Development of immature tiger-fly Coenosia attenuata (Stein) reared on larvae of the fungus gnat Bradysia impatiens (Johannsen) in coir substrate

Authors: ZOU, DEYU - Tianjin Institute Of Plant Protection; Coudron, Thomas; XU, WEIHONG - Tianjin Institute Of Plant Protection; GU, XISHU - Tianjin Institute Of Plant Protection; WU, HUIHUI - Tianjin Institute Of Plant Protection

Submitted to: Phytoparasitica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2017
Publication Date: 1/29/2017
Citation: Zou, D., Coudron, T.A., Xu, W., Gu, X., Wu, H. 2017. Development of immature tiger-fly Coenosia attenuata (Stein) reared on larvae of the fungus gnat Bradysia impatiens (Johannsen) in coir substrate. Phytoparasitica. 45(1):75-84. https://doi.org/10.1007/s12600-017-0564-3.
DOI: https://doi.org/10.1007/s12600-017-0564-3

Interpretive Summary: The development of immature tiger-fly Coenosia attenuata Stein (Diptera Muscidae) was examined when reared in coir substrate and fed third-instar larvae of the fungus gnat Bradysia impatiens Johannsen (Diptera Sciaridae). Single larvae of C. attenuate were fed 3, 5, 7 and 9 prey per day and two larvae were fed 6, 10, 14 and 18 prey per day. Optimal prey density was determined for larval developmental rate, time to adult eclosion, larval survival, and percentage of pupation. Other biological characteristics, such as pupal weight, pupal length, and adult body length, continued to increase with an increase in prey density. The use of coir for a rearing substrate resulted in a more efficient use of prey, less cannibalism, and improved developmental time, and survival than previously reported when agarose gel or a mixture of soil and coir were used for rearing substrates. These improvements in rearing methods are significant advancements for the use of C. attenuata as a biological control agent against whiteflies, leaf miners, fungus gnats and winged-aphids.

Technical Abstract: The ability to rear a beneficial predatory insect is often required for its use in inoculative releases for classical biological control applications. However, affordable mass production is required before a beneficial predatory insect will be commercialized for large scale repetitive releases. The tiger fly is an effective predator of whiteflies, leaf miners, winged aphids, leafhoppers, midges, fruit flies and several other agricultural pest insects. Unfortunately, previously reported rearing methods for producing the tiger fly were complicated and costly. We report a simplified method of rearing the tiger fly that is cost-effective, utilizes readily available material, produces a high quality predator, and is easily scaled up for mass production. These rearing improvements will enable commercial-scale production of the tiger fly at a cost that is affordable to producers for control of several pest insects common to the vegetable industry.