Effects of exogenous ecdysteroids on reproduction in crickets,Gryllus bimaculatus

Abstract

Adult field crickets, Gryllus bimaculatus, with a low endogenous moulting hormone titre (animals reared at constant 20°C) were injected with ecdysone and 20-hydroxyecdysone. Repeated injections of 2-5 pgjfemale caused an increase in ovarian fresh weight and stimulated oviposition. The response to exogenous moulting hormones was shown to be dose dependent. In adult males injections of moulting hormones as well as ringer solution lowered the total number of spermatophores.

Juvenile hormone and reproduction in crickets, Gryllus bimaculatus De Geer: corpus allatum activity (in vitro) in females during adult life cycle

“…For example the influence of photoperiod, mating and starvation on JH synthesis and subsequent effect on vitellogenesis has been shown in a variety of insects (Tobe & Chapman, 1979;Ferenz, 1981;Lanzrein et al, 1981;Weaver & Pratt, 1981;Khan et al, 1982a, b). In previous papers we reported that diurnal thermoperiods and rapidly oscillating temperatures stimulate reproduction in Gryllus bimaculatus (Hoffmann, 1974;Behrens et al, 1983). Titre determinations and ecdysteroid injection experiments revealed that ecdysteroids play a role in adult development and reproduction in crickets under different temperatures (Hoffmann et al, 1981;Behrens & Hoffmann, 1983;Behrens et al, 1983).…”

Juvenile hormone titer and morph-specific reproduction in the wing-polymorphic cricket, Gryllus firmus

“…This is to be expected since numerous studies have identified hormones other than JH that influence ovarian growth (e.g. ecdysteroids and various neurohormones; Renucci and Strambi, 1981;Behrens and Hoffman, 1983;Nijhout, 1994;Strambi et al, 1997;Pener and Yerushalmi, 1998).…”

Endogenous ecdysteroid levels and rates of ecdysone acylation by intact ovaries in vitro in relation to ovarian development in adult female house crickets,Acheta domesticus

“…In an alternative approach to the problem of ecdysteroidal function(s), application of exogenous ecdysteroids to adult female crickets (Chudakova et al, 1982;Behrens and Hoffmann, 1983) provided conflicting results depending on whether low or high concentrations of ecdysteroid were used: low concentrations stimulated ovarian development and fecundity, whereas high concentrations were inhibitory. The results of such experiments are difficult to interpret unless the identity, amount, and timing of the exogenous ecdysteroids can be related to what is physiologically relevant, but stimulation by low (more physiological) doses of ecdysteroid may suggest a role in enhancing ovarian development.…”