SOUTH AUSTRALIAN GIANT NEUROPTERAN:
A stilbopterygid life history (Aeropteryx linearis)
NOTES ON THE LIVING ADULT AND EARLY STAGES OF
Aeropteryx linearis (Mymeleontoidea: Stilbopterygidae)
FROM LAKE EYRE, SOUTH AUSTRALIA
PO Box 277, Hereford, Arizona 85615, USA
This paper follows an earlier publication (McFarland, 1968), wherein the living larva of this stilbopterygid was depicted in a large newsletter cover photograph (dorsal view), accompanied by only a brief text on the back of the same page. See also Kimmins (1940). During all of the seven years of this rearing (1965-1971), I was primarily involved with moth life history studies (rearing and photography), plus the duties of a full-time job as Assistant Curator of Insects, on the staff of the South Australian Museum of Natural History (North Terrace, Adelaide As the Neuroptera have always ys been among my special secondary interests, this unique opportunity to rear a little-known species could not be passed up! At the time of my first (and only) encounter with Aeropteryx adults on the wing (March of 1965), the male of this species was still unknown. Two of the wild-collected male specimens were later provided to Kimmins, leading to his published description of the male in 1970. [There is an error in this second Kimmins paper which must be mentioned here: on page 3, in both places where the date is given, it states "iv" (= April); this should be iii (= March) in both cases. I was only in the locality from late February to early March, 1965.]
All information recorded below has been adapted directly from my field notebooks, as written between 1965 - 1971. The life history observations that follow were only rendered possible due to a unique feature of most (if not all?) Myrmeleontoidea: their ability to withstand months -- even years -- of neglect and deprivation in the larval stage, just sitting in some dry and waterless niche, waiting for a meal to come along.
(Code-number STL. 1 in McFarland larval collection, South Australian Museum, Adelaide)
(Abbreviations used below: FW = forewing; HW - hindwing)
Locality Data: South Australia, Muloorina Homestead, SE of Lake Eyre, and at Prescott Point on the Sulphur Peninsula (Madigan Gulf), Lake Eyre North -- 3 March 1965. Noel Mc Farland with F.J. (John) Mitchell (then herpetologist at the S.A. Museum). This is a severely dry inland desert locality, about 400 miles north of Adelaide.
The original female for this rearing came to light (160-watt mercury vapor), at the base of some low, pinkish sandhills, about 5 km. W. of the Muloorina Homestead buildings, just across the Frome River. Fourteen other specimens (12 females and 2 males) of this species were also collected at m.v. light, between "late dusk" and 2100 hrs., in the second location -- Prescott Point, amongst pale (whitish) sandhills, with an abundance of Nitraria clumps (Zygophyllaceae); also present was a Scaevola sp. (Goodeniaceae). Between March 1st and March 10th, all of the evenings were very warm and still, following extremely hot days. During this 10-day period, we remained (camping) in exactly the same location at Prescott Point, and I ran the m.v. light every night, starting at early dusk.
Colors of living adult female: Abdominal ground color shiny deep gray with partially black-edged colorful lateral blotches of shiny, clear, pale yellow. Thorax covered with soft, pale gray hairs, shading to pale yellowish anteriorly. Antennae yellow-brown basally, becoming deep yellow on the clubs. Vertex of head (between eyes) dull chocolate brown. Wing venation yellow in part. This fades to a paler yellow in dry specimens, and the yellow spots on the abdomen will eventually darken (discolor) to brownish. Pale yellow on venter of thorax between forelegs, and also at the bases of all legs.
The original female, captured on 3 March 1965, was kept alive by frequent hand feedings over a period of about four weeks (i.e., until early April)! She was fed as much as she would consume once every evening, just at dusk. This was accomplished by holding her in one hand (with the wings folded over the dorsum so that she couldn't flutter), and offering live insects held with forceps. If suitable, they would be quickly devoured upon contact with the mandibles. She would also usually grab the prey with her legs while feeding. (Her feeding behavior was reminiscent of a hand-held dragonfly under the same circumstances.) She was amazingly voracious! [Do these stilbopterygids perhaps "hawk" through the air at dusk, eating their captures while on the wing? This seems likely.]
