COMPARATIVE PREDATORY POTENTIAL AND ASEXUAL REPRODUCTION OF SECTIONED DUGESIA-DOROTOCEPHALA AS THEY RELATE TO BIOLOGICAL-CONTROL OF MOSQUITO VECTORS

Individuals regenerated from the head, middle, and tail-sections of Dugesia dorotocephala (Woodworth) were studied in the laboratory to ascertain their predatory and asexual reproductive potential. In 2 predatory experiments head-sectioned Dugesia consumed a larger number of Culex p. quinquefasciatus larvae during the 1st 24 h than either the middle or tailsectioned planarians. At low predatonprey ratio the maximum consumption was low while at higher ratio of 20:50/replicate, predation percentages were higher. A total of 98, 97 and 95.5% larvae was consumed by the unsectioned, head, and middle-sectioned groups, respectively. Asexual reproduction was highest among tail-sectioned Dugesia in 2 tests, increasing from an initial 100 to 280 in 30 days, while the unsectioned control increased to only 262. In all tests the planarians doubled their initial numbers in 20 days. © 1979 Entomological Society of America.