Bradysia impatiens ( Johannsen, 1912 )

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 : 205-209

Bradysia impatiens ( Johannsen, 1912)

( Figs 1 A–E , 2 A–C )

Sciara impatiens Johannsen, 1912 [ Johannsen (1912): 136, figs 137, 252]. Common synonyms: Bradysia difformis ( Frey, 1948) ; Bradysia paupera Tuomikoski, 1960 ; Bradysia agrestis Sasakawa, 1978 .

Literature: Frey (1948): 61, 83, fig. 98 (as Bradysia (Chaetosciara) tristicula var. difformis ); Tuomikoski (1960): 130, 134, figs 28 c, 31 l, 32 b (as Bradysia paupera ); Steffan (1973a): 355; Steffan (1974): 43–44; Kühne et al. (1994): 34–45, figs 26–41 (as Bradysia paupera ); Menzel & Mohrig (2000): 146, figs 129–131; Menzel et al. (2003): 449, figs 1–10 (both as Bradysia difformis ); Mohrig et al. (2013): 162–163.

Material studied. QUEENSLAND: 2 males, hand collection, 4.xii. 2013, in PEQ greenhouse with bromeliads, Canvey Road, Ferry Grove, #3B, leg. M. Watts; 3 males, hand collection, 22.x.2014, in greenhouse with tomato and banana plants, Ecosciences Precinct, Dutton Park, #24B, leg. D. Beasley; 8 males, hand collection, 11.xi.2014, Geldart Road, Chandler, in greenhouses with Selaginella , Hydrangea , Euphorbia , Sutera cordata , Fittonia , African violets, #38 & 42B, leg. A. Manners; 4 males, hand collection, 12.xi.2014, in greenhouse with Azalea, Ixora , Mandevilla plants, Orchard Road, Redland Bay, #39A, leg. A. Manners; 3 males, 11.xi.2014, in greenhouse with Gahnia , Banksia , Eucalyptus , Lomandra and Acacia, Sunnydene Road, Capalba , #45B, leg. A. Manners; 3 males, hand collection, 11.xi.2014, in greenhouse with Gerbera , Eustoma , passionfruit and Chrysanthemum, Dundas Street, Ormiston , #46, leg. A. Manners; 2 males, hand collection, 5.ii.2014, in greenhouse with avocado, citrus, hoop pine and passionfruit plants, Ecosciences Precinct, Dutton Park, #43B, leg. A. Manners; 3 males, 11.xi.2014, in greenhouse with Liriope, Hardenbergia , Lophostemon , Eustrephus and Schoenoplectus plants, New Cleveland Road, Gumdale, #50, leg. A. Manners; 2 males, 12.xi.2014, hand collection, in greenhouse with Banksia , Hymenocallis , Harpullia , Dracaena and Lomandra plants, Mt Cotton Road, Burbank, #52, leg. A. Manners; 2 males, 12.xi.2014, hand collection, in greenhouse with Anthurium , Hoya and Bougainvillea plants, German Church Road, Redland Bay, #54B, leg. A. Manners; 1 male, 12.xi.2014, hand collection, in greenhouse with Callistemon , Grevillea , Westringia and Agapanthus plants, Worthing Road, Victoria Point, #55, leg. A. Manners; 3 males, hand collection, 16.i.2015, in greenhouse with Mentha requienii plants, Burow Road, Waterford West, #79, leg. A. Manners.

