The pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae), is a well-studied species in terms of its colour polymorphism, where it occurs as two distinct colour morphs, red and green. It is proposed that the occurrence and maintenance of this polymorphism is an adaptive response to environmental factors, in particular natural enemies and host plant quality. We hypothesized that these adaptations are directly mirrored in the energy reserves accumulated by the different colour morphs during their pre-adult stages and reflect their specialization for particular ecological roles. We quantitatively measured the different energy reserves of red and green pea aphids and found that the total energy reserves of these morphs did not differ. Interestingly, these reserves were made up of different components in the red and green colour morphs. There was a higher percentage content of water-soluble carbohydrates and lipids in the red clones and higher percentage content of protein in green clones. These finding are in accordance with green clones being more fecund than red ones and needing more protein for reproduction than red clones, which produce more winged offspring when crowded or in response to the presence of natural enemies and so, need more lipids and carbohydrates to fuel their walking and flight. Apparently, different colour morphs are physiologically specialized to adjust their energy reserves in relation to their specific ecological adaptations and maximize their fitness in terms of dispersal, reproduction, defense and survival., Seyed Mohammad Ahsaei ... []., and Obsahuje seznam literatury
1_Monogeny, the production of unisexual broods by individual females, is widely recorded in gall midges (Diptera: Cecidomyiidae). Theoretical models propose that the adjustment of offspring sex ratio by females may pre-dispose the evolution of monogeny in gall midges however empirical studies in this field are superficial. Expressed more simply, monogeny may enable individual female gall midges to decrease or increase the number of male and female progeny they produce in response to changes in environmental conditions. Host quality/size is repeatedly reported to influence sexual investment in insects in terms of sex ratio adjustment. In this paper, we examined the sex ratio of the offspring of the monogenous predatory gall midge Aphidoletes aphidimyza attacking low and high abundances of the cotton aphid, Aphis gossypii. Two consecutive generations of female gall midges were presented with either a low or high abundance of aphids in each generation and the sex ratio of their progenies determined. There was no difference between the sex ratio of the progenies that developed on the high or low abundance of A. gossypii in the two generations. Apparently, the females did not regulate the number of female and male progenies, or adjust the numbers of male or female’s eggs they produced in response to the changes in the abundance of prey. Results of this study do not support the theory of sex ratio regulation proposed for monogenous gall midges. It is likely that the skewed sex ratio in most species of monogenous gall midges is a consequence of differential mortality of male and female progenies under harsh conditions., 2_The finding that male and female larvae did not differ in the number of aphids they require to complete their development supports this claim., Seyed Mohammad Tabadkani, Ahmad Ashouri, Farhad Farhoudi., and Obsahuje seznam literatury