Females of the pine sawfly Neodiprion sertifer (Hymenoptera Diprionidae) usually avoid Pinus pinea trees as host plants. In contrast, this sawfly species is highly attracted by P. sylvestris and P. nigra trees. Here, we investigated which pine volatiles might mediate this behavior by in situ sampling experiments and olfactometer laboratory tests. Volatiles emitted from P. pinea, P. sylvestris, and P. nigra foliage were sampled by solid-phase microextraction (SPME). Analysis of these volatiles by coupled gaschromatography/mass spectrometry revealed that the relative amounts of the compounds emitted by the three species were significantly different. A discriminant analysis showed that the amounts of limonene and myrcene significantly contributed to the species-specific volatile patterns. Pinus pinea emitted higher relative amounts of limonene than the other pine species. Pinus sylvestris emitted the highest relative amounts of myrcene. When testing the response of N. sertifer females to these pine terpenoids in an olfactometer bioassay, a low amount of limonene was attractive, while a repellent effect was evident when higher amounts were used. The sawfly females showed no significant olfactory response to myrcene. These data suggest that low relative amounts of limonene have a significant function in attracting N. sertifer females, while high amounts might contribute to avoidance of a tree.

S-100 proteins represent a group of closely related acidic, calcium binding proteins originally isolated from the mammalian nervous system and later detected in non-neural cell types and in a wide variety of vertebrate and invertebrate species. The present study used immunochemical and immunohistochemical methods to extend the investigation of S-100 during phylogenesis to plant tissues. The presence of S-100-like immunoreactive material was detected in extracts of spinach (Spinacia oleracea L.) terminal buds and young leaves by the ELISA method and by Western blotting using different anti-S-100 rabbit antisera. Using the PAP method, serial sections of young spinach leaves treated with the same antisera exhibited an immunoreaction product that was confined to the cytoplasm and nucleus (but absent from the vacuoles) in meristematic, epidermal, and parenchymal cells. The present data enlarge the field of investigation of S-100 proteins in the search of the function(s) of S-100 in biological organisms.