Journal of Insect Science: Vol. 7 | Article 15

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 parasitoids or 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 often 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. Correspondence: [email protected] Received: 21 February 2006 | Accepted: 20 October 2006 | Published: 19 March 2007 Copyright: Creative Commons Attribution 2.5 ISSN: 1536-2442 | Volume 2007, Number 15 Cite this paper as: Crowder DW. 2007. Impact of release rates on the effectiveness of augmentative biological control agents. 11pp. Journal of Insect Science 7:15, available online: insectscience.org/7.15 Journal of Insect Science | www.insectscience.org ISSN: 1536-2442 Journal of Insect Science: Vol. 7 | Article 15 1