Life History Characteristics of Ringlegged Earwig (Dermaptera: Labiduridae): Emphasis on Ovarian Development

Juvenile hormone in earwigs: Roles in oogenesis, mating, and maternal behaviors

“…(Data from Fig. 2, Rankin et al, 1995b. ) (Caussanel, 1973b), and release of material at the neurohemal aorta accompanied egg-laying (Juberthie and Caussanel, 1980).…”

“…Earwigs have highly unusual, primitively polytrophic ovaries in which a single trophocyte contributes to the development of its associated oocyte within a follicle (Bonhag, 1956;Nath et al, 1959). In E. annulipes, each ovary typically contains five ovarioles; up to ten follicles may develop in the ovarioles during a single gonadotropic cycle (Rankin et al, 1995b). After eclosion there is a period of little basal follicle growth and low JH production (days 0-5), followed by oocyte growth culminating in a 1-2 day ovipositional period and near maximal JH production.…”

“…Assays of follicle length and corpus allatum activity were performed on the same earwigs (n = 5 samples, each with corpora allata from three females, except for that of the day of oviposition, wherein four samples of three corpora allata each were assayed). Vertical bars represent the standard error of the mean (SEM) (modified from Rankin et al, 1995cRankin et al, ). 1995bRankin et al, , 1996.…”

“…Using the method of Fig. 3, Rankin et al, 1995b. ) Hammock and Sparks (1977), Palmer et al (1996) showed that in untreated female E. annulipes, levels of hemolymph JH esterases are high in newly eclosed adults, but rapidly decline and remain low through the onset of the second gonadotropic cycle.…”

“…This species is easily reared in mass quantities in the laboratory and can thus provide large samples of animals of known age and physiological state. A primary asset of this species for JH studies is that it possesses a precisely regulated gonadotropic cycle followed by an extended period of maternal care (Rankin et al, 1995b).…”