256 Annals Entomological Society of America [Vol.1, 



Wingless oviparous female. — Head pale dirty green and with a median promi- 

 nence projecting anteriorly. Antennae dusky and faintly imbricate; one sen- 

 sorium near the extremity of V, and several at the distal end of the basal portion 

 of VI; placed on frontal tubercles, and the first segment soinewhat gibbous; 

 about one-half the length of the body; (PI. XXII, fig. 16.) Eyes black. Beak 

 reaching to the coxas of the second pair of legs. Dorsum of prothorax almost 

 entirely covered with a colored patch, the coloration being a mixture of red, 

 brown, and black, intermixed with lighter colors; other thoracic segments with 

 a similar coloration, but the bars of color are broken along the median line. 

 Legs dusky, excepting the basal halves of the femora, which are pale green; the 

 hind tibias very noticeably swollen and bearing many circular sensoria. (PI. XXI, 

 fig. 10.) The three anterior segments of the abdomen with markings similar 

 to those on the meso- and metathorax; the remaining segments with darker 

 markings which are more or less contiguous, and appear as a large dark patch 

 on the dorsum. Cornicles green at the bases and becoming dusky at the tips, 

 extending almost to the end of the abdomen; and the distal two-thirds strongly 

 incrassate. Style pale dirty green, conical, and less than half the cornicles in 

 length. 



Measurements. — (Taken from specimens mounted in balsam.) Length of 

 body, 2.0798 mm.; width, 1.0544 mm.; antenna, I, 0.0733; II, 0.0570; III, 

 0.2559; IV, 0.1G95; V, 0,1768; VI, basal. 0.1255; VI, filament, 0.1532; total, 

 1.0112 mm.; cornicles, 0.4352 mm.; style, 0.1793 mm.; hind tarsus, 0.1304 inm. 



Eggs. — The elliptical-oval eggs are orange-yellow when first laid, but grad- 

 ually change to a jet black. 



Winged male. — Head black and with gibbous frontal tubercles. Antennae 

 black, except the two basal segments; reaching beyond the tip of the abdomen; 

 segment I gibbous, III the longest, and the last three more or less imbricate; 

 irregularly placed sensoria as follows: 19-29 on III, 5-10 on IV, 5-7 on V, and 

 several at the distal end of the basal portion of VI. (PI. XXII, fig. 14.) Eyes 

 black. Thoracic plates black. Wings hyaline and with dark veins; the first 

 and second discoidals branching about one third (sometimes varying to one half) 

 the distance from the margin to the third discoidal. Legs dirty yellow, except 

 the articulations, which are dark, and the tarsi, which are black. Abdomen 

 yellow with black transverse bars, the anterior ones being broken along the me- 

 dian line. Cornicles concolorous with the abdomen and darkening towards the 

 apex, extending beyond the tip of the abdomen; distal two-thirds strongly 

 incrassate, and the tip more or less flaring. Style dusky to black, conical, and 

 slightly longer than the hind tarsus. 



Measurements.-^(Taken from specimens mounted in balsam.) Length of 

 body, 1.2784 mm.; width, 0.5360 mm.; length of wing, 2.5997 mm.; width, 

 1.0425 mm.; vAng expanse, 5.6449 mm.; antenna, I, 0.0652; II, 0.0570; III, 

 0.4373; IV, 0.2934; V, 0.2836; VI, basal, 0.1752; VI, filament, 0.2315; total, 

 1.5432 mm.; cornicles, 0.3260 mm.; style, 0.1276 mm.; hind tarsus, 0.1167 mm. 



Male pupa. — Entire body pale greenish-yellow. Eyes dark red-brown. 



The Yellow Clover Plant-louse (Callipterus trifolii Monell). 

 This yellow Callipterus is common in all parts of Illinois, liv- 

 ing solitary, usually on the undersides of the leaves of red clover 

 (Trifolium pratense). C. trifolii was first described by Mr. J. T. 

 Monell in the Canadian Entomologist, Vol. XIV, p. 14 (1882), 

 from specimens collected in Washington, D. C, June 8, 1880. 

 In the literature it has been reported from Iowa (Osborn and 

 Sirrine) , and from Delaware (Sanderson) . I have received speci- 

 mens from Mr. Paul Hayhurst, collected in Minnesota, and he 

 writes that he has also found it in Kansas, Minnesota, North 

 Dakota, and Virginia. Mr. Monell writes that he has found it in 



