title: Intraguild predation and competitive displacement between Nesidiocoris tenuis and Dicyphus maroccanus, two biological control agents in tomato pests.
abstract: Dicyphus maroccanus Wagner and Nesidiocoris tenuis Reuter (Hemiptera: Miridae) are 2 biological control agents in tomatoes. Through the crop seasons, a natural shift in the occurrence of both mirids in favor of N. tenuis has been observed at the end of the cropping cycle in eastern Spain. To better optimize their conservation, the reasons for the observed change, such as intraguild interactions (IGP) or the influence of environmental conditions, are worth elucidating. To do this, we first studied the IGP of adult females on heterospecific nymphs in the laboratory. We next studied exploitative competition between adults and nymphs of each species when feeding on Ephestia kueniella Zeller (Lepidoptera: Pyralidae) eggs in the laboratory. Finally, to analyze the competitive displacement between both mirids, we conducted a semifield experiment in which both predators were released together. All experiments were conducted at 2 temperature regimes (20 and 25°C). Adult-to-nymph intraguild interactions occurred only at 25 ºC at very low levels, showing that N. tenuis attacked and consumed a greater proportion of heterospecific nymphs. Nesidiocoris tenuis was a better competitor than D. maroccanus when feeding on the shared prey in the presence of its heterospecific nymph at 25 ºC. In semifield conditions, N. tenuis showed a competitive advantage over D. maroccanus at both temperatures. We conclude that there is not direct interference between both species, however, N. tenuis has a greater ability to outcompete, since it is best adapted to higher temperatures and it is able to remove food sources for D. maroccanus.
authors.affiliation: Centro de Estudios Parasitológicos y de Vectores (CEPAVE -CCT La Plata- CONICET-UNLP), Boulevard 120 e/ 60 y 64, 1900 La Plata, Argentina.
authors.forename: Nadia G
authors.initials: NG
authors.lastname: Salas Gervassio
authors.affiliation: Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Unidad Asociada de Entomología UJI-IVIA, Carretera de Moncada - Náquera Km. 4.5, 46113, Moncada, Valencia, Spain.|Unitat Associada d'Entomologia UJI-IVIA, Departament de Ciències Agràries i del Medi Natural, Universitat Jaume I, UJI, Campus del Riu Sec, E-12071, Castelló de la Plana, Spain.
authors.forename: Meritxell
authors.initials: M
authors.lastname: Pérez-Hedo
authors.affiliation: Centro de Estudios Parasitológicos y de Vectores (CEPAVE -CCT La Plata- CONICET-UNLP), Boulevard 120 e/ 60 y 64, 1900 La Plata, Argentina.
authors.forename: María G
authors.initials: MG
authors.lastname: Luna
authors.affiliation: Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Unidad Asociada de Entomología UJI-IVIA, Carretera de Moncada - Náquera Km. 4.5, 46113, Moncada, Valencia, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Urbaneja
mesh_terms: D000818:Animals; D005260:Female; D006430:Hemiptera; D018551:Solanum lycopersicum; D009036:Moths; D009758:Nymph; D010572:Pest Control, Biological; D011235:Predatory Behavior
keywords: Mediterranean crops; Miridae; competition; temperature; tomato