Impact of Release Rates on the Effectiveness of Augmentative Biological Control Agents

Abstract

To access the effect of augmentative biological control agents, 31 articles were reviewed that investigated the impact of release rates of 35 augmentative biological control agents on the control of 42 arthropod pests. In 64% of the cases, the release rate of the biological control agent did not significantly affect the density or mortality of the pest insect. Results where similar when parasitoidsor predators were utilized as the natural enemy. Within any order of natural enemy, there were more cases where release rates did not affect augmentative biological control than cases where release rates were significant. There were more cases in which release rates did not affect augmentative biological control when pests were from the orders Hemiptera, Acari, or Diptera, but not with pests from the order Lepidoptera. In most cases, there was an optimal release rate that produced effective control of a pest species. This was especially true when predators were used as a biological control agent. Increasing the release rate above the optimal rate did not improve control of the pest and thus would be economically detrimental. Lower release rates were of ten optimal when biological control was used in conjunction with insecticides. In many cases, the timing and method of biological control applications were more significant factors impacting the effectiveness of biological control than the release rate. Additional factors that may limit the relative impact of release rates include natural enemy fecundity, establishment rates, prey availability, dispersal, and cannibalism.

Local augmentation efficiency of Anaphes nitens (Hymenoptera, Mymaridae), the egg parasitoid of Gonipterus platensis (Coleoptera, Curculionidae)

“…Under these conditions, the efficacy of both low and high release rates is quite unsatisfactory and we did not detect a significant increase in the parasitism rate. The limited effect of the high release rate found in our plots agrees with the revision paper published by Crowder (), who reported that of 19 crop pests, in the 63% of the cases increasing the release rate of parasitoids did not affect the density, mortality or parasitism rate of the herbivores. To achieve a higher protection of the stands from G. platensis attack, a release of A. nitens by massive inundation could be the better strategy, but a more appropriate approach may be to limit eucalypt plantations to low altitude areas where natural biological control is satisfactory (Cordero Rivera et al, ).…”

Preplant release of Nesidiocoris tenuis and supplementary tactics for control of Tuta absoluta and Bemisa tabaci in greenhouse tomato

“…modify the control capacity of a natural enemy (Collier & van Steenwyk, 2004;Stiling & Cornelissen, 2005;Crowder, 2006;Desneux et al, 2007). Nesidiocoris tenuis was released 5 days before transplanting and the first whitefly release was carried out just after transplanting (week 0).…”

The evolution of food preferences in Coccinellidae

“…Within Scymninae, the genera Zilus Mulsant (Scymnillini) and Nephaspis Casey (Scymnini) also feed primarily on whiteflies (Gordon, 1985(Gordon, , 1994. Nephaspis oculatus (Blatchley) is another important predator of Bemisia whiteflies (Liu and Stansly, 1996;Crowder, 2006).…”