A Review of the Scientific Literature on Fungus Gnats (Diptera: Sciaridae) in the Genus Bradysia2

Abstract

The majority of the literature concerning fungus gnats in the genus Bradysia (Family Sciaridae) can be divided into two groups, addressing their cytogenetics or their role as economically important pests. Cytological anomalies in sciarids are recognized in (1) chromosome complement, (2) differential chromosome contributions of the sperm and egg, (3) alteration of chromosome complement during embryogenesis, (4) and alteration during gametogenesis. The literature concerning these cytological events is reviewed within the context of the development of the science of cytogenetics and as they relate to the taxonomy and systematics of this group. Although species of Bradysia were recognized as pests of various seedling plants over a century ago, their economic importance in plant and mushroom production was largely overlooked until recently. A review of the scientific literature on the biology and management of the sciarids indicates that members of the genus Bradysia may be especially pestiferous in greenhouse plant production. Although, a fungal food source appears to be critical to successful development and reproduction of fungus gnats, larvae also will feed on healthy plant tissue. Feeding activities of larvae directly damage seedlings, whereas both larvae and adults indirectly contribute to plant damage through the spread of fungal phytopathogens. The relatively recent confirmation of fungus gnats as potential disseminators of plant pathogens has placed these insects in the category of a more serious pest. As expected with any recently recognized pest, critical information regarding monitoring and economic thresholds is lacking. However, because these flies have been considered a nuisance, chemical control methods are available, as are alternatives which have been integrated most successfully into management programs in European glasshouses.

Sciarid and shore flies as aerial vectors of Fusarium oxysporum f. sp. cucumerinum in greenhouse cucumbers

“…The lack of relationship between disease onset and fly abundance supports the hypothesis that the insects are passive vectors of the pathogen (Gillespie and Menzies 1993;Harris et al 1996;El-Hamalawi 2008). These results indicate that while the timing of disease onset does not depend on the presence of sciarid flies, the high level of disease incidence indicates that the pathogen is rapidly disseminated through the crop by insect activity.…”

“…Herbivorous insects can be highly destructive and cause significant crop loss (Zepa-Coradini et al 2010;Dimetry et al 2013). While damage caused by herbivorous insects is recognizable, seemingly harmless insects can play a hidden role as vectors of plant pathogens (Dennis 1978;Harris et al 1996;Jarvis et al 1993;Konam and Guest 2004;Cloyd and Zaborski 2004;Elmer 2008).…”

“…are recorded as the prominent Sciaridae species (Steffan 1989). The larvae of these flies feed on fungi and other organic matter (Harris et al 1996), including algae and plant roots, causing wounds that reduce plant vigour and facilitate the entry of pathogens (Leath and Newton 1969;Graham and McNeill 1972;Kennedy 1974;Springer 1995a,b).…”

Attract effect of mushroom flies with different wavelength of light emitting diode(LED)

“…특히, 많은 파리목 (Diptera)의 유충과 성충들은 강한 주광성 행동을 보이는 것으로 보고되어 있다 (Glick and Hollingsworth, 1955;Jacob et al, 1977;Sivinski, 1998). 그래서 광트랩들이 버 섯파리과(Mycetophilidae)에 속하는 종들을 채집하는데 이용되어 왔다 (Mikolajczyk, 2001 (Harris et al, 1996). 버섯파리 성충은 광주성을 띄며, 재 배사에서 밝은 부위인 균상 가장자리와 출입구에 주로 산 란한다 (Brar and Sandhu, 1989;Lee, 1997 Kostelc et al, 1980), 황색 끈 끈이트랩과 같이 색상을 이용하여 성충을 유인하는 방법 들도 이용되고 있다 (Ishitani et al, 1997;Lee, 1997).…”

Formation of the Unusual Semivolatile Diterpene Rhizathalene by the Arabidopsis Class I Terpene Synthase TPS08 in the Root Stele Is Involved in Defense against Belowground Herbivory

“…Rhizathalene synthase is largely expressed in the vascular tissue and is targeted to root plastids. To determine possible defensive activities of rhizathalenes, we established bioassays with larvae of the common opportunistic root herbivore fungus gnat (Bradysia spp) (Harris et al, 1996). We demonstrate that roots of tps08 gene knockout plants, which are deficient in rhizathalene formation, are more susceptible to insect herbivory and the removal of peripheral cell layers.…”