Induction of precocious adult eclosion by the eclosion hormone extracted from the heads of Bombyx mori (Lepidoptera: Bombycidae) and Samia cynthia ricini (Lepidoptera: Saturniidae)

In order to compare the eclosion hormone activity between two different species of lepidoptera, eclosion hormone (EH) extracted from adult heads of Bombyx mori or Samia cynthia ricini was subjected to the bioassay to induce precocious adult eclosion. By performing reciprocal injection of the EH in both species, the authors demonstrated that Bombyx crude EH can induce the precocious eclosion of the pharate-adult of the Samia, while Samia crude EH has the same effect to the pharate adults of Bombyx. The hormonal activities were not reduced throughout the several purification steps in both cases. Necessary amount of EH to induce the precocious eclosion in more than 50% of the assayed pharate-adults of Bombyx mori was equivalent to 3 heads in Bombyx and equivalent to 2.5 heads in Samia. The results may suggest that eclosion hormone is not species-specific, so far as two lepidopteran species used in the present experiments are concerned

Ecdysteroid Synthesis in Dissociated Cells of the Prothoracic Gland of the Silkworm, Bombyx mori

Volume: 11Start Page: 107End Page: 11

Ovarian prothoracicotropic hormone activity in the silkworm, Bombyx mori (Lepidoptera: Bombycidae)

Prothoracicotropic hormone (PTTH) activity assayed in brainless pupae of Samia cynthia ricini is present in the mature eggs of the silkworm, Bombyx mori. Comparable activity was also found in eggs which had matured in brainless moths and in isolated abdomens. No significant differences in chemical components were shown in the eggs developed at three different hormonal milieus. It is possible to conclude that the ovarin PTTH is synthesized during egg maturation

Induction of precocious adult eclosion by the eclosion hormone extracted from the heads of Bombyx mori (Lepidoptera: Bombycidae) and Samia cynthia ricini (Lepidoptera: Saturniidae)

In order to compare the eclosion hormone activity between two different species of lepidoptera, eclosion hormone (EH) extracted from adult heads of Bombyx mori or Samia cynthia ricini was subjected to the bioassay to induce precocious adult eclosion. By performing reciprocal injection of the EH in both species, the authors demonstrated that Bombyx crude EH can induce the precocious eclosion of the pharate-adult of the Samia, while Samia crude EH has the same effect to the pharate adults of Bombyx. The hormonal activities were not reduced throughout the several purification steps in both cases. Necessary amount of EH to induce the precocious eclosion in more than 50% of the assayed pharate-adults of Bombyx mori was equivalent to 3 heads in Bombyx and equivalent to 2.5 heads in Samia. The results may suggest that eclosion hormone is not species-specific, so far as two lepidopteran species used in the present experiments are concerned

Ovarian prothoracicotropic hormone activity in the silkworm, Bombyx mori (Lepidoptera: Bombycidae)

Prothoracicotropic hormone (PTTH) activity assayed in brainless pupae of Samia cynthia ricini is present in the mature eggs of the silkworm, Bombyx mori. Comparable activity was also found in eggs which had matured in brainless moths and in isolated abdomens. No significant differences in chemical components were shown in the eggs developed at three different hormonal milieus. It is possible to conclude that the ovarin PTTH is synthesized during egg maturation

A monoclonal antibody against a synthetic carboxyl-terminal fragment of the eclosion hormone of the silkworm, Bombyx mori : characterization and application to immunohistochemistry and affinity chromatography : Immunology

Volume: 7Start Page: 47End Page: 5

Data from: Asynchronous hatching in the burying beetle, Nicrophorus quadripunctatus, maxmises parental fitness

Life history theory predicts that natural selection favours parents who balance investment across offspring to maximize fitness. Theoretical studies have shown that the optimal level of parental investment from the offspring's perspective exceeds that of its parents, and the disparity between the two generates evolutionary conflict for the allocation of parental investment. In various species, the offspring hatch asynchronously. The age hierarchy of the offspring usually establishes competitive asymmetries within the brood and determines the allocation of parental investment among offspring. However, it is not clear whether the allocation of parental investment determined by hatching pattern is optimal for parent or offspring. Here, we manipulated the hatching pattern of the burying beetle Nicrophorus quadripunctatus to demonstrate the influence of hatching pattern on the allocation of parental investment. We found that the total weight of a brood was largest in the group that mimicked the natural hatching pattern, with the offspring skewed towards early hatchers. This increases parental fitness. However, hatching patterns with more later hatchers had heavier individual offspring weights, which increases offspring fitness, but this hatching pattern is not observed in the wild. Thus, our study suggests that the natural hatching pattern optimizes parental fitness, rather than offspring fitness