Speleon Miller and Stange, 2012

Miller, Robert B. & Stange, Lionel A., 2012, The cave mouth antlions of Australia (Neuroptera: Myrmeleontidae), Insecta Mundi 2012 (250), pp. 1-65 : 17-18

Speleon Miller and Stange , new genus

Type species: Speleon yallingup Miller and Stange , by present designation.

Diagnosis. Adult: antennal rim with several setae that project over eye; Miller’s organ developed; midfemoral sense hair not developed.

Description. Adult: body 18-21 mm, forewing 24-27 mm, hindwing 23-26 mm. Structure: antenna sturdy, moderately long; antennal fossae separated by about lateral width of scape; antennal rim with several short setae that project over eye; palps short, distal palpomere weakly swollen, oval palpomaculum about in center; pronotum longer than greatest width; forecoxa about l.5 longer than greatest diameter as viewed laterally; foreleg shorter than midleg which is shorter than hindleg; forefemoral sense hair short, inconspicuous; midfemur without distinguishable sense hair; forefemur about five times longer than middle diameter, shorter than foretibia; tibial spurs absent or very short (no more than one-half basitarsal length); tarsus shorter than one-half length of tibia, basitarsus of hindleg longer than distal tarsomere; pretarsal claws small, about as long as tarsomere IV, not opposable; male pilula axillaris present; forewings slightly longer than hindwing; forewing vein CuP originates slightly distad of basal crossvein; forewing costal area simple, without interconnected crossveins, highest near middle of wing; Banksian lines absent; hindwing posteriorly at highest point higher than greatest presectoral area; Miller’s organ present (small gland-like structure) on abdominal sternite I; abdomen shorter than wings; male ectoproct without lobes; male paramere plate-like, gonarcus strongly arched; female terminalia without digging setae; posterior gonapophysis short, incurved ( Figure 25), anterior gonapophysis present, but usually weakly swollen.

Larva (based on S. yallingup ): mandible longer than head capsule, three teeth increasing in length distally; distance between teeth much longer than distance between mandibular base and basal tooth; mesoscutum without specialized setae medially; mesothoracic spiracle borne on very short tubercle; anterior thoracic scolus about three times longer than middle diameter, swollen distally; posterior mesothoracic scolus a little longer than middle diameter; metathoracic scoli weakly developed, much broader than long; abdominal scoli absent; abdominal spiracles small, flush with integument; sternite VIII without submedian teeth; abdominal segment IX about one-half as long as wide.

Distribution. Only Australia.

Biology. The larvae of Speleon are found in Zone 2C which is sun and rain protected, but warm enough to support species living in horizontal, sometimes lichen filled ( S. cavernicolus ), rock cracks, with 90 degree angles, characteristic of areas with shale. The mostly immobile larvae were nearly exposed because they lived in tight cracks usually oriented horizontally. They only had a partial covering of dust on their bodies.

Discussion. Speleon is distinct from the other 18 genera of Dendroleontini in Australia. In the key to genera presented by New (1985), this genus would key out to Compsoleon Banks. However , the pretarsal claws are opposable in Compsoleon which is probably closely related to Froggattisca . Several species of the speciose genera Glenoleon Banks and Austrogymnocnemia Esben-Petersen are known and the larvae have a mesoscutal setal lure which is not found in the larvae of Speleon . The presence of Miller’s organ, a small gland-like structure located on sternite I (function unknown) is an apomorphy of Speleon found also in Austrogymnocnemia Esben-Petersen , Platyleon Esben-Petersen and some Glenoleon Banks. There are three species known in this genus.

Etymology. The genus name is from the Greek spelos (cave) and leon (lion), and is masculine in gender.