| Since cockroaches rely on pheromones in several aspects of their lives, pheromones can be powerful tools for monitoring and control of these serious pests. Studies on cockroach aggregation pheromones and sex pheromones have been reviewed. A recently identified female sex pheromone from Supella longipalpa, 5-(2;The aposematic coloration of coccinellid beetles is often linked with the presence of alkaloids in their hemolymph. Continuing search for new alkaloids among the acid-soluble components extracted from Chilocorus cacti has led to a new hexacyclic alkaloid, chilocorine C, which has been isolated by preparative TLC and characterized on the basis of its UV, LC-MS, and NMR data. This alkaloid's structure is closely related to that of the "dimeric" coccinellid alkaloid, exochomine, isolated from Exochomus quadripustulatus, and also to chilocorine A and B, isolated from the C. cacti.;Aposematic coloration is also observed in some water beetles species, e.g. the "sunburst diving beetle", Thermonectus marmoratus. Previous studies have shown that steroids, especially pregnene and pregnadiene derivatives are found in the defensive secretions produced by the prothoracic glands of dytiscid beetles. A novel steroid, thermonectone, has now been isolated from the prothoracic gland secretion of Thermonectus marmoratus, and it is characterized by analysis of its MS, UV, FT-IR, and NMR data. Thermonectone is a hemiketal derived from 18-hydroxypregn-4,6-diene-3,20-dione. |
