A Generic Review Based on Larvae of the Acanthaclisine Antlions (Neuroptera: Myrmeleontidae)L
Total Page:16
File Type:pdf, Size:1020Kb
Vol. 1, no. 1, January 1985 INSECTA MUNDI 29 A Generic Review of the Acanthaclisine Antlions Based on Larvae (Neuroptera: Myrmeleontidae)l Lionel A. Stange2 and Robert B. Miller3 IITRODUCTIOI The tribe Acanthaclisini Navas contains 14 (Rambur), whereas Steffan (1975) provides described genera which we recognize as additional data on this species as well as valid. We have reared larvae of 8 of these on Acanthacliais occitanica (Villers). Our (Acanthaclisis Rambur, Centroclisis Navas, best biological data on the Acanthaclisini, Fadrina Navas, Paranthaclisis Banks, Phano excluding larval behavior, are based on clisis Banks, Synclisis Navas, Syngenes observations of Paranthaclisis congener Kolbe, and Vella Navas). In addition, we (Hagen) made near Reno, Nevada. In common have studied preserved larvae from Aus with most antlions, P. congener lay eggs at tralia which probably represent the genus dusk. Aa the female expels the eggs, she Beoclisis Navas. This represents the ma evenly coats them with sand, using the pos jority of the taxa, lacking only the small terior gonapophysis. The eggs are shallowly genera Avia Navas, Cosina Navas, Madrasta buried, in contrast to other known non Navas, Mestressa Navas, and Sti~hroneuria acanthaclisine species which lay their eggs Gerstaecker. Studies of these larvae have on the surface. Some females caught just revealed structural differences, especially after dusk still had egg material on the of the mandible, which we have employed to end of their abdomens where some had been provide ident ification of these genera by broken. Their abdomens appeared empty. means of descriptions, keys, and illustra Like most antlion species with thick abdo tions. Also, since no modern key exists, mens, Paranthaclisis species lay eggs in we are providing a key to the genera based batches rather than a few every day. One on adults which will provide some further female captured at dusk had a plump abdomen ins ight on the generic relat ionships. Ob and layed 20 eggs which left her abdomen servations on the tribal differences of empty. The eggs were large and oblong and Myrmeleontidae based on larvae are made hatched in 24 days. Little or no expansion with a preliminary key to the known tribes. of the head capsule and mandibles takes place upon hatching in Paranthaclisis. Tribe Acanthaclisini Navas 1912 This is unlike other tribes where upon hatching the head capsule and mandibles Included genera: Acanthaclisis Ram expand with the mandibles hanging like limp bur, Avia Navas (=.Jaya Navas), Centroclisis spaghetti before expansion. Other char Navas (=Sogra Navas, =Reboda Navas, =Reo acteristics are similar to larvae in other clisis Navas, =Stenoclisis Navas, =Sograssa tribes. There are three larval instars, Navas), Cosina Navas, Beoclisis Navas, and diapause, if assumed, occurs in the Madrasta Navas, Mestressa Navas, Parantha larva in the sand and not in the cocoon nor clisis Banks, Phanoclisis Banks (-Rora in the egg. The cocoon is constructed of Navas), Stiphroneuria Gerstaecker (=Reriga silk beneath the sand with sand grains Navas), Syncliais Navas, Syngenes Kolbe covering the surface. The mobile pupa digs (=Onclua Navas), Vella Navas (=Gyroplectron its way to the surface of the sand where Esben-Petersen) [Note: The genus Vellasaa the adult emerges and then climbs any con Navas is of uncertain status]. venient object before expanding its anten nae, wings, and abdomen. General Biology: Principi (1947) de Description (based on larvae): Three tailed the biology of Synclisia baetica segmented labial palpus shorter than basal width of mandible; distal palpomere 1.5 to 1. Contribution No. 603, Bureau of Ento 3.0 times longer than wide; sensory opening mology, Div. Plant Industry, Fla. Dept. Agric. & Cosnumer Services, variable in size; mandible with 1 (Paran Gainesville, FL thaclisis), 2 (Centrocliais), or 3 teeth 2. Taxonomic Entomologist, Div. Plant when 3, basal tooth shorter than distal Industry, P. O. Box 1269, Gainesville, one; lateral margin with or without long FL 32602. setae, but setae never longer than one-half 3. FSCA Research Associate, P. O. Box 1092, Project City, CA 96079. greatest width of mandible; mesothoracic spiracle not borne on tubercle; scoli ab- 30 INSECTA MUNDI Vol. 1, no. 1, January 1985 sent; dolichasters absent on head; abdomi and "uncati" (tibial spurs evenly curved). nal sternite VIII without submedian teeth; These 2 groups appear to be fairly natural sternite IX without enlarged pair of dig divisions but since the names are not de ging setae; tergite IX without median lobe rived from included genera they are noaina bearing median sclerotized process. nuda. Perhaps when the larval stages of Larval