Apocleinae
Amblyonychus
Eccritosia
Furcilla
Mallophora
Megaphorus
Nevadasilus
Proctacanthella
Proctacanthus
Promachella
Promachus
Efferia-group
Albibarbefferia
Aridefferia *
Carinefferia
Efferia
Nerax
Pogonioefferia
Triorla
Tuberculefferia

Nearctic species:

1. Aridefferia apache (Wilcox, 1966)
2. Aridefferia arida (Williston, 1893)
3. Aridefferia basingeri (Wilcox, 1966)
4. Aridefferia coulei (Wilcox, 1966)
5. Aridefferia cuervana (Hardy, 1943)
6. Aridefferia harveyi (Hine, 1919)
7. Aridefferia pinali (Wilcox, 1966)
8. Aridefferia prattii (Hine, 1919)
9. Aridefferia snowi (Hine, 1919)
10. Aridefferia subarida (Bromley, 1940)
11. Aridefferia subpilosa (Schaeffer, 1916)
12. Aridefferia tolandi (Wilcox, 1966)

 
 
 
 
 
 
 
 

- female -

 
 
 
 
 

	Males
	Females

	Abdominal segments 4-7 silvery tomentose, segment 4 with white parted hairs. Bristles of tarsi usually black.
	At most abdominal segments 5-7 silvery tomentose, without white parted hairs on any segments. Bristles of tarsi white

	Mystax yellowish, sometimes with some black hairs below on the sides. Abdominal segments 1-3 black haired, tergite 8 brownish tomentose and sternite 8 with a dense fringe of brotvn hairs apically. Length 15-23 mm . . . . . Aridefferia snowi (Hine, 1919) [KS, CO, NM, TX, OK, SD?, MEX]
	Mystax white, about 3 black bristles and some black hairs below on the sides. Abdominal segments 1-3 largely white haired, tergite 8 polished brown or black and sternite 8 with a sparse fringe of white hairs. Length 13-17 mm . . . . . Aridefferia coulei (Wilcox, 1966) [WA, BCA]

	Mystax mith many black hairs on the sides and below, white centrally.
	Mystax white, the black hairs if any below.

	Wings tinged with yellow along the veins, third vein usually branched before the end of the discal cell. Hairs above on the antennae black. Ffringe on the lower forceps sparse. Length 18-26 mm . . . . . Aridefferia pinali (Wilcox, 1966) [AZ]
	Wings hyaline, third vein usually branched beyond the end of the discal cell. Hairs above on the antennae white. Fringe on lower forceps dense.

	Legs black. Scutellar bristles usually white. Discal hairs subequal in length to the bristles. Surstyli dorsally with black hairs. Length 16-26 mm . . . . . Aridefferia arida (Williston, 1893) [CA, NV, UT, OR]
	Basal half or more of the tibiae reddish. Scutellar bristles usually all black. Discal hairs 2/3 length of bristles. Surstyli white haired, sometimes a felt, black dorsally. Length 14-22 mm . . . . . Aridefferia subarida (Bromley, 1940) [AZ, NM, UT, TX]

	Surstyli from dorsal view of nearly uniform width.
	Surstyli from dorsal view nearly twice as wide apically as at the base.

	Abdomen white haired, at most a few black hairs at base of segments 1-3. Antennae and humeri white haired
	Dorsum of abdominal segments 1-3 broadly black haired. Antennae and humeri in part black haired.

	Abdominal segments 5-7 white tomentose. Pulvilli 20/35 length of the clans. Length 19-23 mm . . . . . Aridefferia apache (Wilcox, 1966) [AZ, UT, NM]
	Abdominal segments 6-7 white tomentose. Pulvilli 26/36 length of the claws.

