189 



Usinger: Hemiptera 



forewing 

 clavus corium membrane eye 



pronotal disk.. 



pruinose area of 

 claval suture 



embolium 



nodal furrow 



post-nodal 

 pruinose area 



metaxyphus 



left clasper 

 aedeagus 



ght clasper 



upperf 

 palmar 

 bristles 



upper 

 palmar 

 bristles 



palmar 

 bristles 



Fig, 7:3. Structural details of Corixidae. Hesperocor/'xa laevigata (Uhler) male: a, dorsal view; 

 b, ventral view; c, front leg of male; d, genital capsule of male; e, Graptocorixa cal ifornica 

 Hungerford, front leg of male. 



sharp lateral cephalic margin of the head." According 

 to Hungerford members of the following California 

 genera should be capable of sound production: Cori- 

 sella, Hesperocorixa, and Cenocorixa. 



Corixids have entered into commercial trade chan- 

 nels- for at least three hundred years and probably 

 for many centuries. According to Hungerford (1948) 

 Corisella mercenaria (Say) "is often found in Mexican 

 markets mixed with C. edulis, C. tarsalis (Fieb.) . . . 

 Krizousacorixa femorata (Guer.), K. azteca Jacz., 

 and Notonecta unifasciata Guer. Tons of these dried 

 insects are also shipped abroad for bird or fish food, 

 and their eggs are gathered for human food from Lake 

 Texcoco, Mexico." The adult bugs are called "Mosco" 

 and the eggs "ahuatle." They are for sale over the 

 counter throughout Mexico, and the adults are pack- 

 aged in cellophane envelopes and sold as food for 

 birds and pet turtles in pet stores in the United 

 States. The eggs are laid in enormous numbers on 

 submerged objects, each egg attached by a short 

 petiole. In Mexico eggs are collected (Ancona, 1933) 

 by placing reeds in the water and returning at a later 

 date to harvest them. 



An interesting oviposition relationship between a 

 corixid and a crayfish was first noted by Forbes 

 (1878). According to Griffith (1945) the eggs of Ram- 

 phocorixa acuminata are preferably deposited upon 



crayfish, usually Cambarus immunis and C. simulans. 

 These species are typically associated with the 

 corixid in water holes. The oviposition habit is not 

 obligatory, amounting to a fixation of choice in the 

 behavior pattern of the insect, in which preference 

 extends to areas affected by branchial current. Protec- 

 tion of eggs from drought and enemies is a possible 

 benefit accruing from the association; aeration by 

 branchial currents may be a factor in the choice of 

 special areas; while the convenience of the crayfish 

 in long association with the ovipositing water bugs 

 serves largely to explain the relationship. 



Flight. — Some corixids are attracted to lights in 

 enormous numbers. The most striking example of this 

 in California is Corisella decolor. On the day after a 

 large flight dead specimens of this species are seen 

 in heaps on the ground beneath lights. This has been 

 observed at Davis and elsewhere in the Central Valley. 



Habitats. — The various species of Corixidae show 

 marked preferences for particular habitats and thus 

 may serve as indicators of local conditions. In Cali- 

 fornia Trichocorixa reticulata and T. verticalis are 

 the halobionts, living exclusively in brackish or 

 saline waters. The former species has been found in 

 the ocean (Hutchinson, 1931) and occurs in the brine 

 pools (Leslie Salt Company) on the south shore of 

 San Francisco Bay together with the brine shrimp, 



