First records of Helina pulchella (Ringdahl) (Diptera, Muscidae) from Finland and notes on the biology of the species

Abstract

Helina pulchella (Ringdahl, 1918) is reported from Finland for the first time. One male specimen was reared by JP from a pheasant wing in north Karelia and a second male was collected by active netting in the Inari Lapland. As these locations are almost 1000 km apart, the species is likely to be widespread, but scarce in Finland.

Full text

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Dipterists Digest 2019 26, 111-115
First records of Helina pulchella (Ringdahl) (Diptera, Muscidae)
from Finland and notes on the biology of the species
JAAKKO POHJOISMÄKI
*
and ANTTI HAARTO
§
*University of Eastern Finland, 80130 Joensuu, Finland; jaakko.pohjoismaki@uef.fi
§Zoological Museum, Biodiversity Unit, University of Turku, FI-20014 Turku, Finland;
ahaarto@gmail.com
Summary
Helina pulchella (Ringdahl, 1918) is reported from Finland for the first time. One male specimen was reared by JP
from a pheasant wing in north Karelia and a second male was collected by active netting in the Inari Lapland. As
these locations are almost 1000 km apart, the species is likely to be widespread, but scarce in Finland.
Introduction
Helina pulchella (Ringdahl, 1918) (Fig. 1) is a medium-sized (~6 mm) species with partly yellow
legs, bare eyes, 2+4 dorsocentral setae, 4 rows of short presutural acrostichal setulae, 0+1
acrostichal setae, 1+2 katepisternal setae, radio-cubital node dorsally and ventrally bare, narrow
frons in males (0.25x width of an eye), arista short pubescent, bases of the postpedicel and pedicel
yellow, and yellow palpi darkened only in the apical part (Hennig 1958: 211-212).
Helina species are difficult to identify and the available keys do not capture all of the
variation seen in the specimens. This became apparent when the authors tried to identify an
unknown specimen, reared by JP. Using the key in Gregor et al. (2002) the result was either
Helina balsaci (Séguy, 1946) or H. pulchella. Both species would have been new to the Finnish
fauna. When the specimen was compared against the descriptions in Hennig (1958: 211-212), it
proved to be almost a perfect match for H. pulchella apart from the dark fore femora. However,
both Ringdahl (1918: 149) and d'Assis-Fonseca (1968: 52) stated that the fore femora are almost
entirely black.
The species was described by Ringdahl (1918: 149) based on a male specimen from
Abisko, Swedish Lapland. In the original description, Ringdahl placed H. pulchella in Mydaea,
but later transferred it to the recently defined Helina (Ringdahl 1924: 61). The female was
described by Ackland (1961) based on British specimens. Prior to the Finnish records, Helina
pulchella had been reported from Britain and there are apparently unpublished records from
Norway, Austria, Czech Republic, Spanish mainland and European Russia (Pont 2004). In
Britain H. pulchella is listed as provisionally Near Threatened (Falk and Pont 2017).
Considering the known localities in northern Sweden (Ringdahl 1918, Engelmark and
Engelmark 1989), finding the species from neighbouring Finland is no surprise. It is perhaps
more interesting that the species is known from several locations in England (Smith 1961,
Ackland 1965, Pont 1990, Jones and Perry 2019), which as habitats are quite contrasting to those
in Nordic countries.
Finnish records
The records here are given in the standard format for Finnish zoological specimens. Additional
explanations and notes are provided in brackets. The abbreviations for locations refer to the
geographical provinces (see https://laji.fi/theme/emk) and coordinates on the labels are given in
the old national Finnish coordinate system (YKJ; see Ollikainen and Ollikainen 2004); both are
still in use for biological sampling.

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1♂: Kb [Karelia borealis or North Karelia], Liperi, Hovattavaara, 6947455:3626464
[N62.620565°, E29.473213°], ex larva 2017, J. Pohjoismäki leg. Specimen is deposited in the
research collection of AH.
1♂: Li [Lapponia Inarensis or Inari Lapland], Utsjoki, Ravdaskaidi, 77109:35056 [N69.4777°,
E27.1402°], July 1–4 2017, E. Rundgren leg. Specimen is deposited in the research collection of
Iiro Kakko.
Fig. 1. Helina pulchella male, Kb: Liperi, Hovattavaara, 6947455:3626464, ex larva 2017, J.
Pohjoismäki leg: A, habitus; B, oblique dorsal view of the head; C, cerci.

