In Mediterranean habitats, the specialist butterfly Euphydryas aurinia oviposits on Lonicera implexa. Previous work has shown that ovipositing females select and lay a higher number of egg clusters on certain plants. In this paper the results of a field study aimed at assessing whether females use plant size and/or plant or leaf greenness (i.e., chlorophyll concentrations) as cues for oviposition are described. Size of plants did not appear to be an important factor in determining host plant selection, probably because even small plants provide enough resources for the young larvae to reach the diapausing stage and because last instar larvae, the most likely to face resource depletion, can move great distances in search of food. Measurements of both spectral reflectance and chlorophyll concentration of plants failed to reveal differences between host and non-host plants. On the other hand, reflectance and chlorophyll concentration of leaves were found to be important in oviposition choice as egg clusters were generally located on the greenest leaves with the highest chlorophyll contents. This suggests that females use visual cues to select the leaves that will provide optimal growth opportunities for newly hatched larvae. Although there was some indication that plants receiving a greater number of egg clusters also had more leaves of high chlorophyll content, multiple egg batches on single plants could also be a consequence of females being attracted by the presence of conspecific egg clusters.
On October 2006, during an episode of abnormally warm weather, the African moth Cornifrons ulceratalis (Lederer, 1858) was captured simultaneously for the first time in several sites in north-eastern Spain, the Balearic Islands and southern France. A deep depression situated over the Atlantic at the time gave rise to warm south-westerly winds, accompanied by suspended dust, that blew towards the north-western Mediterranean Basin. Back trajectories of air masses at two different altitudinal levels indicate that the moths most probably originated from an area located in Morocco and northern Algeria, where C. ulceratalis can be extremely abundant. With winter approaching, this invasion of a typically non-migratory species into the north-western Mediterranean Basin provides a good example of the so-called "pied piper" phenomenon, by which wind-borne insects may be carried into areas unfavourable for survival or reproduction. However, because climate change may make the establishment of this and other African species more likely in the future, we suggest that monitoring of this process may become an essential issue in the coming years.