Fig. 7:36. Merragata hebroides White, Oahu, T. H. 

 (R. L. Usinger) (Zimmerman, 1948). 



Benito County, May 3, 1946 (H. P. Chandler); French- 

 man's Flat, Tehachapi Mountains, California; Pine 

 Canyon, Mt. Diablo, May 23, 1937 (R. L. Usinger); 

 Navarro River, Mendocino County, June 15, 1950 

 (H. B. Leech); and Lake Houghtelin near Bard, Im- 

 perial County (R. L. Usinger). 



Merragata hebroides White is very common in Cali- 

 fornia, being found in low elevations throughout the 

 state. It was originally described from the Hawaiian 

 Islands but was almost certainly introduced there from 

 California. M. brevis Champion has been reported 

 from California (Drake and Harris, 1943), but I know 

 it only from Mexico. 



Taxonomy. — The two principal genera of Hebridae 

 are differentiated by a rather superficial character, 

 that is, the number of antennal segments. No other 

 characters appear to support this division so it may 

 very well be that the present classification will prove 

 to be one of convenience only. At the species level 

 the form and proportions of antennal segments and 

 sculpturing of the head and pronotum are the most 

 useful external characters. In some species of Hebrus 

 long setae project from the margins of the male genital 

 segment, and these provide useful characters for 

 differentiating species. The most comprehensive treat- 

 ment of the taxonomy of our species is by Drake and 

 Harris (1943) with additional new species described 

 by Porter (1952). 



221 



Usinger: Hemiptera 



Key to the Genera of Hebridae 



1. Antennae 5-segmented (fig. 7:35) . . .Nebrua Curtia 1888 



— Antennae 4-segmented (fig. 7:.'((i) 



Verragota White 1S77 



Key to Species of Hebrus 



1. Male genital capsule with long hairs at sides, plainly 



visible in ventral view (fig. 7:35) ..sobrinus Uhler 1877 



— Male genital capsule without long hairs projecting at 



sides; Palm Springs hubbardi Porter 1952 



Key to the Species of Merragata 



1. Third and 4th antennal segments relatively long and 

 slender, 1/2 again as long a.s 1st and 2nd segments; 



Los Angeles County, Drake and Harris, 1943 



brevis Champion 1898 



— First 3 antennal segments subequal or 3rd slightly 

 shorter than 2nd, 4th a little longer, fusiform (fig. 

 7:36); California, widely distributed, also Hawaii 



hebroides White 1877 



REFERENCES 



DRAKE, C. J. 



1917. A survey of the North American species of Mer- 

 ragata. Ohio Jour. Sci., 17:101-105. 

 DRAKE, C. J., and H. M. HARRIS 



1943. Notas sobre Hebridae del Hemisferio Occidental. 

 Notas del Museo de la Plata, 8:41-58. 

 HUNGERFORD, II. B. 



1920. The biology and ecology of aquatic and semi- 

 aquatic Hemiptera. Kansas Univ. Sci. Bull., 11:1-327, 

 2 color pis. plus 30 pi. 

 KULGATZ, TH. 



1911. Die aquatilen Rhynchoten Westpreussens. Bericht. 

 Westpreuss. Bot. Zool. Ver., 33:175. 

 PORTER, T. WAYNE 



1952. Three new species of Hebridae (Hemiptera) from 

 the Western Hemisphere. Jour. Kansas Ent. Soc., 

 25:9-12. 6 figs. 



Family MESOVE LIIDAE 



Water Treaders 



Members of the genus Mesovelia are small, delicate, 

 surface and shore dwellers. Apterous specimens show 

 no sign of hemelytral pads, and the thorax is reduced 

 to simple segments separated by simple sutures. 

 Macropterous specimens, which are less common than 

 the wingless forms, have an enlarged pronotum and 

 both a mesonotal and a metanotal scutellum. The 

 hemelytra are long and have two or three closed cells 

 on the outer half. The membranous apices of the 

 hemelytra are frequently broken, presumably during 

 mating. Mesovelia is related to Macrovelia and to 

 the hebrids, both of which share the following char- 

 acteristics: ocelli, apical claws, and a single median 

 scent gland opening on the fourth abdominal tergite 

 in the nymphs. 



Life history. — The biology of the American species 

 of Mesovelia was summarized by Hoffmann (1932). It 

 is thought that the winter is passed in the adult stage, 



