Cannibalism and Interspecific Predation in a Phytoseiid Predator Guild from Cassava Fields in Africa: Evidence from the Laboratory

Abstract

Interspecific predation and cannibalism are common types of interaction in phytoseiid predator guilds, but the extent and nature of these interactions have not been determined yet in phytoseiid guilds composed of African native and neotropical exotic phytoseiid predators found in cassava habitat in southern Africa. We determined in laboratory experiments the level of cannibalism and interspecific predation among the three phytoseiid mite species Euseius fustis, Iphiseius degenerans, and Typhlodromalus aripo in the absence of food and in the presence of limited or abundant quantities of two food types--Mononychellus tanajoa and maize pollen--commonly found on cassava in Africa. When confined without food, only two T. aripo females laid each two eggs within 5 days, and this species survived longer than I. degenerans and E. fustis. In the presence of con- or hetero-specific larvae or protonymphs, the three species fed more on the former than on the latter, and more on hetero-specifics than on con-specifics. Oviposition rates of the three species did not exceed 0.7 egg/female/day on con- and hetero-specific immatures. Typhlodromalus aripo and E. fustis survived longer on con-specific and hetero-specific larvae and on hetero-specific protonymphs than in the absence of any food, while T. aripo survived longer than the two other species on the same diets. Provision of limited quantity of food decreased interspecific predation rate by I. degenerans and T. aripo, but not by E. fustis, and increased oviposition rate and longevity of all three species. Provision of abundant food, however, eliminated cannibalism by all three species and further reduced interspecific predation rates, but their oviposition and longevity remained relatively unchanged compared with limited food provision. Potential consequences of cannibalism and interspecific predation among phytoseiid mites on cassava for the biological control of M. tanajoa are discussed.

Effect of cannibalism on predation, oviposition and longevity of the predacious mite,Agistemus exsertusGonzalez (Acari: Stigmaeidae)

“…These data agree with those of Zannou et al (2005) who indicated that the oviposition rate of E. fustis and I. degenerans was significantly lower on conspecific immatures than on limited or abundant provision of M. tanajoa and maize pollens. On the contrary, adult females of N. californicus and P. persimilis cannibalising conspecific larvae were not able to lay eggs compared with those fed on T. urticae (Sabelis 1981;Walzer and Schausberger 1999a;Rahmani et al 2009).…”

“…Cannibalism rate on conspecific eggs by immatures and adult females of A. exsertus was significantly lower than the predation rate on prey eggs in no-choice tests. These patterns are similar to those reported on adult females of the generalist phytoseiid species, Neoseiulus californicus (McGregor), Euseius fustis (Pritchard & Baker), Iphiseius degenerans (Berlese) and Typhlodromalus aripo DeLeon (Walzer and Schausberger 1999a;Zannou et al 2005). It is interesting to note that the juvenile experience of consuming a given prey is retained through development and affects the predation, oviposition and survival of adult females of phytoseiid predators (Schausberger 2007).…”

“…Females of N. californicus and P. persimilis were able to lay eggs when fed on T. urticae larvae and conspecific larvae provided simultaneously (Walzer and Schausberger 1999b). Zannou et al (2005) also reported that limited or abundant provision of M. tanajoa and maize pollens to females of E. fustis, I. degenerans and T. aripo in the presence of conspecific immatures significantly increased the oviposition rate.…”

“…Similar results were obtained by MacRae and Croft (1997) who indicated that increasing availability of T. urticae larvae reduced cannibalism on conspecific larvae by adult females of the generalist, Typhlodromus pyri Schueten and the specialist, Galendromus (Metaseiulus) occidentalis (Nesbitt). Also, Zannou et al (2005) reported that limited or abundant provision of the cassava green mite, Mononychellus tanajoa (Bondar), and maize pollens significantly reduced ISP on conspecific immatures by adult females of E. fustis, I. degenerans and T. aripo. A. exsertus generally fed less on conspecific eggs 982…”

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

“…Aggressiveness (chance and latency to attack) and predation rates were moderate in comparison to other phytoseiid species (e.g., Croft et al 1996;Schausberger 1997;Walzer and Schausberger 1999b;Schausberger and Croft 2000;Zannou et al 2005) with shorter latency to attack for P. bickleyi than N. paspalivorus. However, provision of free water in our experiments may have considerably reduced the propensity to IGP (Schausberger 1997).…”