Potencial de Neoseiulus barkeri Hughes (Acari: Phytoseiidae) como biocontrolador de Raoiella indica Hirst (Acari: Tenuipalpidae)

Abstract

Raoiella indica Hirst (Acari: Tenuipalpidae) is an exotic species that, after its introduction in the Americas, has expanded its host range, and has caused serious damage in the areas where it has established itself. In order to reduce the populations of this pest, producers have adapted strategies used to control other pest mites, as there are still no control methods registered for R. indica. One of these strategies is the use of botanical extracts, however, there are no records of the efficiency of this tool. Another possible strategy is the use of predatory mites. Biological control of R. indica is considered a promising strategy in several countries. However, Amblyseius largoensis (Muma) (Acari: Phytoseiidae) identified as the most promising species in the combat against R. indica is not yet commercially produced, limiting its use in the field. Thus, the need arises to search for alternative strategies. Therefore, the objective was to evaluate the potential of the predatory mite Neoseiulus barkeri Hughes (Acari: Phytoseiidae) as a biocontroller of R. indica, since it is a generalist mite, already commercialized and effective in the management of some pest species in different cultures. To determine its potential, the following were evaluated: the developmental stage of R. indica preferred by N. barkeri; consumption and oviposition of N. barkeri on different stages of development of R. indica; the performance of predation and oviposition of N. barkeri and A. largoensis when fed with eggs of R. indica; the functional and numerical response of N. barkeri on R. indica eggs; development, immature survival and instantaneous population growth rate of N. barkeri fed different stages of development of R. indica; longevity, reproduction and fertility life table of N. barkeri females on R. indica eggs; and field performance of N. barkeri in controlling R. indica when released at densities of 900, 600 and 300 predators per plant compared to spraying with botanical extracts. Neoseilus barkeri showed a preference for eggs in relation to other stages of R. indica. The consumption of N. barkeri was inversely related to the life stage of R. indica, and all stages of development of R. indica allowed the reproduction of N. barkeri. Predation and oviposition of N. barkeri was higher than that of A. largoensis. Neoseiulus barkeri exhibited a type II functional response and all densities tested provided oviposition of females, with an average of 2 eggs/female/day. The predator also completed its development and reached adulthood feeding on all stages of R. indica. All the biological parameters obtained indicated that in addition to R. indica being a suitable food for the development of N. barkeri, it is also suitable to support its reproduction, allowing its survival for long periods and ensuring the growth of the population in the field. In addition, releases of N. barkeri at densities of 900 and 600 predators/plant resulted in significant reductions in populations of R. indica, which suggests that the predator N. barkeri has the potential to be used to control this pest mite.