430 



Wirth and Stone: Diptera 



excavated, with marginal row of hairs entirely across 

 sternite 3 



2. Ninth sternite with 3 hairs on each caudolateral margin; 

 caudomedian lobe of aedeagus rounded (fig. 14:38,/) 



occidentalis Wirth 



— Ninth sternite with compact group of 3 to 5 hairs in row 

 in middle of posterior margin; median point of aedegus 

 sharp websteri (Coquillett) 



3. Parameres expanded broad and platelike and almost 

 meeting mesad, anterior arm reduced; aedeagus quadrate 

 with semidetached, dorsoposterior sclerite bearing 2 

 small distal spines arcticus (Coquillett) 



— Parameres hooklike with distinct anterior arm; aedeagus 

 without spinose, detached, dorsoposterior sclerite 



4 



4. Aedeagus with broad, caplike apex 5 



— Aedeagus with apex rounded or with sharp median point 

 6 



5. Ninth sternite about twice as broad as long, caudal 

 margin transverse; dististyles with very slender tips; 

 parameres expanded caudad fusculus (Coquillett) 



— Ninth sternite more than 3 times as broad as long, with 

 broad, shallow, mesal excavation; dististyles tapering 

 to moderate tips; parameres not expanded mesad 



minutus (Meigen) 



6. Aedeagus with caudomedian rounded lobe; 9th sternite 

 transverse, with about 20 hairs transversus Wirth 



— Aedeagus with distinct sharp caudomedian point; 9th 

 sternite with broad, shallow, excavation with about 

 10 hairs levis (Coquillett) 



Genus Forcipomyia Meigen 



(Figs. 14:38J,m; U:S9k-m,ff-ii) 



Saunders (1924) has published our best account of 

 the immature stages of Forcipomyia. Most of the 

 species are terrestrial, the gregarious larvae breeding 

 under tree bark, in manure or moist decaying vegetable 

 matter, in ant nests, and the like. However, there are 

 many subaquatic species frequenting damp moss and 

 algae, and in tropical America they often breed in the 

 water inside the leaf bases of bromeliads and other 

 plants. One such species was imported to Hawaii in 

 pineapple plants. F. calcarata (Coquillett) larvae (fig. 

 14:39£,m) were found along the rocky margin of a 

 warm mineral spring at Alum Rock Park in Santa Clara 

 County (Wirth, 1952). Females of eques (Johannsen) 

 and related species suck the blood from the wing 

 veins of lacewing flies, butterflies, and other insects. 

 The closely related genus Pterobosca, which is found 

 in the southeastern states and more commonly through- 

 out the tropics, has modified tarsi for attachment to 

 the wings of dragonflies. 



Keys to Adults of the California Species of Forcipomyia 

 Females 



1. Tarsal ratio (length of 1st segment of hind tarsus 

 divided by length of 2nd) less than 1.2; 2nd radial cell 

 not elongate (subgenus Forcipomyia) 2 



— Tarsal ratio greater than 1.2; 2nd radial cell elongate 

 14 



2. Tarsal ratio 0.4-0.9; 3rd palpal segment swollen to 

 tip; tibiae without lanceolate scales 3 



— Tarsal ratio 0.75-l.*2; 3rd palpal segment swollen at 

 base only; tibiae with or without lanceolate scales 



5 



3. Abdominal segments without apical yellow bands: legs 

 with long yellow bristles, femora and bases of tibiae 

 brown; wing with dark stigma of long, shaggy black 

 hairs; tarsal ratio 0.5-0.6; San Joaquin Valley 



brookmani Wirth 1952 



— Abdominal segments with apical yellow bands; legs 

 uniform brown, with long black bristles; wing without 

 dark costal spot; tarsal ratio 0.67-0.9; larvae under 

 tree bark - 4 



4. Tarsal ratio 0.9; southern California 



texana texana (Long) 1902 



— Tarsal ratio 0.67; northern California 



texana simulata Walley 1932 



5. Mid and hind tibiae each with an external row of sub- 

 erect, lanceolate scales 6 



— Mid and hind tibiae without lanceolate scales 8 



6. Front tibia without external row of lanceolate scales; 

 widespread in California . .bipuncatata (Linnaeus) 1767 



— Front tibia with an external row of lanceolate scales 

 7 



7. Shining black species with prominent, long, black 

 bristles; wing about 2.0 mm.; transition in northern 

 California cilipes (Coquillett) 1900 



— Dull brown species without prominent bristles; wing 

 about 1.5 mm.; widespread, squamipes (Coquillett) 1902 



8. Mesonotum shining black (tarsi whitish, wings, exten- 

 sively pale; tarsal ratio 1.2); widespread; larvae in 

 manure, etc brevipennis (Macquart) 1826 



— Mesonotum dull brown to yellow 9 



9. Wing with at least 2 light marginal spots 10 



— Wing with not more than 1 light costal spot 11 



10. Wing with 6 pale marginal spots (fig. 14:382); legs 

 unhanded; central California; larvae in compost piles 

 macswaini Wirth 1952 



— Wing with 2 pale costal spots; legs with broad yellow 

 bands; widespread; larvae under pine bark 



cinctipes (Coquillett) 1905 



11. Halteres with dark knobs; unmarked, dull brown spe- 

 cies; tarsal ratio 0.5; widespread 



occidentalis Wirth 1952 



— Halteres entirely whitish 12 



12. Mesonotum dull golden yellow with lighter median 

 band; abdomen banded; Kern County. . .quatei Wirth 1952 



— Mesonotum uniform dull brown 13 



13. Wings with definite yellow costal spot; northern and 

 central California townesi Wirth 1952 



— Wings with uniform brown hairs; Riverside County 



hurdi Wirth 1952 



14. Tarsal ratio 1.5-2.0; (subgenus Euforcipomyia); south- 

 ern and central California . .calcarata (Coquillett) 1905 



var. sonora Wirth 1952 



— Tarsal ratio 2.0 or more (subgenus Thyridomyia) .... 15 



15. Last 5 antennal segments moniliform; tarsal ratio 2.9; 

 northern and central California 



monilicornis (Coquillett) 1905 



— Last 5 antennal segments each about twice as long as 

 broad; tarsal ratio 2.2; southern and central California 



colemani Wirth 1952 



Mole Genitalia 



1. Parameres present and well developed; generally elon- 

 gate (fig. 14:38m) 2 



— Parameres absent or in form of short hyaline plates 

 (subgenus Euforcipomyia) 16 



2. Parameres short and stout, not connected mesad at 

 bases, arising from an expanded triangular plate extend- 

 ing cephalad of root of basistyles; 9th sternite with 

 deep caudomesal excavation or window (subgenus 

 Thyridomyia) 15 



— Parameres usually nearly as long as basistyles (fig. 

 14:38m), connected mesad on posterior margins (sub- 

 genus Forcipomyia) 3 



3. Parameres fused at bases for distance greater than 4 

 times basal width of free parts 4 



