Host plant effects on the functional response of Neoseiulus cucumeris to onion thrips larvae

• Published in: Journal of applied entomology (1986) 2007-12, Vol.131 (9-10), p.728-733
• Main Authors: Madadi, H, Enkegaard, A, Brodsgaard, H.F, Kharrazi-Pakdel, A, Mohaghegh, J, Ashouri, A
• Format: Article
• Language: English
• Subjects: Allium cepa; Biological and medical sciences; biological control; Cucumis sativus; Fundamental and applied biological sciences. Psychology; Phytopathology. Animal pests. Plant and forest protection; Phytoseiidae; Protozoa. Invertebrates; Thripidae; Thrips tabaci; tritrophic interactions
• ISSN: 0931-2048; 1439-0418
• DOI: 10.1111/j.1439-0418.2007.01206.x

The performance of herbivores, natural enemies and their interactions may be affected directly or indirectly by host plant traits, e.g. the physical plant characteristics may influence the search pattern and the functional response of predators. We studied the functional response of adult females of the predatory mite Neoseiulus cucumeris to first instar larvae of Thrips tabaci on three host plants (sweet pepper, eggplant and cucumber). The 24-h leaf disc experiments conducted at 25 ± 1°C, 60 ± 10% relative humidity and 16 : 8 h (light : dark) showed that N. cucumeris exhibited a type II functional response on all host plants. The following search rates and handling times were estimated from fitting the data to the disc equation 0.043/h and 1.798 h (cucumber); 0.048/h and 1.030 h (sweet pepper) and 0.0441/h and 2.294 h (eggplant) giving an estimated maximum predation of 13.35, 23.31 and 10.46 larvae per day respectively. The data from sweet pepper could also be described by the random predator equation (a': 0.051/h; Th: 0.472 h). The host plant species interacted significantly with prey density on the functional response of N. cucumeris with the relative differences in the number of thrips eaten on each host plant increasing with density. It is suggested that it is mainly the difference in trichome density between the three host plants that is responsible for the observed differences in the functional response of N. cucumeris. These results emphasize the importance of the host plant characteristics on the performance of natural enemies and for optimizing their use in biological control of pests.