were significantly lower than in second or third instars and about the same as for the fourth instars. Infection levels of firstand fourth-instar larvae exposed in mixed larval stages were significantly different (P < 0.05) than first and fourth instars exposed alone under similar conditions, whereas differences were not significant for secondand third-instar larvae. These data clearly indicate...

Malaria and filariases are prevalent in Sudan and their control depends largely on preventive measures against mosquito vectors. The present work aimed to investigate the larvicidal, adults emergence inhibition and oviposition deterrent effects of aqueous extracts from leaves of Ricinus communis L. against the mosquitoes, Anopheles arabiensis and Culex quinquefasciatus as a biological control m...

Drosophila melanogaster born and reared in constant darkness exhibit circadian locomotor activity rhythms as adults. However, the rhythms of the individual flies composing these populations are not synchronized with one another. This lack of synchrony is evident in populations of flies commencing development at the same time, indicating that a biological clock controlling circadian rhythmicity ...

The crude extract of mangrove plant Rhizophora mucronata was prepared in this present work. The extract was testified for its anti-mosquito larvicidal property against two species of mosquito viz: Anopheles stephensi and Aedes aegypti. The 48 hours exposure of various dilutions of 100, 200, 300, 400, 500 ppm were given to the III to IV instar larval population. Percentage mortality data was ana...

Isoform-specific null mutations were used to define the functions of three orphan members of the nuclear receptor superfamily, E75A, E75B, and E75C, encoded by the E75 early ecdysteroid-inducible gene. E75B mutants are viable and fertile, while E75C mutants die as adults. In contrast, E75A mutants have a reduced ecdysteroid titer during larval development, resulting in developmental delays, dev...

The larval instars of Pnigalio gyamiensis Myartseva and Kurashev are described in detail for the first time. This species is a larval-pupal ectoparasitoid of Chrysoesthia sexguttella (Thunberg) (Lepidoptera, Gelechiidae), which forms leaf mines in the plant Chenopodium album L. (Caryophyllales: Amaranthaceae). The female of Pnigalio gyamiensis lays a single egg on the skin of the host larva or ...

The antennae of male Periplaneta americana acquire a large number of olfactory receptors at the adult stage. Electrophysiological methods (single unit and electroantennogram recording) show that a portion of the receptors added at the adult ecdysis are sex attractant receptors. Sex attractant receptors are not present in large numbers on larval and adult female antennae. The differentiation of ...

BACKGROUND Insulin and ecdysone are the key extrinsic regulators of growth for the wing imaginal disks of insects. In vitro tissue culture studies have shown that these two growth regulators act synergistically: either factor alone stimulates only limited growth, but together they stimulate disks to grow at a rate identical to that observed in situ. It is generally thought that insulin signalin...

Larval development time is a critical factor in assessing the potential for larval transport, mortality, and subsequently, the connectivity of marine populations through larval exchange. Most estimates of larval duration are based on laboratory studies and may not reflect development times in nature. For larvae of the American lobster (Homarus americanus), temperature-dependent development time...

The third larval instar of Goliathus goliatus (Drury, 1770), Goliathus orientalis Moser, 1909 and Goliathus albosignatus Boheman, 1857 are described and illustrated for the first time and compared with the immature stages of other Cetoniinae. Larval development of Goliathus goliatus is investigated under laboratory conditions, with particular emphasis on food requirements. These results support...