The Insects of the "Danmark" Expedition. 57 



Halid. occurs on the west coast ^, and it is therefore probable that 

 the cocoons mentioned belong to this species. 



6. Bombus hyperboreus Schönh. 



7. В. balteatus Dhlb. 



Both the two Greenland humble-bees are common; the hiber- 

 nating females appear in the middle of June and the workers appear 

 already at the end of this month. They fly on Salix, Potentilla, 

 Saxifraga. Pediciilaris and Cassiope. Both species build their nests 

 under the ground in deserted marmot holes. 



A nest of B. balteatus was found on July 15th 1908 ca. 17 cm. 

 under the surface. The entrance to the nest was ca. 35 cm. long. 

 The nest was padded with a thin layer of moss and indeterminable 

 bits of plants. Close to the entrance there was a small clump of 

 food on which were laid about a score of humble-bee eggs, and 

 behind this lay another clump containing a pair of tiny larvae. The 

 nest contained some bundles of cocoons, namely, a clump of worker- 

 cocoons which were all empty (in all 20 cocoons), further cocoons 

 containing mature male-pupae (in all 11) and lastly cocoons with 

 full-grown female larvae (in all 11). Some workers were found in 

 the nest but no males or females. 



A female of B. hyperboreus was found at the end of June in the 

 act of crawling down into a marmot hole, presumably seeking for 

 a place to build its nest. On digging out the marmot hole a clump 

 of old, moulded, humble-bee cocoons was found in it. 



The life-history of the Greenland humble-bees does not differ, 

 therefore, from that of the more southern species. 



Diptera. 



From East Greenland ca. 50 species of flies were hitherto known, 

 of which 15 occur in the collections, in addition also a pair of 

 indeterminable Muscidae, as also two species which are new (Rham- 

 phomyia sp., Catabomba groenlandica). 



1. Tipula arctica Curt. 



This species is common and was brought home in numbers. 



The larvae are found in circular holes ca. 2 — 3 cm. deep in the 

 ground, especially under Cassiope-iuh'^. The change to the pupa 

 stage also takes place here. 



The pupae were found at the end of June and empty pupa-cases 

 were found already on the 25th of the same month. The period of 

 flight lasts till the beginning of August. 



1 W. Lundbeck: Hymenoptera j^rocnlandica (Vidcnsk. Meddelelser fra den natur- 

 hist. Forening i København, 190(), p. 242). 



