Bradysia Difformis Frey and Bradysia Ocellaris (Comstock): Two
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SYSTEMATICS Bradysia difformis Frey and Bradysia ocellaris (Comstock): Two Additional Neotropical Species of Black Fungus Gnats (Diptera: Sciaridae) of Economic Importance: A Redescription and Review 1 2 FRANK MENZEL, JANE E. SMITH, AND NELSON B. COLAUTO Deutsches Entomologisches Institut, ZALF e.V., PF 100238, D-16202 Eberswalde, Germany Ann. Entomol. Soc. Am. 96(4): 448Ð457 (2003) ABSTRACT The Þrst records for Brazil of two sciarid species, Bradysia difformis Frey, 1948 [ϭ paupera (Tuomikoski, 1960)] and Bradysia ocellaris (Comstock, 1882) [ϭ tritici (Coquillett, 1895)] (Diptera, Sciaridae) are presented. These are the Þrst records of these species for the Neotropical region. Males and females of both species are fully described and illustrated. Information is given about synonymy and the location of the type material. Bradysia agrestis Sasakawa, 1978 is a new synonym of Bradysia difformis. Information about the zoogeographic distribution and habitats, of Bradysia difformis and Bradysia ocellaris is provided. KEY WORDS Diptera, sciaridae, Bradysia difformis Frey, Bradysia ocellaris (Comstock), descrip- tions, new synonym, new records, mushroom pests THE DIPTEROUS FAMILY SCIARIDAE (Black Fungus Gnats) signiÞcant losses in crop production (Menzel and is found on every continent and is characterized by its Mohrig 2000). high number of species and individuals. According to Some species belonging to Bradysia Winnertz, a species inventory by Menzel and Mohrig (2000), 1867 s. l. [species group of the Bradysia amoena (Win- Ͼ1,700 valid species have been described in the world. nertz, 1867) species group], and Lycoriella Frey, 1948 Despite their ecological importance, these micro- s. str. are common pests in mushroom cultures and in Diptera have largely been neglected because of their glasshouses (Binns 1976; Menzel and Mohrig 2000; small body size (1Ð7 mm), their often cryptic mode of White et al. 1996, 2000). In Europe, Bradysia difformis life and the difÞculties involved with their identiÞca- Frey, 1948 and Bradysia ocellaris (Comstock, 1882) tion. are common and serious economic pests of glasshouse The larvae of the Black Fungus Gnats live in rotting crops, but are less commonly found in association with organic matter (humus) in the soil, under the bark of the cultivation of the mushroom Agaricus bisporus decaying trees, on the mycelium or in the fruiting Lange (Imbach) (Agaricaceae), in which two Lyco- bodies of fungi, or they mine in the stems and leaves riella species [L. castanescens (Lengersdorf, 1940) and of herbaceous plants. A sample of 1 m2 of substrate can L. ingenua (Dufour, 1839)] are the main problem. produce up to 2,600 larvae in soil from open country- However, the specimens described in this work were side and 200,000 larvae of a single species in mushroom collected from a mushroom farm in Brazil, in which compost (Deleporte and Rouland 1991). Plant roots there was a serious sciarid infestation, but the mush- have commonly produced larval densities of 20Ð80 room being cultivated was Agaricus blazei Murr. individuals per plant and the stems from 220 to 830 In addition to observations about the area and cul- individuals (Gerbachevskaja 1963). Under optimal tivation practices on the farm in which the ßies were conditions, there can be up to nine generations in the found, the two species of sciarid are redescribed and yearÑmore in protected environments such as glass- illustrated in this study, and a detailed literature re- houses or mushroom tunnels (Osmola 1970). Mass view is provided. occurrences are not uncommon and can cause exten- sive damage in forestry and agriculture, leading to Materials and Methods Bradysia difformis and Bradysia ocellaris are named according to the new nomenclature and systematics 1 Horticulture Research International, Wellesbourne, Warwick CV35 9EF, England, UK (e-mail: [email protected]). by Menzel and Mohrig (2000) and are new records for 2 Universidade Paranaense, IPEAC, Pc¸a Mascarenhas de Moraes, the Neotropics. The descriptions given in this study s/n, 87.502-210 Umuarama-PR-Brazil, Brazil. are based on an examination of 418 specimens from 0013-8746/03/0448Ð0457$04.00/0 ᭧ 2003Entomological Society of America July 2003M ENZEL ET AL.: B. difformis AND B. ocellaris: NEW RECORDS FOR THE NEOTROPICS 449 many localities in the Afrotropical, Australasian, Observations Palaearctic, Nearctic, Neotropical and Oriental re- The sciarid infestation was found in a cultivated gions. Of these, 313 were Bradysia difformis and 105 mushroom crop (Agaricus blazei) in Botucatu, Sa˜o Bradysia ocellaris. Paulo State, Brazil, during February and March 2000. In addition, 30 type specimens were reassessed, Botucatu is 400 km from the coast and lies on latitude and of these 21 were identiÞed as Bradysia difformis 22Њ 51ЈS and longitude 48Њ 26ЈW, is situated on low- and9asBradysia ocellaris. These included the type lying hills at an average height of 786 m above sea level, specimens of Bradysia agrestis