ISSN:
1572-9702
Keywords:
Phytoseiulus persimilis
;
Tetranychus urticae
;
biological control
;
selection
;
adaptation
;
life-history traits
;
food quality
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The predatory mite Phytoseiulus persimilis is frequently reported to perform poorly on greenhouse tomatoes. As the predators are mass-reared on another host plant (bean), we supposed that they are poorly adapted to tomato, a plant densely packed with poisonous and sticky glandular hairs. This hypothesis was tested by comparing the control capacity of a stain of P. persimilis directly obtained from a mass rearing with the same strain after four generations on tomato. Both strains were released in a tomato crop in two identical compartments of a greenhouse and the population dynamics of prey (a tomato strain of Tetranychus urticae) and predator were recorded at weekly time intervals. It was found that the strain previously exposed to a tomato environment performed better than the unexposed strain: (1) its population increased faster; (2) the prey population declined faster; and (3) the damage to new-grown tomato leaved was considerably lower. To investigate the caused of the difference in performance between the exposed and unexposed strains, oviposition and survival rates were assessed on a diet of two spotted spider mites on tomato leaf sections. In addition, the unexposed strian was tested on a diet of two-spotted spider mites on bean leaf sections. The difference in oviposition rates of both predator strains was small compare to the overall mean. however, the oviposition rate of the first generaton of predators since transfer from hean to tomato dropped to less than half of the original value. Moreover, mortality in the first generation increased from 14% to 89%, whereas it decreased to 0% after four generations. Future research should clarify whether these changes in life history are due to selection or tho physiological adaptation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/B:APPA.0000018885.35044.c6
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