Bradysia ocellaris ( Comstock, 1882 )

Broadley, Adam, Kauschke, Ellen & Mohrig, Werner, 2018, Black fungus gnats (Diptera: Sciaridae) found in association with cultivated plants and mushrooms in Australia, with notes on cosmopolitan pest species and biosecurity interceptions, Zootaxa 4415 (2), pp. 201-242 : 210-213

Bradysia ocellaris ( Comstock, 1882)

( Fig. 3 A–E )

Sciara ocellaris Comstock, 1882 [ Comstock (1882): 202 –204, plate 17, figs 2–4]. Common synonym: Bradysia tritici ( Coquillett, 1895) .

Literature: Coquillett (1895): 399–402; Steffan (1973a): 356; Steffan (1974): 45; Gagné (1983): 705–706, figs 2 and 2 a–b; Menzel & Mohrig (1991): 21–22 (all as Bradysia tritici ); Johannsen (1912): 119, 138, plate 7, figs 263 and 265; Lengersdorf (1928 –1930): 56, plate 4, fig. 83 (as Lycoriella (Neosciara) tritici ); Tuomikoski (1960): 133–134; Menzel & Mohrig (2000): 155–156; Menzel et al. (2003): 448, 452, figs 11–22; Mohrig et al. (2013): 162–163; Shin et al. (2015): 1–8.

Material studied. QUEENSLAND: 2 males, hand collection, 4 xii.2013, in PEQ glasshouse with bromeliads, Canvey Road, Ferry Grove, #3A, leg. M. Watts; 3 males, hand collection, 22.x.2014, in greenhouse with tomato and banana plants, Ecosciences Precinct, Dutton Park, #24A, leg. D. Beasley; 1 male, hand collection, 12.xi.2014, in greenhouse with Azaleas, Ixora and Mandevilla plants, Orchard Road, Redland Bay, #39B, leg. A. Manners; 3 males, hand collection, 11.xi.2014, in greenhouse with Euphorbia and African violets, Geldart Road, Chandler, #42A, leg. A. Manners; 4 males, hand collection, 5.ii.2014, in greenhouse with avocado, citrus, hoop pine and passionfruit plants, Ecosciences Precinct, Dutton Park, #43A/43B, leg. A. Manners; 4 males, hand collected, 12.xi.2014, in greenhouse with Calathea and Maranta plants, Serpentine Creek Road, Redland Bay, #44, leg. A. Manners; 3 males, hand collection, 11.xi.2014, in greenhouse with Gahnia , Banksia , Eucalyptus , Lomandra and Acacia plants, Sunnydene Road, Capalaba, #45A, leg. A. Manners; 3 males, hand collection, 16.i.2014, in greenhouse with Cyclamen plants, Wilkes Court, Tinbeerway, #53, leg. A. Manners; 3 males, hand collection, 12.xi.2014, in greenhouse with Anthurium , Hoya and Bougainvillea plants, German Church Road, Redland Bay, #54A, leg. A. Manners; 2 males, hand collection, 17.xii.2013, in PEQ greenhouse with Tradescantia , Ficus, Tabernaemonona , Ixora , Aglaonema , Codiaeum and Costus plants, Mossman, #77 (Bottle 162985), leg. C. Smith (all in PABM).

NEW SOUTH WALES: 1 male, hand collection, 5.xi.2013, in PEQ greenhouse with Yucca gigantea and Sansevieria trifasciata plants, Moores Road, Glenorie, #15, leg. D. Thackeray ( PABM); 2 males, mercury vapour light trap, xi.1978, Wollongbar, ASCT 00053527 & 53528, leg. N. Cartwright; 1 male, 25.xi.1994, Rydalmere, ex BCRI Entomology building, ASCT 00049087, leg. R. George; 1 male, 9.ix.1994, ex E125, BCRI, Rydalmere, ASCT 00054349, leg. D.K. Knihinicki; 1 male, 23.vii.1971, Rydalmere, ASCT 0053515, leg. P.J. Walters; 1 male, mercury vapour light trap, 20.i.1979, Barrington Tops National Park, ASCT 00053537, leg. G.R. Brown; 2 males, 26.vi.1980, Spring Grove near Lismore, ASCT 00053716/ 53717, leg. J. Rand; 1 male, 23.vii.1971, Rydalmere, ASCT 00053736, leg. P. Walters (all in ASCU).

