Compatibility of Neoseiulus paspalivorus and Proctolaelaps bickleyi, candidate biocontrol agents of the coconut mite Aceria guerreronis: spatial niche use and intraguild predation

Abstract

The eriophyid mite Aceria guerreronis occurs in most coconut growing regions of the world and causes enormous damage to coconut fruits. The concealed environment of the fruit perianth under which the mite resides renders its control extremely difficult. Recent studies suggest that biological control could mitigate the problems caused by this pest. Neoseiulus paspalivorus and Proctolaelaps bickleyi are two of the most frequently found predatory mites associated with A. guerreronis on coconut fruits. Regarding biological control, the former has an advantage in invading the tight areas under the coconut fruit perianth while the latter is more voracious on the pest mites and has a higher reproductive capacity. Based on the idea of the combined use/release of both predators on coconut fruits, we studied their compatibility in spatial niche use and intraguild predation (IGP). Spatial niche use on coconut fruits was examined on artificial arenas mimicking the area under the coconut fruit perianth and the open fruit surface. Both N. paspalivorus and P. bickleyi preferentially resided and oviposited inside the tight artificial chamber. Oviposition rate of P. bickleyi and residence time of N. paspalivorus inside the chamber were reduced in the presence of a conspecific female. Residence of N. paspalivorus inside the chamber was also influenced by the presence of P. bickleyi. Both N. paspalivorus and P. bickleyi preyed upon each other with relatively moderate IGP rates of adult females on larvae but neither species yielded nutritional benefits from IGP in terms of adult survival and oviposition. We discuss the relevance of our findings for a hypothetic combined use of both predators in biological control of A. guerreronis.

Social familiarity modulates group living and foraging behaviour of juvenile predatory mites

“…For example, Griffiths et al (2004) observed that socially familiar fish consumed more food items per time unit than unfamiliar fish and suggested that familiarity allowed to switch attention from within-group aggression to foraging. However, higher feeding rates do not necessarily indicate enhanced foraging efficiency and do not necessarily translate into enhanced life history traits (Stearns 2000; Illius et al 2002; Lawson-Balagbo et al 2008). In our study, familiar mites apparently optimized energy gain per prey item eaten or reduced energy invested in other activities, allowing to feed less at the same developmental speed.…”

New Phytoseiid mites of the FrenchWest Indies, with description of a new species, and new records (Acari: Mesostigmata)

“…This species thrived on the coconut eriophyid, Aceria guerreronis Keifer as primary food source resulting in shorter developmental time, higher ovipositon rate and higher intrinsic rate of increase than on any other diet (Lawson-Balagbo et al, 2007). Neoseiulus paspalivorus is dorso-ventrally flattened giving it an advantage in accessing the area under the bracts (Lawson-Balagbo et al, 2008b). This species is thus cited as a promising candidate for the biological control of the coconut eriophyid (LawsonBalagbo et al, 2008a).…”

Life history of Proctolaelaps bulbosus feeding on the coconut mite Aceria guerreronis and other possible food types occurring on coconut fruits

“…Fungivory has also been reported for other species in this same genus, namely Proctolaelaps pygmaeus (Muller) (Shereef et al 1980), P. striatus Westerboer (Afifi et al 1984), P. bickleyi (Lawson-Balagbo et al 2008b) and P. deleoni Nawar, Childer and Abou-Setta (Nawar 1992). The determined rates of population growth of P. bulbosus were slightly lower than that determined for P. bickleyi by Lawson-Balagbo et al (2007a), on both A. guerreronis and R. aff.…”