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ARS Home » Research » Publications at this Location » Publication #72627
Title: IMPORTANCE OF EXTRAFLORAL NECTARIES ON FOOD AND HOST SEARCHING BEHAVIOR OF MICROPLITIS CROCEIPES (HYMENOPTERA: BRACONIDAE) IN COTTON

Author
item STAPEL, O. - UNIVERSITY OF GA, ENTOMO.
item CORTESERO, A. - UNIVERSITY OF GA, ENTOMO.
item DE MORAES, C. - UNIVERSITY OF GA, ENTOMO.
item Tumlinson Iii, James
item Lewis, Wallace

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/3/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Plant feeding insects are costly pests of agricultural crops. Resistance to chemical pesticides and residue problems have caused scientists to seek better ways to use natural enemies for the control of insect pests. Understanding natural enemies and how they interact with crops and crop pests is essential to their dependable use in pest control. ARS scientists at Tifton, GA are seeking to better understand the host searching behavior of parasitic wasps which attack the caterpillar stages of earworm, bollworm and armyworm. The presence of food sources for parasitic wasps increases the wasp's performance as a biological control agent. Extrafloral nectar in cotton is a nutritious food source for insects. Extrafloral nectar is found in easy accessible glands on leaves and squares and it is produced during an extended time of the cotton growing season. This study shows that in cotton with extrafloral nectaries wasps stay much longer and attack more caterpillars than in cotton varieties without these nectaries. This information can be used to design ways for manipulating the retention and effectiveness of beneficial wasps so that more pest caterpillars can be parasitized.

Technical Abstract: The influence of extrafloral nectar, sucrose or whitefly honeydew on host- and food- searching behavior of hungry Microplitis croceipes females was investigated in different cotton patch treatments. Parasitoids, starved for two days at time of release and that fed in patches with either sucrose or extrafloral nectar, showed the longest retention times and highest rates of parasitization. The presence of food in the patch increased the time allocated to damaged leaves, but did not improve efficiency by reducing the time interval between host attacks. Parasitoids that fed in patches with honeydew showed a similar performance to parasitoids in patches without any food. This was probably caused by the relatively low quantity and quality of this food source for M.croceipes. The detectability of different food sources was also investigated. More parasitoids found extrafloral nectar than sucrose. Parasitoids showed an innate attraction to nectar, whereas learning may have influenced orientation to sucrose. The importance of cotton extrafloral nectar as an adult food source for parasitoids and the means of using extrafloral nectar as a pest management strategy are discussed.