NOTULAE ENTOMOLOGICAE - Helda

126 NOTUI^AE ENTOMOr.OGICAE XIJII, 19f):{
4. Notes on the dipterous families and species
in the material
Trichoceridae. This family is comparatively richly represented but there is
only a single male specimen (badly damaged by spiders). The Trichocera species
of arctic and subarctic areas are very difficult to identify, especially the females.
In the material there are at least two species of this genus, but I have left the
matter at that. As larvae the Trichocera species live phytosaprophagously in the
soil and can be reckoned with as tychocoenous members of the burrow community
(see further HACKMAN 1963, pp. 29, 35 and 43). Most specimens were
trapped in Kevo during the third week of June (Table 3).
Mycetophilidae (sensu lat.). Probably most, if not all, of the species trapped
must be classed as occasional guests. The fungus gnats are known to seek shelter
from drought in various pits and holes in the ground.
Sciaridae. Among this family important members of the liurrow fauna occur.
The numerous specimens of Corynoptera fulvicollis Tuom. (se p. 128) attract attention,
especially as this species also occurs in burrows in Bonäs and Smaholmen.
The biology of the Corynoptera species is not known in detail. Lycoriella
brevtpila Tuom., L. lundstroemi Frey and Scaptosciara vivida Winn, (all three
reared by me from rodent droppings at Evitskog in 1961) clearly belong to the
tychocoenous elements. Bradysia subalpina Frey and B. peraffinis Tuom. are
northern species and their biology is still unknown. The Sciaridae were kindly
identified by Prof. R. TUOMIKOSKI.
Chironomidae, Simulidae and Psychodidae. The species of these families in the
material are probably all occasional guests in the burrows.
Phoridae. Among the few species in the material only one, Anevrina thoracica
Meig., has been identified as to species. A. thoracica obviously belongs to the
burrow fauna, and is well represented in rodent burrows in Bonäs and on vSnuiholmen.
In Kevo all the specimens captured were males.
The strong dominance of males in the samples and the habits of this species
have been discussed earlier (HACKMAN 1963 p. 42). The species is supposed to ])e
mainly necrophagous but it undoubtedly belongs to the subsoil fauna.
Dryomyzidae. A few specimens of Dryoniyza senilis Zett. and flaveola were
trapped with bait of cheese. These flies can be considered as occasional guests.
Helomyzidae. Very few specimens of this family were caught in traps without
bait. On the other hand, the cheese bait attracted numerous specimens of Neoleria
tibialis (sensu Czerny) and N. inscripta Meig. from outside. Typical subsoil
Helomyzidae, such as Oecothea and Eccoptomera spp., were not found at all.
Piophilidae. Some specimens of Piophila vulgaris were attracted by the cheese
bait.
Borboridae. This family includes the most important species of the burrow
flies found in Kevo. Stratioborbortis fimetarius Meig. is one of the dominant
species in all three types of burrows. The species is mainly coprophagous, occurring
in various habitats but often found in rodent burrows. (H.\CKMAN 1963 p.44).
Copromyza borealis, similis and stercoraria have also previously been recorded
from rodent burrows (HACKMAN, op.cit., RICHARDS 1930). Crumomyia rufoanntilata
Duda needs a special comment. DUDA (1935) described Crumotnyia glacialis var.
rufoanntilata from Kamtchatka. The description agrees in every detail with an