The soil mite Cunaxa capreolus (Acari: Cunaxidae) as a predator of the root-knot nematode, Meloidogyne incognita and the citrus Nematode, Tylenchulus semipenetrans: Implications for biological control

Abstract

Plant-parasitic nematodes (PPNs) are dangerous pests, causing serious losses to the world’s agricultural crops. As soil-dwelling predaceous mites are known as potential biological control agents against many pests, we investigated the interactions between the cunaxid mite, Cunaxa capreolus (Berlese), and two plant parasites (root-knot nematode, Meloidogyne incognita (Kofoid and White) and the citrus Nematode, Tylenchulus semipenetrans Cobb under laboratory conditions. The predatory mite C. capreolus completed its life-span when fed on egg masses EM and second-stage juveniles J2 of M. incognita and J2 juveniles of T. semipenetrans as food sources in the laboratory in sealed arenas at 32ºC, 60% relative humidity in the dark. Males developed slightly faster than females irrespective of different prey. Adult females lived longer than males and showed a higher rate of food consumption. Life table parameters indicated that feeding C. capreolus on J2 juveniles of M. incognita and J2 juveniles of T. semipenetrans led to the highest reproduction rate (r_m= 0.185 and 0.167 females/female/day), while feeding on EM of M. incognita gave the lowest reproduction rate (r_m= 0.085). The results show that C. capreolus multiplied rapidly when juveniles of M. incognita and T. semipenetrans were offered as prey, indicating the mite’s potential for regulating population densities of these two pests. Future research should focus on understanding the crop and soil management applications required to enable this cunaxid mite and other predatory species to thrive. The implications of these results on biological control of plant parasitic nematodes are discussed.