The European Elm Scale 9 



to an acutely-pointed, three-lobed apex, whose central lobe is long and 

 pointed and far broader than the two small, rounded, lateral lobes. 

 Division into head, thorax, and abdomen fairly distinct. Wing-sacs 

 longer than broad, nearly lateral in position. Legs and antennae 

 longer than in the first pupa; their segmentation distinct. Through 

 the integument the structure of legs and antennae may be seen dis- 

 tinctly in advanced specimens. 



the wingless male 



Length of head and body, 1.20 to 1.32 mm. Breadth of thorax, 

 .42 to .45 mm. Breadth of abdomen, .44 to .51 mm. Lateral margins 

 of abdomen full and curved, rounding posteriorly to a three-lobed 

 apex, whose pointed central lobe bears the generative organs. The 

 two rounded lateral lobes bear several short hairs as in the winged 

 male, but lack the long, white terminal filaments. Wing pads about 

 twice as long as broad, their length being usually less than the width 

 of the thorax. Surface of pad wrinkled and folded in a most complex 

 manner. Halteres fleshy, often irregularly constricted in the central 

 portion, the terminal hook short, stout, only partially developed. 

 Antennae as in the winged male, but more compact. Legs as in the 

 winged male, but somewhat fuller in outline. Plate VI. 



None of the above characters are at all constant. The wings are 

 often long enough to cover half of the abdomen, which is occasionally 

 slender and elongate as in the winged male. Anal filaments frequently 

 partly developed, but crooked and slender. The wingless male is 

 sexually mature, mating with the newly-moulted females, (1908). 



"WINGED male 



Length of head and body, from 1.32 mm. to 1.56 mm. Body of 

 slender form, broadest at the thorax. The abdomen tapers back in 

 lines nearly straight from its point of union with the thorax ; in fully 

 matured specimens the outline of the abdomen is trapezoidal, while in 

 specimens removed from their cocoons after full development of the 

 wings and anal filaments, the abdomen is broader, with rounded lat- 

 eral margins as in the pupae. The posterior extremity of the abdomen 

 is three-lobed ; the pointed central lobe bears the generative organs ; 

 the rounded lateral lobes give rise to two long white, waxen bristles 

 whose length is to that of the head and body as 17 is to 14. 



Wings white-hyaline, iridescent in sunlight, about twice as long as 

 broad. Halteres with fleshy lobe tapering bluntly at the distal end 

 to a slender rod with hooked extremity, which engages the rim of a 

 purse-like cavity in the posterior margin of the wing. Antennae long, 



