Thelytokous parthenogenesis is a type of sex determination in which females are produced from unfertilized eggs. Genetic and endosymbiont-induced forms of thelytoky have been described in the Hymenoptera. Our study has revealed that Wolbachia, Cardinium, Spiroplasma and other endosymbionts are probably absent in Iberian populations of harvester ants, Messor barbarus and Messor capitatus (Hymenoptera: Formicidae: Myrmicinae) and are thus not involved as factors in the sex determination of these two species. Our results lend weight to previous suggestions that bacterial parthenogenesis induction in Hymenoptera is probably limited to the reproductive systems of chalcidoid and cynipoid parasitoid wasps (Hymenoptera: Apocrita: Chalcidoidea and Cynipoidea, respectively)., Paloma Martínez-Rodríguez ... [et al.]., and Obsahuje seznam literatury
Hexamerins are hemocyanin-related haemolymph proteins that are widespread in insects and may accumulate to extraordinarily high concentrations in larval stages. Hexamerins were originally described as storage proteins that provide amino acids and energy for non-feeding periods. However, in recent years other specific functions like cuticle formation, transport of hormones and other organic compounds, or humoral immune defense have been proposed. During evolution, hexamerins diversified according to the divergence of the insect orders. Within the orders, there is a notable structural diversification of these proteins, which probably reflects specific functions. In this paper, the different possible roles of the hexamerins are reviewed and discussed in the context of hexamerin phylogeny., Thorsten Burmester, and Lit
In order to determine when during the development of H. armigera CYP6B6 is expressed, we measured the width of the head capsule, the length of the body and weight of the different life stages of the cotton bollworm reared under laboratory condition. The larvae took about 20 d to complete their development under these conditions, the pre-pupae about 4 d, pupae about 9 d, and the adults lived for about 9 d and the eggs took about 4 d to hatch. Knowing this it was possible to determine the pattern of cytochrome P450 CYP6B6 expression at different stages in the life cycle of H. armigera using real-time quantitative polymerase chain reaction (RT-qPCR). The CYP6B6 gene was expressed in all the developmental stages of the cotton bollworm. The results indicate that the level of expression was lower in the egg, pre-pupal, pupal and adult stages than in larvae. The level of expression of CYP6B6 decreased from the 1st to the 3rd instar larva, with the lowest level recorded in the 3rd instar larvae and then increased reaching its highest value in 6th instar larvae. A similar trend in the expression of CYP6B6 was detected using immunohistochemistry. As the results show, more efficient control of the cotton bollworm can be achieved if insecticides are applied when the larvae of H. armiger are in the 3rd instar, because at that stage the eat little food and there is a low level of detoxifying enzymes in the larvae., Xuetao Zhang ... [et al.]., and Obsahuje seznam literatury