Lycoriella ingenua

Lycoriella ingenua (Dufour, 1839)

(Fig. 5 A–E)

Sciara ingenua Dufour, 1839 [Dufour (1839): 29 –31, plate I, figs 20–28].

Common synonyms: Lycoriella caesar (Johannsen, 1929); Lycoriella mali (Fitch, 1856); Lycoriella solani (winnertz, 1871).

= Sciara womersleyi Séguy, 1940 syn. n. [Séguy (1940): 210, fig 6].

we studied 2 females collected from the Kerguelen Islands on 21.xi.1929, deposited in the South Australian Museum, Adelaide (3 slides #29-003430-29003432, marked as syntypes). when compared with European specimens and taking into account the corresponding body size, it is a junior synonym of L. ingenua.

Literature: Fitch (1856): 484 (as Molobrus mali); winnertz (1871): 855 (as Sciara solani); Tuomikoski (1960): 79, 84, figs 18 e, 20 e (as Lycoriella solani); Steffan (1972): 429–431, figs. 1 a–h (both as Lycoriella solani); Steffan (1973a): 357–358; Steffan (1974): 47 (both as Lycoriella mali); Menzel & Mohrig (2000): 393–396; Menzel & Müller (2009): 43–48, figs 1– 5; Mohrig et al. (2013): 211–212.

Material studied. NEW SOUTH WALES: 5 males, 11.v.1978, George’s Hall, Sydney, ex mushroom compact, ASCT00054761 (PWMP) / 54762/54763 (ASCU) / 54765 (PWMP)/54770 (ASCU), leg. A. D. Clift; 1 male, 13.vii.1979, Rydalmere, ex lab culture, ASCT00049035, leg. B.J. Loudon (ASCU); 3 males, 6.xi.1979, Maralya, ex mushroom compost, ASCT00054753/54755/54756, leg. A.D. Clift (ASCU).

TASMANIA: 1 male, 5.v.1984, Devonport, hyacinth bulbs, 7207, 82844, leg. unknown (TAIC).

AUSTRALIAN ANTARCTIC TERRITORY: 5 males, 2004, Casey Station, Waste Water Treatment Depot, leg. S. Richards (PABM).

The species was reared and described from larvae feeding on champignons (Boletus imbricans). It is common in mushroom farms, greenhouses, rotting potatoes and a range of other crops and is common in open landscapes. It is phytosaprophagous and mycetophagous, and also feeds on plasmodia of slime moulds. Females are digenic (Steffan 1973a). The species is reported as common and with stable populations on subantarctic islands and has been reported from Casey Station in the Australian Antarctic Territory after being transported there via human activity (Séguy 1940; Steffan 1974; Hughes et al. 2005).

Diagnostic remarks. The species can easily be identified as belonging to Lycoriella s. str. because of the following characteristics: a horseshoe-shaped border surrounds the tibial organ on the fore tibia, a 3-segmented palpus with a deep and dark sensory pit on the basal segment, a hairy intergonocoxal lobe on the ventral base of the hypopygium, a slender gonostylus with an apical tooth and a different number of spines as well as a long whiplash hair on the inner side. It differs from the other two pest species by having a long gonostylus, evenly pointed toward the apex, and 6–7 short hyaline spines on the inner side.

Economic importance. Recorded from decaying potatoes in the USA (Felt 1898). “Normally feeds on rotting plant tissues and is frequently found in damaged bulbs, slug-eaten celery roots, potato tubers, and on tomato roots affected by brown root rot” although it also damages the roots of azalea and Mesembryanthemum sp. (Hussey et al. 1969). Freeman (1983) stated that “it is common around houses, breeding in decaying potatoes, bulbs, household refuse etc. and can be a damaging pest in mushroom houses.” This species has also been reported damaging mushrooms and cucumbers under glass and table beets in storage in Leningrad province, Russia (Gerbatchevskaya 1963).

Distribution. Holarctic; Hawaii, Subantarctic Islands, Australia, Australian Antarctic Territory (new record).

Additional notes. The first record of this species in the BCRI material is from 1978, so L. ingenua, like L. agraria, appears to be a relatively recent arrival in Australia. We have so far examined material collected from New South Wales and Tasmania. We also examined specimens collected from the waste water treatment depot at Casey Station in the Australian Antarctic Territory. The fly has been present there since 1998 (Hughes et al. 2005). According to Clift & Larsson (1984) and Greenslade & Clift (2004), L. ingenua replaced L. sativae as the major mushroom pest in New South Wales in the mid 1980’s. However, we found during our examination of the BCRI slide collection that L. ingenua was the least common of the three Lycoriella species [L. ingenua: 50 slides (14.5%); L. agraria: 145 slides (42%); L. sativae: 150 slides (43.5%)]. Many specimens that had previously been identified as L. ingenua in the BCRI material were misidentified and were actually L. agraria. Fresh collections of sciarids from mushroom houses should be made to confirm which Lycoriella species are the primary pests of cultivated mushrooms in Australia today.