Print version ISSN 1519-566X
FIGUEIRA, Liliane K. and LARA, Fernando M.. Predator: prey ratios of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) for the control of greenbug in sorghum genotypes. Neotrop. Entomol. [online]. 2004, vol.33, n.4, pp. 447-450. ISSN 1519-566X. http://dx.doi.org/10.1590/S1519-566X2004000400008.
The use of host plant resistance associated with biocontrol agents may be a viable alternative to Schizaphis graminum (Rondani) control in sorghum. This work aimed to study different predator:prey ratios on genotype resistant (TX 430 x GR 111), moderately resistant (GB 3B) and susceptible (BR 007B) for the aphid control by the predator Chrysoperla externa (Hagen). Thus, the lacewings were released at the predator:prey ratios of 1:5; 1:10; 1:25 and 1:50 under greenhouse conditions. The genotype TX x GR 111 was the most efficient to control S. graminum, as well the 1:5 and 1:10 predator: prey ratios on the three genotypes. The interaction between plant resistance and biological control with C. externa was positive and permitted a control over 80% at the predator:prey ratios of 1:5 and 1:10; on the GB 3B genotype the best control was at the 1:5 predator:prey ratio.
Keywords : Insecta; integrated control; host plant resistance; Schizaphis graminum.