rounded; Modoc and Mono counties 



culicoidithorax (Hoffman) 1926 



4. Mesonotum with marked bluish-gray pruinescence; wings 

 intensely whitish, the surface with ridges; anterior 

 radial cells only slightly infuscated; Siskyou and 



Mono counties pruinosa Wirth 1952 



— Mesonotum shining black; wings milky white; anterior 

 radial cells deeply infuscated, forming a black stigma 

 (fig. 14:38r,s); Modoc, Mono, Nevada, and Humboldt 

 counties stigmalis (Coquillett) 1902 





Tribe STILOBEZZIINI 



Genus Stilobezzia Kieffer 



(Fig. 14:4 Id) 



According to Thomson (1937) the larvae of Stilobezzia 

 are commonly found in mud and algae along pond 

 margins, and because of their curved bodies and slow, 

 crawling motion they closely resemble the larvae of 

 Dasyhelea. The food habits were not stated. The 

 North American species have been revised by Wirth 

 (1953). 



Key to Adults of the California Species of Stilobezzia 



1. Wings without macrotrichia (subgenus Stilobezzia), 

 small, pruinose brown species with distinct gray 

 pruinose mesonotal pattern; El Dorado and San Luis 



Obispo counties pruinosa Wirth 1952 



— Macrotrichia present on distal part of wing (subgenus 

 Neostilobezzia). Larger dull yellowish-brown species; 

 mesonotum with 3 indistinctly darker vittae; Tulare 

 County fuscula Wirth 1952 



Genus Serromyia Meigen 



Strenzke (1950) found the larvae of S. femorata (Mei- 

 gen) in damp moss in Germany. There is only one 

 known California species. 



barberi Wirth 1952. 



Humboldt, San Luis Obispo 



Genus Monohelea Kieffer 



(Fig. 14:38d,e) 



The American species have been revised by Wirth 

 (1953). Their habits are not known. Strenzke (1950) 

 found larvae of M, calcarata Goetghebuer in moss in 

 a spring. 



maculipennis (Coquillett) 1905. Monterey County 



Tribe STENOXENINI 



Genus Neurohelea Kieffer 

 nigra Wirth 1952. Mono, Tulare counties 



435 



Wirth and Stone: Diptera 



Genus Clinohelea Kieffei 



San Luis Obispo County 



usingeri Wirth 1952 

 (Fig. 14:38n-5) 



Genus J ohannsenomyia Malloch 



Wirth (1952) described the pupa of </. sybleac Wirth 

 (fig. 14:42&,£) which was taken from a cattail-choked 

 pond near the beach. Malloch (1914) also described 

 the pupa of J. flavidula (Malloch) taken from the 

 Illinois River. The pupae are characterized by ex- 

 tremely short prothoracic respiratory organs. 



Key to Adults of the California Species of Johann senomy ia 



1. Halteres and pedicel of antennae white to yellowish 

 (fig. 14:39o-C); northern and central California 



sybleae Wirth 1952 



— Halteres and pedicel of antennae brown to black .... 2 



2. Hind tibia yellowish on basal 2/3; anterior wing veins 

 yellowish; Modoc County halteralis (Malloch) 1915 



— Hind tibia all black; anterior wing veins brown 3 



3. Femora and tibiae extensively yellow; size 2.5 mm.; 



northern and central California 



caudellii (Coquillett) 1905 



— Femora and tibiae entirely black; size 2.0 mm.; Imperial 

 and San Bernardino counties pullata Wirth 1952 



Genus Sphaeromias Curtis 



Species of this predaceous genus are among the 

 largest in the family. Thomsen (1937) described the 

 larva and pupa of S. longipennis (Loew). The larvae 

 of this genus, together with those of Palpomyia and 

 Bezzia, are predaceous, and are often present in 

 large numbers in blanket algae in ponds and shallow 

 lakes. 



Key to Adults of the California Species of Sphaeromias 



1. Femora, especially on fore legs, with apices yellowish, 

 broad brown bands in middle; legs very spiny; large 

 species more than 4 mm.; antennae long, flagellar 

 segments annulated; Modoc County 



longipennis (Loew) 1861 



— Femora with apices brown, bases broadly yellowish; 

 legs moderately spiny; medium-size or small species 

 less than 3.5 mm.; antennae long or short, segments 

 not annulated 2 



2. Antennae shorter than height of head including probos- 

 cis; abdominal tergites uniformly pale yellow; size 

 2.5-3.5 mm.; Colorado River brevicornis Wirth 1952 



— Antennae nearly twice as long as height of head; at 

 least some abdominal tergites brown, with narrow 

 apical light border; size less than 2.0 mm.; Kern, Mono, 

 San Bernardino, and Imperial counties 



minor Wirth 1952 



Genus Palpomyia Meigen 

 (Fig. 14:39d,e; UA2a,f,g,o,r) 



