Dietary Ecology of Predatory Insects Examining the Role of Prey and Non Prey Foods of Ladybird Beetle

Abstract

Ladybird beetles consume a wide variety of non-prey items in their natural habitats, including aphids, fruits, plants, fungi, honeydew, and nectar. These non-prey foods play several critical roles, such as boosting fertility, decreasing mortality during dormancy, supporting migration, and enhancing survival during times when prey is scarce. Larval ladybird beetles have more specialized nutritional needs compared to adults, with simple carbohydrates being crucial nutrients that can improve adult beetle function and reproductive success. Non-prey foods often provide similar or greater nutritional and caloric content compared to prey. Each non-prey item has distinct defense mechanisms and nutritional benefits, influencing its suitability for ladybird beetles. Research comparing diets consisting solely of prey with mixed diets that include non-prey foods revealed that while pollen improved larval and adult performance, a diet high in sugar alone was less effective for reproduction compared to an aphid-based diet. Wheat, which lacks essential nutrients such as proteins, could not adequately support egg production and larval development. Although pollen did enhance overall performance, it could not completely offset the nutritional shortcomings of a diet high in sugar. Adding sugar to a diet did not markedly enhance the performance of ladybird beetles compared to a diet composed entirely of prey. This review underscores the need to understand the varied diet of ladybird beetles within their ecological context, as it has significant implications for the success of conservation-oriented biological control effort.