Ecology of Elasmopalpus lignosellus1 Parasite Complex on Peanuts in Texas2

Thirteen species of parasites were identified from Elasmopalpus lignosellus (Zeller) on peanuts in Texas. Means of 8.55, 5.21, and 4.98% parasitism were recorded from medium-larval, large-larval, and pupal stages, respectively, from 1975 to 1977. The dominant medium-larval parasite was Orgilus elasmopalpi Muesebeck (4.53% parasitism), followed by Apanteles sp. (1.46% parasitism), and Pristomerus spinator (F.) (0.73% parasitism). The dominant large-larval parasite was O. elasmopalpi (3.06% parasitism), with P. spinator (1.07% parasitism) second. The dominant pupal parasite was Invreia deceptor Grissell and Schauff (3.47% parasitism), with no pupal parasitism detected in the first generation. Parasites not previously reported from E. lignosellus include Orgilus nitidus Muesebeck, Macrocentrus sp., Agathis sp., and Geron aridus Painter. Parasitism was density independent and had little impact on E. lignosellus populations. Examination of all E. lignosellus parasite studies led to the conclusion that tachinid parasitism, an important component of E. lignosellus parasitism on many crops, is rare on peanuts. Restriction of tachinids from E. lignosellus parasites on peanuts is a result of larval behavior associated with plant growth form and larval feeding damage.