Effect of non‐lethal sampling on life‐history traits of the protected moth Graellsia isabelae (Lepidoptera: Saturniidae)

Abstract 1. Non‐lethal genetic surveys in insects usually extract DNA from a leg or a piece of wing. Although preferable to lethal sampling, little is known about the effect of leg/wing non‐lethal sampling on fitness‐related traits. 2. Graellsia isabelae (Graells, 1849) is a European moth protected by the Habitats Directive and the Bern Convention. Conservation genetics surveys on this species should therefore use non‐lethal sampling. 3. The present study aimed to (1) quantify the effects of both leg and hind‐wing tail sampling on survivorship and reproductive behaviour of adult males and females, and (2) assess the quality and quantity of DNA obtained from those tissues. 4. Both hind‐wing tails and mid‐legs proved to be good sources of high quality nuclear and mitochondrial DNA. DNA concentration was significantly higher when extracted from a large (130 mm²) piece of the hind‐wing tails than from about half of the mid‐leg. Using mark–release–recapture experiments with adults, it was found that neither mid‐leg nor hind‐wing tail sampling significantly reduced male survivorship or total number of matings. However, although mid‐leg sampling did not significantly affect female survivorship, it had a negative effect on female mating success. 5. Wing‐tail clipping on males appeared to be the best non‐lethal sampling procedure for G. isabelae. It is a fast procedure, similar to natural wing impairment, and did not significantly affect survival or mating behaviour.     

Assessing the Conservation Status of an Iberian Moth Using Pseudo-Absences

ABSTRACT Knowing the distribution of endangered species is of substantial importance for conservation. We considered a useful approach for modeling species distribution when managing information from atlases and museums but when absence data is not available. By modeling the distribution for Graellsia isabelae, a threatened moth species, we assessed its current conservation status and identified its most relevant distribution explanatory variables using Geographic Information System and Generalized Linear Models. The distribution model was built from 136 occurrence records and 25 digitized explanatory variables at a 10 × 10 km resolution. Model predictions from logistic-regressed pseudo-absences, obtained from a presence-only method (Ecological-Niche Factor Analysis), explained 96.23% of the total deviance. We found that the best predictor variables were summer precipitation, aridity, and mean elevation. With respect to host plants, the presence of G. isabelae associated mainly with Scots pine (Pinus sylvestris) and Austrian pine (P. nigra). The finding of 8 areas, exclusively in the eastern Iberian territory, and a larger unoccupied habitat in the western Iberian Peninsula indicates that this species is probably not in equilibrium with its environment by historical factors. Sites of Community Importance under protection do not seem sufficient to maintain current populations, necessitating the protection of suitable neighboring habitats. Our methodology is useful to manage the conservation status of species for which reliable absence data is not available. It is possible to determine those variables that most affect the distribution of species as well as the potential suitable areas with the purpose of evaluating protected areas, connectivity among populations, and possible reintroductions.     

Variation in the suitability of Pinus sylvestris to feeding by two defoliators, Diprion pini (Hym., Diprionidae) and Graellsia isabellae galliaegloria (Lep., Attacidae)

Abstract: Feeding bioassays were conducted on several Pinus sylvestris clones to establish if there were any differences in suitability for two pine defoliators: the sawfly Diprion pini L. (Hym., Diprionidae), which causes considerable damage in Europe, and the rare and protected moth Graellsia isabellae galliaegloria Oberthür (Lep., Attacidae). There were significant differences in survival, weight, sex-ratio and female fecundity of D. pini on Scots pine clones. However, sawfly survival appeared to be the most stable variable in time and three clone categories were revealed by conducting feeding bioassays on 16 clones. The survival of G. isabellae galliaegloria until the formation of the chrysalis was significantly different among clones. It varied from 35 to 75% but no clear clone category was distinguished . The two clone classifications according to insect survival showed differences. In particular, one unsuitable clone for D. pini development appeared to be favourable to moth development. The 3-carene richness of foliage was significantly linked with sawfly survival and the monoterpene composition of foliage was not linked with G. isabellae galliaegloria survival.