h. Associated with this event, which we re...

When the butterfly Eurema hecabe is infected with two different strains (wHecCI2 and wHecFem2) of the bacterial endosymbiont Wolbachia, genetic males are transformed into functional females, resulting in production of all-female broods. In an attempt to understand how and when the Wolbachia endosymbiont feminizes genetically male insects, larval insects were fed an antibiotic-containing diet be...

the spotted amber ladybird, hippodamia variegata (col.: coccinellidae) is one of the most prominent coccinellid predators in iran. it is omnivorous and feed on aphids and psylla. the effects of two diets brevicoryne brassicae l. (hemiptera: aphididae)and eggs of ephestia kuehniella (lepidoptera: pyralidae) on some biological aspects of hippodamia variegata (goeze) (coleoptera: coccinellidae) we...

Cellular and humoral local responses were investigated following repetitive artificial Oestrus ovis infections in lambs. The presence of larvae induced a huge local recruitment of either leucocytes (T and B lymphocytes, macrophages) or granulocytes (eosinophils, mast cells and globule leucocytes). This cellular response was more pronounced in the ethmoid and sinus (development sites of second a...

1. A new method for the assay of insect prothoracicotropic hormone (PTTH) is described, using fourth instar larvae of Manduca sexta. Larvae neck-ligated at a critical time to prevent release of PTTH from the head fail to undergo the next larval moult. Such ligated larvae moult to fifth instar larvae or larval-pupal intermediates after injection of brain homogenates from Manduca larvae, pupae or...

Four larval instars viz. II,III ,IV & V were fed on diet treated with four different concentrations i.e. 1x10, 1x10, 1x10, 1x10 POB/ml to evaluate highest mortality and maximum viral yield. Findings suggest that Ha-NPV should be applied to III instar larvae in vitro to achieve high larval mortality (78.33 %) and maximum viral yield (4.319 x10 POB/g of cadavar) at 1x10ml dose inoculum. Mortality...