417 

 Wirth and Stone: Diptera 



Fig. 14:28. Tendipedinae, Hydrobaeninae, and Clunioninae. o,e-g, Hydrobaenus: a, female; 

 e, globule of eggs; f, pupa; g, larva. b-a' # Calopsecfra: b, female; c, string of eggs; d, larval 

 head, h-l, Telmafogeton, Pupa: h, ventral view; i, respiratory organ; j, caudal shield. Male: 

 k, habitus. Larva: /, lateral view (Williams, 1944). 



Subfamily HYDROBAENINAE 



(Figs. 14:20a,;,?; 14:276-o; U:28a,e-g; 

 U:29h-p; 14:31m) 



This subfamily is so large and so little known except 

 in Europe that it is practically hopeless to attempt 

 any sort of discussion of it. The recently published 

 key by Thienemann (1944), however, as well as the 

 recent papers by Strenzke on the terrestrial forms 

 (1950, particularly), will attract much needed attention 

 to these tiny midges in this country. Habits are as 

 diverse as the species and genera are numerous. Some 

 species (Saunders, 1928) breed together with the 

 Clunioninae on algae-covered, intertidal rocks along 

 seacoasts where their swarms are often apparent in 

 contrast to the nonswarming scampering movements of 

 the true marine midges. The species of Cricotopus 

 (figs. 14:20a,?; 14:27?-o), Corynoneura (fig. 14:276-e), 

 Metriocnemus, and Brillia are more often strictly 

 aquatic, breeding in a wide variety of ponds and 

 streams. Some Cricotopus (Berg, 1950) mine the leaves 

 of aquatic plants, and several species are economic 

 pests of rice (Risbec, 1951). Two undescribed Cali- 

 fornia species of Cricotopus have recently been found 

 living in pads of the alga Nostoc, probably in close 

 biological association. Two species of Metriocnemus 

 breed in the water-filled cups of pitcher plants, M. 



knabi Coquillett (fig. 14:27/-A;) in the eastern Sarra- 

 cenia and M. edwardsi Jones (fig. 14:29A-p) (1916) in 

 Darlingtonia, the California pitcher plant. The genus 

 Cardiocladius is restricted to rapidly flowing water, 

 whereas species of Symbiocladius (fig. 14:31m) live 

 as commensals or parasites under the wing pads of 

 mayfly nymphs of the genus Rithrogena (Claassen, 

 1922; Codreanu, 1939; Roback, 1951). The genus 

 Hydrobaenus (fig. 14:28a,e-a) as known in this country 

 is a dumping ground for most of the remaining members 

 of the subfamily including many aquatic species, but 

 especially for the subaquatic and terrestrial species 

 which breed in damp and wet ground along stream 

 margins, swampy areas, mossy banks, bogs, or in 

 almost any moist situation. Many of the more terres- 

 trial species show a reduction of the posterior prolegs 

 or anal gills of the larva or the prothoracic respiratory 

 organs of the pupa. 



Subfamily TENDIPEDINAE 



Students of stream and lake ecology and fish produc- 

 tion are most concerned with the larvae of the larger 

 species of this subfamily, which are commonly spoken 

 of as bloodworms. With the exception of a few species 

 of Calopsectra most of the members of the Tendipe- 

 dinae live in sluggish or quiet water, some in lpk«s 

 at great depths. 



