Compatibility and Efficacy of the Parasitoid and the Entomopathogenic Fungus for Biological Control of Whitefly .

Biological control is an effective method for whitefly management compared to the potential problems caused by chemical control, including environmental pollution and the development of resistance. Combined use of insect parasitoids and entomopathogenic fungi has shown high efficiency in control. Here, we assessed the impacts of an entomopathogenic fungus, on the parasitism rate of a dominant whitefly parasitoid, , and for the first time also compared their separate and combined potential in the suppression of under semi-field conditions. Six conidial concentrations of (1 × 10, 1 × 10, 1 × 10, 1 × 10, 1 × 10 and 1 × 10 conidia/mL) were used to assess its pathogenicity to the pupae and adults of . Results showed that the mortality of increased with higher concentrations of , but these higher concentrations of fungus had low pathogenicity to both the pupae (2.00-28.00% mortality) and adults (2.67-34.00% mortality) relative to their pathogenicity to nymphs (33.33-92.68%). Bioassay results indicated that was harmless (LC = 3.91 × 10) and slightly harmful (LC = 5.56 × 10) to the pupae and adults of respectively on the basis of IOBC criteria, and that could parasitize all nymphal instars of that were pretreated with , with its rate of parasitism being highest on second-instar nymphs (62.03%). Interestingly, the parasitoids from second and third-instar nymphs infected with had progeny with increased longevity and developmental periods. Moreover, experimental data from 15 day semi-field studies indicate that combined application of and suppresses with higher efficiency than individual applications of both agents. Therefore, combined applications of (1 × 10 conidia/mL) and is a more effective and compatible biological control strategy for management of than using either of them individually.