	Abdominal segments with a few black hairs basally. Mesonotal crest formed entirely of hairs. Tooth on the lower forceps acute. Length 24-25 mm . . . . . Aridefferia basingeri (Wilcox, 1966) [NV, CA, OR, UT]
	Abdomen white haired. Mesonotal crest formed mainly of bristles. Tooth on lower forceps rounded apically. Length 19-29 mm . . . . . Aridefferia harveyi (Hine, 1919) [BCA, CA, OR, WA, UT]

	Abdominal segments 1-3 and 4 in part with black hairs, longer at the sides, venter white haired. Length 22 mm . . . . . Aridefferia subpilosa (Schaeffer, 1916) [UT, CA, NV, NM]
	Dorsum of abdominal segments 1-3 black haired, long hairs on sides white, venter of abdominal segments 2-4 largely black haired. Length 20-31 mm . . . . . Aridefferia tolandi (Wilcox, 1966) [CA, NV]

	Legs, abdominal segments 3-7 and genitalia, red. Vestiture of scutum and scutellum white. Leg bristles black. Length 10-12 mm . . . . . Aridefferia cuervana (Hardy, 1943) [NM]
	Femora black, tibiae and tarsi pale bkownish. Abdomen and genitalia black. Scutum black haired. Leg bristles in part pale. Length 16 mm . . . . . Aridefferia prattii (Hine, 1919) [TX]

	Legs red. Abdomen reddish brown . . . . . Aridefferia cuervana (Hardy, 1943) [NM]
	Femora and abdomen black.

	Ovipositor 5.5 mm long or longer.
	Ovipositor 4.5 mm long or less.

	Mystax with many black hairs below and on the sides. Scutellar bristles black. Ovipositor 5.5 mm long . . . . . Aridefferia pinali (Wilcox, 1966) [AZ]
	Mystax at most with a few black hairs below. Scutellar bristles largely white

	Ovipositor slender, about 1/10 as wide as long at the middle.
	Ovipositor broader basally, about 1/7 as wide as long at middle.

	Abdominal segments 2-7 usually white haired, venter 1-5 with fine erect hairs. Pulvilli 20/35 length of claws. Ovipositor 5.8 mm long . . . . . Aridefferia apache (Wilcox, 1966) [AZ, UT, NM]
	Abdominal segments 2-7 usually with black hairs dorsally, venter 1-2 with fine and 3-6 with coarse erect hairs. Pulvilli 26/36 length of claws. Ovipositor 5.5-5.9 mm long . . . . . Aridefferia basingeri (Wilcox, 1966) [NV, CA, OR, UT]

	Scutellar hairs all or largely white. Abdominal segment 1 white haired, 2-7 at most narrowly black haired dorsally. Ovipositor 5.5 mm long . . . . . Aridefferia harveyi (Hine, 1919) [BCA, CA, OR, WA, UT]
	Scutellar hairs all or largely black. Broad dorsum of abdominal segments 1-3 and 4-7 dorsally, black haired. Ovipositor 6.1 mm long . . . . . Aridefferia tolandi (Wilcox, 1966) [CA, NV]

	At most 8 scutellar bristles. Bristles of tibiae and tarsi in part black.
	About 20 scutellar bristles. Bristles of tibiae and tarsi largely white.

	Scutellar hairs black. Ovipositor 4.0 mm long . . . . . Aridefferia prattii (Hine, 1919) [TX]
	Scutellar hairs white or yellowish

	Mystax yellowish. 8 black scutellar bristles. Femora reddish at tip. Ovipositor 3.6 mm long . . . . . Aridefferia snowi (Hine, 1919) [KS, CO, NM, TX, OK, SD?, MEX]
	Mystax white. 4-6 white or black scutellar bristles. Femora all black. Ovipositor 3.8 mm long . . . . . Aridefferia coulei (Wilcox, 1966) [WA, BCA]

	Legs all black. Ovipositor 4.5 mm long . . . . . Aridefferia arida (Williston, 1893) [CA, NV, UT, OR]
	Basal half or more of the tibiae reddish. Ovipositor 4.0 mm long . . . . . Aridefferia subarida (Bromley, 1940) [AZ, NM, UT, TX]

Contents: © Fritz Geller-Grimm, Jorge N. Artigas, 2007
Layout & images: © Fritz Geller-Grimm, 2007