168 Forty-ninth Report on the State Museum 



the common cucumber plant-louse. The melon leaves and tips when" 

 received were badly infested with this aphis, ApJiis cucumeris Forbes, and 

 had been sent for the purpose of showing the extent of their injury and. 

 obtaining a remedy for it. 



Diplosis setigera n. sp. 



The Hairy Melon-vine Midge. 

 (Ord. Diptera: Fam. CECiDOMYiDiE.) 



The preceding insect was reared from melon-tips for several years and 

 it was only after close study that a second species was discovered operat- 

 ing in a similar manner. The general appearance of the two insects is 

 so close that they might easily be confused, and only during the year of 

 1 89 1 were specimens of this species secured; the rearings of former 

 years were all D. cucumeris. It is worthy of record that two distinct 

 species of this genus are injurious to melon-tips, and it will be seen by 

 the following description that they are by no means so closely aUied 

 as one might possibly expect from their attacking the same plant and 

 upon the same grounds at Lowell, Mass. 



Description. 



Diplosis setigera n. sp. Plate III. — Eyes black, coarsely granulated 

 deeply emarginate anteriorly, broadly united dorsally in the male, less so 

 in the female, and composing most of the head. Numerous large setae 

 arise on the dorsum of the head and curve anteriorly. Male antenna one- 

 fifth longer than body, composed of fourteen segments, basal two short, 

 the others much elongated; basal and medial bulbs subspherical, nearly 

 equal; subbasal and distal shafts equal (fig. i); on each bulb there is a 

 whorl of setae {s) of nearly uniform length which extend about to the 

 next bulb; there is also on each bulb a whorl of arched filaments, ''Jile/s 

 argues^' {a), of a length nearly equal to that of the set.^ and arising just 

 distal of them. Female antennae a little shorter than body, composed of 

 fourteen segments; the two basal short; third about one-half and fourth 

 a httle longer than the normal segments; the others are nearly cylind- 

 rical, a little over twice as long as broad and pedicellate distally (fig. 

 2); each segment with a well-defined whorl of large setae at its base, 

 a less complete whorl at the apex of the enlargement, the latter invested 

 with numerous small setae; the small ones are absent along certain lines 

 on the enlargement and the naked places are occupied by what appear to 

 be transparent tubercles, but which are probably special sense organs; there 

 is a transverse row at the basal third and oblique rows pass over the distal 

 angles of the enlargement; the basal and apical rows are connected by 

 longitudinal rows ; there are also a few scattering tubercles near the lat- 

 ter; the more usual arrangement of these interesting structures is shown 



