RESUMEN
Green lacewings are valuable predators, utilized in augmentative biological control against various agricultural pests. However, further studies are required to comprehend the performance of these predators when consuming natural prey. We investigated the capacity of Chrysoperla externa (Hagen) to utilize the following three distinct prey types: the pupae of the coffee leaf miner Leucoptera coffeella (Guérin-Mèneville & Perrottet), the eggs of the sugarcane borer Diatraea saccharalis (F.), and the eggs of the Mediterranean flour moth Ephestia kuehniella (Zeller). The first two of these species are naturally occurring prey found in field crops, while the last serves as a factitious prey species for the mass rearing of natural enemies. We hypothesized that the type of prey would differentially affect the life history and population-level parameters of C. externa. Laboratory experiments were conducted to compare the pre-imaginal survival and developmental times, adult longevity and reproduction, and population growth of C. externa when larvae were provided with each of the three prey items. Results indicated that C. externa utilized the two natural prey items, L. coffeella pupae and D. saccharalis eggs, for its development, reproduction, and population growth. However, larvae developed significantly faster and females exhibited higher reproductive parameters, including fecundity and daily oviposition, when consuming the factitious prey, E. kuehniella eggs. This resulted in a higher intrinsic rate of population increase, as well as shorter times for the population to double in size. Understanding the population dynamics of C. externa when consuming different prey items is crucial for optimizing their utilization in augmentative biological control programs.
RESUMEN
Green lacewings (Neuroptera: Chrysopidae) are predators commonly found in coffee plantations in Brazil that can serve as important biological control agents against insect pests such as the coffee leaf miner, Leucoptera coffeella (Lepidoptera: Lyonetiidae). However, the efficacy of different lacewing species in controlling L. coffeella needs to be evaluated before they are used in augmentative biological control programs. Here, laboratory experiments were conducted to investigate the effects of the L. coffeella developmental stage on the functional response of 3 species of green lacewings: Chrysoperla externa, Ceraeochrysa cincta, and Ceraeochrysa cornuta. The attack rate, handling time, and the number of prey attacked during 24 h with different densities (1, 2, 4, 8, 16, 32, and 64 individuals) of either L. coffeella larvae or pupae were recorded for each of the 3 lacewing species. Based on logistic regression models, all 3 predators showed a Type II functional response when consuming both larvae and pupae of L. coffeella. All 3 species also had similar attack rates (0.0091 larva/h and 0.0095 pupa/h), handling times (3.5 and 3.7 h for larvae and pupae, respectively), and estimated number of prey attacked during the observation period (6.9 larvae and 6.6 pupae) for L. coffeella larvae and pupae. Therefore, our laboratory studies show that the 3 green lacewings Ch. externa, Ce. cincta, and Ce. cornuta have potential for the biological control of L. coffeella, although these results need to be confirmed under field conditions. These findings have implications for the selection of lacewings for augmentative L. coffeella biocontrol.