Acceptability and Suitability of Three Liriomyza Species as Host for the Endoparasitoid Halticoptera arduine (Hymenoptera: Pteromalidae)

Abstract

In the scope of using Halticoptera arduine (Walker; Hymenoptera: Pteromalidae) in a classical biological control program in East Africa, laboratory bioassays were conducted to evaluate the acceptability and suitability of the three economically important Liriomyza leafminer species to the exotic parasitoid. Searching time, number of oviposition attempts, F1 parasitoid developmental period, parasitism rates, sex ratio, host mortality, and body size indices were assessed. H. arduine parasitized and developed successfully in the three Liriomyza species reported in East Africa. Female parasitoids took on average between 10.45 ± 0.83 to 15.80 ± 0.91 (means ± SE) seconds to encounter their first host and made significantly more oviposition attempts on Liriomyza huidobrensis (Blanchard; Diptera: Agromyzidae) than Liriomyza sativae (Blanchard; Diptera: Agromyzidae) and Liriomyza trifolii (Burgess; Diptera: Agromyzidae) (P = 0.0006). Parasitoid development period from egg to adult ranged between 19.32 ± 0.96 and 22.86 ± 0.27 d. Parasitism rate ranged from 27.96 ± 3.86 to 44.10 ± 4.56 in the three host species and was significantly higher in L. huidobrensis than in L. sativae (P = 0.0397). H. arduine did not induce significant nonreproductive host mortality in any of the three Liriomyza hosts. A female-biased parasitoid sex ratio was observed in L. huidobrensis, a balanced sex ratio in L. sativae and a male-biased in L. trifolii. Parasitoids progeny were significantly larger on L. huidobrensis for both tibia and wing length than L. sativae and L. trifolii (P = 0.0109 and P = 0.0192, respectively). The implication for the environmentally friendly management of Liriomyza leafminers in East Africa is discussed.