Juvenile Hormone As a Key Factor Regulating Larval Diapause of the Rice Stem Borer, Chilo suppressalis(Lepidoptera : Pyralidae)

Juvenile Hormone.....in Retrospect and in Prospect

“…Thus, as discussed elsewhere (Nijhout and Williams, 1974b; see also Yagi and Fukaya, 1974;Chippendale and Yin, 1975), the indications are that the CA remain continuously active in diapausing larvae and are shut off only after exposure to the environmental conditions that potentiate escape from diapause. Evidently, in non-diapausing larvae the shutting-off of the CA during the second half of the final ins tar does two things: it allows the brain to secrete PTTH and thereby stimulate the pro thorcic glands and, secondly, it permits the resulting ecdysone to activate the pupal gene-set.…”

“…This study made use of thousands of carefully timed larvae reared in the "Harvard Manduca factory" which is capable of turning out several hundred pupae per day. I venture to think that this Symposium will document the debt of thanks we owe to the unsung heroes who developed a practical method for the large-scale rearing of Manduca on an artificial diet (Yamamoto, 1969;Bell, private communications;Bell and Joachim, 1975). Figure 2, taken from the paper by Nijhout and Williams (1974b), presents the results of bioassays of JH in the hemolymph of dietreared hornworms throughout the final (Sth) larval instar.…”

The hormonal and circadian basis for insect photoperiodic timing

“…JH inhibits metamorphosis and induces a steady slowdown of food intake followed by supernumerary larval moults, until it elicits an arrest of larval development and induces diapause [52,53]. An analogous JH morphostatic action also occurs in the larval diapause of other related species, such as the rice stem borer Chilo supressalis [54], the Southwestern corn borer D. grandiosella [55][56][57][58][59] and European corn borer Ostrinia nubilalis [60,61]. Surprisingly, JH seems to play a development-promoting rather than an inhibitory role, in the bamboo borer Omphisa fuscidentalis, which enters diapause as a mature fifth instar larva [62].…”

Endocrine Strategies for Insect Control

“…Fukaya & Mitsuhashi. 1961: Yagi & Fukaya. 1974: the southwestern corn borer, Diatraea grandiosella, Chippendale & Yin, 1973).…”