In vitro pathogenicity of northern Peru native bacteria on Phyllocnistis citrella Stainton (Gracillariidae: Phyllocnistinae), on predator insects ( Hippodamia convergens and Chrisoperna externa), on Citrus aurantifolia Swingle and white rats

Abstract

In Peru, the leaf miner Phyllocnistis citrella attacks citrus crops, including the economically important species Citrus aurantifolia, adversely affecting production. The objective of this work was to determine the in vitro pathogenic ability of enterobacteria isolated from within P. citrella. In addition, the pathogenic effects of these enterobacterias were tested on the predator insects Hippodamia convergens and Chrisoperna externa, on the host plant C. aurantifolia and on rats. The insects were captured in plantations of C. aurantifolia in the Piura Region. Phyllocnistys citrella was the most frequently occurring pest (98%), among other identified pests. From diseased larvae of P. citrella, the bacteria Serratia sp., Pseudomonas sp., and Enterobacter aerogenes were isolated. The three bacterial species had a similar pathogenic effect on P. citrella after 48 h (74.1% average mortality). Serratia sp. caused the highest mortality after 24 h in H. convergens (40%) and C. externa (30%), whereas the Lowest mortality rates were induced at 72 h by E. aerogenes on C. externa (3%) and by Pseudomonas sp. on H. convergens (10%). The bacteria did not affect neither C. aurantifolia or the rats, which gained the same weight as control animals.