304 THE CANADIAN ENTOMOLOGIST. 



THE MESILLA VALLEY COTTONWOOD LEAF-MINER 



DETERMINED. 



BY C. H. TYLER TOWNSEND, KINGSTON, JAMAICA. 



Among the first insects which I found upon my arrival in the Mesilla 

 Valley of New Mexico, in March, 1891, was a small sawfly. My notes 

 on this species were made as follows at the time : — 



March, 1891. — Specimens of a small yellowish and brownish sawfly 

 were found quite abundant flying everywhere from middle to last of 

 March. They were not found on any plant, but their numbers make it 

 probable that they will turn up as injurious to some plant. Det. by Dr. 

 Riley as Blennocampa, nov. sp. 



In an article in Zoe., vol. iii., p. 234-6, Oct., 1892, under the title of 

 a leaf-miner of Popultis fremontii, I described the larvae, there supposed 

 to be tineid, and gave an account of their great destructiveness to the 

 foliage of these trees in the Mesilla Valley in 1891 and 1892. All 

 attempts to breed the miner were futile. 



However, in April, 1893, the trees were watched carefully during the 

 time when the leaves were opening. The result was that on April 9th, 

 adult sawflies were found very numerous on the cottonwoods, flying about 

 and (apparently) ovipositing in the partially opened leaf bunches. The 

 leaves were one-third to one-half opened at the time. 



Specimens of these sawflies were captured on the spot. On being 

 carefully compared with the specimens taken in March, 1891, which, as 

 above mentioned, had been determined by Dr. Riley as a new species of 

 Blennocampa, they were found to be the same. Dr. Riley has since ex- 

 pressed doubt in lift, that the two were the same. Though I did not 

 breed the species, I am sure quite beyond any doubt that the sawflies 

 caught April 9, 1893, are the adults of the leaf-miner referred to as 

 described in Zoe. I am quite as certain also of the identity of these saw- 

 flies with the Blennocampa, n. sp., determined in 1891 by Dr. Riley. 



Dr. Riley has given me in litt. the MS. name Blennocampa populi- 

 foliella to use for this species. I therefore place these notes on record, 

 so that my stand in the matter may be known. It appears that the pre- 

 cise name of the cottonwood of the Mesilla Valley is Populus fremontii, 

 Watson, var. wislizeni, Watson, as Prof. Cockerell has pointed out to me. 

 (See Bull. 2, Forestry Division, U. S. Dept Agric, 1889, p. 188). 



I should also point out that 1 found in New Mexico other tenthredinid 

 (?) leaf-mining larvae in Populus angustifolia, in the Canada Alamosa 

 (see Journ. N. Y. Ent. Soc, i., No. 2), which belong to a different genus 

 without doubt. 



