234 Transactions. — Zoology. 



Subsection A. 



Cross-vein, if present, placed between the root and tip of the 

 first longitudinal vein. 



Sub-genus 2. Cecidomyia, Loevv. — Antennae 2-f9 to 2 + 22 

 jointed ; generally the same number of joints in the 

 male and female ; joints pedicelled or sessile alike in 

 both sexes, or pedicelled in the male and sessile in the 

 female. 



Cecidomyia destructor, Say. (Plate V., fig. 2.) — Length, 

 3min. Eyes brownish-black. Front of head black, and clothed 

 with long black hairs. Palpi yellowish, of four joints, partly 

 covered by minute black scales, entirely covering the terminal 

 joint. Antennge yellowish-brown to almost black, composed 

 of seventeen joints, with short black verticillate hairs ; the 

 first two joints very thick, first cup-shaped, second glo- 

 bular, third smooth, cylindrical, and elongated, gradually 

 becoming smaller and ending in a long tapering point longer 

 than any of the preceding. Proboscis minute, and rose- 

 coloured. Thorax black, with grey tints in certain lights ; 

 white hairs on the sides, and also scattered on the ventral 

 region. Scutellum black, hairy. Halteres yellowish -pink, 

 with occasional black scales. A light-red line running from 

 the neck to the base of the wing, along the side of the 

 thorax. Abdomen pinkish, consisting of eight segments ; the 

 first segment is nearly black, the remaining segments are 

 mxrked by a large square black spot on each side — these 

 nearly unite on the seventh and eighth segments ; the 

 last two segments have a curious V-shaped marking, with 

 two small lines, one on each side of it, and placed on a 

 somewhat darker area than the general colour of the seg- 

 ments. Oviduct pale-reddish, yellow-brownish at the tip, 

 composed of three joints ; the last is pointed, and with- 

 out lamelhe. Legs pink to light-red, clothed with black 

 hairs. Second longitudinal nearly straight, then bends down 

 and reaches margin before apex. 



This insect has occurred in the colony within recent years. 

 It is undoubtedly mtroduced. I have seen no specimens. 



Sub-genus 3. Diplosis. — Second longitudinal vein reaching 

 the margin of the wing either at or beyond the apex. 

 Antennae of the male 2 + 24 jointed ; joints pedicelled ; 

 simple joints alternating with the double ones, or all the 

 joints quite simple — in the latter case the joints only have 

 one hair- whorl ; joints sometimes with the hair-whorls 

 equally long on the upper and under sides ; often decorated 

 with long stiff hairs on the upper side. Antennae of the 

 female 2 + 12 jointed ; joints subsessile, or having very 