Examples of some insects fed to the hand-held female: 4 March 1965 -- 1 plump female noctuid (25 mm. long), one scarab beetle (13 mm. long), eight bushflies (Musca); March 5th -- one plump female noctuid. She also drank water from a spoon (while hand-held), and would take small scraps of raw meat. Eggs were usually deposited in fine sand (inside a gallon jar), within one or two hours (or less) after feeding, during the early evening hours. On March 5th, eight eggs were deposited; on March 6th, eleven eggs, which was the most for one night. Before her death, a total of 65 eggs (all fertile) had been gradually accumulated over a period of 4 weeks in confinement, with regular "forced"feedings almost every evening.
During the entire period of oviposition, the female was confined in the same wide-mouthed glass jar, containing only fine sand from the habitat. There were no holes in the lid of the jar. She was kept cool and out of the sun by day, and was well fed each evening at dusk, using any suitable insects available at the lights. The eggs were left free in the sand, some on top and some of them buried. All of them hatched successfully after about 39 to 40 days (indoors, at prevailing early autumn temperatures in Adelaide). The eggs were coated with fine sand grains, which adhered to them. They were at first pale pinkish-white, later becoming more deeply pinkish, and finally darkening to grayish prior to hatching. About half of these 65 living eggs were sent to several other entomologists, to attempt rearing. (I am not aware that any of them succeeded; or, if they did, they never bothered to inform me.)
The newly hatched larvae were rather slow and clumsy, crawling only forward when on the surface. The abdomens were wooly-pubescent. They soon buried themselves just below the surface (never with any pit or depression), where they would remain motionless, in exactly the same position for days on end, with the mandibles held fully open to 180°, and usually faintly visible as is a thin, straight black line just at the sand surface. To be captured, the insect had to step directly onto the mandibles (or slightly behind them), or there would be no reaction. These larvae would never make the least effort to pursue moving prey, even if the insect approached to within 2 mm. of a mandible tip! The most suitable prey items were found to be small, soft-bodied spiders (slightly stunned), or various small, soft-bodied insects, especially stunned flies, soft beetles, stunned small antlion larvae, plump beetle larvae, small moths, etc.
March, 1966 - Unfortunately, all of the larvae were neglected during most of 1965. Nine were still surviving in February, 1966, and these were once again started on regular feedings, having changed very little after twelve months without food or moisture! If nothing else, this served to illustrate how long they could go without feeding. Throughout all of this period, they just remained motionless and waiting, with the mandibles constantly held wide open and ready to snap shut.
During feeding, the prey is held high up in the air (well above the sand). The captured insect is waved slowly about, and the positions of mandible-insertion are shifted several times while feeding, in order to suck it completely dry. The resultant "husk" is eventually dropped after feeding, right beside the resting larva, with no attempt being made to remove it or even to toss it further away. And the larva remains in exactly the same place as before, all buried but for the visible thin black "hair-line" of its fully open mandibles.
From 1967 until 1970, I managed to keep five larvae alive, all slowly growing and feeding sporadically. They were fed mostly on hot summer evenings (November - March), with little or no feeding during colder weather (May to September). Full size was reached in 1969 and 1970. Cocoons were made by two of them in early 1971, when I was away overseas and they were left in the care of Mr. K.J. Sander (then of Highbury, South Australia). Two perfect and full sized males (in no way deformed or dwarfed) emerged on March 17th & 24th, 1971, and were pinned for the collection. One was deposited in the South Australian Museum; the other was given to the Australian National Insect Collection, C.S.I.R.O. (Canberra, A.C.T.).
Development from egg to pupation continued slowly but steadily over nearly seven years! Three of the five larvae still had not pupated by July of 1971, but all were quite strong and healthy. These three individuals were larger than the first two, and may have been females (?)... Two of them were preserved, at the maximum larval size, in July - August, 1971. (One is in the S.A. Museum, Adelaide, and one is still in the private collection of the author.) The three remaining larvae were measured just prior to pupation, when very plump and close to maximum size; these measurements are given as straight lines, not following the body curvature: 22 x 11 mm., 22 x 12 mm., 23 x 12 mm. (length = front of head to tip of abdomen; the smaller dimension is maximum width). One last individual was still in the larval stage at the time these notes were written (1 December 1971). However, it had ceased accepting food two weeks ago, and has since buried itself deeper into the sand (about 12 to 18 mm. beneath the surface); there are some traces of silk in the sand, but no sign of a cocoon as yet.