NEW SOUTH WALES: 2 males, 22.ii.2008, Sydney, biosecurity intercept (Bottle 130465), Pelargonium plants ex Ethiopia, leg. C. Gillian; 2 males, 11.vi.2009, Sydney, biosecurity intercept (Bottle 140909), Euphorbia plants ex Germany, leg. E. Nikolic; 2 males, 22.iii.2010, Sydney, biosecurity intercept (Bottle 159764), Hemerocallis plants ex USA, leg. M. Coleman; 1 male, 27.xi.2007, Sydney, biosecurity intercept (Bottle 81011), decaying Plumeria plant ex USA, leg. D. Mercado-Escueta; 3 males, 22.x.2013, Sydney, biosecurity intercept (Bottle 205856), Stachys byzantina plants ex Netherlands, leg. M. Brinkworth (all in PABM); 2 males, 13.i.1978, Rydalmere, ex lab culture, ASCT 00053399-53400, leg. A.D. Clift; 1 male, 23.v.1978, Parramatta, ASCT 00053414, “in numbers around compost outside mushroom farm”, leg. A.D. Clift; 2 males, 6.vi.1978, Alstonville, ASCT 00053412 & ASCT 00053413, “pot plants”, leg. B.J. Loudon; 1 male, xii.1979, Port Macquarie, Branch’s Nursery, ASCT 00053411, “larvae attacking Maidenhair fern roots”, unknown collector; 3 males, 21.iv.1980, Yanco, ASCT 00054860/ 54848/ 54844, “attacking Lucerne seedlings in glasshouse”, unknown collector; 4 males, 17.v.1977, Rydalmere, ASCT 00054850/54853/54857/54859, “in pot plant”, unknown collector (all in ASCU); 3 males, 4.iii.2014, PEQ greenhouse with cacti and succulents, Cowlong Road, Mcleans Ridge, #8, leg. V. Brake and C. Marston; 2 males, 8.xi.2013, PEQ glasshouse with gerberas, Doyalson North, #23, leg. P. Jennings; 1 male, 17.vi.2008, Sydney, biosecurity intercept (Bottle 131174), bromeliad plants ex Netherlands, leg. C. Gillian (all in PABM); 1 male, 13.i.1978, ex lab culture, Rydalmere, ASCT 00054866, leg. A.D. Clift ( ASCU); 3 males, 17.vi.2014, hand collection, in greenhouse with Leucanthemum, Clivea , lavender, Agapanthus , Buddleia , passionfruit and daisy, Arcadia Road, Arcadia, #51, leg. A. Manners ( PABM).

AUSTRALIAN CAPITAL TERRITORY: 3 males, v.1981, Canberra, CSIRO, ASCT00053406/ 53407/ 53409, “ex pot plants”, leg. D.H. Colless; 2 males, 8.v.1963, Canberra, ASCT00053408/54863, “ex pots, plants & gardens”, leg. D.H. Colless; 3 males, ix.1968, Canberra, CSIRO Black Mountain, ASCT00053404/53405/54862, “seedlings in glasshouse pots”, leg. D. Johns (all in ASCU); 3 males, hand collection, 6.xii. 2013, Canberra, CSIRO, Black Mountain, #2, PEQ rearing room for dung beetles, leg. P. Gleeson and B. Boyd; 1 male, 4.xi.2014, in PEQ glasshouse with cotton, CSIRO Black Mountain, #19A, leg. L. Apps (all in PABM).

VICTORIA: 1 male, 25.ix.2014, biosecurity intercept, Melbourne (Bottle 237624), Dracaena plants ex China, leg. M. Mazumder; 3 males, 12.ii.2014, biosecurity intercept, Melbourne (Bottle 224519), Dracaena plants ex China, leg. V. Garzarella & A. Czelusta; 2 males, 1.xii.2014, biosecurity intercept, Melbourne (Bottle 224666), Phalaenopsis plants ex Taiwan, leg. E. Weeks; 1 male, 12.iii.2014, biosecurity intercept, Melbourne (Bottle 226093), Phalaenopsis plants ex Taiwan, leg. S. James; 3 males, 10.xi.2014, biosecurity intercept, Melbourne (Bottle 246278), Phalaenopsis plants ex Taiwan, leg. V. Garzarella & A. Czelusta; 4 males, 21.vii.2014, biosecurity intercept, Melbourne (Bottle 224721), Phalaenopsis plants ex Taiwan, leg. R. Protacio; 2 males, 20.x.2014, biosecurity intercept, Melbourne (Bottle 246906), Phalaenopsis plants ex Taiwan, leg. W. Houston; 3 males, 9.v.2014, biosecurity intercept, Melbourne (Bottle 227591), Phalaenopsis orchids ex Taiwan, leg. A. Kosmer; 2 males, 5.i.2015, biosecurity intercept, Melbourne (Bottle 246858), Phalaenopsis orchids ex Taiwan, #56, leg. T. Lee & R. Skipper; 1 male, 10.xi.2014, biosecurity intercept, Melbourne, (Bottle 246278), Phalaenopsis plants ex Taiwan, leg. V. Gazarella & A. Czelusta (all in PABM); 1 male, xi.2015, yellow pan trap in vegetable garden, Twin River Drive, South Morang, # 86, leg. A. Broadley (PWMP); 3 males, 5.xii.2013, hand collection, in PEQ greenhouse, Keysborough, #9, leg. R. Skipper; 3 males, 23.x.2013, hand collection, in PEQ glasshouses with strawberry, stonefruit and potato plants, Knoxfield, #17B, leg. A. Broadley and L. Sullivan; 1 male, 21.x.2014, hand collection, in PEQ glasshouse with Iris, Lilydale , #20, leg. R. Skipper; 2 males, 30.x.2013, hand collection, in PEQ glasshouse with Ficus , Tillandsia , Sansevieria , Dracaena and bromeliads, Heatherton Road, Narre Warren, #22, leg. R. Skipper (all in PABM); 3 males, hand collection, 4.ix.2001, Somerville, emerged from potting mix under flax plants, #26 (VAIC73176), leg. M. Malipatil (VAIC); 2 males, 1.vi.1999, Officer, Victoria, on decaying roots of cuttings, hand collection, #29 (VAIC73181), unknown collector (VAIC); 4 males, 18.xi.2014, yellow pans in seed houses, Royal Melbourne Botanic Gardens, #37A, leg. D. Robbins; 3 males, 19.vi.2014, hand collection, in greenhouse with Impatiens, Fuchsia , Cyclamen , parsley, tomato and basil plants, Perry Road, Keysborough, #47, leg. A. Manners; 2 males, 19.vi.2014, hand collection, in greenhouse with Sansevieria , sage, various herbs and vegetables, Old Dandenong Road, Heatherton, #48B, leg. A. Manners (all in PABM).

