Banker plant system for the biological control of Liriomyza leafminers: Reproductive performance of a leafminer, Pseudonapomyza spicata（ Malloch）

Abstract

The reproductive traits of Pseudonapomyza spicata（Malloch）（Diptera: Agromyzidae）were examined on barley and other crops in the laboratory. The regression equation relating temperature（ X,℃） to development rates（Y,d^-1） on barley was Y=0.0037X－0.0406 for the eggpupal stage. The estimated lower threshold temperature was 10.8 ℃ and the total effective temperature was 270 degree-days. The longevity and fecundity of P. spicata females on barley were 27.7 days and 195.7 eggs, respectively. Mean generation time （T）, net reproductive rate （R₀）, and intrinsic rate of natural increase per day（r） were 35.2, 97.83, and 0.147, respectively. The number of mines as an index of oviposition preference was examined for 10 host plants by exposing each plant for 24 hours. Mean number of eggs laid was estimated as follows: barley（6.9 eggs）, wheat （9.8 eggs）, sorghum （6.5 eggs）, and triticale （2.3 eggs）. However, female adult flies did not lay eggs on other plants tested such as kidney bean, tomato, cherry tomato, chrysanthemum, pak-choi, and oat. These results strongly suggest that P. spicata is a promising candidate as an alternative host for a banker plant system against Liriomyza leafminers.