Previous studies have shown that: (1) plant defensive compounds may have medicinal properties; and (2) defensive compounds present in aposematic insects are often sequestered from their host-plant(s). This study addresses whether aposematic insects can be used as guides to detect plants containing medicinally-active compounds. First, ten tropical medicinally-active plants and ten non-active plants, selected using previous ICBG bioassay results, were observed regularly to determine their insect populations. Aposematic insects were found more frequently on active than non-active plants ( X2=8.167, P=0.01). Second, three aposematic insects feeding on Tithonia diversifolia were examined chemically to determine the fate of the plant's pharmaceutically-active compounds. They were not found to sequester or excrete these compounds. Therefore, using aposematic insects could increase the likelihood of finding plants with medicinally-active compounds; however, these insects may not necessarily utilize these compounds for defensive purposes. The underlying basis for this significant association between aposematic insects and medicinally-active plants requires further investigation.

No description available.

This thesis investigates the possibility of using aposematic insects as guides to plants that contain pharmacologically-active compounds. Plants were monitored within national parks in the Republic of Panama over a period of six months and all insects feeding on them were collected and raised in captivity. The insects were then extracted and analyzed to determine how they were treating toxic chemical compounds in their host plant. Two principal plants were investigated with their associated insects: (1) Vismia baccifera and (2) Mikania guaco. One generalist and one specialist Lepidopteran species were found to sequester vismione B from their host plant Vismia baccifera, a cytotoxic compound active against three cancer cell lines. Two specialist Coleopterans were found to sequester the novel compound Guacanone, isolated by the primary author from the vine Mikania guaco and active against Trypanosoma cruzi, the causative agent of Chagas' disease. A generalist Coleopteran was found to not sequester this compound. (Abstract shortened by UMI.)

No description available.