18 THE CANADIAN liNTOMOLOGIST 



also in the colouring, with the exception that there is never orange on the elytra 

 of B. viridisiituralis as far as I have observed them. The females of B. viri- 

 disuturalis are also usually 1 or 2 mm. longer than B. gibbsii. 



My B. gibbsii were taken in Trinity Co., Calif., breeding in oak, (a fallen 

 log), while my specimens of the other were taken from dead wood of a Uve 

 standing cottonwood at Oro Grande, San Bernardino Co., Calif. Gibbsii I 

 believe breeds only in oak (vide Leach & Van Dyke), while Van Dyke says that 

 so far as he knows, B. viridisiituralis is confined to the cottonwoods. 



NOTES ON MYCOTRETUS PULCHRA, SAY AND ITS FUNGOUS HOST. 



BY HARRY B. WEISS, 

 New Brunswick, N.J. 



This member of the family Erotylidse was found breeding in Polyportts 

 chionens at Monmouth Junction, N.J., on September 8. At this time larva?, 

 pupcC and several adults were present, with the larva? most plentiful. The 

 infested fungus was moved to the laboratory and kept moist by being placed 

 close to a wet sponge. The larvse continued to feed in the context of the fungus 

 until they were full grown, when they then entered the pores of the sponge and 

 pupated, the sponge being rather dry at that time. From this it appears likely 

 that pupation in the field takes place in the wood to which the fungus is at- 

 tached. Under laboratory conditions the pupal stage required from ten to 

 twelve days during the last half of September. The appearance of the adults 

 this late in the season indicates that hibernation takes place in this stage. 



Polyporus chioneus Fries^ has a soft and watery pileus when fresh, and 

 occurs on the dead wood of deciduous and coniferous trees. Numerous speci- 

 mens of other fungi were examined during the past year, but Mycotretiis pulchra 

 Say was found associated only with chioneus. However, it is extreme'y probable 

 that other watery forms such as P. borealis, P. albellus, etc., are attacked. 



Full-grown Larva. — Length 6.2 mm. Width L5 mm. Whitish, head often 

 slightly browned; subcylindrical, prothorax twice as long as mesothorax; meso- 

 thorax and remaining body segments except last two are subequal in length; 

 last two segments shorter; head, prothorax, and last two abdominal segments 

 narrower than remaining segments which are subequal in width (some larva' 

 have expanded grub like abdomens); body and legs sparsely hairy, hairs short; 

 abdominal spiracles project slightly from the body appearing as minute, some- 

 what blunt spines. 



Pupa. — Length 4.4 mm. Width across wing-cases L9 mm. Whitish, 

 suboval, rounded anteriorly, tapering to a point posteriorly; head, prothorax 

 and wing-cases thickly clothed with spines each bearing a long hair; fewer 

 spines on leg-cases and ventral abdominal segments; anterior edge of prothorax 

 bears a pair of median irregularly shaped knob- like tubercles each bearing 

 several spines; smaller, somewhat similar median pairs of tubercles on posterior 

 edges of pro-, meso- and metathorax; each abdominal segment bears a transverse 

 dorsal row of spines with a rosette-like group of five or six at the lateral edge, 

 these rows continued on the ventral surface but with fewer spines; body ter- 

 minated dorsally by two comparatively long, curved spines and ventrally by 



1. Identified hv Mr. Erdnian West. 

 January. 192{) 



