140 MISCELLANEOUS STUDIES 



37. Genus Cerataphis Liechtenstein 



Lichtenstein, Bull. Soci6te ent. de France, vol. 2, p. 16, 1882. Type Coccus 

 lataniae Boisd. 



162. Cerataphis lataniae Boisduval 



Boisduval, Ent. Hort., 1867. Coccus (orig. desc.). 

 Davidson, Jour. Econ. Ent., vol. 5, p. 404, 1912 (list). 

 Essig, Univ. Calif. Publ. Entom., vol. 1, p. 342, 1917 (list). 

 Eecords. Fern, Stanford University (Davidson) ; orchid, Oakland (Essig). 

 This coccid-like species has been reported twice in the San Fran- 

 cisco Bay region, by Davidson and by Essig. Morrison and the author 

 have also taken it on the same ferns on which Davidson found it in 

 the Stanford University nursery. 



Group Pemphigina Lichtenstein 



Below is a key to the California genera of this group, adapted 

 from Mordwilko, Tullgren and Del Guercio. Del Guercio described 

 a genus in 1909 for Pemphigus radicicola Essig, which he called 

 Trifidaphis. 



1. Antennae of alate females five-jointed Trifidaphis Del Guer 



Antennae of alate females six-jointed 2 



2. Stem mothers with five- join ted antennae. Wax-gland plates on head always 



present and usually large. Spring and fall migrants with wax-gland plates 

 always on mesothorax and abdomen, and usually on head. Dorsal pores 

 never present 3 



Stem mothers with four -jointed antennae. Head normally without wax-gland 



plates. Dorsal pores sometimes present. Stem mothers and spring migrants 

 (fundatrix and fundatrigenia) at first live in the same closed galls. 



Pemphigus Hartig 



3. Secondary sensoria furnished with hairy fringe (Wimperkranz). Wax-gland 



plates generally large. In stem mothers there appear four very large pro- 

 notal wax-gland plates, placed in a transverse row. All plates have a 

 clearly chitinized border. Stem mother and migrants live together. 



Prociphilus Koch 



Secondary sensoria without hairy fringe (Wimperkranz). Wax-gland plates 



generally small. In stem mothers there are six pronotal plates, of which 

 the four middle ones are arranged in the form of a trapezium. In the 

 winged fall migrants (sexupara) there are also transverse abdominal gland 

 plates, which are without clearly chitinized borders. Stem mothers and 

 spring migrants live in separate galls Thecabius Koch 



