78 The Ottawa Naturalist. [Aug. -Sept. 



tibiae dark yellowish brown, the tarsi darker, almost black. 

 Ovipositor moderately stout, as long as the body ; terminal lobes 

 broad, the length thrice the width and thickly setose. Other 

 characters practically as in the male. Type Cecid a2 520. 



Leaf galls. The primary infestation, as we have shown 

 elsewhere, frequently begins in the bud. Deformations belong- 

 ing in this class are not very important, though Thecodiplosis 

 liriodendri O. S. is responsible for serious disfiguration, and 

 probably some weakening of tulip leaves, particularly in the 

 latitude of North Carolina. The recently established box leaf 

 miner, Monarthropalpus btixi Lab. of Europe, appears to be a 

 serious pest of the highly prized ornamental Box. The yotmg 

 leaves of the Black Locust, Robinia, may be seriously defonned 

 by the larvae of Dasyneura pseudacaciae Fitch, or the margins 

 rolled by those of Obolodiplosis robmiae Hald. Coniariiiia 

 canadensis Felt, the probable producer of the midrib gall on ash, 

 is so abundant locally in the Hudson valley as to seriously affect 

 the foliage of saplings. The extent to which leaf infestation may 

 go is shown bv the fact that some 22 soecies of gall mida^es 

 are known to infest the leaves of hickory and about 20 those of 

 oak. Most of these, as well as numerous other leaf-inhabiting 

 forms, are of comparatively little importance. 



Stem galls. Irregular, subcortical galls are produced in 

 living tissues by species of Rhabdopha^a and Lasioptera, the 

 former being . confined mostly to willow. The European 

 Rhabdophaga salicis Schr. has become established in some 

 localities where basket willows are- grown and causes consider- 

 able loss by ruining the shoots for both basket work and the 

 binding of bundles of nursery- trees. Willow twigs are attacked 

 by 21 American species of gall midges. Lasioptera querciperda 

 Felt lives in the subcortical tissues of white oak twigs, producing 

 gnarly areas and, presumably, defects in the wood. Several 

 species of Itonuia, I. resinicola 0. S. and /. resinicoloides Wlms. 

 attack the inner bark of young pines, and in some instances 

 considerable pitch exudes and rather serious injury mav result 

 in the case of individtial trees. Itonida inopis O. S. is a sub- 

 cortical form, the larvae producing a swollen, gouty condition 

 of the twigs and a marked lowering in the vigor of badly infested 

 trees. 



Root galls arc known in only a very few cases, probal)ly 

 because of the difficulty of discovering them, and, so far as forest 

 trees are concerned, none of importance have been recorded. 



A general survey of the gall midges known to infest forest 

 trees, shows that the hickories, the oaks and the willows, and to 

 a less extent the poplars, all representing genera with a number 



