Improvement of the mass rearing of larvae of the neotropical lacewing Chrysoperla externa through the incorporation of a new semiliquid artificial diet

Abstract

Two new semiliquid artificial diets (A and B), the aphid Rhopalosiphum padi L. (Hemiptera: Aphididae) and combinations of these were evaluated to improve the rearing of the Neotropical lacewing predator Chrysoperla externa (Neuroptera: Chrysopidae). Additionally, a nutritional analysis of the aforementioned diets was conducted. The developmental time, pupal weight, preoviposition period, fecundity, and fertility were used to evaluate the impact (i.e., potential benefit) of these artificial diets on the predator. We recorded the shortest development time in the treatment group that was given diet A + prey or prey alone ad libitum. Pupal weight was significantly higher with diet A + prey. No difference was found in the female preoviposition period between the five different diets. Fecundity was higher with diet A + prey or prey ad libitum, while fertility on the first day was higher with diet A + prey, cumulative fertility was optimal with diet A and B as food. In conclusion, diet A proved to have the optimal nutritional properties (proteins and carbohydrates) to improve lacewing rearing when used as a nutritional supplement. Furthermore, use of this diet allows a reduction in the use of prey for rearing, and is suitable to be used for mass-rearing programs

An improved core–shell microcapsule diet for rearing larvae of Mallada basalis (Neuroptera: Chrysopidae)

“…For green lacewings fed with artificial diet, the developmental durations from first instar to emergence (20–25 days), adult survival rate (40%–80%) and fecundity (300–450 eggs/female) have been reported for Chrysopa sp. and Chrysoperla sp., and M. basalis using the single‐rearing and single paired methods . The development times of M. basalis fed on the new microcapsule diet for the single‐rearing method were within the range reported by previous studies or slightly shorter .…”

“…and Mallada sp. using natural prey such as aphids, substitute prey such as anaesthetized mealworms, moth eggs, or factitious formulations of liver, ground beef, chicken eggs, yeast, sugar, pollen and honey …”

“…It not only prevents evaporation and biological contamination of the food caused by direct contact with the air, but also provides a dry surface that prevents sticky and/or moist food particles from adhering to the cuticles of larvae. Many studies have investigated the encapsulation of diets for mass‐rearing larvae of lacewings and other carnivorous insects . Cohen described a particulate diet coated with a molten wax mixture and embedded in stretched waterproof film.…”

“…The liquid food formula in each of the 100 mL capsules contained 5 g of honey, 5 g of sugar, 5 g of brewer's yeast, 6 g of yeast autolysate, 1 g of casein hydrolysate, 10 g of egg yolk and 68 mL of water. This spherical or particulate microcapsule diet of several hundred microns with a wax shell‐based core structure was completely different in volume and size from the parafilm‐embedded diets several millimetres in diameter . This microcapsule diet was sufficiently stable for detailed investigations into the rearing of M. basalis …”

“…using natural prey such as aphids, 11 substitute prey such as anaesthetized mealworms, 12 moth eggs, 13 or factitious formulations of liver, ground beef, chicken eggs, yeast, sugar, pollen and honey. [3][4][5][14][15][16][17][18][19] Packaging or encapsulation is an industrial method for embedding or enclosing a core material within a sealed or coated shell. 20,21 This method is crucial in preparing food for rearing predatory insects.…”