An optimized method for mass rearing the tiger-fly, Coenosia attenuata (Diptera: Muscidae)

Abstract

Abstract. The tiger-fly Coenosia attenuata Stein (Diptera: Muscidae) is a predator that is currently thought to be a useful biological control agent in greenhouses, especially in the Mediterranean region. Here, we present a method for rearing this predator in the laboratory by feeding it on fungus gnats (fed on Pleurotus ostreatus fungus) and drosophilids (Diptera). Over the past two years, this method has been continuously used to successfully produce predators for bioecological studies in the laboratory. Rearing cages with one, five or 10 male-female pairs, either of laboratory or field origin, were compared using females that were either unmated and recently emerged, or mated and about 20 days old (post-emergence). We evaluated the following parameters: number of rearing cages in which adults emerged, number and sex ratio of emerged adults, period from the introduction of parental pairs into cages and the emergence of the first offspring adults, and the period over which emergence occurred in the cages. Based on our results and in order to minimize the space needed for the colony, cages should be stocked with ca. 10 parental pairs, either of field or laboratory origin, with at least some mated females about 20 days post emergence. We also found that the predator's rearing substrate in the cages is improved if coconut fibre is mixed with the soil. These findings will improve the efficiency of C. attenuata rearing, an important step if it is to be used as a biological control agent.

First report of Coenosia attenuata (Stein, 1903) (Diptera, Muscidae) in Uruguay, confirmed by DNA barcode sequences

“…The presence of Coenosia attenuata on most continents, its ability to live in high-temperature environments, and its predatory behavior make it an excellent biological control agent (Martínez and Cocquempot 2000;Pohl et al 2012). In addition, this species adaptable to laboratory conditions and can be bred in captivity for release in commercial crops (Martins et al 2015).…”

Environmental factors affecting the behavior of Coenosia attenuata, a predator of Trialeurodes vaporariorum in tomato greenhouses

“…Temporal patterns of sex emergence and differences in male:female ratios in relation to modalities of rearing were reported by Martins et al (2014); there is currently no information on the incidence of cannibalism of males by females in this species and a possible effect of the greater visibility of females in the observation area cannot be excluded. Temporal patterns of sex emergence and differences in male:female ratios in relation to modalities of rearing were reported by Martins et al (2014); there is currently no information on the incidence of cannibalism of males by females in this species and a possible effect of the greater visibility of females in the observation area cannot be excluded.…”

“…The sex ratio of C. attenuata did not differ from equality in the 1st year of the study, but there were more females than males in the second study season. Temporal patterns of sex emergence and differences in male:female ratios in relation to modalities of rearing were reported by Martins et al (2014); there is currently no information on the incidence of cannibalism of males by females in this species and a possible effect of the greater visibility of females in the observation area cannot be excluded. However, Mateus (2012) also reported fewer males than females in natural populations of C. attenuata.…”

The predator Coenosia Attenuata Stein (Diptera, Muscidae) on cultivated plants from Brazil

“…Some progress in this area has been reported recently by Martins et al (2015), who described a method for rearing muscid flies in the laboratory and established the optimal levels for various critical parameters such as number of rearing cages and adequate substrates for oviposition and rearing of larvae. Such methods may be applicable to other members of the "greenhouse predator community", which includes Coenosia species such as C. atra Meigen (1830), C. humilis Meigen (1826), C. strigipes Stein (1916), C. tigrina Fabricius (1775) and C. testacea Robineau-Desvoidy (1830), since they all prey on whiteflies, black fungus gnats and leaf-miner flies and have potential application as biological control agents (Kühne 2000).…”