Biological control of aphids and coccids: a comparative analysis

Abstract

A comparison of the biological control of aphids and coccids was carried out by analyzing success rates for the three major types of biological control, i.e., classical, augmentative, and conservational. Because of the higher intrinsic rates of increase for aphids versus coccids, the working hypothesis that biological control of aphids is less successful compared to coccids was adopted. However, this hypothesis was not supported by an analysis of classical biological control using the BIOCAT database. In this analysis, parasitoids were more successful than predators when used against either aphids or coccids, but the control of Icerya spp. with Rodolia spp. (predators) was highly successful. Some reasons for success of Rodolia spp. are adduced, but field studies on the long‐term population dynamics of Icerya–Rodolia systems are needed for determining the mechanisms of regulation. Comparative analyses of augmentative and conservational biological control of aphids and coccids were inconclusive, due to lack of adequate databases; some possible factors involved in the success of these types of biological control are discussed. It is suggested that parasitoids could be better control agents than predators in augmentative biological control of aphids in production greenhouses. Conservational biological control of either aphids or coccids should be aimed at enhancing populations of indigenous natural enemies, especially mobile generalist predators that are capable of keeping pace with mobile pests.

Why is Coccinella septempunctata so successful? (A point-of-view)

“…Dixon, 2000, p. 217) that assume negligible impact is inevitable. We agree with Hirose (2006), who recommends a focus on conservation biological control utilizing mobile natural enemies of aphids with high reproductive potential. C7 seems eminently well-suited to comply with this requirement.…”

Host instar preference and functional response of Aphidius transcaspicus, a parasitoid of mealy aphids (Hyalopterus species)

“…Classical biological control, which involves the introduction of exotic natural enemies for the control of invasive pests, has been attempted with at least 23 species of parasitic wasps in the subfamily Aphidiinae (Hagvar and Hofsvang 1991). While these introduced parasitoids appear to have had a greater success rate in controlling aphid pests than introduced predators, their success rate is 14% (Hirose 2006), the typical success rate for all groups of introduced parasitoids (Mills 1994;Mills 2000).…”

Variations in the occurrence patterns of male moths of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae) among Southeastern Asian countries, as detected by sex pheromone trapping

“…As it is reasonable to estimate that denser networks exist there between insect hosts and their natural enemies than in non-breeding area, immigration of the moths to a non-breeding area would enable better population growth as a result of escaping from natural enemies if sufficient food resources are available in the new habitat, as has been demonstrated in mobile pests (Kennedy and Margolies, 1985;Hirose, 2006). …”