Use of life tables to asses host plant resistance in cowpea to aphis craccivora Koch (homoptera : aphididae)‎

الملخص EN

The effects of seven cowpea cultivars on the development periods and some life table parameters on bean aphid Aphis craccivora Koch, were studied in the laboratory.

Data revealed that the duration period of nymphal stages ranged from 7.22 d on Six-Weeks to 8.19 d on B-Crowder cultivar.

Aphid individuals fed on Six-Week cultivar developed significantly faster than those on any other cultivars, whereas, it was longer development time was on B-crowder cultivar.

The intrinsic rate of natural increase (rm) for A.craccivora on IT82 D889 cowpea cultivar was the highest.

The estimates of (rm) varied from 0.271 on IT82 D889 to 0.190 on Balady.

The mean doubling time (DT) of aphid population on these cultivars ranged from 2.68 to 3.65 d.

at 25 oC.

The reproductive rate (R0) ranged from 28.42 individuals on IT82 D889 to 15.23 individuals on Tvu-21.

Based on life- table analysis of cowpea aphid populations, it could be concluded that IT82 D889 was the most suitable host plant for A.craccivora while development on B-Crowder was the least suitable.