Monday, December 10, 2007 - 10:05 AM

The role of olfaction in differential settling by the green peach aphid on potato leaf roll virus-infected and non-infected potato plants

Esther Ngumbi,, Sanford Eigenbrode,, Hongjian Ding,, and Nilsa A. Bosque-Pérez, University of Idaho, Plant Soil and Entomological Sciences, Ag Sci 242, Moscow, ID

We examined the role of olfaction in differential settling by the green peach aphid (GPA) onto Potato leaf roll virus (PLRV)-infected and non-infected potato plants. The antennae of apterous GPA were surgically removed and settling patterns of antennectomized GPA and untreated controls with intact antennae were compared in a dual-choice bioassay. In each of 11 replications, 30 aphids were released into a container from which they could climb to a platform in contact with two leaflets: one from a PLRV-infected plant and one from a non-infected plant. The location of aphids was recorded hourly for the first three hours and after 12 hours. The antennectomized GPA settled equally on PLRV-infected and non-infected plants, whereas GPA with intact antennae settled more on PLRV-infected plants. Emigration bioassays were conducted using synthetic volatile organic compound (VOCs) blends made to mimic headspace from PLRV-infected and non-infected potato plants. The rate of emigration of antennectomized aphids did not differ from the vicinity of paper strips treated with the two blends, but intact aphids were arrested by the blend mimicking PLRV-infected plants. Emigration rates from non-treated paper strips (no VOCs) did not differ between antennectomized and control aphids, indicating that surgery did not affect aphid mobility. Our results show that the GPA is guided by olfactory cues in discriminating between PLRV-infected and non-infected plants and suggest that gustatory and tactile cues are not involved.

Species 1: Hemiptera Aphididae Myzus persicae (green peach aphid)