Attraction, Oviposition and Larval Survival of the Fungus Gnat, Lycoriella ingenua, on Fungal Species Isolated from Adults, Larvae, and Mushroom Compost

Abstract

We previously showed that the females of the mushroom sciarid, Lycoriella ingenua (Dufour, 1839) (Diptera: Sciaridae), one of the most severe pests of the cultivated white button mushroom, Agaricus bisporus (J.E. Lange) Emil J. Imbach (Agaricales: Agaricaceae), are attracted to the mushroom compost that mushrooms are grown on and not to the mushrooms themselves. We also showed that females are attracted to the parasitic green mold, Trichoderma aggressivum. In an attempt to identify what is in the mushroom compost that attracts female L. ingenua, we isolated several species of fungi from adult males and females, third instar larvae, and mushroom compost itself. We then analyzed the attraction of females to these substrates using a static-flow two choice olfactometer, as well as their oviposition tendencies in another type of assay under choice and no-choice conditions. We also assessed the survival of larvae to adulthood when first instar larvae were placed on each of the isolated fungal species. We found that female flies were attracted most to the mycoparasitic green mold, T. aggressivum, to Penicilium citrinum isolated from adult female bodies, and to Scatylidium thermophilium isolated from the mushroom compost. Gravid female flies laid the most eggs on T. aggressivum, Aspergillus flavus isolated from third instar larval frass, Aspergillus fumigatus isolated from adult male bodies, and on P. citrinum. This egg-laying trend remained consistent under no-choice conditions as females aged. First instar larvae developed to adulthood only on S. thermophilium and Chaetomium sp. isolated from mushroom compost, and on P. citrinum. Our results indicate that the volatiles from a suite of different fungal species act in tandem in the natural setting of mushroom compost, with some first attracting gravid female flies and then others causing them to oviposit. The ecological context of these findings is important for creating an optimal strategy for using possible semiochemicals isolated from these fungal species to better monitor and control this pestiferous mushroom fly species.

Heterologous Production and Functional Characterization of Ageritin, a Novel Type of Ribotoxin Highly Expressed during Fruiting of the Edible Mushroom Agrocybe aegerita

“…In nature, ageritin might thus function in the natural defense of A. aegerita against insect antagonists of mushrooms, like fungus gnats. In cultivation facilities of the button mushroom (Agaricus bisporus), fungus gnats like Lycoriella ingenua (Sciaridae) can cause severe damages, e.g., by larval feeding on the mushroom cultures (37). Entomotoxic activity is a common The amino acid sequence of ageritin was used as a query sequence for a BLAST search against the database of the Gene Catalog Proteins (GCP) at the JGI MycoCosm fungal database.…”

Phoretic relationship between the myceliophagous mite Microdispus lambi (Acari: Microdispidae) and mushroom flies in Spanish crops

“…Mushroom yield losses are either directly due to the larvae of mushroom flies feeding on mycelia or mushrooms, or else due to other pests and diseases vectored by the flies (Erler & Polat, ). There is evidence of the transport of spores of different species of fungi by phorid and sciarid flies (Cloonan, Andreadis, Chen, Jenkins, & Baker, ; Geels, van de Geijn, & Rutjens, ; Shamshad, Clift, & Mansfield, ; White, ). Similarly, both phorids as well as sciarids have been described as vectors of mites (Clift & Larsson, ; Clift & Toffolon, ; Keum, Kang, & Jung, ).…”

Fungal Volatiles as Olfactory Cues for Female Fungus Gnat, Lycoriella ingenua in the Avoidance of Mycelia Colonized Compost

“…The fungi Scytalidium thermophilum and Chaetomium spp. found in mushroom compost was favorable for oviposition and larval development of L. ingenua (Cloonan et al 2016b). Even though various fungi were shown to increase the attractiveness for oviposition (Braun et al 2012) and enhance larval development (Chang and Miles 2004), the high mycelial density of white button mushroom (Agaricus bisporus) decreases the preference (Kielbasa and Snetsinger 1981).…”