There were three larval instars, the final instar lasting from the (Australian) summer of 1967-68 until the summer of 1970-71. During all the years of this rearing, no changes were observed in larval behavior. They just remained incredibly sedentary right to the end.
Speculation: It seems very likely that an important prey item in the Lake Eyre habitat could be the abundant, large, and very active wandering larvae of Acanthaclisis spp., found in most sandy habitats throughout Australia. They may, in fact, be the most important larger prey item for these stilbopterygids, perhaps in addition to wandering spiders or tenebrionid beetle larvae, etc. (?)... They avidly snap their mandibles shut onto anything soft and plump, and of adequate size to trigger the snapping reflex. Interestingly, the usually won't even attempt the capture of larger ants running over their open mandibles (Iridomyrmex, for example, many of which were offered from time to time, just to see if there might be a response).
Observations on adult emergence and wing expansion: A male was seen eclosing at 2235 hrs., on 4th March 1972. It took only about two minutes to exit from the cocoon, once it began to come out, although it had been sitting ready for some time (one or two hours, or more?), with a slight hole chewed in the top of the cocoon, which extended just above the sand surface; this is how I knew it was close to emergence. At this time I was no longer in Adelaide, but had been living in tropical North Queensland (Atherton Tableland) since January of 1972. (These notes were written in a chalet at Tinaroo Pines Caravan Park.)
After forcing itself upward and pulling free of the cocoon and pupal skin, it scrambled rapidly over the sand surface and climbed up onto the screen side of its cage. Soft and "callow" appearance upon emergence. All four "wingpads" were intensely crenulathe and very compact (12 mm. x 3 mm. wide) before expansion began. The abdomen appeared very soft, plump and "heavy," but already with strong maculation and colors. Expansion began at 2250 hrs., after 15 minutes of hanging quietly from the bottom edge of a curtain, near an open window (no wind, warm evening, temp. near 70° F). It was clinging to the curtain only by the T1 and T2 legs; the T3 legs were bent at an angle to the substrate and were not involved in clinging. The wings began rapidly expanding downward, the hindwings expanding a little faster than the forewings. More than half of the wing length had been attained in only 5 minutes, by 2255 hrs. (29 mm., base to tip). The wing tips (apex only) remained curled outward somewhat as expansion continued. The expanding wings hung limply, straight down, nearly vertical to the thorax. The abdomen was also hanging straight down, directly behind the wings. During expansion, the wing margins were still slightly crinkled, reminiscent of crepe paper that is in the process of being stretched out. The antennae were held clasped together and straight out behind (above) the head for their full length, except for the apical clubs, which diverged; they were entirely pale yellow in color. The wings had reached a length of 36 mm. by 2300 hours. The insect still had not moved or shifted its position in the least degree, but gave small twitches occasionally, whereupon the wings were jerked together tightly and then reopened (to the original small gap between them), as they hung parallel and close together. The wing tips remained outward-curled a little (and still wrinkled) until full size was reached; then they finally straightened out and became flat. The external genitalia were held widespread the whole time. Markings on the abdomen were intense and contrasty, right from the moment of eclosion (yellow and deep sooty-gray). Colors on the thorax were pale gray and pale yellow. Legs were deep brown.
2313 hrs. -- The wings are now close to full expansion (FW. = 48 mm. and HW. = 46 mm.), except that the tips are still cloudy (not fully transparent), and are a little wrinkled (not completely smoothed out yet). The antennae were gradually being separated at this time. At 2315 hrs., the wings were flipped over into a semi-tectiform pose, approaching the normal resting posture, but were still somewhat more flattened than they would be later, after the typical resting position has been assumed.
