158 MICHIGAN SURVEY, 1908. 



II. Notes on the Habitat Relations of Beetles. 



The beetles collected by our party were tabulated by Stations to • 

 determine if marked habitat preferences were evident. The tabulation 

 shows that at most stations only a relatively few species were found. 

 At those stations where the largest variety was found, as at our camps, 

 the conditions were exceptional. The occurrence of the flowers of the 

 Cow Parsnip attracted many species. It is quite evident that these 

 flower frequenting species did not breed there, so that in a strict sense 

 they do not belong to these open areas, as the breeding places of in- 

 sects must furnish the only substantial basis for the determination 

 of insect habitats. In many cases only provisional habitats can be 

 assigned with our present incomplete knowledge of life histories. In 

 many species the larval and adult habits are very different, particular- 

 ly with regard to their food. For this reason error is very liable 

 to occur and caution is necessary. In the present provisional dis- 

 cussion the haunts frequented by the adults have been primarily utilized. 

 This is an unfortunate limitation, but it is hoped that this will not 

 confuse the main feature of the problem. 



On the Lake Superior beach (I, 1) the following 14 species were 

 found: Galosoma frigid um, BeniMdium {five species), Rhantus Mnota- 

 tus, Anatis 15-punctata, Maervpogon rufipes, Corymhites medianus, 

 Podahrus diadema, MaltJwdes niger, Sericea vespertina and Lep- 

 utiira chrysocoma. It is evident that some had been washed up 

 by the waves {Galosoma and Anatis) while others normally frequent 

 sandy beaches {Bemhidiiim) or the beach pools {Rhantus), while still 

 others were here because of the open character of the beach and the 

 proximity of the forest. Hay ward ('97, p. 37) says concerning the 

 habitat of Bemhidium: "Most of them are riparial in their habits, 

 occurring under stones and refuse near the water's edge along streams, 

 the shores of ponds, or on the seamoss, while a few occur almost any- 

 where." 



The clearing about the Light-house (I, 7) had the greatest variety 

 of beetles found at any station. It included 37 out of the 89 species ' 

 found at all stations. There were several circumstances which com- 

 bined to make this number large. The greater opportunity of .those 

 about camp to make collections; the season of the year (July); the 

 presence of the Cow Parsnip in large numbers (which acted as insect 

 traps, and upon which beetles congregated in such num'bers that they 

 were easily brushed into the cyanide bottles in large numbers) ; and 

 the presence of logs, stumps, brush, etc. The flowers were a very con- 

 spicuous factor, and on these Leptura chrysoooma gathered in large 

 numbers. The open space was favorable to the Carabids, the flowers, 

 for the Coccinellids, Elaterids, Buprestids, Trichias and the Cerambycids. 

 The two latter frequent also the logs and stumps. The wandering, 

 tramp-like existence of these adult wood-boring beetles should not con- 

 fuse one as to the true habitat of the immature stages which is in the 

 forest. The surrounding forest was mainly composed of White or Paper 

 Birch, Balsam and Spruce. 



At the camp on Siskowit Bay (V, S') somewhat similar conditions 

 were found to those at the Light-house (I, 7), but there were fewer 

 flowers, more cut timber, furnishing logs, stumps, brush; a log shack 



