Navasoleon lithophilus Miller 2018, new species
Creators: name: Stange, Lionel A.
name: Miller, Robert B.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Neuroptera
Myrmeleontidae
Navasoleon
Navasoleon lithophilus

description: Navasoleon lithophilus Miller, new species
Figures 6, 15, 24, 43, 50, 59, 60, 65, 66, 67
Type locality. La Libertad, Peru.
Description. Vertex without anterior row of dark brown markings; interantennal area with large dark brown mark; forewing with small dark brown rhegmal mark; hind femur without dark spots; pronotum with many long setae, as long as, or longer than the longest setae on the clypeus; mid femoral sense hair short and dark brown; tarsomere 3 of foreleg shorter than distal tarsomere; tarsomeres I-IV of midleg not flattened ventrally.
Holotype male. Length of body 18 mm., forewing length 27 mm., width 5.5 mm., hindwing length 26.5 mm., width 4.5 mm.; wing span 56 mm. Coloration: Face (Fig. 6) nearly all pale brown with diagonal dark brown area below antenna socket; small band above antennae, v-shaped at middle; palpi all pale brown; antenna mostly pale brown with most dark brown areas laterally; vertex pale brown with L-shaped dark brown mark submedially near middle, anterior row of dark brown markings missing, posterior row of dark brown markings reduced to small spots submedially; pronotum (Fig. 15) mostly pale brown with complex dark brown pattern consisting anterior area, sublateral spot near anterior margin, small median dark brown stripe at anterior, and large sublateral curved stripe on posterior two-thirds; some dark brown laterally; pterothoracic nota (Fig. 24) mostly pale brown with dark brown mostly confined laterally, prescutum with most margins dark brown and with small dark brown stripe medially; dark brown strip lateral of scutella which are mostly pale brown with dark brown on lateral margin and with dark brown medial stripe; pterothoracic pleura (Fig. 24) mostly pale brown with scattered small dark brown areas; coxae mostly pale brown with scattered dark brown spots; femora and tibia pale brown with numerous dark brown spots at setal bases; tarsi pale; abdominal tergites brown with darker area on tergites 1–2; sternites brown with pale brown stripe near pleural membrane; forewing (Fig. 43) with small dark brown rhegmal mark. Chaetotaxy: Face (Fig. 6) with inconspicuous setae; pronotum with many long setae, as long as, or longer than the longest setae on the clypeus; forefemoral sense hair about equal to that of midfemur and about 1.5 times as long as femoral diameter; ventral setae on distal tarsomere of foreleg longer than middle diameter of tarsomere, apically hooked; ventral setae on other legs as long as middle diameter of tarsomere, not hooked; all setae on hindtibia shorter than tibial diameter; female ectoproct with short setae ventrally. Structure: Distal palpomere of labius (Fig. 6) weakly swollen, palpimacula before center; antenna not clavate; pronotum longer than wide; foreleg tarsomere 2 slightly shorter than distal tarsomere which is bent subapically. Male genitalia (Fig. 50): With gonarcus nearly uniform in width, weakly arched; no mediuncus; paramere elongate and strongly divergent, about 6 times longer than greatest width, with sculpture limited to posterior margin; small ovoid sclerite apically behind paramere
Female. About as described for male. Female terminalia (Fig. 59, 60): Posterior gonapophysis swollen, narrowed apically, about five times longer than greatest diameter, without setae exceeding length of gonapophysis, distal setae longest, longer than gonapophyseal diameter; lateral gonapophyses transverse, fused, with many moderately long, curved, scraping setae; pregenital plate small; spermatheca serpentine, strongly bent posteriorly.
Larva (Fig. 65–67). Flattened with length about 12 mm. (not including jaws). Coloration: Pale yellow colored with dark brown pigmentation as follows: all setal bases; dorsal 3 stemmata; entire first antennal segment; maxillary lobe; mandibular teeth apically and apical curved part of mandible; head capsule dorsally with dark brown on area anterior in epistomal suture; transverse bar near posterior margin of epistomal suture; submedian dark brown spot near middle, and small submedian, converging stripe at about posterior one-half; large spot at anterolateral margin extending mesally about one-half distance where mark points anteriorly; two lateral spots before spiracular tubercle; thorax and abdomen with irregular dark speckling as in figure 65; all setae white with elevated dark bases except for a few dark ones on legs and brownish digging setae on sternite IX. Chaetotaxy: Dorsal head capsule with small dolichasters present; long, white, weakly plumose hairs on lateral surface of head and all scolus-like processes, those laterally on head capsule longer than antenna; mandible with abundant white setae on exterior margin, those on exterior margin extending nearly to distal mandibular tooth; elsewhere hairs abundant but short, plumose white setae dorsally and long fine plumose setae abundant ventrally; mandible with about 17 stout setae on elevated sockets from base to basal tooth, about three setae between tooth 1 and 2 and one setae between tooth 2 and 3; mandibles with abundant white, weakly plumose setae from near base to tooth 3; ocular tubercle with several small setae and with one prominent setae above stemmata; sternite 9 with small, relatively stout brown setae reduced to two groups of five subapically. Structure: Head almost quadrate, thickest near middle; posterior margin cordate; dorsum somewhat more convex than venter; labium strongly bilobed with broad emarginate at midline; ocular tubercle small, directed nearly laterally, broad than long; dorsal 3 stemmata smaller than others; antennal tubercle less than one-half length of ocular tubercle; antenna with about 19 segments, narrowing toward apex; scape swollen about three times longer than wide; all antennal segments longer than wide; antenna reaching far beyond end of ocular tubercle, about two times as long as basal width of jaw; labial palpus longer than basal width of mandible, first segment about three times longer than wide, longer than second but shorter than distal palpomere which is swollen with sensory orifice before middle; mandible falcate, about 1.5 times longer than head capsule, smoothly tapering to distal tooth just beyond which is strongly curved tip; three teeth located well beyond midpoint of mandible; middle tooth slightly longer than distal one and about 1.3 times longer than basal tooth; middle tooth usually closer to distal tooth than to basal tooth (Fig. 69); left mandible of one exceptional specimen with teeth nearly equidistant; ventral mandibular condyle bounded medially by a large curved arm of anterior end of subgenal ridge; postlabium bilobate, rounded anteriorly; broadly articulating with widely separated prelabial lobes; latter mostly straight, strongly curved along anterior margin in apical fifth; pronotum about 1.5 times broader than long, anterior margin gently curved at anterolateral margin, somewhat prolonged posteriorly; forepretarsal claws small, midpretarsal claws somewhat larger and hind pretarsal claws larger still but less than twice as long as mesothoracic claws; mesothoracic spiracle borne on large cone-shape tubercle; metathoracic scolus-like processes double pair, followed by double lateral pair on abdominal segment I, followed in decreasing size by single lateral scolus-like processes to abdominal segment 7, weakly flattened, all more than two times longer than wide; spiracles not borne on tubercles; sternite 8 without odontoid processes.
