72 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. 



certain that this species is a true Pemphigus. This will thus make 

 the genus Amycla a synonym. 



In 1847 Rondani described the genus Aphioides of which bursaria 

 Fab. was indicated as the type and Aphioides, therefore, is a synonym. 



In 1854 Koch erected the genus Pachypappa of which marsupialis 

 Koch has been made the type. • Marsupialis, however, is a typical 

 Pemphigus. Pachypappa Koch, therefore, must become a synonym. 

 Tullgren (1909) used Pachypappa in a different sense, but this is 

 discussed under the genus Pachypappella. 



In 1886 Lichtenstein erected the genus Kessleria for spirotliica 

 and this name was replaced by Hamadryaphis Kirk, in 1904. A 

 study of this species, however, shows that it is a typical Pemphigus. 

 Therefore, these two names will become synonyms. 



Characters. — Cornicles present; wax plates, if present, weakly developed; stem- 

 mother with four-segmented antenna;; alate form with six-segmented antennae which 

 are armed with narrow, oval or somewhat irregular sensoria. Fore wings with the 

 media simple; hind wings with both media and cubitus present. Sexes small, apter- 

 ous, and beakless. Oviparous female developing only one egg. 



Forms living in galls, the stem-mother and her offspring in the same gall, the alate 

 forms typically leaving the galls in the spring. 



Type (fixed by Passerini, 1860), Aphis bursaria L. 



Genus PHLOEOMYZUS Horvath. 



Plate XI, W-BB. 



1S86. Lowia Lichtenstein, Mon. Puceron Peupl., p. 37. 

 1S9G. Phlocomyzus Horvath, Wien. Ent. Zeit., v. 15, p. 5. 



In 1S86 Lichtenstein erected the genus Lowia with ScMzoneura 

 passerinii Sig. as type but as this name had been used previously it 

 was replaced in 1896 by Phloeomyzus Horvath". 



It is with some hesitation that the writer places this genus in the 

 Pemphigini. In some respects it suggests the Melaphini, while 

 in many respects it strongly suggests the Thelaxini or even the 

 Phyllaphidina. Indeed, to the Melaphini it shows striking 

 resemblances. Without a study of the sexual forms it will be very 

 difficult to place the genus definitely. All that can be done at the 

 present time is to place it tentatively with the forms with which it 

 appears to be related, and if further study shows this to be incorrect 

 the genus can be placed definitely with its allies. 



Characters. — Cornicles present, very slightly elevated. Apterous form with six- 

 segmented antennae. Alate form with six-segmented antennas which are rather 

 slender and without secondary sensoria. Fore wings with the media once branched, 

 hind wings with both media and cubitus present. Large wax plates present on the 

 abdomen. Wings held flat in repose. 



Forms living free upon the bark of trees in colonies. 



Type (monotypical i, ScMzoneura passerinii Sig. 



Study based on specimens received from Mordwilko from Warsaw, 

 Poland, and notes by Pergande on type specimens loaned by Horvath. 



