Entomopathogenic Nematode Exploitation: Case Studies in Laboratory and Field Applications from South Africa

Abstract

The first record of an entomopathogenic nematode (EPN) (belonging to the order Rhabditidae, and to the families Steinernematidae and Heterorhabditidae) in South Africa was that of Harington (1953), who reported nematodes from the larval, pupal, and adult stages of the black maize beetle, Heteronychus arator Fabricius (Coleoptera: Scarabaeoidea), which were collected from a maize field near Grahamstown in the Eastern Cape province. After an elapse of 35 years, the first attempt was made to use EPN for the control of the sugarcane stalk borer, Eldana saccharina Walker (Lepidoptera: Pyralidae), and three local EPN isolates were evaluated in laboratory and field trials by the South African Sugarcane Research Institute (SASRI) in KwaZulu-Natal (Spaull, 1988, 1990, 1991). From 1993 to 1994, soil samples were collected from deciduous fruit orchards in the Western Cape province. Heterorhabditis were then isolated from the soil samples, and used for the control of the banded fruit weevil, Phlyctinus callosus (Schonerr) (Coleoptera: Curculionidae) (Basson, 1993). The specimens were sent to France, where they were the first to be identified as Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), using species–specific satellite DNA as diagnostic probes (Grenier, Bonifassi, Abad, & Laumond, 1996; Grenier, Laumond, & Abad, 1996). Ten years later, the first new species to be described for South Africa was Steinernema khoisanae Nguyen, Malan & Gozel (Rhabditida: Steinernematidae) (Nguyen, Malan, & Gozel, 2006). A revived interest in applied research on EPN ensued during early 2000 (Hatting & Kaya, 2001) with research starting in earnest in 2003 at the South African Agricultural Research Council–Small Grain Institute (ARC–SGI) near Bethlehem, Free State province, continuing a year later at Stellenbosch University, in the Western Cape province (Table 20.1).