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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #183394
Title: INTERACTIVE-WEB OF FACTORS GOVERNING EFFECTIVE NATURAL ENEMY FORAGING BEHAVIOR: OVERVIEW OF FOOD RESOURCES AS A CRITICAL COMPONENT

Author
item Olson, Dawn
item Lewis, Wallace
item TAKASU, K - KYUSHU UNIV/JAPAN

Submitted to: International Symposium on Biological Control of Arthropods
Publication Type: Proceedings
Publication Acceptance Date: 8/22/2005
Publication Date: 9/10/2005
Citation: Olson, D.M., Lewis, W.J., Takasu, K. 2005. Interactive-web of factors governing effective natural enemy foraging behavior: Overview of food resources as a critical component. In: Proceedings of the Second International Symposium on Biological Control of Arthropods, September 12-16, 2005, Davos, Switzerland. p. 389-397.

Interpretive Summary: The importance of adult food for natural enemy species such as predators and parasitoids has been recognized for decades. Parasitoid species (species that lay their eggs on or in other insect species, eventually killing them) are often used as models of natural enemy foraging behavior because of the relatively direct link between their foraging behavior and reproductive fitness when compared with predator species. Numerous laboratory studies have shown that suitable food sources can substantially increase longevity and fecundity of adult hymenopteran and dipteran parasitoids and that consumption of non-host food can influence many other vital aspects of parasitoid biology. Different parasitoid species have varying requirements for an adult food source based on their genetics. Parasitoids also need hosts, shelter and mates throughout their life, and they must balance these needs by effectively responding to stimuli associated with each of these resources and in accordance with their physiological state. These sources of variation are not mutually exclusive; rather they overlap extensively, even within a single individual. Therefore, it is important that we have a means of clearly delineating the sources, roles, and interacting effects of the variations. The conceptual model of Lewis et al., (1990) for collectively describing the various foregoing factors and their sum effect on foraging behavior of parasitoids are presented. The three major sources of intrinsic variability in the behavior of foraging female parasitoids are represented: (1) genetic diversity among individuals, (2) phenotypic plasticity within individuals because of experience, and (3) the parasitoid's physiological state relative to other needs. The behavior manifested is also dependent on the foraging environment, so the final foraging effectiveness of a parasitoid is determined by how well the parasitoid's net intrinsic condition as a result of these three components is matched with the foraging environment in which it operates.

Technical Abstract: Effective biological control of pests is determined by the abundance, retention and searching efficacy of natural enemies. To assure their reproductive fitness, natural enemies such as predators and parasitoids must effectively balance competing resource needs such as an adequate frequency of encounter with prey and hosts for reproduction, requirements of food other than prey and hosts, and other needs such as shelter and mates. The other food requirements consist primarily of short-term nutritional needs and are often separate from the target pest, such as plant nectar in the case of parasitoids. The appropriate quality, adequate availability, and ability to detect these non-mutually exclusive requirements in the target area, strongly affect the natural enemy's retention and pest foraging efficacy. We present a conceptual model of factors determining eventual foraging behavior of parasitoids that would guide empirical studies of the resource needs of parasitoids and other insects. An increased understanding of the interplay of the resource web with the habitat would allow us to leverage this information to design habitat management practices that allow the use of natural enemy species for biological control in a consistent and reliable manner.