Machimus latapex Martin, 1975

Dennis, D. Steve & Barnes, Jeffrey K., 2013, Pupal cases of three Nearctic species of Machimus (Diptera: Asilidae), Zootaxa 3683 (5), pp. 561-570 : 562-564

Machimus latapex Martin, 1975

( Figs. 1–3 )

Machimus latapex Martin, 1975: 20

This description is based on one pupal case and associated pinned male labeled, “Riverside Cal. May 19, 1947, pupa in ground, Issued June 3, 1947, Timberlake Coll., Machimus latapex Mtn. det. J. Wilcox 76, UCR. USNMENT00876153”.

Description. Pupal case straight. Greatest length, including anterior antennal processes 16.5 mm; greatest width of thorax 3.5 mm; greatest width of abdomen 3.0 mm, tapering to 1.75 mm at greatest width of abdominal segment 8. Subshining light yellowish brown, smooth to variably rugose (wrinkled) or rugulose (minutely wrinkled). Spurs, dorsal spines, and antennal processes, and processes of abdominal segment 9 uniformly light reddish brown to darker apically; dorsolateral, postspiracular, and ventral bristlelike spines pale yellowish ( Figs. 1– 3 ).

Head with pair of basally rugose, dorsally rounded to flattened, ventrally wedge shaped anterior antennal processes not joined at base; with group of 3 subequal, basally fused posterior antennal processes located ventrolaterally on each side; innermost process not widely separated from outermost processes; 2 outermost processes closer together, basally fused for greater distance; innermost and middle processes dorsally rounded, ventrally wedge shaped; outermost process wide for entire length, dorsoventrally flattened, apically blunt; basal sensory pore present on proximal side of outer process, in flattened, oval to elongate, sclerotized area. Facial area lacking median and lateral spines. Labral sheath rugulose, with posterior rugose tubercle extending over proboscidal sheath. Proboscidal (= proboscial, olim, incorrect spelling) sheath about 1/3 longer than labral sheath, smooth, with shallow median groove extending to vertical posterior tubercle. Maxillary sheaths smooth to rugulose, extending 2/3 length of proboscidal sheath, lacking apical processes or tubercle-like swellings. Palpal sheaths not visible between maxillary and labral sheaths.

Anterior coxal sheath smooth to irregularly rugulose, with anterior median longitudinal split. Posterior coxal sheath not visible, folded inward. Paired elongate oval prothoracic spiracles slightly directed posteriorly on stalk on small callosity, situated midlaterally at anterior margin of thorax. Pair of anterior mesothoracic spines present on each side of thorax above bases of mid leg sheaths, dorsally rounded to ventrally slightly wedge shaped or dosoventrally flattened; spines equal in size, basally rugose, straight or anterior spine slightly curved towards venter. Posterior mesothoracic callosity at base of wing sheath large, smooth to rugose; with apically rounded posterior mesothoracic spine with sclerotized edge. Wing sheath mostly smooth, but posterior third rugose; basal and medial tubercles absent. Thoracic area above wing sheaths smooth to rugulose, especially on posterior margin. Leg sheaths smooth to apically rugulose and slightly bilobed with small medial projection. Hind leg sheath reaching to slightly beyond posterior margin of abdominal segment 3.

Abdominal segment 1 with slight median space dividing transverse row of long, recurved spurs. Abdominal segments 2–7 generally lacking dorsal median space dividing transverse row of spurs and spines, with or without median broad, bifurcate spine, with transverse rows of alternating long, recurved spurs and short, straight spines; some spines broad and apically blunt, spines generally slightly anterior to spurs, and some lateral spurs and spines becoming shorter. Dorsolateral and lateral postspiracular bristlelike spines generally become longer on posterior segments; some spines very close together and not equally spaced. Ventral bristlelike spines mostly long, subequal, some becoming shorter laterally.

Abdominal segments 1–7 with spiracles situated along midline laterally, shining reddish brown, oval to elongate oval, on slight stalk or callosity that is smooth to rugose.

Abdominal segment 1 with slight median space dividing anterodorsal transverse row of 10 long, equal, apically recurved spurs; lacking dorsolateral bristlelike spines; with 3–4 mostly long postspiracular bristlelike spines; venter obscured by wing and leg sheaths.

Abdominal segment 2 with short, broad, bifurcate dorsomedian spine flanked on each side by rows of 6 alternating long, straight to apically recurved spurs and short, straight spines; with 6–7 mostly long, equal dorsolateral bristlelike spines; with 7–8 mostly long postspiracular bristlelike spines; with 8 mostly long ventral bristlelike spines extending under wing and leg sheaths on each side, becoming shorter towards midline.

Abdominal segment 3 with dorsomedian transverse row of 13 straight, short spines alternating with straight to slightly apically recurved long spurs; with outer spine short on each side; with 5–6 mostly long, equal dorsolateral bristlelike spines; with 6–8 mostly long postspiracular bristlelike spines; with ventromedian transverse row of 23 mostly long bristlelike spines, with median spine very short and indistinct.

Abdominal segment 4 with short, slightly bifurcate dorsomedian spine flanked on each side by 6 alternating long spurs and short, straight to slightly apically recurved spines, with additional short spine on each side; with 6– 8 mostly equal dorsolateral bristlelike spines; with 6–7 mostly long postspiracular bristlelike spines; with ventromedian transverse row of 18 mostly long bristlelike spines, with some short spines indistinct.

Abdominal segment 5 with broad, slightly bifurcate dorsomedian spine flanked on each side by 6 alternating long, apically recurved spurs and short, straight, spines; with 5 mostly long dorsolateral bristlelike spines; with 6–7 mostly long postspiracular bristlelike spines; with ventromedian transverse row of 20 mostly long bristlelike spines, some short spines indistinct.

Abdominal segment 6 with short, broad, slightly bifurcate dorsomedian spine, flanked on each side by 6 alternating apically recurved long spurs and straight, short spines; with 5 mostly long dorsolateral bristlelike spines; with 6 mostly long postspiracular bristlelike spines; with ventromedian transverse row of 20 mostly long bristlelike spines, some short spines indistinct.

Abdominal segment 7 with short, straight dorsomedian spines flanked on each side by 3 long, apically recurved spurs alternating with short, straight spines; with 2–3 mostly long dorsolateral bristlelike spines; with 5–6 mostly long postspiracular bristlelike spines; with ventromedian transverse row of 20 mostly long bristlelike spines.

Abdominal segment 8 with dorsal transverse row of 5 mostly medium spines divided by wide dorsomedian space; with 7–8 mostly long lateral bristlelike spines; laterally with small spherical reddish brown spiracle flush with cuticle; with ventromedian pair of short bristlelike spines flanked on each side with 5 mostly long bristlelike spines, some apically bifurcate.

Abdominal segment 9 with about equal length dorsal posterolateral and ventral posterolateral processes, apically curved towards each other; with very small anterior ventromedian tubercle and medium size midventral tubercle on each side of midline.

Figures

FIGURES 1 – 3. Machimus latapex male pupal case. 1, dorsal view. 2, lateral view, showing abdominal segments 1 – 9. 3, ventral view. aap = anterior antennal process, absr = abdominal spiracles, absr 8 = abdominal spiracle 8, amsp = anterior mesothoracic spines, dpp = dorsal posterolateral process, lesh 1 = fore leg sheath, lesh 2 = mid leg sheath, lesh 3 = hind leg sheath, pap = posterior antennal processes, pmc = posterior mesothoracic callosity, pthsr = prothoracic spiracle, vpp = ventral posterolateral process, wsh = wing sheath.