The application of systematics and phylogenetic work can have very practical effects on applied entomology. Phylogeny is the study of the evolutionary relationships of organisms; systematics uses the results of phylogeny to construct systems of classification. If one knows something about the phylogenetic and systematic relationships of a pest or a crop, then one knows the wild relatives of pest or crop, and can predict what either might do in the future. Such knowledge and predictions are especially important in developing countries which are now diversifying their agriculture. Insects now feeding on wild plants may become pests when relatives of those plants are introduced as crops. Similarly, wild relatives in these countries of pests elsewhere, may themselves become pests when the same crop is introduced. The ability to make such predictions allows countries to be prepared for pests before they actually become pests. Heteropteran examples of such predictions for Brazilian crops are: certain Blissidae (pests of rice and sugarcane in Asia), certain Alydidae (pests of legumes in Asia, and of soybean now in Brazil); also some triatomine Reduviidae (vectors of Chagas' disease in the neotropics, potentially of Chagas' disease in India). In addition, knowledge of phylogeny and systematics may allow one to control lygus bugs, a Holarctic group of pests (Miridae).
Insecta; hemipterans; taxonomy; applied entomology