220 



Usinger: Hemiptera 



indicate a relationship with the Hebridae and Meso- 

 veliidae whereas the concealment of the mesonotal 

 scutella by the backward extension of the pronotum 

 is a typically veliid character. Brachypterous spec- 

 imens are known in which the pronotum is smaller 

 and the wings are reduced to short pads. 



Macrovelia hornii Uhler (fig. 7:34) was described 

 (as a veliid) eighty years ago from specimens col- 

 lected in New Mexico, Arizona, and California. 

 McKinstry (1942) first called attention to its anom- 

 alous position and recorded it from the Dakotas and 

 from Colorado. California records span the entire 

 state from Siskiyou County to Palm Springs. It occurs 

 at low elevations in the Coast Range and in the 

 foothills of the Sierra. Typical habitats are in the 

 vicinity of permanent streams or springs. Nymphs and 

 adults are found in moss at the water's edge, usually 

 in protected niches behind rocks or logs or among 

 debris. They are never found in or on the water, being 

 incapable of walking on the surface film because of 

 their terminal claws. On the other hand, they are 

 never more than a few feet away from water. Detailed 

 life history studies have not been made. 



REFERENCES 



CHINA, W. E., and R. L. USINGER 



1949. Classification of the Veliidae (Hemiptera) with a 

 new genus from South Africa. Ann. Mag. Nat. Hist., 

 (12)2:343-354. 

 McKINSTRY, A. P. 



1942. A new family of Hemiptera-Heteroptera proposed 

 for Macrovelia hornii Uhler. Pan-Pac. Ent., 18:90-96. 



Family HEBRIDAE 



Velvet Water Bugs 



The velvet water bugs are inconspicuous because of 

 their small size, less than 2% mm. They are stocky 

 with well-developed ocelli, four or five-segmented 

 antennae, very prominent bucculae, and a trough or 

 rostral groove continuing along thoracic sterna. The 

 hemelytra have a single closed cell, and the clavus 

 and corium are continuous and without veins in our 

 species. Brachypterous forms are not common. The 

 body is clothed with a velvety pile of hydrofuge hairs. 

 The claws are apical and are provided with minute, 

 padlike arolia. The nymphs have a single median 

 scent gland opening on the fourth abdominal tergite. 



Life history. — No detailed life history studies have 

 been published for our species of Hebridae. Kulgatz 

 (1911) suggests that the European Hebrus ruficeps 

 overwinters as an adult. Hungerford (1920) observed 

 ovipositing bugs in June near Ithaca, New York (H . 

 concinnus Uhl.), the eggs being laid partly concealed 

 between the loaves of sprigs of moss. The eggs are 

 elongate-oval with rounded ends. 



Habitat. — Hebrus lives in moist places at the edge 

 of the water. It is found most commonly beneath 

 stones or in trash along the margins of streams. 

 Hungerford (1920) fed his specimens on plant lice, 

 midges, and mosquitoes, but they doubtless feed on 



Fig. 7:35. Hebrus sobrinus Uhler, male, Lake Houghtelin, near 

 Bard, Calif. Nov. 13, 1951 (R. L. Usinger). 



any small insects that they can overpower in their 

 secluded habitat. 



Merragata is an inhabitant of floating plants and 

 is found most commonly on mats of Spirogyra at the 

 surface of the water. Drake (1917) describes them as 

 "aquatic pedestrians." He states further that, "It is 

 not uncommon to find them on the under side of float- 

 ing leaves, or even among the roots of floating water 

 plants. When submerged in the water, the insects are 

 surrounded by a film of air which enables them to 

 stay beneath the surface film for a considerable period 

 of time." I found enormous numbers of M. hebroides 

 in flight in the Sacramento Valley near Williams in the 

 summer of 1932. 



Distribution. — Both Hebrus and Merragata are widely 

 distributed throughout the world. Hebrus is the larger 

 genus with twenty-two species known from the Western 

 Hemisphere. Hebrus sobrinus Uhl., H. concinnus Uhl., 

 and H. hubbardi Porter (1952) have been reported from 

 California, but I have seen only sobrinus and hubbardi. 

 The latter was described from Palm Springs. Sobrinus 

 is apparently rather widely distributed. Records at 

 hand include the Pinnacles National Monument, San 



