Transgenerational maternal effects on performance (rm) after host transfer were evaluated in the generalist aphid Myzus persicae s.s., and in its subspecies specialized on tobacco, M. persicae nicotianae Blackman. We tested whether the performance of these taxa, when reared separately on optimal and suboptimal hosts (as sources of different maternal background) and then transferred to optimal hosts, experienced variations along four successive generations. Additionally, to compare the tolerance of both taxa to stress following host transfers, developmental instability (fluctuating asymmetry and body abnormalities) along the four generations was assessed. Taxon, rearing host, and generation affected the performance after host transfer. In the generalist, there was a significant improvement of rm along generations when transferred from suboptimal to optimal host and a significant decrease when transferred from optimal to optimal host; in the specialist, no increase or decrease occurred in any host transfer treatment. Transfer from suboptimal to optimal hosts caused higher losses of remaining replicates along generations than transfers from optimal to optimal hosts, and the specialist showed higher losses than the generalist. The only significant effect detected in comparisons involving fluctuating asymmetry values was that of taxon on length of siphunculi. Frequency of body abnormalities was not affected by treatments. Collectively, these results show a transgenerational weakening of maternal effects in the generalist but not in the specialist aphid, and suggest that rearing the latter in a suboptimal host causes not easily reversible changes that further give rise to constraints in performance.

In eusocial Hymenoptera, females are more tolerant towards nest-mate than towards non-nest-mate females. In solitary Hymenoptera, females are generally aggressive towards any conspecific female. Field observations of the nest biology of Manuelia postica suggested nest-mate recognition. Experiments were performed involving two live interacting females or one live female interacting with a dead female. Live females from different nests were more intolerant to each other than females from the same nest. Females were more intolerant towards non-nest-mate than towards nest-mate dead females. When dead females were washed with pentane, no differences in tolerant and intolerant behaviours were detected between non-nest-mate and nest-mate females. Females were more intolerant towards nest-mate female carcasses coated with the cuticular extract from a non-nest-mate than towards non-nest-mate female carcasses coated with the cuticular extract from a nest-mate. The compositions of the cuticular extracts was more similar between females from the same nest than between females from different nests. The results demonstrate for the first time nest-mate recognition mediated by cuticular chemicals in a largely solitary species of Apidae. The position of Manuelia at the base of the Apidae phylogeny suggests that nest-mate recognition in eusocial species apical to Manuelia represents the retention of a primitive capacity in Apidae.

Artículo de publicación ISIInbreeding depression refers to a decrease in fitness components in the offspring of closely related sexual pairs. Given the disadvantages of inbreeding depression, it is of interest to study the mechanisms involved in its avoidance, particularly in social insects. In termites, colonies are founded by dispersing individuals. Two types of mechanisms may account for inbreeding avoidance: indirect mechanisms that occur before the dispersing individuals come into contact (sex-biased production at colony level, sex-biased emergence timing, dispersal, and sex-biased dispersal), and an active mechanism (kin recognition) that occurs when dispersing individuals come into contact. We have used ecological, behavioral and genetic approaches to study the mechanisms of inbreeding avoidance along the complete process of colony foundation by Neotermes chilensis, i.e., from the production of dispersing individuals in the colony to the production of siblings by the newly formed reproductive pair. This is the first report to address both indirect and active mechanisms of inbreeding avoidance in the same study, in the same termite species, and through the complete process of colony foundation. The results show that dispersal is the main indirect mechanism of inbreeding avoidance and that kin recognition is unlikely as an active mechanism of inbreeding avoidance.FONDECYT Grant 1120210 to HMN, CONICYT Grant 79100013 to LF-P, CONICYT PFB-23 and ICM P05-002 Grants to DV, and CONICYT fellowship for PhD studies and MECESUP internship programto DA-O

Laboratory studies of Coptotermes formosanus Shiraki (Blattodea: Rhinotermitidae) often employ the use of field-collected foraging populations of individuals as defined colonies. The biological relevance of this practice is often called into question, because these colonies lack a full composition of reproductive castes and brood, which may have physiological and behavioral consequences. Rearing intact laboratory colonies can be done; however, it is time-consuming and labor-intensive. The artificial fusion of field-collected foraging populations with a young, laboratory-reared incipient colony may provide whole, intact colonies for laboratory research. The current study measures survivorship of fused colonies using laboratory-reared complete incipient colonies ranging in age from 0 to 5 mo, fused with 100 workers and 10 soldiers from field-collected populations of different colonial origin. Results indicate that 60% of colony fusion was successful when the incipient colony introduced is 5 mo of age. This method of colony fusion will provide researchers with intact colonies using minimal resources.