Behavior: None of the larvae Avia, Cosina, Hadrasta, Mestressa, and studied construct pitfall traps. Two dis Stiphroneuria are known, a logical sub tinct types of locomotion are present. division of the tribe can be made. The two Backward movement only is found in the most highly evolved genera based on larval genera Phanoclisis and Vella. Forward and structure and behavior are Centroclisis and backward movement are found in Acantha Parantbaclisis. Both appear to be select eliaia, Centroclisis, Fadrina, Beoclisis, feeders in the laboratory and show re Paranthaelisia, Syngenes, and Synelisis. ductions in the mandibular teeth to 2 (Cen The latter three genera are fast runners troelisis) or 1 (Paranthaclisis). Also, and burrowers. Centroclisis larvae are both genera have highly reduced antennae slow creepers and diggers. Aeanthaelisis, which are also reduced in one species of Beoelisis, and Fadrina larvae are fast Fadrina. Synclisis and Syngenes appear to burrowers but seldom move forward rapidly, have evolved convergently in structure and at least under laboratory conditions. The behavior. Both genera are fast runners and larvae usually inhabit open tracts of sand burrowers, apparently favoring coastal where considerable sand depth is required beach dunes, having relatively long man for temperature regu lat ion, protection of dibles and with sternite IX relatively the large cocoon, escape and concealment pointed and without peg-like setae on ster from predators, as well as space for ni te VIII (Figs. 8, 9). Fina lly, Pbano hunting prey. Most species are incessant cliaia appears to be relatively plesio feeders (except notably Centroelisis and morphic in many adult characters (distal Paranthaclisis) and require a fairly high palpomere, pretarsal claws) but its larva sand surface temperature to pupate. The moves only backward, a behavioral trait cocoon is constructed in a single day and shared by the unrelated Vella. the period from construction of the cocoon Measurements: Measurements (in mm) of to the emergence of the adult is 54±3 days the head capsule were made from the ventral in all of the genera reared so far except surface. The longitudinal measurement was Fadrina (35 days). All of the genera made along the midline from the base of the studied, except Centroclisis, feed when the head capsule to the level of the mandible sand temperature is warm, but avoid extreme base. The width was measured at the widest temperatures above or below safe levels by part of the head capsule. The mandible burrowing deeply in the sand. It is common length was measured (dorsal side) from the to see them active on the surface in mid base to, the distal side of the distal morning, late afternoon, and very warm tooth. The width was measured at the nights. Centroclisis is the exception as widest part of the mandible. The average the species studied is strictly nocturnal. measurements are given with the number of Disenssion: This tribe is well de specimens examined in parenthesis. fined by both larval and adult characters Illustrations: The photographs are and shows limited structural diversity in all of the 3rd ins tar larva except for comparison to most tribes of antlions. Figure 8 (Synclisis baetica) which is based Some group characters are present which on a 2nd instar larva. Figure 16 of Acan suggest at least 4 subgroups: Group 1 - tbaclisia sp. shows a deformed middle tooth Centroclisis and Paranthaclisis; Group 2 - of the right mandible. The left mandible Syngenes and Synclisis; Group 3 - Acantba of Figure 16 and both mandibles of Figure clisis, Fadrina, and Phanoclisis; Group 4 - 20 show the normal condition of the man Beoclisis and Vella. Navas (1912) divided dibular teeth. The photographs were taken the tribe into 2 groups; "uncinati" (adult by Robert B. Hiller. tibial spurs bent at nearly right angle) Vol. 1, no. 1, January 1985 INSECTA MUNDI 31 Key to Genera of Acanthaclisini LARVAE 1. Sternite VIII without short, blunt, peg-like setae although stout but point- ed digging setae present (Figs. 8 -11) ••••••••••••••••••••••••••••••••••••• 2 Sternite VIII with numerous short, peg-like setae (apex truncate) (Figs. 3-7) ....................................................................• 5 2. Ventral head capsule densely setose, except along midline (Fig. 21); Western Hemisphere ........................................................... Vella Ventral surface of head capsule glabrous except laterally (Fig. 25) ...... 3 3. Mandible with prominent setae on interior margin of mandible between tooth 1 and mandibular base; sternite IX broadly rounded (Fig. 11); Australia ........•...........................................•............. Be 0 eli 8 i 8 Mandible without setae between tooth 1 and mandibular base;sternite IX pointed (Figs. 12, 13) .................................•........•.......