title: Can Interactions Between an Omnivorous Hemipteran and an Egg Parasitoid Limit the Level of Biological Control for the Tomato Pinworm?
abstract: Relationships between the omnivorous predator Nesidiocoris tenuis (Reuter) and the egg parasitoid Trichogramma achaeae Nagaraja and Nagarkatti were studied in the laboratory (no-choice and choice assays, and functional responses) and in a greenhouse experiment. Both natural enemies are utilized in the biological control of tomato pinworm on greenhouse-grown tomato crops. Three different food items were offered to the predator: nonparasitized prey, prey parasitized for less than 4 d by T. achaeae, and prey parasitized for more than 4 d by the parasitoid. There were significant differences in consumption of food types, with highest consumption for nonparasitized prey, followed by parasitized (<4 d) and then parasitized (>4 d), both in no-choice and choice trials. At the same time, the predator causes a significant mortality in the prey (over 80%) regardless of previous parasitism, resulting in a very coincidental intraguild predation detrimental to the parasitoid. It has also been observed that there was a change in the functional response by the predator from Type II in presence of nonparasitized prey to Type I when there was a combination of parasitized and nonparasitized prey. This represents an increase of instantaneous search rate (a') and a decrease of handling time (Th), which indicates a change in feeding behavior on the two prey types. Under greenhouse conditions, the intraguild predation reduced the percentage of parasitism by T. achaeae in just over 20%. However, when both natural enemies were present, a better control of pest Tuta absoluta (Meyrick) was achieved than in the case of application of any of them alone.
authors: Center for Agribusiness Biotechnology Research, University of Almeria, Ctra. Sacramento s/n, ES 04120 Almeria, Spain. Current address: Department of Biology and Geology, University of Almeria, Ctra. Sacramento s/n, ES 04120 Almeria, Spain. Corresponding author, e-mail: tcabello@ual.es.
authors: Tomas
authors: T
authors: Cabello
authors: Center for Agribusiness Biotechnology Research, University of Almeria, Ctra. Sacramento s/n, ES 04120 Almeria, Spain.
authors: Francisco
authors: F
authors: Bonfil
authors: Center for Agribusiness Biotechnology Research, University of Almeria, Ctra. Sacramento s/n, ES 04120 Almeria, Spain.
authors: Juan R
authors: JR
authors: Gallego
authors: Center for Agribusiness Biotechnology Research, University of Almeria, Ctra. Sacramento s/n, ES 04120 Almeria, Spain.
authors: Francisco J
authors: FJ
authors: Fernandez
authors: Center for Agribusiness Biotechnology Research, University of Almeria, Ctra. Sacramento s/n, ES 04120 Almeria, Spain.
authors: Manuel
authors: M
authors: Gamez
authors: Department of Plant Taxonomy and Ecology, L. Eötvös University, Pázmány Péter Sétány 1/c., Budapest, H-1117, Hungary.
authors: Jozsef
authors: J
authors: Garay
mesh_terms: D000818:Animals; D002755:Choice Behavior; D005247:Feeding Behavior; D020062:Heteroptera / Q000502:physiology*; D018551:Solanum lycopersicum / Q000469:parasitology; D009036:Moths / Q000469:parasitology*; D010063:Ovum / Q000469:parasitology; D010572:Pest Control, Biological / Q000379:methods*; D011235:Predatory Behavior; D014863:Wasps / Q000502:physiology*
keywords: Omnivorous predator; functional response; intraguild predation; parasitoid; synergism