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

The metabolic basis of life history variation: genetic and phenotypic differences in lipid reserves among life history morphs of the wing-polymorphic cricket, Gryllus firmus

“…In contrast to suggestions made by Tanaka (2001), absence of oviposition material has no detectable inhibiting effect on ovarian development in either morph of G. firmus during the first week of adulthood under experimental conditions used in our typical trade-off studies (e.g. first week of adulthood with adults reared at 28°C; see Zera et al, , 1998Cisper et al, 2000;Zera and Brink, 2000;Zera and Cisper, 2001;Zera and Bottsford, 2001; present study). In the absence of oviposition material, the flightless morph of G. firmus exhibits 2-4 fold greater ovarian growth compared with the flight-capable morph during early adulthood (e.g.…”

“…Energy reserves were compared between morphs on days 5 and 8 of the 13-day last nymphal stadium, on the day of the molt to adulthood, and on days 2 and 5 of adulthood. These days were chosen to determine whether differences between the morphs in energy reserves are produced prior to or during days 3-5 of adulthood, when dramatic differences in ovarian growth first occur between morphs Cisper et al, 2000;Zera and Cisper, 2001). …”

Endocrine regulation of the reproductive arrest in the long-winged females of a flightless bug, Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

“…A morph-specific daily cycle in the in vitro rate of JH biosynthesis was tightly correlated with the haemolymph JH titre on days 5-7 of adulthood (Zhao & Zera, 2004b). However, a relatively long (two weeks) period of reproductive arrest and oviposition delay in macropterous females of P. apterus associated with low or intermediate activity of the CA and enhanced dispersal activity resembles the "oogenesis-flight" syndrome rather than the decreased early fecundity found in the wing-polymorphic crickets (Tanaka, 1993(Tanaka, , 1994Zera et al, 1993;Cisper et al, 2000).…”

“…Earlier data on adult morphs of a wing-polymorphic cricket, Gryllus firmus, indicated that an elevated JH titre may be at least partly responsible for the increased early fecundity of flightless females (Cisper et al, 2000). Recently, a morph-specific daily cycle in the haemolymph JH titre, starting on day 5 of adulthood, has been revealed in G. firmus (Zhao & Zera, 2004a).…”

Morph-associated JH titer diel rhythm in Gryllus firmus: Experimental verification of its circadian basis and cycle characterization in artificially selected lines raised in the field

“…After bleeding, individual crickets were placed in test tubes and frozen at −20 °C. JH concentration in hexane extracts was measured using a well-validated JH radioimmunoassay (Cisper et al, 2000;Zera and Cisper, 2001;Zhao and Zera, 2004a). In vitro rate of JH biosynthesis was determined using the radiochemical assay of Pratt and Tobe (described in detail in Zhao and Zera, 2004b White bars denote photophase while black bars denote scotophase of standard rearing conditions (16L:8D photoregime, 28 °C).…”