The group composition of epicuticular waxes of the five Polish varieties of Solanum tuberosum were studied by HPLC, GC, and GC/MS. Alkanes, alcohols (primary and secondary), fatty acids and ketones (terminal and internal) were identified and quantified. The quantitative compositional results were analysed by chemometrie methods such as cluster and principal component analysis. A correlation was found between Colorado potato beetle infestation and quantities of specific chemical groups in epicuticular waxes.

The process of plant selection by insects is mediated by repellents and attractants. Several compounds may be involved in this interaction. Thus intraspecific variation of the compounds concentration play an important role in the herbivory. The best tool for the characteristic of this variation is chemometrics. The strategy of the analysis with the use of literature data on terpen es and sesquiterpenes variations in Pin us caribaea needles in relation to Atta laevigata herbivory is exemplified herein. Simple cluster analysis and principal components analysis were used for the data study. Two factors were found lo be sufficient to describe total variation in more than 90%. Factor I is responsible for repellent properties. From factor loading, the relevant chemical compounds were identified.

The artificially made kernels from ground wheat grain, commercial wheat starch and wheat proteinaceous a-amylase inhibitors in different proportions were used as feed for adults of the granary weevil iSitophilus granarius L.). In the case of larvae of the confused flour beetle (Tribolium con/usum Duv.) and the Mediterranean flour moth (Anagasta kuehniella Zell.) the friable feed mixture were used. The survival of S. granarius adults has not been correlated with the soluble proteins extracted from wheat and amylolytic activity located in this protein fraction. On the other hand the weight of dust (the index of feeding intensity) produced during feeding has depended on the presence of a-amylase and trypsin inhibitors in wheat-based feed. A. kuehniella larvae have not developed at all on feed consisted of 50% wheat starch and 50% of crude a-amylase inhibitors from wheat. The same feed has caused 15.1 days of extension in development time of T. confusum larvae. It attests to specific native enzymatic apparatus existing in alimentary canals of three damaging grain species which can overcome some obstacles even if extremely highly active insect a-amylase inhibitors were present in feed. However, the sufficient nutrient should be available in feed compounds. Nevertheless, some reduction of insects population can be expected.

The aim of the work was to study the feeding deterrent activity ofprecocenes, their synthetic analogues, and some related compunds to storage pests: Sitophi/us granarius L., Tribolium con/usum Duv., Trogoderma granarium Ev., and aphids: Myzuspersicae (Sulz.). Among all tested compounds precocenes I and 11 exhibited the best feeding deterrent activity against all tested insects. 4-Chromanols ( 16, 17 and I 8), alcohols 19, 20 and 3-chromanone (15) showed high deterrence towards the larvae of T con/usum. The best antifeedant activity towards the adults of both T confusum and S granarius was observed for substituted phenols with methoxy group at benzene ring. The biological tests carried out on aphids showed that the presence ofmethoxy group in the molecule was a crucial structural factor for the appearance of antifeedant activity against these insects.