Ladybird predators in natural and agricultural landscapes in Mexico: diversity and parasitism

Abstract

Ladybirds (Coleoptera: Coccinellidae) are a significant predator group that plays a role in agricultural contexts. They serve as important biocontrol agents against several agricultural pests. However, there is limited information available about how ladybirds’ populations are regulated by their natural enemies and habitat perturbation. In this study, we evaluated ladybird communities associated with natural and managed areas during the agricultural cycle of 2018 (June–September). We identified seven ladybird species; the most abundant species were Hippodamia convergens (70% individuals) and Cycloneda sanguinea (20% individuals), followed by the exotic species Harmonia axyridis (3.33% individuals), while Paranaemia vittigera, Coleomegilla maculata, Brachiacantha sp., and Olla v-nigrum represented less than 3% each. Ladybirds were more abundant in agricultural fields than in natural habitats. We identified several natural enemies associated with the collected ladybirds, including parasitoids (Dinocampus coccinellae, Hymenoptera: Braconidae), ectoparasitic Acari (Coccipolipus sp., Podapolipidae), and nematodes (Mermithidae). However, none of the natural enemies affected more than 10% of the ladybirds, so natural enemies do not appear to be exerting substantial control over their populations. Our results corroborated that ladybirds can efficiently thrive in anthropogenic habitats in Mexico and therefore may represent good biocontrol agents for agriculture. It is important to consider the ecology of agriculturally important ladybirds in programs for integrated pest management. This includes factors contributing to the mortality of ladybirds, including their natural enemies.