2320 hrs. -- The abdomen is now being hunched or bent downward toward the substrate, and all six legs are clasping the curtain. The bulbous mid-dorsal area on A3 is now bulging out far more prominently than it was earlier, and the associated bend or arch in the abdomen is at the A3-A4 intersegmental joint, just behind the bulge.
2324 hrs. -- The wings are at last clear and smooth, right out to the tips and margins, so expansion could now be considered complete (FW = 50 mm. and HW = 47 mm., maximum final length). The wings are still very soft and callow, showing the usual high degree of shine. The antennae are now being held more widely apart, but still back over the head (tips now at 9 mm. apart).
2345 hrs. -- The normal tectiform wing position of total rest is now fully established. [See McFarland, 1988: 235-243, for an extensive discussion of resting positions and a proposed terminology.]
A single hard, smooth, shiny and whitish waste-pellet (9 x 2-3 mm.) was dropped by this adult a few hours after eclosion.
The various components of this rearing (photographs of the living larvae and the Lake Eyre habitat, pinned adults, preserved dry egg shells, alcoholic larvae, and notebook pages) all bear the rearing code - number of STL.1, and will be found in the South Australian Museum, Adelaide (c/- Jan Forrest), or the Aust. Nat. Insect Collection (Canberra).
I wish to thank Julie Klein (of Hereford, Arizona) for her expert typing of this manuscript and its several revisions. I also wish to thank Elliot Price, owner of Muloorina Homestead (in 1965), for his kindness and hospitality when we visited there. And finally, I wish to thank Ken Sandery, now of Bucasia (Mackay), North Queensland, for his expert and attentive care of these larvae when I was away overseas in 1971, and they were at a critical stage in their later development.
EBSEN-PETERSON, (1923) -- Proc. Linn. Soc. N.S.W. 48:585.
KIMMINS, D.K. (1940) -- Ann. Mag. Nat. Hist. (11) 5: 465 + fig. 12 [abd. of ???].
---------- (1970) -- The Entomologist: 1-3. [??? orig. descrip.]
Mc FARLAND, N. (1968) -- Friends of the South Australian Museum , 7 (Dec. issue) [B. & W. photograph, depicting the dorsal view of a living larva in early third instar, appears on the front cover.]
---------- (1988) -- Portraits of South Australian Geometrid Moths. Lawrence, Kansas: Allen Press (400 pp.) ISBN 0-935868-32-1
NAV???'S, (1911) -- Ent. Rdsch. 28: 12 [??? O.D.]
NEW, T.R. (1982) -- A reappraisal of the status of the Stilbopterygidae (Neuroptera: Myrmeleontoidea). J. Aust. Ent. Soc. 21(1): 71-75 & text fig's. 1-18.
RIEK, E.F. (1968) -- A new genus and key to the species of Australian Stilbopterygidae (Neuroptera). J. Aust. Ent. Soc. 7(2): 105-108 & pl. 1. [regarding the name Aeropteryx].
TILLYARD, R.J. (1926) -- Insects of Australia and New Zealand : 324.
| (above) FEMALE, collected nr. Elliot Price's Muloorina Homestead, Lake Eyre South, S. AUST.|
showing the typical resting posture of a living adult female clinging to a stick.
[3 MAR 65], McF
| (at left) FEMALE, collected nr. Elliot Price's Muloorina Homestead, Lake Eyre South, S. AUST.|
Living adult female at rest (not in typical r.p.), which was originally collected at mv. light.
[3 MAR 65], McF
Article: THE FAMILY STILBOPTERYGIDAE (NEUROPTERA) IN AUSTRALIA
Author: RIEK, E. F.
Journal: Australian Journal of Entomology
The Fijian Antlion Dictyoleon nervosus
, T.R. New Pacific Insects
vol. 24, no. 3-4, pp. 214-218, 1982 (pdf
src: Bishop Museum: http://hbs.bishopmuseum.org/pi/pdf/24(3)-214.pdf
Article: A REAPPRAISAL OF THE STATUS OF THE STILBOPTERYGIDAE (NEUROPTERA: MYRMELEONTOIDEA)
Author: New, T. R.
