428 



Wirth and Stone: Diptera 



12 hooks; habits clambering (fig. 14:380 (DASYHE- 

 LEINAE) Dasyhelea Kieffer 



— Last body segment without proleg or hooks, with fine 

 hairs only; habits swimming (fig. 14:39ee; 14:42A) 

 (HELEINAE) 5 



5. Head short and thick, not more than 1.5 times as long 

 as broad (fig. 14:39aW); body segments each slightly 

 longer than head 6 



— Head long, more than twice as long as broad (fig. 

 14:42t,;'); body segments long and slender 7 



6. Head pear-shaped; body segments wider than head; 

 length more than 5 mm 



Palpomyia Meigen (part), Sphaeromias Curtis 



— Head oval; body segments not wider than head; length 

 4-5 mm. , Culicoides Latreille 



7. Anal hairs as long as, or longer than, last segment 

 alluaudomyia Kieffer 



— Anal hairs usually shorter than last segment (fig. 



14:42A) Palpomyia 



Meigen (part, Bezzia Kieffer, Johannsenomyia Malloch 



Pupae 



1. Pupa with larval exuviae attached to last 3 segments 

 (fig. 14 :39m); respiratory organ short, knoblike (fig. 

 14:39Z,M) (FORCIPOMYIINAE) 2 



- Pupa free from larval exuviae; respiratory organ elon- 

 gated (fig. 14:39n-q,u,v) 3 



2. Abdomen with branched or setaceous projections on 

 first 5 segments (fig. 14:416) Atrichopogon Kieffer 



- Abdomen with spines or stumplike projections on all 

 but last segment (fig. 14:39ii) Forcipomyia Meigen 



3. Anal segment with pair of setigerous protuberances in 

 addition to apicolateral processes (fig. 14:39s) (DASY- 

 HELEINAE) Dasyhelea Kieffer 



- Anal segment without additional setigerous protuber- 

 ances (fig. 14:42o-<) 4 



4. Respiratory organ ending in short, dark, ovate, or 

 barrel-shaped structure with about 10 spiracles (fig. 

 14:406, d) (LEPTOCONOPINAE) Leptoconops Skuse 



- Respiratory organ funnel-shaped, clavate, or tubular 

 (fig. 14:42a-/,A) (HELEINAE) 5 



5. Respiratory organ funnel-shaped, entirely covered with 

 scales; with spiracles in pairs (fig. 14:38u) 



Alluaudomyia Kieffer 



- Respiratory organ clavate or tubular, with spiracles 

 not in pairs 6 



6. Respiratory organ tubular (fig. 14:39u,fl,y) 7 



- Respiratory organ clavate or spoon-shaped 8 



7. Respiratory organ with constriction near base; oper- 

 culum without spines . . Stilobezzia Kieffer 



- Respiratory organ with constriction at basal 4th or 

 3rd, operculum with spines (fig. 14:39io,£) 



Culicoides Latreille 



Operculum with 1 pair of setae (fig. 14:42^) 



Palpomyia Meigen 



Operculum with 2 to 4 pairs of setae (fig. 14:42Z-n) 



Bezzia Kieffer 



California Species of Heleidae 



Subfamily LEPTOCONOPINAE 



Genus Leptoconops Skuse 



(Figs. 14:37oe; 14:40) 



Species of Leptoconops are most prevalent in desert 

 and semidesert regions the world over. The shiny 

 black females with milky white wings are vicious 

 biters, preferring to attack in the open in the bright 



8 



Anterior pharyngeal arch^ 

 Posterior pharyngeal arch 



Dorsomedian rod 



Horizontal 

 [" pharyngeal arch 



Antennal arch 



Fig. 14:40. Leptoconops. a,<z,d, L. torrens (Towns.). Larva: 

 a, cutaway view of head and two thoracic segments. Pupa: c, 

 caudal segments; d, respiratory organ, b, L. kerteszi K., pupa, 

 ventral view (Smith and Loew, 1948). 



sunlight. The biology of the "Bodega gnat" and the 

 "Valley black gnat," our two commonest American 

 species, has been described in detail by Smith and 

 Lowe (1948). The orange-colored larvae of L. kerteszi 

 Kieffer, the Bodega gnat, seem to prefer sandy soil 

 near the water line in tidal marshes or on saline 

 lake margins of 'the western states, whereas those of 

 L. torrens (Townsend), the valley black gnat, have 

 been found in wet sinks of the finely compacted clay- 

 adobe soil regions of the western Sacramento Valley 

 and Santa Clara Valley. Development is slow, requir- 

 ing a year for a generation of kerteszi and at least 

 two years for torrens. 



Keys to the California Species of Leptoconops 

 Adults 



1. Frons with numerous long hairs; basitarsi with 15 to 

 20 short, stout, dark spines (fig. 14:37a-<i); body and 

 legs with vestiture of dense, long hairs; coastal 

 marshes in Ventura County; Monterey County; San 

 Nicolas Island freeborni Wirth 1952 



— Frons bare or with a pair of short hairs between eyes; 

 basitarsi with no more than 8 slender spines; body and 

 legs with sparse hairs, mostly short 2 



2. Antenna of female 14-segmented (flagellum 12-seg- 

 mented); basitarsi with no strong differentiated ventral 

 spines; 9th tergite of male with 2 long, widely spaced, 

 apicolateral processes; west side of Central Valley; 

 Santa Clara Valley; Riverside County 



torrens (Townsend) 1893 



— Antenna of female 13-segmented (flagellum 11-seg- 

 mented); basitarsi with 2 to 8 spines; 9th tergite of 

 male with a caudomesal pair of short processes (fig. 

 14:37e); coa.stal salt marshes and salt and alkaline 

 lakes throughout California kerteszi Kieffer 1908 



Larvae 

 1. Mature larva orange colored; body with apparently 23 



