66 BULLETIX 10S9, U. S. DEPAETMENT OF AGRICULTURE. 



as are seen in sheep, a form of dizziness induced no doubt by the irri 

 tation caused by the larvae. Bergman mentions a disease callec 

 " varka " in Lapland which he attributes to C epJienomyia jw^sali 

 and Tvhich he says may cause death. ^^ In Alaska there are no rec 

 ords of reindeer dying from grubs in the nose, but it is quite possibL 

 that occasional deaths do occur. 



After the larva has fallen to the ground it pupates rapidly, in five oi 

 six hours as a rule. It differs in this respect from Oedemagern 

 tarandi^ which is much slower. The pupal period is shorter than i 

 is for O. taraTidi. According to Bergman, the pupal stage may b* 

 from 16 to 31 days. In observations made in Alaska, the pupa 

 period lasted up to 56 days, but this was under adverse conditions 

 and only 20 flies emerged out of a total of 54 pupae. 



The treatment or prevention of nostril flies seems even mori 

 hopeless than is the case with warble flies. The only means of pre 

 vention that seems at all likely to succeed would be to provide dark 

 ened shelters for the reindeer to go into when the flies are attacking 

 them. In northern Europe, especially on the Finnish side in Lap 

 land, long dark sheds are provided, and the Lapps sa}' that withou 

 such protection reindeer would suffer greatly in some districts 

 Shelters would be most helpful against the warble fly as well anc 

 would also afford the reindeer some protection from other forms o: 

 insect life. Unfortunately, in arctic latitudes the insects are a 

 work the greater part of the 24 hours ; consequently, during the ho 

 weather the reindeer might not get very much chance for feeding 

 But on the other hand, if the animals have no means for protecting 

 themselves they suffer so much annoyance and worry that the los; 

 of a little food would seem preferable. 



Lapp names for Cephenomyia nasdlis are as follows: The larvE 

 is called saula ; and the imago or fly, boaro. 



SCREW WORMS (PHORMIA TERRAE-NOVAE) . 



Blowflies are found in abundance on all the reindeer allotments 

 Both natives and whites are careless in the disposition of refuse ; con 

 sequently, on approaching a reindeer herder's cabin, swarms of blow 

 flies may be seen rising from rubbish heaps containing reindeer offal 

 fish refuse, and other offensive material. Reindeer that die on th( 

 range are usually left where they lie. It is no wonder, therefore 

 that wounds may become infected with screw worms. A heavilj 

 infected skin taken from a reindeer on May 20 is illustrated ir 

 Plate XXII, Figure 2. 



The most important factor predisposing reindeer to infestatioi 

 with screw worms in the warble fly. When the warble larvae emerg( 



18 Bergman, Arvid, On the Oestridae of reindeer : Entomologisk Tidskrift, vol. 38, pp 

 1-32, 113-146, 1917. 



