302 



Leech and Chandler: Coleoptera 



tibiae faint and confined to distal half; elytra very coarsely 

 rugose; color dull black; length 1 1 to 14.5 mm.; Alaska 

 to southern California, east to Montana; in California, south 

 at least to San Jacinto Mountains of Riverside County 

 insolens LeConte 1853 



REFERENCES 



(For a full bibliography see Edwards, 1951) 



EDWARDS, J. G. 



1951. Amphizoidae (Coleoptera) of the World. Wasmann 

 Jour. Dial., 8:303-332, 4 pis. 



1953. The real source of Amphizoa secretions. Coleopt. 

 Bull., 7:4. 



1954. Observations on the biology of Amphizoidae. 

 Coleopt. Bull., 8:19-24. 



HATCH, M. H. 



1953. The beetles of the Pacific Northwest. Part I: 

 Introduction and Adephaga. Univ. Wash. Publ. Biol., 

 16:vii+ 1-340, incl., front., 2 text figs., 37 pis. 



PIIOSTCRNAL 



PKOCCSS 



CPIPLCUKON i_ 



ANTCCOXAL 

 JCLCI«ITC_ 



Family HALIPLIDAE 



Crawling Water Beetles 



Though known as the crawling water beetles, haliplids 

 are fairly good swimmers in ponds and lakes. They 

 are found in running and in quiet waters, usually 

 near the shore, and especially in association with 

 algae (Chara, Nitella, Spirogyra, and others). They 

 eat both plant and animal matter, and are in turn 

 preyed upon by fish. Adults and larvae are aquatic, 

 but pupal cells are formed on the shore, in damp soil 

 or sand. 



Relationships.— The Haliplidae are included in the 

 Caraboidea, but are at once distinguished by their 

 greatly enlarged platelike hind coxae, which cover at 

 least the first two abdominal sternites and the basal 

 halves of the hind femora (fig. 13:3a, b). The antennae 

 are inserted more nearly between the eyes than in 

 other Caraboidea (except the Cicindelidae), and the 

 elytra almost always have longitudinal rows of large 

 punctures (fig. 13:4a). An origin from terrestrial forms, 

 but independently of other aquatic groups, has been 

 suggested. 



Respiration. — The young larvae of haliplids obtain 

 oxygen by cutaneous respiration; after the second 

 instar they have spiracles. Adults must come to the 

 surface of the water for air, and their methods of 

 respiration have been reported by Hickman (1931). He 

 found that a beetle which has a supply of air in both 

 the reservoir under the elytra and its connection, the 

 chambers formed by the expanded hind coxae, is able 

 to float up and break the surface film with the tip of 

 its abdomen. With air supply replenished it dives, and 

 shows a large bubble protruding from the hind coxal 

 cavity. This bubble has both respiratory and hydro- 

 static functions; a beetle deprived of it cannot float 

 up and break the surface film with its abdomen, but 

 must swim up and crawl out to obtain air. Since the 

 subelytral and hind coxal air reservoirs are connected, 

 a beetle can live if only the latter are allowed contact 



Fig. 13:3. Haliplidae. a, Peltodytes callosus, part of under- 

 surface; b, Haliplus sp., underside of hind leg to show coxa, 

 trochanter, and part of femur covered by hind coxal plate; c, 

 Peltodytes lengi, pupa; of, Peltodytes lengi, front leg of larva; 



e, Haliplus (ongu/us, left side of pronotum to show basal plica Fig. 13:4. Haliplidae, adults, a, Peltodytes simplex; b, Brychius 

 (a, Leech, 1948; b, Matheson, 1912; c, d, Hickman, 1930; e, hungerfordi (o, Leech, 1948; b, Spongier, 1954). 



Wollis, 1933). 



