BioControl (2008) 53, 797-812
Jean Pierre Kapongo, Les Shipp, Peter Kevan and Bruce Broadbent (2008)
Optimal concentration of Beauveria bassiana vectored by bumble bees in relation to pest and bee mortality in greenhouse tomato and sweet pepper
BioControl 53 (5), 797-812
Abstract: Greenhouse cage trials were conducted to determine the optimal concentration of Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) (BotaniGard 22WP® formulation) as vectored by the bumble bee, Bombus impatiens (Cresson) (Hymenoptera: Apidae) pollinator for control of greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) on greenhouse tomato, tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae) and green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) on greenhouse sweet pepper. Three inoculum concentrations of B. bassiana: low, 9 × 109; middle, 6.24 × 1010; and high, 2 × 1011 conidia g−1 of inoculum and two controls (one with bees and heat-inactivated inoculum, and the other which contained only the host plants and pest species) were tested in a completely randomized block design. Beauveria bassiana killed 18, 54 and 56% of the adult T. vaporariorum and 33, 70 and 67% of the adult L. lineolaris, respectively, at the low, middle and high concentrations; but no infection from B. bassiana occurred in each of the control treatments. Internal infection rates after surface sterilization of the pest insects were 11, 34 and 35% for adult T. vaporariorum, 29, 54 and 58% for adult L. lineolaris, 22, 34 and 30% for nymphal M. persicae and 17, 29 and 32% for nymphal T. vaporariorum, respectively, at the low, middle and high concentrations. Significantly more bumble bees died at the high concentration of B. bassiana (42-45%) than at the other concentrations (9-15%) and the controls (5-7%). Spores of B. bassiana were collected throughout the plant canopy with the greatest numbers sampled from the top third of the canopy [ca. 1,200 colony forming units (CFU) per cm−2]. The middle concentration was selected as the optimal concentration because it provided the best pest control with the least impact on the bees.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): J.L. Shipp, A. Bruce Broadbent
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
application technology
