Rearing Chrysoperla externa Larvae on Artificial Diets

Development, Predation, and Prey Preference of Chrysoperla externa on Liorhyssus hyalinus and Nysius simulans, Two Emerging Pests of Quinoa

In recent years, Liorhyssus hyalinus (Fabricius) (Hemiptera: Rhopalidae) and Nysius simulans Stål (Hemiptera: Lygaeidae) have emerged as important pests of quinoa in Peru, when the crop started to be cultivated at relatively low elevations. The potential of the native lacewing Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) was evaluated as a biological control agent of these two pest species. Prey consumption on all immature stages of L. hyalinus and N. simulans was assessed, as well as development on first instars of these heteropterans and eggs of Sitotroga cerealella (Olivier) (Lepidoptera: Pyralidae) as a factitious prey. In addition, prey preference was examined in the absence and presence of a preferred prey, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae). Larvae of the predator were not able to feed on L. hyalinus eggs, but they effectively did on N. simulans eggs as well as on all nymphal instars of both species. Nymphs of L. hyalinus were less suitable prey for larval development of C. externa than eggs of S. cerealella, whereas N. simulans was overall an unsuitable prey. There was a clear prey preference of C. externa for aphids over the two heteropteran species, as well as a preference for N. simulans over L. hyalinus. The predation rates in this study indicate the potential of C. externa as a predator of these heteropteran pests that can play a role in both conservation and augmentation biological control programs.

Predators and Parasitoids-in-First: From Inundative Releases to Preventative Biological Control in Greenhouse Crops

Repeated mass introductions of natural enemies have been widely used as a biological control strategy in greenhouse systems when the resident population of natural enemies is insufficient to suppress the pests. As an alternative strategy, supporting the establishment and population development of beneficials can be more effective and economical. The preventative establishment of predators and parasitoids, before the arrival of pests, has become a key element to the success of biological control programs. This “Predators and parasitoids-in-first” strategy is used both in Inoculative Biological Control (IBC), and in Conservation Biological Control (CBC). Here, we provide an overview of tools used to boost resident populations of biocontrol agents.

Morphology of the male and female reproductive tracts of virgin and mated Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae)

Predatory insects have reproductive organs rich in complex changes that may be responsible for the success of their population growth. The species Chrysoperla externa is a predator used in biological control programs in Latin America. However, there is no morphological data about the morphology of the reproductive tract in this insect. This study describes the morphology of the reproductive organs of virgin and mated C. externa male and female. The male has a pair of testes yellow in color and five pairs of accessory glands closely associated with the seminal vesicles. The testis follicles are twisted filled with cysts in different developmental stages. The pair of ovaries in the females shows asymmetry with 9-11 ovarioles per ovary with oocytes in different developmental stages and a spherical spermatheca. Virgin and mated males have no differences in the size of the testes, seminal vesicle, and accessory glands. C. externa females show morphological changes in the reproductive tract according to sexual maturation, which is triggered by mating. The ovary activation occurs after female mating. The ovaries are of merotistic polytrophic type. The spermathecal reservoir is lined by a flattened epithelium with a thin cuticular intima and associated with well-developed muscles. It is concluded that the reproductive tract of C. externa is similar in virgin and mated males and females. Egg production is activated only after mating and the development of reproductive tract structures is faster in mated females.