Íslenskar landbúnaðarrannsóknir - 01.09.1981, Blaðsíða 68

66 ÍSLENZKAR LANDBÚNAÐARRANNSÓKNIR
in the samples of Icelandic hay. The
strikingly similar member of the genus, T.
similis, is known (under the synonym of T.
dimidiatus) to be a free-living species in
Iceland (Hughes, 1960). There are no
quantitative records of mites in stored hay
from the other Nordic countries but
judging from the sporadic reports from
Great Britain it appears that the species
composition of the fauna in stored hay in
Iceland is quite different.
Public healt considerations
Most likely the majority of airborne mite
remains from Icelandic stored hay origin-
ates frorn Acarus farris and Lepidoglyphus
destructor. This is primarily predicted from
their concentrations and high frequencies.
They are known to be the cause of allergic
reactions among farmers on the Orkney
Islands (Cuthbert et al. 1980 and Ing-
RAMet. al. 1979). Tarsonemus sp. might also
be a potent sensitizer but there is no doc-
umentation for this. The Icelandic Tar-
sonemus sp. is different (Lindquist det.)
from the Tarsonemus cf. floricolus from
ACKNOVVLEDGEMENTS
The author wishes to thank Dr. C. Athias-Henriot
(France) for the identification of P. fimetorum, Dr.
E.E. Lindquist (Canada) for the determinadon of
Tarsonemus sp., and Dr. K. Arevad (Denmark) for
the identification of the Coleoptera.
Danish house dust, which is believed to be
the cause of at least some of the hitherto
unexplained allergic reactions to house
dust (Korsgaard & Hallas, 1979).
Quantitatively the Icelandic Tarsonemus
sp. may produce less remains than the
same number of A. siro and L. destructor.
The last two run through three nymphal
stages while Tarsonemus sp. develops di-
rectly from larva to adult. Furthermore,
Tarsonemus spp. are fluid feeders and like
C. eruditus and T. interruptus they do not
leave large amounts of faecal pellets. The
allergenity of Cheyletus has been tested by
Lozano (1979) but no defmite conclusion
was obtained.
The build-up of large mite populations
could theoretically be prevented by keep-
ing the hay dry and well ventilated. The
success of such measures depends, how-
ever, on local factors such as cool or humid
zones in the barn, predator mites, etc.
Therefore, a study of the local factors de-
terming the resultant allergen exposition
when handling hay has to be done before
reliable avoidance measures could be
proposed.
Travel expenses for this study were supplied
through the office of the Director of Public Health
(Iceland), and Dr. S.H. Richter gave me collegiate
guidance in Iceland.