Functional response of chrysoperla externa, chrysoperla rufilabris, ceraeochrysa sp. nr. cincta, and ceraeochrysa valida (neuroptera: chrysopidae) as natural enemies of diaphorina citri (hemiptera: liviidae)

Diaphorina citri is considered the most serious pest of citrus. It transmits the bacterium Candidatus Liberibacter spp., which causes Huanglongbing disease. Augmentation biological control of D. citri involves the release of the parasitoid Tamarixia radiata and entomopathogenic fungi. The following potential predators were evaluated in the present study: Ceraeochrysa valida, Ceraeochrysa sp. nr. cincta, Chrysoperla externa and Chrysoperla rufilabris. The evaluated parameters included maximum predation rate, functional response, handling time and search time. C. externa showed the highest predation rate (274.1 +/- 3.1a). The correlation coefficient for the four species was higher than R-2 = 0.95, while the linear coefficient P-1 was negative and significant, indicating a type II functional response. The third instar of C. externa showed high search capacity (1.7905 +/- 0.0737), while the first instar of C. valida was associated with low search capacity (0.6243 +/- 0.1118). The highest and lowest values of handling time were recorded in the third (0.00891 +/- 0.00105) and second instars (0.00931 +/- 0.000075) of C. valida. The species C. rufilabris showed the highest search capacity value (1.3551 +/- 0.0261) and the lowest handling time (0.00899 +/- 0.00008904). The results show that the predatory capacity of the four species is a function of their stage of development and the density of the prey. The species C. externa and C. rufilabris showed to be the most suitable natural enemies for population regulation of D. citri.