Distribution. Peru.
Collection times. July.
Material studied. Holotype male, 2 adult male paratypes, 2 adult female paratypes, 1 larva.
PERU. La Libertad: 9 km. west Samne, Peru, 20.VII.1982, R. Miller and L. Stange, reared (3m, 2f, l larva, FSCA).
Biology. The biology of this species was originally discussed in Miller and Stange (1985), though at the time it had been misidentified as Navasoleon boliviana. In 1982, 18 larvae were collected at the type locality. The well camouflaged larvae sit and wait for days on a large rock overhang to ambush any suitable passing prey. A larva in the field was observed eating a fly. In the laboratory in 1982, larvae were selective regarding what types of food were acceptable. Larvae would remain still and refuse small spiders, small caterpillars, and termites, whereas flies, small moths, and small immature crickets were readily accepted. They lack the ability to dig. We have observed larvae in the same position in a tube, lined with coarse paper, for several months. In the tubes the larvae always oriented themselves head downward with the mandibles at a 180-degree angle. In the field, they may also be found horizontal on ceilings.
Cocoon construction is unique among known antlions since it is a double cocoon attached to vertical rock. The cocoon consists of an outer and inner cocoon structure. The larva first builds a domed, porous outer cocoon about 12 mm in diameter and 6 mm in height upon the rock face, over a three-day period. The larva spends three or four days spinning a spherical, dense inner cocoon, which also contacts the rock face. Scattered threads connect the rest of the inner spherical cocoon structure to the outer cocoon structure (Fig. 70).
The elapsed time from the start of the cocoon to emergence was about 52 days in four reared specimens. Orientation of the pupa during the emergence in N. lithophilus is different from that of other known antlion genera which spin cocoons in the soil and orient themselves by gravity to emerge from the top of the cocoon. The N. lithophilus pupa chews its way out of the cocoon at dusk through the center of the area of greatest light intensity (straight out from the rock wall. This was demonstrated when a cocoon was partially constructed on clear plastic and light was directed at the back of the cocoon. The pupa began chewing at the back of the cocoon toward the light. When the area in the back of the cocoon was covered with black tape and light was most intense at the front of the cocoon, the pupa chewed through the center of the exposed area of the cocoon as is normal.
Expansion of the adult N. lithophilus after ecdysis is different from that of any other antlion genus yet studied. In other genera, the adults emerge from the pupal skin which may or may not be half embedded in the soil after the pupa digs to the surface. The teneral adult then crawls to a vertical object to climb. There it expands its wings and abdomen at the same time. However, in N. lithophilus, after chewing open the front of the cocoon, the pupa protrudes the forward half of its body from the cocoon with the ventral surface of the pupa facing upward. The pupal skin splits along the dorsal center line of the thorax and the legs, head, and wings are pulled free of the pupal skin as the abdomen partially expands. This pushes the anterior portion of its body out and away from the cocoon. The adult remains protruding from the cocoon by its partially expanded abdomen, the end of which is firmly in the cocoon. The body protrudes from the cocoon at an angle of about 15 degrees down from the horizontal. The head, antennae, and legs are held for about an hour in the same position as when they were in the pupal skin. At the end of this interval the legs have hardened sufficiently to grasp the wall or cocoon, climb it, and finish expanding the abdomen and expanding the wings. Species in other studied genera were able to use the legs shortly after getting free of the pupal skin.
Discussion. The larva is ascalaphid-like in structure with a weakly cordate head, ten pairs of scoluslike processes, hind pretarsal claws only somewhat larger than mesothoracic pretarsal claws, elongate mandible with teeth beyond middle and flattened appearance. The only other known Navasoleon larva, N. venezolanus, moves more frequently than does N. lithophilus and has one scolus–like process on abdominal segment one as opposed to the two found on N. lithophilus.
Etymology. The species name, litho (Greek for rock) and philus (Greek for loving), is in recognition of the rock-loving nature of the larvae.
description: Published as part of Stange, Lionel A. & Miller, Robert B., 2018, A revision of the genus Navasoleon Banks (Neuroptera: Myrmeleontidae: Nemoleontini), pp. 1-25 in Insecta Mundi 619 on pages 11-14, DOI: 10.5281/zenodo.3699409