THE OAK GALL-MITE. 213 



but the two lateral rows are continued by smaller tubercles until near the base of 

 the labrum. Rostrum reaching the second coxae. Nectaries yellow, about as long 

 as the tarsi, slightly enlarged at base, the mouth conspicuously flaring. Style not 

 perceptible. 



Winged individuals. — Autennj© very slightly pilose ; fourth joint subequal to the 

 fifth and two-thirds as long as the third joint ; sixth about half as long as the pre- 

 ceding, and very little longer than the seventh wings, with the stigma and veins 

 much as in Ch. populicola, the veins lying in narrow dusiiy bands. Length of apter- 

 ous individuals 1.52-2.02 '"t". ; length of wing 2.54 """. 



On the under side of the leaf near the midrib. Quercus prinus May to June^ 

 Peoria, 111, 



Of this interesting species I have seen a number of apterous indi- 

 viduals, but only a single winged specimen, which was mounted on a 

 slide, kindly communicated by Miss E. A. Smith, of Peoria, 111. The 

 dorsum of the winged individual is probably not tubercular, but this 

 can not be decided with certainty on account of the manner in which 

 the specimen is mounted. 



Though the antennse of this species are not sufficiently pilose to jus- 

 tify its being placed in Chaitophorus, its general appearance seems to 

 point to this as its rightful position. (Thomas). 



302. Chaitophorus spinosus Oestlund. 



Mr. Oestlund has found this aphid on the under side of the leaves of 

 the oak, confining itself to the higher parts of the tree. 



Wingless oviparous female. — Head subquadrate in outline, straight in front, pale red 

 or orange colored, with blackish spines in front and above like those on the abdo- 

 men. AntenniB very remote at base, about one half the length of the body ; joints 

 1 and 2 as usual, 3 longest, 4 a little shorter, 5 a little shorter than 4, 6 hardly one- 

 half of 5, 7 not longer than 6 or shorter, basal joints pale, apical black, with long 

 white hairs as usual in this genus. Eyes large and round, with a distinct tubercle ; 

 the facets are reddish-brown, the space between them whitish, giving the eye the 

 appearance of a ripe raspberry just picked with the bloom still on ; no ocelli in this 

 form. Beak not more than reaching second coxse, stout and hairy, pale except at tip ; 

 second joint widest. Abdomen widest in the middle, tapering into a very long ovi. 

 positor behind, strongly convex above. Color pale yellow ; last segments sometimes 

 reddish as the head ; above with grass-green markings, generally in the shape of a 

 ring, leaving a large irregular white-like patch in the middle of the same color as 

 theabdomen. Honey-tubes short and thick. Style short and thick. Length2 to 3™™, 

 (Oestlund's Synopsis of the Aphididae of Minnesota). 



303. Burr-oak gall mite. 



Fhytoptus querci Garman. 



Class Arachnida ; order Acarina. 



Produces galls on the leaves of the burr-oak, Quercus macrocarpa 

 Michx. 



The mite is long and slender, and in a specimen seen among washings from a ceci- 

 dium, there appeared to be an abrupt descent in the outline of the back from the 

 abdomen to the cephalothorax. Length .005 inch. 



