INSECTS AFFECTING PARK AND WOODLAND TREES 



571 



birches in Quebec have been placed on record. The larva may be recog- 

 nized by its jet-black eyes and yellowish red head, and specially by the six 

 rows of conspicuous black, nearly confluent spots down the back, in connec- 

 tion with a lateral row of elongated ones and the two rows of black spots on 

 the underside of the body at the base of the legs. The dorsal rows of spots 

 are nearly confluent, about three to each segment, except on the last, which 

 is naked and sparsely clothed with rather coarse hairs. This species feeds 

 on white birch in the neighborhood of Quebec during August and Septem- 

 ber. Dr Fletcher has recorded this insect as very abundant in several 

 Quebec localities in 1887, they being present in myriads in the eastern 

 portion of the province. These false caterpillars spin cocoons on attaining 

 full growth, the adults appearing the following July or early in August and 

 deposit eggs for a subsequent generation. The perfect insect has black 

 antennae and head, with spots on the breast and ovipositor blue black, the 

 remainder of the body, excepting the legs which are steel blue, being yel- 

 lowish red. This species has a general distribution in the northeastern 

 United States and Canada, and is probably rather abundant some seasons 

 in the Adirondacks. There is no practical method of preventing its 

 depredations, particularly as birch has very little commercial value. 



Nematus unicolor Marlatt 



A brown-headed, greenish sawfly larva resting alone on its venter on the underside 

 of birch leaves belongs to this species. 



This sawfly was met with by Dr Dyar on white birch at Keene Valley 



N. Y. Its larva has been characterized by him as follows : 



Larva. Head slightly granular, shagreened, a little pilose, pale brown- 

 ish, pale around mouth, not shining; eye on a black spot; two blackish 

 shades on the back of head behind the vertex ; width 1.8 mm. Thorax 

 a little enlarged, its feet spreading; venter flattened; feet on joints 6-11 

 and 13; subventral region slightly fluted with a few pale setae; segments 

 not very completely 5- to 6-annulate, segmental incisures folded ; not 

 shining, translucent greenish, food giving a dusky tint ; subdorsally below 

 the skin a series of emerald-green or pale green granules and streaks, form- 

 ing a nearly continuous band, or even an evident white subdorsal band ; 

 tracheal line evident ; spiracles pale. When mature the larvae became pale 