SOUTH AUSTRALIA: 3 males, hand collection, 22.xi.2013, Waite Institute (SARDI), in glasshouse with cabbage, #6, leg. N. Luke (PABM).

WESTERN AUSTRALIA: 3 males, hand collection, 9.xii.2013, in PEQ greenhouse with Phalaenopsis orchids, Oldbury, #10A, leg. J. Cruttenden and S . Boud ; 1 male, hand collection, 1.v.2014, in greenhouse with Orthrosanthus laxus, Bingham Road, Bullsbrook , #40B, leg. A. Manners ; 3 males, hand collection, 1.v.2014, in greenhouse with Grevillea and Gardenia plants, Bahen Road, Hacketts Gully, #41A, leg. A. Manners; 4 males, hand collection, 26.vii.2012, infesting Chia stems, Kununurra, #76 (LH1098), leg. L. Halling (all in PABM).

NORTHERN TERRITORY: 1 male, yellow pan, 3.ii.2015, in propagation shade house with Curcuma , jackfruit and figs, Makagon Road, Darwin, #85B, leg. M. Finlay-Doney ( PABM).

TASMANIA: 3 males, hand collection, 31.x.2013, in glasshouse with sunflowers in peat mix, New Town Research Labs, #14A, leg. G. Anderson ; 2 males, yellow pan in glasshouse with Hebe and barley, 4.xi.2013, Westbury Road, Prospect, #4, leg. G. Westmore; 1 male, 30.x.2013, Tasmania, Kingston, glasshouse with Peony roses, barley, #16, hand collection, leg. J. Davies and G. Anderson ; 2 males, 20.xi.2014, hand collection, in Glasshouse 3 with Begonia plants, Royal Tasmanian Botanical Gardens, Queens Domain, Hobart, #78B, leg. N. Tapson (all in PABM).

NORFOLK ISLAND: 6 males, hand collection, 1.xii.2014, on plant pots in shade house, #30 ( RAB013 ), leg. A. Broadley ; 4 males, yellow pans, 1.xii.2014, in shade house with native plants, #31 (RAB005a), leg. A. Broadley (all in ANIC).

Form B: 2 males, 30.x.2013, Tasmania, Kingston, glasshouse with Peony roses, barley, hand collection, #16, leg. J. Davies and G. Anderson (PWMP); 1 male, 4.xi.2013, Tasmania, glasshouse with Hebe , barley, yellow pan, #4, leg. G. Westmore (TAIC); 2 males, 21.x.2014, Lilydale, Victoria, in PEQ greenhouse with Iris plants (Bottle 246807), #20, leg. R. Skipper (PABM); 1 male, 1.vi.1999, Victoria, Officer, on decaying roots of cuttings, hand collection, leg. unknown (VAIC); 1 male, Victoria, Twin River Drive, South Morang, #86, xi. 2015, yellow pan trap in vegetable garden, leg. A. Broadley (PABM); 1 male, 19.vi.2014, hand collection, in greenhouse with Sansevieria , sage, various herbs and vegetables, Victoria, Old Dandenong Road, Heatherton, #48B, leg. A. Manners (PABM); 1 male, 4.xi.2014, in PEQ glasshouse with cotton, CSIRO, Australian Capital Territory, Black Mountain, #19A, leg. L. Apps (PABM); 1 male, 22.ii.2008, New South Wales, Sydney, biosecurity intercept (Bottle 130465), in consignment of Pelargonium plants ex Ethiopia, leg. C. Gillian (PABM).

