In mid-Atlantic estuaries, three fiddler crab species, Uca pugilator, pugnax and minax, co-occur, with their adults occupying different habitat types distinguished by salinity sediment size. Some evidence exists that selective settlement is responsible for this separation but the mechanism largely unknown. We tested hypothesis field-caught megalopae would be stimulated to molt in presence of ad...

An eight-week experiment was conducted to evaluate the effects of eight light intensities (0, 0.83, 1.61, 8.17, 15.89, 31.38, 63.69, and 124.31 ?mol m -2 s -1 ) on survival, growth, antioxidant, molting-related apoptosis-related gene expression juvenile swimming crab Portunus trituberculatus . The results showed that survival rate crabs highest under 8.17 15.89 Under this intensity, had lowest ...

Scanning and transmission electron microscopy (SEM and TEM) revealed unique structures and development of the venomous spicules of tussock moth caterpillars of the genus Euproctis: (1) Flower-like structure at the distal end and a longitudinal minute depression on the proximal subapical wall of these spicules were observed by SEM. This depression was revealed to be a small hole by TEM. (2) Duri...

Conventional insecticides are highly toxic to many living organisms as well as to the environment; consequently, new biorational and more specific approaches to pest control have been developed. In this paper, we present an update of those approaches resulting from studies on inhibition of enzymes involved in key processes of insects life, particularly growth, molting and development of larvae ...

This paper describes the ultrastructural modifications that cockroach campaniform sensilla undergo at three major stages in the molting cycle and finds that the sensilla are physiological functional at all developmental stages leading to ecdysis. Late stage animals on the verge of ecdysis have two completely separate cuticles. The campaniform sensillum sends a 220-mum extension of the sensory p...

Six naturally occurring C27 ecdysteroids were isolated and identified from the tobacco hornworm during pupal-adult development five days after peak titer of molting hormone activity. In order of decreasing quantities the hormones were: 20,26-dihydroxyecdysone, 3-epi-20-hydroxyecdysone, 20hydroxyecdysone, 3-epi-20,26-dihydroxyecdysone, 3-epi-ecdysone, and ecdysone. 20-Hydroxyecdysone, in an earl...