Abstract:
The main objectives of this research work were to study the biology and
controlling methods of pests of Lima-bean. As the first step in this research, the life
cycle of Maruca testulalis (Geyer) was studied. The life span of M. testulalis was
about 21 - 25 days at 28 - 30°C and 80.2 - 82% relative humidity. It had five larval
instars while life cycle o[ Lampedes boeticus spanned nearly 20 - 24 days. It had
five larval in stars as well.
The next step was to test the interaction between host plant resistance in different
Lima-bean and insecticidal control of Maruca testulalis Geyer (Cowpea pod borer)
in laboratory-' conditions. The larvae of M. testulalis feeding on 'Bushita’ showed
reduced Relative Growth Rate (R.G.R.) and fecundity compared with larvae
feeding on 'Polon-maa' 'Bushita’ and ‘Polon-maa’ were selected as relatively
resistant and relatively susceptible varieties, respectively. M. testulalis also showed
reduced final body weight and higher first instar larval mortality and may contain
higher levels of secondary plant substances on resistant variety (Bushita) than
when on susceptible variety (Polon-maa). These characteristics arc known to affect
the susceptibility of M. testulalis to insecticides.
