Compatibility of Beauveria bassiana with Neoseiulus barkeri for Control of Frankliniella occidentalis

摘要

The entomopathogenic fungusBeauveriabassiana (Balsamo) Vuilemin and predatory miteNeoseiulusbarkeri Hughes are effective biological control agents ofFranklinielaoccidentalis Pergande (Thysanoptera: Thripidae), one of the most important pests of ornamentals and vegetables world-wide. Combined application of both may enhance control efifciency. The functional response forN.barkeri on the ifrst instar larvae of western lfower thrips which were infected byB.bassiana for 12 and 24 h in the laboratory ((25±1)°C, (70±5)% RH, L:D=16 h:8 h) was determined. The virulence ofB.bassiana against the second instar and pupae of the thrips attacked byN.barkeri were also tested. The results showed that N.barkeri exhibited a Holing type II functional response on treated thrips. After having been treated with the fungus for 12 h and then offered to the predator, thrips were more vulnerable to be kiled byN.barkeri. The second instar larvae and pupae of the thrips which had been attacked by predatory mites were markedly more susceptible toB.bassiana infection than normal thrips; the cumulative corrected mortality ofB.bassiana of the second instar and pupae which were attacked byN.barkeri were 57 and 94%, respectively, compared to 35 and 80% in controls on the day 8. These ifndings highlight the potential use ofB.bassiana in combination withN.barkeri to controlF. occidentalis.