AUSTRALIAN CAPITAL TERRITORY: 2 males, vi.1981, Canberra, infesting CSIRO dung beetle cultures, ASCT00053534/53535, unknown collector; 2 males, 12.iii.1966, Canberra, ex cockroach colonies at ANIC, ASCT00053530/53531, leg. M.J. Mackerras (all in ASCU); 2 males, hand collection, 4.ix.2014, in PEQ glasshouse with cotton plants, CSIRO, Black Mountain, #19B (707B-A1288), leg. L. Apps (PABM).

VICTORIA: 1 male, 18.vii.2014, biosecurity intercept, Melbourne (Bottle 224720), Ficus plants ex China, leg. R. Protacio; 3 males, hand collection and yellow pans, 23.x.2013, in PEQ glasshouses with strawberry, stonefruit and potato plants, Knoxfield, #17A, leg A. Broadley and L. Sullivan; 3 males, hand collection, 8.xi.2013, in PEQ glasshouse with Yucca plants, Heatherton, #18, leg. R. Skipper; 4 males, hand collection, 8.xi.2013, in PEQ glasshouse with Lilium and tulips, Monbulk, #21, leg. R. Skipper; 2 males, yellow pans, 18.xi.2014, in seed houses with various ornamentals at Royal Melbourne Botanic Gardens, #37B, leg. D. Robbins; 2 males, hand collection, 19.vi.2014, in glasshouses with Sansevieria , sage, various herbs and vegetables, Old Dandenong Road, Heatherton, #48A, leg. A. Manners; 3 males, hand collection, 20.vi.2014, in glasshouse with Eucalyptus , Acacia , Correa reflexa, Dianella longifolia and Billardiera scandens plants, Jolimont Road, Forest Hill, #49, leg. A. Manners; 2 males, 9.v.2014, biosecurity intercept, Melbourne (Bottle 227591), Phalaenopsis orchids ex Taiwan, leg. A. Kosmer; 1 male, yellow pan, 18.i.2015, in vegetable garden, Twin River Drive, South Morang, #74A, leg. A. Broadley; 1 male, hand collection, 5.i.2015, in PEQ glasshouse with Clivia plants, Cardigan Road, Mooroolbark (Bottle 246857), #75, leg. R. Skipper (all in PABM).

SOUTH AUSTRALIA: 2 males, hand collection, 22.xi.2013, in PEQ glasshouse with barley plants at Waite Institute (SARDI), #13, leg. N. Luke (PABM).

WESTERN AUSTRALIA: 3 males, hand collection, 25.xi.2013, in PEQ glasshouse 46 with rice, wheat and palm plants, Department of Agriculture and Food, Baron Hay Court, South Perth, #11, leg. J. Cruttenden & S. Boud; 2 males, hand collection, 25.xi.2013, in PEQ glasshouse 45 with barley and wheat plants, Department of Agriculture and Food, Baron Hay Court, South Perth, #12, leg. J. Cruttenden & S. Boud; 3 males, yellow pans, 17.iii.2014, in PEQ glasshouse with Phalaenopsis orchids, Oldbury, #1, leg. J. Cruttenden & S. Boud; 2 males, hand collection, 20.xii.2013, in PEQ glasshouse with Ficus macrophylla , Sansevieria laurentii , Bambusa textilis , Dracaena marginata and Ophiopogon jaburan plants, Safari Place, Carabooda, #7, leg. S. Boud; 4 males, hand collection, 9.xii.2013, in PEQ glasshouse with Phalaenopsis orchids, Oldbury, #10B, leg. J. Cruttenden & S. Boud; 4 males, hand collection, 1.v.2014, in glasshouse with Orthrosanthus laxus plants, Bingham Road, Bullsbrook, #40A, leg. A. Manners; 4 males, hand collection, 1.v.2014, in glasshouse with Grevillea and Gardenia plants, Bahen Road, Hacketts Gully, #41B, leg. A. Manners (all in PABM).

NORTHERN TERRITORY: 1 male, yellow pan trap, 3.ii.2015, propagation shade house with Cucuma, jackfruit and fig plants, Makagon Road, Darwin, #85A, leg. M. Finlay-Doney ( PABM).

TASMANIA: 3 males, hand collection, 31.x.2013, glasshouse with sunflowers in peat mix, New Town Research Labs, #14B, leg. G. Anderson ; 3 males, hand collection, 20.xi.2014, in Glasshouse 3 with Begonia plants, Royal Tasmanian Botanical gardens, Queens Domain, Hobart, #78A, leg. N. Tapson (all in PABM).