Bradysia impatiens was described after it was bred from larvae, found in soil adhering to roots of an Impatiens species, in Tompkins Co., Ithaca, USA ( Johannsen 1912). It is cosmopolitan in distribution and common in greenhouses and plant nurseries. The larvae feed on roots of different crops such as cucumbers, soybeans, peas, beans, lettuce, etc. The species is found in open landscapes as well. The larvae are phytophagous, phytosaprophagous and perhaps mycetophagous, living in rotting plant material in the soil, in compost and in mouse holes. The species belongs to the Bradysia tilicola species group (Menzel & Mohrig 2000).

Diagnostic remarks. The species is characterized by a deep sensory pit on the basal palp segment, very short and uniform brown flagellomeres (l/w index of nearly 1.0), and a rather compact gonostylus with a short claw-like apical tooth amongst 6–8 dense subapical spines. The gonostylus is sometimes slender (form B) and the flagellomeres vary between l/w indexes of 1.0–1.4 [this variability was reported by Steffan (1974) as well].

Economic importance. Bradysia impatiens is an important pest of a variety of crops in protected environments such as greenhouses. Mushrooms may be attacked as well. Harris et al. (1996) conducted a literature review of the crop plants that have been reported as being damaged by this species: Christmas cactus, marigolds, peperomia, pine, alfalfa, bean, carrot and cucumber. It has also been reported damaging Agaricus blazei and A. bisporus mushrooms in Brazil (Menzel et al. 2003), edible fungi in China (Shen 2009), potted lily and cucumbers in greenhouses in Japan (Sasakawa and Akamatsu, 1978) and Phalaenopsis orchid seedlings in greenhouses in Guangdong, China ( Han et al. 2015). Menzel et al. (2003) reported larvae on the stems and roots of young Saintpaulia , Antirrhinum spp., beans, Schlumbergera , carnations, chrysanthemums, pelargonia, cucumbers, cyclamen , freesias, geraniums, hydrangea , lettuce, lilies, lucerne, lupins, maize, melon, peas, poinsettia, potatoes, strawberries and sugarbeet. They also noted the species on moorland, waste ground, in deciduous and coniferous forests, and in gardens.

Host plants. We found B. impatiens in association with the following (listed alphabetically): Acacia , African violets, Agapanthus , Anthurium , avocado, Azalea, banana, Banksia , barley, basil, Begonia , bromeliads, Bougainvillea , Buddleia , cabbage, cacti, Callistemon, Chia , Chrysanthemum , citrus, Clivea, cotton, Curcuma , Cyclamen , daisy, Dracaena , Eucalyptus , Euphorbia , Eustoma , Eustrephus , Ficus , figs, Fittonia , flax, Fuchsia , Gahnia, Gardenia , Gerbera , Grevillea , Hardenbergia , Harpullia , Hebe , Hemerocallis , hoop pine, Hoya , Hydrangea , Hymenocallis, Impatiens , Iris , Ixora , jackfruit, lavender, Leucanthemum, Liriope , Lomandra , Lophostemon, Lucerne seedlings, Maidenhair fern, Mandevilla , Mentha , Orthrosanthus , parsley, passionfruit, Pelargonium, Peony roses, Phalaenopsis , Plumeria , potato, sage, Sansevieria , Schoenoplectus , Selaginella , Stachys , stonefruit, strawberry, succulents, sunflowers, Sutera , Tillandsia , tomato, various herbs and vegetables, Westringia .

Distribution. Worldwide in nurseries and greenhouses and often in open landscapes too. The species is documented in the Holarctic from Japan in the East to California in the West. It is less reported from the Southern hemisphere, since the sciarid fauna is poorly studied there in general. In Hawaii and Australia it is known from greenhouses, gardens and open landscapes.

Additional notes. The earliest Australian record in the material that we have examined is from 1963, when B. impatiens was collected from “pots, plants and gardens” in Canberra. However it is likely to have been present in Australia for many years prior to this. Bradysia impatiens is the most frequently encountered sciarid in Australian greenhouses and it is also widespread, being found in all states and territories, as well as on Norfolk Island ( Anon 2015). Of the 775 sciarid adults collected from greenhouses during this study, 485 (62.6%) were B. impatiens (85.4% ♂, 14.6% ♀) ( Table 1).

Figures

FIGURE 2. Bradysia impatiens (Johannsen, 1912). Form B. (specimen from Kingston, Tasmania, glasshouse). A. Hypopygium.B. Gonostylus.C. Flagellomeres 3–4.

FIGURE1. Bradysiaimpatiens (Johannsen,1912).Form A (typical pestspecimen).A. Hypopygium.B.Flagellomeres 3–5. C. Palpus.D. Fore tibia.E. wing.