Intraguild predation and competitive displacement between Nesidiocoris tenuis and Dicyphus maroccanus, two biological control agents in tomato pests

PEREZ-HEDO M.; SALAS GERVASSIO N.G; URBANEJA A; LUNA M.G

INSECT SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 00 p. 1 - 9

1672-9609

Dicyphus maroccanus Wagner and Nesidiocoris tenuis Reuter (Hemiptera:Miridae) are two spontaneous biological control agents for several tomatopests. Through the crop seasons, a natural shift in the occurrence of bothmirid species in favor of N. tenuis has been observed at the end of thecropping cycle in eastern Spain. To better optimize their conservation, thereasons for the observed change, such as intraguild interactions (IGP) orthe influence of environmental conditions, are worth elucidating. To dothis, we first studied the IGP of adult females on heterospecific nymphs inthe laboratory. We next studied the adult predation of each species onalternative prey in the presence of its heterospecific nymph. Finally, toanalyze the competitive displacement between D. maroccanus and N.tenuis, we conducted a semi-field experiment in which both predators werereleased together. The experiments were conducted at two temperatureregimes (20 and 25°C), which are representative of the crop cycles in theMediterranean Basin. Adult-to-nymph intraguild interactions between bothmirids occurred only at 25ºC, showing that N. tenuis attacked andconsumed a greater proportion of heterospecific nymphs. Moreover, N.tenuis altered the consumption rate of the shared prey, in the presence ofits heterospecific nymph at the higher temperature tested. In semi-fieldconditions, N. tenuis showed a competitive advantage over D. maroccanusat both temperatures, indicating its ability to outcompete. We concludethat N. tenuis is a better competitor and is better ad