An index model on predatory effect of female adults of Coccinella septempunctata L. on Macrosiphum euphorbiae Thomas

Abstract

The predatory effect of female adults of Coccinella septempunctata L. (Coleoptera: Coccinellidae) on aphid Macrosiphum euphorbiae (Thomas) was examined under laboratory conditions, in controlled environmental chambers. This study took place on single rose leaves in transparent small plastic cages at varying proportions of predator/number of aphids. Coccinella septempunctata proved to be an effective predator for the biological control of M. euphorbiae under controlled conditions in closed environments. It is proposed to use starved adult females of C. septempunctata in biological control programmes in greenhouses, as a specialized predator of M. euphorbiae in proportions near 1 : 35 predator/aphids. The percentage of aphids that may escape was correlated to the hunger satiation of the predator and the total number of aphids, and the theoretical models describing the predator's behaviour under controlled conditions were defined.

Predatory effect of Coccinella septempunctata on Thrips tabaci and Trialeurodes vaporariorum

“…Coccinella septempunctata has been proved, according to the results of this research, as an effective predator when used for the biological control (in controlled environments) of T. tabaci and T. vaporariorum at proportions near 1 : 30 (predator/total prey) where slope ( b ) of theoretical maximum linear model is near 1 ( Deligeorgidis et al., 2005). At that predator/total prey proportion, hanger satiation and dropping away slow down the predation rate decreasing the efficiency of predation ( Deligeorgidis et al., 2005). In greater pest densities, effective predation and successful biological control is difficult to achieve ( Hansen Stengård , 1989; Deligeorgidis et al., 2005), requiring more predators to control pest.…”

“…Equations describing the models of the predatory effect of C. septempunctata , on both species are also presented in fig. 1, according to the findings of Deligeorgidis et al. (2005).…”

“…2. Theoretical maximum linear models for T. vaporariorum and T. tabaci are included, compared with that for Macrosiphum euphorbiae L. ( Deligeorgidis et al., 2005). There were differences between species in the intercept values ( a ) of theoretical maximum linear models, and a ‐values of T. tabaci were lower than T. vaporariorum (fig.…”

“… Predictions according to the second‐degree model describing the relationship between the total number of insects (total number of insects) and the percentage (%) of insects that may survive (insects escaped %). Theoretical maximum linear models included for Trialeurodes vaporariorum , Thrips tabaci and Macrosiphum euphorbiae (data from Deligeorgidis et al., 2005) …”

Deviations from prediction model of predatory effect for Coccinellidae

“…The behavior of predators described by the seconddegree models, involving number of aphids that consumes C. septempunctata (and other coccinellid species) or the percentage of aphids that escape, reveals more than one factors for reducing efficiency of predation (Deligeorgidis et al 2005a). The purpose of this study was to estimate deviations from predicted values based on the predatory effect model proposed by Deligeorgidis et al (2005aDeligeorgidis et al ( , 2011.…”