55 



tissue produced by this insect causes remarkable tumefaction and dis- 

 tortion of the twigs and scantiness and yellowing of the foliage, result- 

 ing in a complete checking of growth. - 



The perfect insect is a minute fly or gnat, expanding about J inch, 

 having a glossy black body and broad transparent fore-wings, with a 

 rather strong marginal vein, and a faint, forked vein on the lower 

 edge. These gnats emerge from their cells early in .May and lay their 

 eggs (which L have not so far been able to detect) on the succulenl 

 new growth of the tree into which the microscopic larvae easih burrow 

 and begin the formation of their cells, very shortly producing gall like 

 swellings and twisting of the stems. These cells, each about J inch 

 long, and oblong in shape, become, as the season advances, exceed- 

 ingly compact, almost stony, and in some cases almost fill the shoots 

 for a space of from 5 to 7 inches in length. They are placed longi- 

 tudinally, and a cross-section of a twig one fifth inch in diameter will 

 often cut four or five, although they are seldom regularly arranged 

 side by side. The larvae attain their growth in July or August, and 

 remain unchanged in their cells until the following spring. They are 

 at this time from three to four millimeters in length by one in diameter, 

 cylindrical, with segments well defined, of a bright salmon-pink color, 

 with conspicuous "breast-bone" in dark brown. 



The outlet to the surface is probably by the passage through which 

 the larva worked its way within the stem, though in what way extended, 

 to admit of the egress of the much larger pupa, I can not tell. At all 

 events when ready to emerge the pupae are protruded, sometimes 

 singly, in other cases in clusters of three or four where the larval 

 cells have coalesced, from minute orifices all along the stem, giving it 

 quite a friugy appearance with the erect translucent white empty pupa 

 cases. 



Two species of parasites have been bred from these Lasioptera galls, 

 and examinations of infested twigs within a few weeks discloses more 

 larvad of parasites than of the original gall-makers. 



Diplosis spf ON Soft Maple. 



This is a probably undescribed species, also a Cecidomyiid, which 

 destroyed a considerable proportion of the very young leaves of Soft 

 Maple in Kirkwood and vicinity early in the spring. The punctures of 



the insect caused a peculiar curling and shriveling of the leaves, and 

 in every depression would be found a minute white larva not more than 

 2mm in length and 0.5 in diameter across the anterior end, from whence 

 it tapered slightly posteriorly. 



The first brood of flies emerged in June from little flattened oval 

 cocoonets spun against the surface of the leaves. A second brood 

 appeared late in July rolling the edges and crinkling the centers of the 

 more tender leaves, but was far less injurious to the appearance of the 

 trees than the earlier one. 



