Male and female adult wasps belonging to the atomus group of the genus Anagrus Haliday, classified according to morphological techniques, were analyzed for their cuticular hydrocarbons to detect any possible differences between species. Most female specimens that were identified as either A. atomus L. or A. ustulatus Haliday, using morphological and morphometrical characters, showed two distinct cuticular hydrocarbon profiles. These profiles seemed to be independent of the plants the insects were collected from, the potential leafhopper host species (Hemiptera: Cicadellidae), and the emergence period, and they were largely consistent with classification based on morphology. Both A. atomus and A. ustulatus females were shown to emerge from leafhopper eggs found on Vitis vinifera L. (Vitaceae). Males, for which conclusive diagnostic characters are not yet available, showed the same two cuticular hydrocarbon patterns observed in females; on average, specimens displaying one hydrocarbon profile differed from those showing the other profile in three characters used for morphometrical analysis.

1 In north-eastern Italy, the second-generation larvae of Lobesia botrana (Den. & Schiff.) (Lepidoptera: Tortricidae) can develop with two different time patterns. In particular, in 'warmer' areas, the developmental time is shorter than in 'cooler' areas and it is associated with an earlier and more economically important third generation. 2 Because the differences in temperature are not sufficient to explain the two patterns, research was carried out aiming to investigate whether the differences in larval development time are the result of a different number of instars and whether the photoperiod is a factor. 3 In the field, second-generation larvae develop through five instars in a 'warmer' area and through six instars in a 'cooler' area. Laboratory and field data showed that decreasing photoperiod, which induces diapause, is also an important cue for inducing larvae to develop six instars. 4 In the light of climate warming and subsequent changes in L. botrana phenology over the last 30 years, the two different development patterns are interpreted as a means to ensure the best fit of the moth to environmental conditions. In 'cooler' areas, third-generation larvae might not complete development before frost or harvest, and hence second-generation larvae develop through six instars before producing overwintering pupae.

The influence of generation (under field conditions) and photoperiod (under laboratory conditions) on Lobesia botrana larvae development was studied. Some larvae were collected during three annual generations in two grape-growing areas of northeastern Italy, and others were individually reared in the laboratory from egg to pupa on an artificial diet under two different photoperiod conditions (respectively, daylight 16 h/d [long day {LD}] and 14 h/d [short day {SD}]). The mandible lengths of collected larvae were measured and the data analyzed morphometrically to determine the number of larval instars. In the laboratory study, the number of larval moultings, the mandible length of each instar, the development time from hatching larva to pupa, and the pupal weight were considered. The measurement of mandible lengths of larvae collected in the field indicated the existence of five larval instars in all three annual generations, but the size of the two oldest larval instars was significantly higher for third-generation larvae than for the previous generations. Under laboratory conditions, the larvae usually exhibited five instars, but the mandible lengths of larvae and the pupa size were greater for individuals reared under SD. These also took a greater number of days to develop from hatching larvae to pupae. Because a larger size of the final larval instar occurs in individuals that produce diapausing pupae under SD in both the laboratory and the field, a positive association between larval size and the probability of surviving the winter can be inferred.