An Ecological Study of Coccinellidae (Col.) associated with Aphis fabae Scop. on Vicia faba

Abstract

Changes in numbers of adult Coccinellids on nettles infested with Microlophium evansi (Theo.) and on three experimental bean plots infested with Aphis fabae Scop. are described for the spring and summer of 1952 at Rothamsted. Of the three common species, Adalia bipunctata (L.), Coccinella septempunctata L. and Propylea quatuordecimpunctata (L.), the first was always the most abundant.The overwintered Coccinellids produced two broods: one on nettles in the spring and one on beans in early summer.On bean plots, changes in numbers of the adult insects occurred in three phases: (1) overwintered ladybirds, dispersing from nettles and other places, accumulated on the beans in the early stages of the infestations by Aphis fabae; (2) ladybirds, which had developed from eggs laid by the overwintered insects on nettles, emigrated from nettles and accumulated on the beans when A. fabae populations were at their height; (3) ladybirds, developed from eggs laid on the beans also by the overwintered insects, reached the adult stage when the bean aphid infestations had finished. The rise and fall of the A. fabae populations are discussed.One of the bean plots had always a high population of Coceinellids, which was attributed to its situation between two of the nettle sites. The other two bean plots were remote from nettles and one was sheltered by trees and buildings; their coccinellid populations were much lower.

The effect of infection with male-killing Rickettsia on the demography of female Adalia bipunctata L. (two spot ladybird)

“…When do such conditions occur? Past work on A. bipunctata on Vicia faba and Tilia x europa has suggested that oviposition starts before the aphid population has reached peak density: the adults will not be saturated with aphids (Banks, 1955;Hemptinne et at., 1992). The above experiments suggest that uninfected females would lay proportionately more eggs than infected ones during the early period of oviposition.…”

Ecological Studies on the Polymorphic Ladybird Adalia bipunctata in the Netherlands. I. Population Biology and Geographical Variation of Melanism

“…In these regions A. bipunctata is associated with shrubs and trees greater than 1-2 m in height. In Britain the species may more often be abundant on herbaceous plants and field crops (Banks 1955;Dunn 1960). A. bipunctata in the Netherlands has two generations in at least some populations in some years.…”

Role of surface chemical signals in egg cannibalism and intraguild predation in ladybirds (Coleoptera: Coccinellidae)

“…Those species whose eggs and larvae regularly co-occur are the most likely to be well defended against one another. C. septempunctata shows a marked preference for herbaceous plants and although A. bipunctata is not so restricted its immature stages nevertheless frequently co-occur with those of C. septempunctata (Smee 1922;Banks 1955Banks , 1956Smith 1966;Radwan & Lö vei 1982, 1983Hemptinne & Naisse 1988;Hemptinne 1989;Barczak et al 1996;Trouvé et al 1996). As indicated above these two species are protected against predation by one another.…”