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Fig. 2. Helina pulchella distribution in Finland: A, the collection locations of the Finnish
specimens mentioned in the text; B, an overview of the Hovattavaara habitat. The location
is dominated by low-growth heather, bordered by mixed woods of Scots pine (Pinus
sylvestris), birch (Betula spp.) and aspen (Populus tremula); C, open sand where the bird
wing was placed. Flowers include maiden pink (Dianthus deltoides) and Breckland thyme
(Thymus serpyllum); D, rich flora at the scene, including yellow Oxytropis (Oxytropis
campestris), field scabious (Knautia arvensis) and ox-eye daisy (Leucanthemum vulgare).
Description of the biotopes and some notes on the species’ biology
Up until now H. pulchella has only been recorded from two locations in Finland. The
Hovattavaara location is a xerothermic roadside (Fig. 2), characterised by heather (Calluna
vulgaris) and a rich assemblage of herbage growing on sandy soil. The flowering plants include

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specialised species such as mountain everlasting Antennaria dioica, field scabious Knautia
arvensis, Breckland thyme Thymus serpyllum and yellow Oxytropis campestris.
Consequently, Hovattavaara is a refuge for a number of lepidopteran species associated
with these plants, including Nemophora metallica (Poda) (Adelidae), Scrobipalpa artemisiella
(Treitschke) (Gelechiidae), Hemaris tityus (Linnaeus) (Sphingidae) and Cupido minimus
(Fuessly) (Lycaenidae).
The fly fauna is characterised by species such as Systoechus ctenopterus
(Mikan) (Bombyliidae), Paragus constrictus Šimic (Syrphidae), Prosena siberita (Fabricius)
(Tachinidae) and Demoticus plebejus (Fallén) (Tachinidae). In addition, the rare woodland
species Temnostoma sericomyiaeforme (Portschinsky) and Brachyopa panzeri Goffe (both
Syrphidae) have been recorded from the location.
In contrast, the Ravdaskaidi location is a typical fell landscape with alternating heathland,
mires and downy birch (Betula pubescens ssp. czerepanovii (N. I. Orlova)) woods, very similar
to the habitat described for H. pulchella in Engelmark and Engelmark (1989). The male specimen
was collected by a hand net between 1 and 4 July 2017 and determined by AH based on the
Hovattavaara specimen. The exact date is unknown as the specimen was collected during a longer
field trip to the area.
The discovery of H. pulchella from Hovattavaara was somewhat accidental. JP has some
interest in the cadaveric entomofauna (Pohjoismäki et al. 2010) and had in mind to try to find rare
saprophagous Tineidae (Lepidoptera) by placing the wing of a pheasant (Phasianus colchicus
Linnaeus) on open sand on June 20, 2016. The wing was secured with a wire net to prevent
interference from scavengers and was collected in at first snow on November 3, 2016. The wing
was left to overwinter in an unheated garage and was exposed to frost, down to -10°C for several
days. The wing was taken in on January 22, 2017 and the male H. pulchella emerged two weeks
later. The only other insects emerging from the wing were 12 exx. Allopiophila vulgaris (Fallén)
and 2 exx. Stearibia nigriceps (Meigen) (both Diptera, Piophilidae).
In Britain, H. pulchella has been reared from the nest box of a tawny owl (Strix aluco
Linnaeus) (Smith 1961). Owl nests are typically littered by prey remains and probably offer a
similar substrate as a feathered wing, from which the first Finnish specimen was reared. Helina
pulchella does not obviously have a strict habitat requirement, ranging from oak-ash-sycamore
woods, parkland and a suburban garden in England, to montane heathland in Finnish and Swedish
Lapland. Also, the recorded microhabitats, an owl box 15 feet (4.6 m) above ground on an old
oak tree and an exposed feathered wing on open sand in sunlit xerothermic environment, are
highly different. It is possible that the species is specialised on dry animal remains but can be
otherwise opportunistic with its habitat preference. As other Helina species larvae are known to
be predatory (Gregor et al. 2002), it is likely that H. pulchella is also a predator of other
invertebrates, such as Piophilidae larvae living in the same substrate.
Given that H. pulchella has rarely been reported across a wide geographical range, we hope
that our report will encourage fellow dipterists to conduct further studies on the species’ biology
and distribution.
Acknowledgements
We would like to thank Elisabeth A. Harris for her kind help with providing literature and
reviewing this article. Peter Chandler is thanked for helpful suggestions to improve our
manuscript. We are grateful to Adrian Pont and James McGill for reviewing our manuscript, as
well as pointing out key papers on Helina pulchella records that we had missed. Iiro Kakko and
Eerikki Rundgren are acknowledged for their outstanding enthusiasm for Diptera and for
providing the second Helina pulchella specimen.

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