Seasonal Feeding by Phyllophaga crinita and Anomala spp. (Coleoptera: Scarabaeidae) Larvae in Northeastern Mexico
Larval feeding by Phyllophaga crinita (Burmeister) and Anomala spp. (mixed populations of A. flavipennis Burmeister and A. foraminosa Bates) was studied under simulated field conditions in northern Tamaulipas, Mexico. Each month from July 1994 to February 1995, 50 field-collected larvae of P. crinita and Anomala spp. were placed individually in plastic pots with soil and corn seeds, and damage was evaluated 10 d after seedling emergence. Secondinstar P. crinita caused 41% root loss in July, whereas third instars caused most damage (66–88% root loss) during July–September. Feeding by P. crinita decreased gradually from October to December, and ceased in January–February. In contrast, feeding by Anomala spp. peaked in July and again in November (73 and 53% root loss, respectively), a result of the bivoltine life cycle of these species in this region. The relationship of these findings to similar studies is discussed.