Life History of the Green Broomweed Looper, Narraga fimetaria (Lepidoptera: Geometridae)1

Abstract

Larvae of the geometrid moth, Narraga fimetaria (Grote and Robinson), feed on the foliage of common broomweed, Amphiachyris dracunculoides (DC.) Nutt., which is a serious weed of southwestern rangelands. In the laboratory, females laid an average of 251 eggs each; the egg stage lasted 6 days, the larval stage 18 days, and the pupal stage 10 days, and the adult required 2 days to reach peak oviposition, for a generation time of ca. 36 days; the calculated rate of increase thus was 1.13 times per day, and the population would double each 5.6 days. Larvae ate an average total of 1,304 ± 255 mm2 of leaf surface of broomweed during their development; full-grown larvae were 24 mm long. In field cages, ca. 50 larvae per plant produced 45% defoliation of broomweed plants.