**2. Genus** *Lecanicillium,* **as pathogen of plant parasitic nematodes**

Until recently, the form genus *Verticillium* contained a wide variety of species with diverse host ranges including arthropods, nematodes, plants and fungi (Zare and Gams, 2001). The genus has been recently redefined using rDNA sequencing, placing all insect pathogens into the new genus *Lecanicillium* (Zare et al., 2000; Gams and Zare, 2001; Zare and Gams, 2001). These include *L. attenuatum*, *L. lecanii*, *L. longisporum*, *L. muscarium* and *L. nodulosum*, which were all formerly classified as *V. lecanii*. These recent reclassifications bring forth the possibility that several different species were actually involved in previous studies. There is also evidence that in recent literature, some authors have simply replaced the genus name *Verticillium* with *Lecanicillium* without conducting the necessary rDNA sequencing, adding to the confusion (Sugimoto et al., 2003; Koike et al., 2007a). In this review, we refer to the former name, *Verticillium lecanii*, as *Lecanicillium* spp. unless it is specifically known that the species in question was verified using the new nomenclature.

Species of *Lecanicillium* are well known and important nematophagous fungi with potential for development as biopesticides against plant-parasitic nematodes. For instance, *L. psalliotae*, *L. antillanum*, and other *Lecanicillium* spp. infect the eggs of the root-knot nematode *Meloidogyne incognita* (Gan et al., 2007; Nguyen et al., 2007). *Lecanicillium* spp. infect females, cysts and eggs of *Heterodera glycines*, the soybean cyst nematode (SCN), reducing nematode populations in laboratory and greenhouse studies (Meyer et al., 1997). Mutant strains of an SCN active strain were induced through UV radiation which resulted in increased efficacy against this nematode (Meyer and Meyer, 1996).

Some reports indicated that immature eggs are more susceptible to fungal attack than the mature eggs containing second stage juveniles (J2) (Chen and Chen, 2003; Irving and Kerry, 1986; Kim and Riggs, 1991). Furthermore, Meyer et al. (1990) demonstrated that one strain of *Lecanicillium* sp. (as *V. lecanii*) decreased the number of viable SCN eggs from yellow females, whereas the viability of eggs from cysts was not affected. This strain also reduced the viability of SCN eggs without colonization of the egg; however, no such effect was observed in other strains. This suggested that *V. lecanii* produced a natural substance that could affect egg viability and there was a remarkable variation in the ability for producing such a substance among strains.
