130 IOWA ACADEMY OF SCIENCES. 



the Hchizoneura aud Pemphigus females are known to occur under the rough 

 bark of trees. To the naked eye the form taken in June resemble the color 

 of the corrugated leaves, while older specimens of the fundatrici, being 

 covered w^ith a pulverulent secretion, aside from the flocculent secretion 

 near cauda and sides of the body, are of a bluish purple. 



Though this may prove to be the spring migrant of a form already 

 described, and named, as occurring on some other plant, it does not agi'ee 

 with any description of Pemphigus to which I have access, moreover no 

 Pemphigtis has been described as occurring on Hawthorn. Hence the 

 specific name of corrugatans from its habit of corrugating the leaves on 

 which it feeds, is proposed for the present, or until its complete life cycle 

 shows it to be one stage of a known species. The following descriptions of 

 the fundatrix, pupa and alate migrant are appended: 



Pemphigus corrugatans, n. sp. 



Alate Vivip. form. Spring Migrant, from corrugated colored leaves of 

 Crataegus tomentosa (?), June 26th, 1893. 



Expanse of wings, 6.53 mm.; length of body, 2.35 mm.; width, 1.10 mm.; 

 length of antenna?, 0.85 mm.; (Joint I., .05 mm.; II., .07 mm.; Ill, .30 mm.; 

 IV., .13 mm.; v., .17 mm.; VI. plus unguis, .16 mm.); Joint HI, with about fif- 

 teen transverse sensoria. In some cases part of these are double, making 

 upward of twenty-five in all; IV., with from six to twelve; V., with from 

 three to five; VI., slightly roughened. (These sensoria are situated on raised 

 portions of chitine, so they appear as transverse ridges, but not as complete 

 chitinous rings in any case). Rostrum reaching second pair of coxae. Dis- 

 tance between base of first and second discoidals varies from to .08 mm., 

 in some cases the second discoidal is united with the first for a distance of 

 .20 mm. Distance between base of cubital and second discoidal varies from 

 .05 mm. to .10 mm ; the former subobsolete at base. Stigmal with a simple 

 curve. Distance between apices of all the veins approximately equal; (the 

 apices of the stigmal and cubital may average a trifle nearer than the others). 

 Stigma, .59 mm. by .16 mm., rhomboidal. Distance between discoidals of 

 the posterior wings approximately the same as in anterior pair; costal 

 abruptly curved forward where the discoidals issue. 



Color.— (Specimens not mounted, observed with hand lense) antenna?, 

 head and wing callosities black; thorax, yellowish green; eyes, brown; legs, 

 dusky. The two median and the lateral lines of dermal wax glands* secrete 

 the longest flocculent material, so there is a ridge of the latter between the 

 wings, and a margin of the same at the sides of the body. These masses of 

 waxy secretion crowd the wings into an oblique position. (The variation in 

 the length of the secretion from the dermal glands is true for the pupa, and 

 larval fundatrix; those on the latero-caudal portion of the abdomen secreting 

 the longest flocculent material so the body appears flattened.) 



(Specimens mounted in balsam and examined with compound micro- 

 scope) ground color yellowish green, apex of abdomen a shade lighter; 

 wing callosites dusky to black, antenna? and head somewhat darker; pro- 



* On the abdomen there is a dermal gland on each segment between the median 

 pair and the one on the lateral margin. As far as observed in vemphigus there are a 

 pair of these glands on the head, two pairs to each thoracic segment, a median pair 

 and one on each lateral margin; three pairs to each abdominal segment, median, sub- 

 median and lateral. Those on the abdomen are united in some instances, especially 

 toward the cauda. 



