PSYCHE 
Yol. 55 June, 1948 No. 2 
LEPTINUS AMERICANUS LECONTE TAKEN ON A 
SHREW ( COLEOPTER A-LEPTINIDiE ) 
By F. G. Werner and R. L. Edwards 
Biological Laboratories, Harvard University 
A fairly extensive literature has developed on the 
curious “mammal nest beetles’’ and their relationship 
with their hosts. Several cases have been recorded of 
beetles actually being taken in the fur of mammals and it 
is hoped that with the accumulation of data the signifi- 
cance of this occurence will become apparent. 
One of the authors, Edwards, has taken these beetles 
several times in the fur of a shrew, Blarina brevicauda 
talpoides (Gapper). The animals had been caught in 
live-traps and the beetles were on them when they were 
examined for ectoparasites. The actual records are as 
follows : 2 2$, 9-Mile Swamp, Hubbardsville, N. Y., 1 in 
Nov. and 1 in Dec., 1946 ; 1 <?, 1 ?, Lake Piseco, N. Y., May 
3, 1947 ; 1 <J, Murphy Woods, Hamilton, N. Y., June 3, 
1947. No specimens were taken in the nests. 
Mr. H. S. Barber, of the U.S.D.A. Division of Insect 
Identification, suggests that this is a case of phoresy, 
with the primary source of the beetles being the nest of 
another mammal, whose burrows the shrews had invaded. 
He gives three cases, in litt., where large numbers have 
been taken in the nests of moles and one in the nest of a 
bumblebee. Dury, 1892, tells of getting 107 specimens in 
a nest in which he had captured a specimen of Blarina 
brevicauda. The caption of his article is “What I found 
in the Nest of a Field Mouse” so there is some doubt as 
to the actual identity of the nest. Numerous European 
references to Leptinus mention mice, moles and shrews. 
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