No. 9 1998 ARC TIC IN SECT NEWS - Department of Biological ...

6 ARCTIC INSECT NEWS No. 9, 1998
ing to the snow-covered Lowland. Mites
were ubiquitous and the fauna should en -
compass more than the 22 identified spe -
cies, 7 of which are par a sitic.
Eight orders of insects were represented by
156 identified species on the Lowland. These
included sev eral species of lice from birds, and
one from a walrus. The true diversity of lice will
be greater, but is inherently difficult to as sess as
it requires killing and combing vertebrate hosts.
One homopteran species, a male scale, was col -
lected on a sin gle oc ca sion. Aphids were
sought, but not found. Such sea sonal ae rial
plankton mi grants might colonize in the future.
One caddisfly species was collected an nu ally
from the shores of several lakes. Of the three
bee tle spe cies, the pond dwell ing dytiscid
Hydroporus po laris and the carabid
Amara alpina were frequently encoun -
tered, while the 2.5 mm staphylinid
Gynpeta sp. was rare. Four or ders,
Collembola, Lepidoptera, Diptera and
Hymenoptera, dom i nated the in sect
fauna.
Collembola populations and their effects on
soil metabolism were studied intensively by
Addison (in Bliss 1977). Moulting by adults,
and long adult lives, compounded population
anal y ses, but spe cific fo cus on abun dant
Hypogastura tullbergi produced clearer
un der stand ing of the sig nif i cance of
these insects. Thirty species were cited in
the IBP list. Fjellberg (1986) made eight
revisions to this list, including the sig nif -
icant change of H. tullbergi to H. concolor
(Carpenter 1900). Other stud ies are re -
ported by Babenko (1994).
Lepidoptera taxa in cluded two but ter fly
species and 12 moths. Both Boloria but ter -
flies were melanized, a condition that has
been noted to aid solar basking by arctic
insects. Because but ter flies are at trac -
tive to col lec tors, the di ver sity of but ter -
flies offers a simple scale to compare di -
ver sity of insect faunas at other lo ca -
tions. Gynaephora moths, investigated in
detail as models for the study of polar ad -
ap ta tion and en ergy flow (Ryan and
Hergert, in Bliss 1977), remain a focus of
continued study by Olga Kukal and oth -
ers. Larvae of the two Olethreutes moth
species have subsequently received at -
tention from Sharron Meier as min ers
within hollow Pedicularis stems.
Flies comprised the most visibly abundant
group of insects at Truelove. The so viet IBP en -
to mol o gist Yuri Chernov vis ited the site in
1989 and es ti mated that he collected 8 spe cies
of tipulid flies, versus 4 cited in the appendix.
He thought that the single syrphid species prob -
ably belongs in the genus Platycheirus, and
is not Melanostoma n. sp. Chironomid
flies, the species diversity of which is ex -
pected to be greater than the 21 species
indicated in the appendix, emerge from
lakes in great abun dance. They were
noted to be a source of nitrogen enrich -
ment to meadows adjacent to lakes. Don
Pattie observed two arctic foxes eat ing
windrows of lake-edge chironomids, and
their scats revealed distinct evidence of
gnat con sump tion. The two Aedes sp.
mosquitoes were uncommon during the
1970-74 period. Their pestiferous times,
when per haps 20 mos qui toes an noyed
each researcher even at 320 m a.s.l. on
the plateau, lasted about 10 days. Indi -
vid uals fre quently flew away with out
feed ing. As an other an ec dote about
Truelove conditions, a car cass of a win -
ter-killed musk ox calf was colonized by
calliphorid fly larvae in the summer of
1971. Most of these lar vae were unable to
complete development that sum mer, and
were eaten by arctic foxes be fore the next
spring.
The Hymenoptera species list remains un -
changed from the 1977 ap pen dix, al though
Bombus hyperboreus is expected to be
found. Kukal and Pattie (1988) witnessed
two events of snow bunting nests be ing
usurped by B. po laris, forcing these birds
to aban don their eggs.
The fauna was found to in clude no molluscs
(ex cept ma rine molluscs), nor any
orthopteroids, aphids, thrips and neuropteroid
insects. The largest insects were lymantriid and
noc tu id moths, bumble bees and tipulid flies.