Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/1/2005
Publication Date: 2/1/2005
Citation: Williams, L., III, C. Rodriguez-Saona, P. W. Paré & S. J. Crafts-Brandner. 2005. The piercing-sucking herbivores Lygus hesperus and Nezara viridula induce volatile emissions in plants. Archives of Insect Biochemistry and Physiology 58: 84-96. Interpretive Summary: Plant bugs and stink bugs are serious pests of many crops, including cotton and soybean, in the United States. When some insects (e.g., caterpillars and beetles) feed on plants the plants produce odors which affect the behavior of other insects. These odors can attract or repel other pests or beneficial insects that attack the insect that caused the release of plant odors. Thus, a better understanding of plant odor production caused by insect feeding has important implications for pest suppression. We conducted experiments to determine if crop plants damaged by plant bugs and stink bugs produce odors, and included factors such as insect age, gender, and the role of salivary glands. Our results indicate that plant bug and female stink bug feeding induce odor production in plants, and that odor production is affected by gender and life stage of the bug. Although egg-laying and mechanical damage by the bug's mouthparts may increase release of odors, chemicals from salivary glands of the bugs also seem to play a role in the emission of odors in plants. The affect of these odors on insect behavior remains to be seen, but it is possible that manipulation of plant biochemical pathways that regulate production and release of odors has potential for controlling plant bugs and stink bugs in U.S. crops.
Technical Abstract: Plant volatiles induced by herbivore damage are often used as olfactory cues by foraging herbivores and their natural enemies, and thus can be employed for control of agricultural pests. Compared to chewing insects and mites, little is known about plant volatile production following herbivory by insects with piercing-sucking mouthparts. Here, we studied factors that influence the induction of plant volatiles by two agriculturally important hemipterans, Lygus hesperus and Nezara viridula. Feeding on intact cotton by virgin females of L. hesperus induced 2.6-fold greater volatile response compared to that induced by mated females. Feeding damage by N. viridula females also increased volatile emissions in intact maize by approx. 2-fold compared to control plants. Emissions from intact maize damaged by adult males were lower than those emitted by adult females of the same age and did not differ from those emitted by undamaged plants. Feeding by virgin female N. viridula followed by excision led to 64% higher quantities of volatiles compared to untreated plants. Salivary gland extracts of N. viridula led to sesquiterpene emissions ca. 2.5 higher than for controls. Although oviposition and mechanical damage by stylets may increase release of volatiles, elicitors from salivary glands of L. hesperus and N. viridula may also play a role in the emissions of volatiles in plants.