THE CANADIAN ENTOMOLOGIST 125 



AN APPARENTLY NEW SPECIES OF LEPTINILLUS. 

 (COLEOPTERA, LEPTINID^.) 



BY G. F. FERRIS, STANFORD UNIVERSITY, CALIFORNJA. 



The coleopterous family Leptinidse includes but two genera 

 and two species, but it is of especial interest because of the fact 

 that these two species are exactly half of the number of species 

 of Coleoptera that are known to be, or suspected of being, ecto- 

 parasites upon birds and mammals.. Of the other two species 

 one, Platypsyllus castoris Ritsema (the only representative of the 

 family Platypsyllidae) is a permanent, obligate parasite upon 

 beavers in both its larval and adult condition. The other, a 

 Silphid, Lyrosoma opaca Mann, is a resident of the nests of certain 

 maritime birds but is suspected of utilizing the birds for purposes 

 of transportation. Of the two Leptinids one, Leptiniis testaceus 

 Miill. is an oft-recorded resident of the nests of bumble bees and 

 small mammals, but it has once been recorded as occurring on 

 mice^ and once from shrews^. The other, Leptinillus validus (Horn) , 

 is apparently a much less common form and of its habits nothing 

 is known, except that it has once been taken from the skins of 

 Alaskan beavers^. The discovery of a second species of Leptinillus 

 with some definite information in regard to its habits is, therefore, 

 of considerable interest. 



Leptinillus aplodontiae, n. sp. 



Female. — Length 3 mm., depressed and broadly oval in shape, 

 of a reddish brown colour, feebly shiny, the entire dorsum closely 

 and uniformly beset with fine, setiferous punctations, the setae 

 short and slightly lighter in colour than the body. Head hemi- 

 he.xagonal in shape behind the frontal suture, the labrum convex 

 anteriorly, the posterior angles of the head nearly right angles, 

 the occiput much constricted and produced into the prothorax. 

 Beneath the lateral margin at each posterior artgle is a shallow, 

 longitudinal groove which extends forward to the base of the 

 antennseand into which the first antennal segment may be re- 

 ceived. Antennce 11-segmented, slender, reaching but little be- 

 yond the posterior margin of the pronotum. Mentum with the 

 posterior angles produced into a stout process about as long as 



1. Riley, C, V. Insect Life, 1 : 306. (1889). 



2. Kellogg, V. L. Science, N. S., XXXIX : 369-61. (1914). 



April. 1918 



