Asma K. Mahmoud*, Najah E. Yousif and Abdalla A. Satti
Environment, Natural Resources & Desertification Research Institute, National Centre for Research, P.O. Box 6096, Khartoum, Sudan;
*Corresponding author, E-mail:
Accepted: 1st December 2016, Published: 31st December 2016
The family Coccinellidae comprises important predatory insects that contribute significantly to bio-control programs of some major economic pests worldwide. Several species of such predators including Cheilomenes propinqua vicina (Coleoptera: Coccinellidae) are prevalent in Sudan. In this study the effect of three prey (aphid) species (viz., Melanaphis sacchari, Aphis gossypii and Aphis nerii) on the life tables parameters of C. propinqua vicina was investigated under laboratory conditions (23.3ºC & 36.3%R.H) at the Environment, Natural Resources and Desertification Research Institute, Khartoum. The main parameters investigated include: duration of the immature stages, mortality among immature stages and life tables’ data of C. propinqua vicina. The results showed that the total developmental period of pre-adult stages was longer when C. propinqua vicina fed on A. nerii (17.03±0.37), than on M. sacchari (12.69±0.34) or A. gossypii (13.00±0.43). Likewise, the highest mortality rate among such stages was recorded when the predator fed on A. nerii (35.25±11.14%), whereas, less mortality was detected when it fed either on A. gossypii (25.64±11.14%) or M. sacchari (25.26±11.14%). Regarding life tables’ data, both the net reproduction rate and the intrinsic rate of increase were higher when the beetle fed on A. gossypii (769.55 and 0.284, respectively), followed by M. sacchari (176.65; 0.192) and A. nerii (22.43; 0.116). In contrast, the weighted generation time as well as the doubling time was lower when the predator fed on A. gossypii (23.46; 2.43) than on the other aphids; hence, rapid multiplication was achieved compensating other parameters. It is concluded that, A. gossypii is the best prey among the tested aphid species for augmentative program of C. propinqua vicina.
Keywords: Natural enemies, aphidophagous, active metabolite, Aphis gossypii and Aphis nerii.