LOCATION AND BEHAVIORAL-EFFECTS OF LECTIN-BINDING ON ENTOMOPATHOGENICNEMATODES WITH DIFFERENT FORAGING STRATEGIES

Lectins have been used to locate and ascribe a function to sensory org ans of nematodes. We had two objectives: (1) to determine the location of carbohydrate exudates on the surface of three species of entomopat hogenic nematodes with different foraging strategies and (2) to evalua te the importance of carbohydrates in host finding and recognition. St einernema carpocapsae finds hosts by ambushing, and most individuals r espond poorly to host cues. No specific areas of lectin binding were r ecorded for this species. Wheat germ agglutinin bound specifically to the anterior region of Heterorhabditis bacteriophora and to the anteri or and posterior of S. glaseri. These two nematode species are cruise foragers and are highly responsive to host cues. The behavioral effect s of lectins varied. None of the species' responses to volatile host c ues was affected. S. carpocapsae's rate of attachment during ambushing was increased by treatment with WGA, and this effect was negated by t reatment with a competing sugar (N-acetylglucosamine). The infectivity of S. glaseri in an assay that required movement through 5 cm of sand to find the host was significantly decreased by treatment with WGA.