Journal: Australian Journal of Entomology
A Revision of the Australian Myrmeleontidae (Insecta : Neuroptera) (pdf)
MOTH EGGS!, N. McFARLAND - Australian Natural History, 1968 - Australian Museum
MCFARLAND, N. 1968. Cover picture, Stilbopteryx linearis Navas. Friends S. Australian Museum no. 7: 1-2.
Table of Contents
Chapter 1 - Amelora petrochroa
Chapter 2 - Arhodia lasiocamparia
Chapter 3 - Arhodia retractaria
Chapter 4 - Boarmia cognata
Chapter 5 - Boarmia sausaria
Chapter 6 - Capusa cuculloides
Chapter 7 - Chlenias gonosema
Chapter 8 - Chlenias stenosticha
Chapter 9 - Chlenias zonaea
Chapter 10 - Ciampa arietaria
Chapter 11 - Corula spodochroa
Chapter 12 - Cycloprorodes melanoxysta
Chapter 13 - Dichromodes sp.
Chapter 14 - Dinophalus drakei
Chapter 15 - Dinophalus (?)serpentaria
Chapter 16 - Ectropis excursaria
Chapter 17 - Fisera eribola
Chapter 18 - Fisera (?)perplexata
Chapter 19 - Gastrinopa xylistis
Chapter 20 - Hypographa sp.
Chapter 21 - Idiodes apicata
Chapter 22 - Lophothalaina habrocosma
Chapter 23 - Melanodes anthracitaria
Chapter 24 - "Metrocampa" ada
Chapter 25 - "Metrocampa" biplaga
Chapter 26 - Mnesampela comarcha
Chapter 27 - "Mnesampela" fucata
Chapter 28 - Mnesampela privata
Chapter 29 - Monoctenia falernaria
Chapter 30 - Monoctenia smerintharia
Chapter 31 - Niceteria macrocosma, Nisista
Chapter 32 - Oenochroma vinaria
Chapter 33 - Onychopsis lutosaria
Chapter 34 - Paralaea ochrosoma
Chapter 35 - Phallaria ophiusaria, Phelotis, Plesanemma
Chapter 36 - Rhynchopsota rhyncophora
Chapter 37 - "Smyriodes" notodontaria
Chapter 38 - "Smyriodes" serrata, Stenoteras
Chapter 39 - Stibaroma melanotoxa
Chapter 40 - "Stibaroma" trigramma
Chapter 41 - Symmetroctena (?)exprimataria, Symmetroctena sp.
Chapter 42 - Thalaina angulosa
Chapter 43 - Thalaina clara
Chapter 44 - Thalaina macfarlandi
Chapter 45 - Thalaina selenaea
Chapter 46 - Xantholepidote leucaniata
Chapter 47 - Austroterpna idiographa
Chapter 48 - Austroterpna paratorna
Chapter 49 - Crypsiphona ocultaria
Chapter 50 - Cyneoterpna wilsoni
Chapter 51 - Heliomystis electrica
Chapter 52 - Hypobabpta eugramma
Chapter 53 - Hypobabpta percomptaria
Chapter 54 - Lophothorax eremnopis
Chapter 55 - Sterictopsis argyraspis
Chapter 56 - Aeolochroma sp. nov.
Chapter 57 - Chlorocoma (?)assimilis
Chapter 58 - Chlorocoma carenaria
Chapter 59 - Chlorocoma externa
Chapter 60 - Chlorocoma halochlora
Chapter 61 - Chlorocoma melocrossa
Chapter 62 - Chlorocoma vertumnaria
Chapter 63 - Eucyclodes buprestaria
Chapter 64 - Euloxia fugitivaria
Chapter 65 - Euloxia meracula
Chapter 66 - Gelasma semicrocea
Chapter 67 - Prasinocyma ocyptera
Chapter 68 - "Horisme" sp. (?)
Chapter 69 - Poecilasthena pulchraria
Chapter 70 - Xanthorhoe actinipha
Chapter 71 - Xanthorhoe vicissata
Chapter 72 - Idaea philocosma
Stilbopterid Life History
THE HONEY-SNOB'S CORNER