92 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, III 



the larval habitat, the only specimens available being obtained from 

 eggs laid in captivity. 



The homhycinus larva is very closely allied to that of viduus Brown. 

 In the very inadequate material available for study the only observed 

 difference vi^as in the antennae. On the second antennal segment, 

 bombycinus bears 5 "sensory" appendices, whereas viduus has 6. 

 Whether this difference is constant and whether there are other re- 

 liable separating characters cannot be determined until more material 

 of these species is available. Urogomphi as in figure 20, d, f. 



Material used in study. — Only larval exuviae were available for 

 examination. The specimen was reared from eggs secured from 

 adults collected at Walla Walla, Wash., by H. P. Lanchester and 

 identified by M. C. Lane. The parent adults were not retained. The 

 exuviae are deposited in the U. S. National Museum. 



LUDIUS MEDIANUS (Gennar) 



Diacanthus medianus Germar, Zeitschr. fiir die Ent., vol. 4, p. 71, 1843. 

 Corymbites riibidipennis LeConte, Trans. Amer. Philos. Soc, vol. 10, p. 437, 



1853. 

 Ludius medianus (Germar), Brown, Canadian Ent., vol. 68, pp. loo-ioi, 1936. 



This eastern species is recorded by Brown (1936b, p. loi) as 

 occurring from central Manitoba to the Atlantic seaboard and as far 

 south as Massachusetts. The only larvae known were collected from 

 decomposing litter under spruce and were found to attack the cocoons 

 of the European spruce sawfly, Gilpinia hercyniae (Hartig). 



The larva of medianus so strongly resembles that of the European 

 tessellatus (Linnaeus) that separation is best made on the basis of 

 distribution. In medianus the inner prongs of the urogomphi are 

 only slightly longer than the outer prongs. This character suffices 

 to distinguish the larva from its closest known American allies, 

 viduus and bombycinus, in both of which the inner prongs are ap- 

 proximately twice as long as the outer prongs. The second segment 

 of the antenna bears 5 "sensory" appendices and the legs carry as 

 many spinelike setae as on the larvae of viduus. 



Material used in study. — Two examples were examined, one being 

 the last larval exuvium of a reared specimen. These were not col- 

 lected at the same time or in the same location, but both were taken 

 under spruce in New Brunswick. 



i; South Branch, Kent County, New Brunswick; June 17, 1941 ; R. F. Morris; 

 reared to adult. (C.N.C.) 