Sasakawa (7 males and and has an average annual temperature of 17ЊC. Ac- 1 female), Bradysia tristicula variety difformis Frey (1 cording to the Csa-Ko¨ppen classiÞcation (Triantafyl- male), Bradysia paupera Tuomikoski (12 males), Ly- lou and Tsonis 1994), the area is in a humid, temperate coria prothalliorum De Meijere (5 males and 2 fe- zone and is generally windy. males) and Bradysia rubicundula Frey (2 males). In- A. blazei is commonly known in Brazil as the formation about the synonyms is given in the Cogumelo-do-sol, Cogumelo-da-vida, or JUN-17, and discussion of each species. The following abbrevia- abroad as the sun mushroom or Brazilian mushroom. tions are used for the museums in which the type The crop was grown in plastic boxes about 30 cm ϫ 60 specimens and other material are located: cm ϫ 25 cm (w ϫ l ϫ h) in a converted ship container. BPBM, B. P. Bishop Museum, Honolulu, HI (material Compost production was similar to that used for grow- from Thailand; loan via Dr. N. L. Evenhuis). ing A. bisporus, with two composting phases, the sec- CUIC, Cornell University, Department of Entomol- ond being a pasteurization phase. The compost com- ogy, Ithaca, NY, U.S.A. (type material of Sciara ocel- position was 45% Coast-cross straw [cultivar Cynodon laris from United States; loan and information via dactylon (L.) Pers. (Poaceae), a grass used for cattle Prof. Dr. J. Liebherr and Prof. Dr. W. Mohrig). feed in Brazil and the United States], 40% sugar cane DEI, Deutsches Entomologisches Institut, ZALF e.V., bagasse, 3% gypsum, 10% soybean bran (small frag- Eberswalde, Germany (including private collection ments of the grains) and 2% urea and ammonium F. Menzel; material from Australia, Brazil, Europe, sulfate. Pasteurized Brazilian peat was used for the Indonesia, Japan, Taiwan, and Zimbabwe). casing layer (Braga et al. 1998). The average temperature in the growing chambers HRI, Horticulture Research International, Welles- Њ Њ bourne, Warwick, England, U.K. (material from was 25 C (range, 19Ð28 C) with a relative humidity of 70% during the production phase. The concentration Brazil, Europe, and Indonesia). of carbon dioxide in the air was maintained at 200 ppm KPUK, Faculty of Agriculture, Laboratory of Ento- during cropping. Before casing, the compost was col- mology, Kyoto Prefectural University, Kyoto, Japan onized completely with mushroom mycelium, was (type material of B. agrestis from Japan; loan via sweet smelling, and there were no signs of larvae. Prof. Dr. M. Sasakawa). However, the spawn-running period was longer than PWMG, private collection W. Mohrig, Greifswald, usual because of technical problems. Germany (material from Australia, Ecuador, Eu- Throughout the cropping period, electric ßy traps rope, United States, and Zimbabwe; loan via Prof. caught thousands of adult ßies, and larvae were found Dr. W. Mohrig). in the compost. The larvae reached such high numbers SMTD, Staatliches Museum fu¨ r Tierkunde, Dresden, that the compost became badly contaminated with Germany (material from Europe; loan via U. Kall- larval frass and started to smell unpleasant. In parts, weit). the mushroom mycelium was either totally destroyed UZMH, Finnish Museum of Natural History, Univer- by the larvae or was unable to recolonize the con- sity of Helsinki, Finland (type material of B. pau- taminated compost. Consequently, there was a high pera, Bradysia rubicundula, and Bradysia tristicula crop loss and some of the fruit bodies were found to var. difformis from Finland; loan via Dr. P. Vilka- be infested with ßy larvae. A sample of the ßies was maa). collected and preserved in 70% alcohol. Two species ZFMK, Zoologisches Forschungsinstitut und Museum of Bradysia were found in the sample, B. difformis and Alexander Koenig, Bonn, Germany (material from B. ocellaris. The majority of the ßies within the sample Europe; loan via Dr. H. Ulrich). were found to be B. difformis (91 examples), and only ZMAN, Instituut voor Systematiek en Populatiebiolo- four specimens were identiÞed as B. ocellaris. This is gie, Zoo¨logisch Museum, Universiteit van Amster- the Þrst record of these species being found in Brazil dam, The Netherlands (type material of Lycoria and on the cultivated mushroom, A. blazei. prothalliorum from The Netherlands; loan via B. Brugge). Notes on the Species Adults were prepared following the method described by Menzel and Mohrig (2000). For scientiÞc exam- Bradysia difformis Frey, 1948 (Figs. 1Ð10) ination, permanent slides were Þrst made using Type Material. LECTOTYPE (male) in UZMH col- Canada balsam as the mountant. Examination of the lection [designated by Menzel (Menzel and Mohrig ßies and illustration of the morphological structures 2000)]. were done using a light microscope with a magni- Synonyms. Bradysia paupera Tuomikoski, 1960 Þcation of up to 1,875 times. [LECTOTYPE and PARALECTOTYPES in UZMH 450 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 96, no. 4 Fig. 1–8. B. difformis Frey. (1) Hypopygium, male, ventral view. (2) Tergite IX, male. (3) Apex of fore tibia, male. (4) Apical part of gonostyle, male, ventral view.