Economic Importance for Humans: Positive
On the positive side, Latrodectus mactans consumes enormous numbers of harmful insects. It gets rid of troublesome flies and mosquitoes,which carry diseases, as well as locusts and grasshoppers, which destroy grain crops. In addition, this spider ingests beetles and caterpillars, which defoliate plants and trees. The black widow’s entrapment of pests makes it invaluable to man and helps to balance nature. (Kaston, 1953; Shuttlesworth, 1959; Preston-Mafham, 1984) Furthermore, the silk and venom Latrodectus mactans produces has potential uses in biotechnology. Its venom could lead to a new generation of environmentally safe insecticides that leave no residues. Drugs derived from its venom may be able to save lives of future heart attack victims by means of an immediate effect on the blood vessels, allowing the blood to flow more easily.
Positive Impacts: source of medicine or drug ; controls pest population