Population growth in some Mesostoma species (Turbellaria) predatory on mosquitoes

• Published in: Freshwater Biology
• Main Author: KOLASA, JERZY
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1987
• Subjects: Arctic; Subarctic
• Online Access: http://dx.doi.org/10.1111/j.1365-2427.1987.tb01308.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2427.1987.tb01308.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2427.1987.tb01308.x

SUMMARY 1. Turbellarian predators of the genus Mesostoma prey on the aquatic stages of mosquitoes. In order to evaluate their potential as control agents, a comparison of population parameters has been made on three species from Australia, Africa and Papua New Guinea: M. appinum , M. zariae and M. timbunke. 2. The life cycle of these species is relatively short at higher temperature ranges (22–30°C) and varies from 12 to 35 days, depending on the temperature. M. appinum does not increase in numbers at 30°C, white M. timbunke is unable to reach sexual maturity at 15°C. M. appinum , but not M. zariae , multiplies slowly at 15°C, although both species survive at this temperature. The fastest population growth was obtained for M. appinum at 22°C, and for M. zariae and M. timbunke at 30°C. The doubling time for the population is about 6–7 days in the multivoltine species, M. appinum and M. zariae , and about 18.5 days in univoltine M. timbunke . 3. A significant part of the growing population is composed of immature individuals, which corresponds to the high values of the reproductive parameters R o and r m . In M. appinum and M. zariae , individuals rarely produce dormant resting eggs except under deteriorating conditions. M. timbunke produces only dormant eggs, and in this respect resembles arctic and subarctic species. A convergence of the reproductive modes between this equatorial species and the high latitude species might be interpreted as adaptation to harsh environments. 4. The overall population growth of all Mesostoma spp. is several times faster than in Dugesia dorotocephala and D. trigrina , other flatworms studied as potential biological control agents of mosquitoes