May, 1888.] 2G5 



DESCRIPTION OF A NEW SPECIES OF ALEUEODES. 

 BY J. W. DOUGLAS, F.E.S. 



Alkurodes RIBIUM. 

 Head, thorax and abdomen yellow ; antennae and legs pale ; wings milk-white, 

 immaculate. Eyes black, elongate, sub-roniform, ends broadly rounded, contracted 

 on both sides to the middle, and there crossed by a white farinaceous fillet, each 

 portion viewed from beneath with seven straight, transverse rows of distinct white 

 atoms. Antenna} of seven joints ; 1st very short ; 2nd stout, bulbous, almost 

 obconic, the end hollowed out ; the otliers thin ; 3rd longer than 2nd, cylindric ; 

 4th to 6th somewhat shorter, sub-equal ; 7th longer, pointed. 



Expanse of wings, 2-60 — 2'75 mm. 



Larva short broad-oval, flat, shining, at first pale green, afterwards pale citron- 

 yellow, without hairs ; sides sloping upwards and 

 inwards from the circumference to an oval ring, 

 smaller than but parallel to the circumference, the 

 edge of the ring set with a catenulatod series of 

 small, obtuse elevations ; within the ring, on a 

 flattened surface, is a dim outline, in slight relief, of 

 the back of the insect beneath the integument, with 

 segmental indications, and on the median line of the 

 abdomen four or five small obtuse elevations ; the 

 sloped sides with close, delicate, transverse striaj. 

 Length, 1'5, breadth, 1 mm. 



The imago, except as to the doited eyes, as noted above (a struc- 

 ture that, although not recorded, may possibly exist in other species, 

 and be visible only in fresh examples), presents nothing remarkable, 

 the best specific characters, as usual in the genus, being demonstrated 

 in the larva. I believe that before winter the larvae had passed into 

 the pupa state, of which, as is well known there is, in this genus, 

 scarcely an outward and visible sign, but in this species, in the adult 

 larval state the outline of the insect below the integument is more 

 strongly defined in the thoracic region, and there are mostly dark, 

 suffused spots there and on the sides posteriorly, which character 

 disappears in the pupn. 



The number of joints in the antenna) of the imago, even of the 

 same species, has been variously stated by different authors, of which 

 I subjoin some examples. 



A. proletella, Linn, {chelidovii, Latr.), Latreille (Gen. Crust, ct Ins., iii, 174, 1, 

 and Regne Anim., iv, 188, pi. 69, fig. 16), six joints. Burmeistcr (Ilandb., ii, 1, p. 

 82), six joints, 2nd very long, 3 — 5 equal lengths ; his figure pi. 2, fig. 7, represents 

 joint 1 as very short, 2 very long, nearly half the length of the antenna, 3 — 5 nearly 

 equal, 6 longer than 3. Hceger (Sitzungsber. d. k. k. Akad. d. Wissens., 1855, xviii, 

 35) remarks that Burmeistcr has probably overlooked the small, distinctly separated 



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