Bradysia ocellaris was described from galls contaminated with larvae in a laboratory in Ithaca, New York, USA ( Comstock 1882). It is distributed worldwide and very common in greenhouses but also in pot plants in houses. Moreover, it is known as a pest in commercial mushroom cultures. Larvae were found feeding on decaying sugar cane, pineapple, wheat seedlings and many cultivated crops. Females are monogenic or more often digenic in laboratory rearing (Steffan 1974). The species is phytosaprophagous, mycetophagous and phytophagous. In warmer countries it is common in open landscapes. In temperate climates like in Europe it is a thermophile and lives in southern exposed biotopes and in southern countries.

Diagnostic remarks. The species is well characterized by a yellowish body colour with darker spots on the pleural sclerites (in both sexes), yellowish scape, pedicel and first 2–3 flagellomeres (the basal segments of the antenna are seldomly more or less dark). Flagellomeres have a rough surface and bicoloured necks. The palpi have a deep sensory pit on the basal segment. The gonostylus has an apical tooth and 3(–4) subapical spines, 2 within equally long dense hairs on the apex. The third stands isolated at the end of the distal third of the gonostylus. The tegmen is trapezoidal in shape and has a large area of teeth.

Menzel et al. (2003) examined male specimens collected from Kuranda, near Cairns (Queensland) and reported that B. ocellaris males in the Australian region differ from males in other zoogeographic regions by having longer and narrower flagellomeres (4th flagellomere 3.5–4.0 times width). All of the specimens that we examined had flagellomeres of the normal length (4th flagellomere = 2.2–2.5 times width).

The nomenclature of the species is discussed in Menzel & Mohrig (2000): pp. 155–156 and Mohrig et al. (2013): pp. 167–168. Shin et al. (2015) used mitochondrial cytochrome c oxidase (COI) DNA barcoding and detected interspecific genetic divergence of the COI region within the genus Bradysia . They identified these morphologically as B. ocellaris -like within the B. tilicola species group and concluded that B. ocellaris may comprise a complex of at least three cryptic species. We believe that this needs further investigation and that species closely related to B. ocellaris may exist, but they are unlikely to be morphologically identical to this common greenhouse pest species. It is worth noting here too that Mohrig et al. (2013) erroneously reported that B. ocellaris belongs to the B. tilicola species group. Bradysia ocellaris actually belongs to a group of species, originating from the Eastern Palaearctic or East Asia, which may be related to the B. hilaris group.

Economic importance. Referred to by orchid growers as the “moss fly” in a number of earlier publications. Menzel et al. (2003) reported the species from glasshouses, commercial mushroom houses ( Agaricus blazei , A. brunnescens , A. bitorquis, Auricularia spp., Pleurotus cystidiosus and P. ostreatus ), other dwellings, in gardens on ornamental plants, in deciduous woods and on stream banks in reeds and moss. Larvae were found feeding on the roots and/or stems of campanula, carnations, corn, cucumbers, geraniums, lettuce, nasturtiums, young orchid plants, peas, pineapple, poinsettia, potato tubers, primula seedlings, sugar cane, wheat, and in the soil around cactus plants. The species is very common in greenhouses, palm houses, winter gardens and in pot plants. It is a major mushroom pest in Australia according to Shamshad (2010).

Host plants. We found B. ocellaris in association with the following (listed alphabetically): Acacia , African violets, Aglaonema , Anthurium , avocado, Azaleas, Bambusa , banana, Banksia , barley, Begonia , Billardiera , bromeliads, Bougainvillea , Calathea , citrus, Clivia , Codiaeum , Correa , Costus , cotton, Cucuma, Cyclamen, Dianella , Dracaena , Eucalyptus , Euphorbia , Ficus , fig, Gahnia, Gardenia , Grevillea , herbs, hoop pine, Hoya , Ixora , jackfruit, Lilium , Lomandra , Mandevilla , Maranta , Ophiopogon, Orthrosanthros , palms, passionfruit, Phalaenopsis , potato, rice, sage, Sansevieria , stonefruit, strawberry, sunflowers, Tabernaemonona, tomato, Tradescantia , tulips, wheat, Yucca .

Distribution. Cosmopolitan, common in both hemispheres (Menzel & Mohrig 1991; Menzel & Smith 2009).

Additional notes. 290 of the 775 sciarid adults collected from greenhouses during this study were B. ocellaris (37.4%; 80.3% ♂ and 19.7% ♀), the most frequently encountered sciarid in greenhouses after B. impatiens ( Table 1). The earliest record in the material that we have examined is from 1966, when specimens were collected from live cockroach colonies held at the Australian National Insect Collection (ANIC) in Canberra. In Australia B. ocellaris is present in all mainland states and territories as well as Tasmania.

Figures

FIGURE 3. Bradysia ocellaris (Comstock, 1882). A. Hypopygium. B. Head and thorax. C. Basal segments of antenna. D. Palpus.E. Fore tibia.