The Pupal Case of a Nearctic Robber Fly, Proctacanthus brevipennis (Wiedemann, 1828) (Diptera: Asilidae) Author(s): D. Steve Dennis and Jeffrey K. Barnes Source: Proceedings of the Entomological Society of Washington, 115(4):316-324. 2013. Published By: Entomological Society of Washington DOI: http://dx.doi.org/10.4289/0013-8797.115.4.316 URL: http://www.bioone.org/doi/full/10.4289/0013-8797.115.4.316 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/ terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. PROC. ENTOMOL. SOC. WASH. 115(4), 2013, pp. 316–324 THE PUPAL CASE OF A NEARCTIC ROBBER FLY, PROCTACANTHUS BREVIPENNIS (WIEDEMANN, 1828) (DIPTERA: ASILIDAE) D. STEVE DENNIS AND JEFFREY K. BARNES (DSD) 1105 Myrtle Wood Drive, St. Augustine, Florida 32086-4838, U.S.A. (e-mail: [email protected]); (JKB) Department of Entomology, University of Arkansas, 319 Agriculture Building, Fayetteville, Arkansas 72701, U.S.A. (e-mail: [email protected]) Abstract.—The pupal case of the Nearctic robber fly Proctacanthus brevipennis (Wiedemann, 1828) is described, illustrated, and compared with those of P. hinei Bromley, 1928; P. micans Schiner, 1867; P. milbertii Macquart, 1838; P. philadelphicus Macquart, 1838; and P. rufus Williston, 1885. A revised key is provided to the pupal cases of these species. Observations are reported on emerging adults and a newly emerged female P. brevipennis being captured and eaten by a green anole, Anolis carolinensis (Voigt, 1832). Key Words: Asilinae, Asilioidea, Brachycera, Immature Diptera, Insecta, Pupae DOI: 10.4289/0013-8797.115.4.316 There are 29 extant species of Proc- and on sand roads. Depending on location, tacanthus that occur in the Nearctic and adults are generally in flight from March Neotropical zoogeographic regions and through July. Female P. brevipennis, like one fossil species found in the Palearctic all known Proctacanthus, have spines region (Geller-Grimm, 2012). Despite the or acanthophorites at the tips of their widespread occurrence of species in the ovipositors and deposit eggs in the soil two regions, the pupal cases of only five (Dennis 2012), where the larvae and pu- Nearctic species have been described in pae develop. detail (Dennis and Lavigne 1976; Dennis et al. 2008a): P. hinei Bromley, 1928; P. MATERIALS AND METHODS milbertii Macquart, 1838; P. rufus Williston, The following description is based on 1885; P. philadelphicus Macquart, 1838; seven pupal cases, collected from soil, and P. mi ca ns Schiner, 1867. that were subsequently examined with In the United States, Proctacanthus Wild M5 and M8 stereomicroscopes. brevipennis has a broad distribution. It Two male cases (one with a separately occurs in most states east of the Mis- pinned adult) are labeled, “Moses Creek sissippi River, and west into the central Cons. Area St. Augustine FL III-27-12, plains and upper Rocky Mountain States. Drainage Basin by White Trail, 9:25 AM Herein we describe the pupal case of male Proctacanthus brevipennis,DS P. brevipennis (Wiedemann, 1828) col- Dennis Collector”; one female case is lected in Florida, the adults of which are labeled, “Moses Creek Cons. Area St. widely distributed in open, forested areas, Augustine FL III-27-12, Drainage Basin VOLUME 115, NUMBER 4 317 by White Trail, 10:24 AM newly emerged nerves and surrounded at the base by a adult eaten by lizard, D S Dennis Col- membraneous ring or socket called an lector”; and two female cases, one male alveolus (McAlpine et al. 1981; Daly et al. case, and the anterior half of a pupal 1998). case are labeled, “Moses Creek Conser- Except in the subfamily Laphriinae, vation Area St. Augustine FL III-28-12, all robber fly pupal cases for which there Drainage Basin by White Trail, 9:45 AM are detailed descriptions have a distinct pupal cases of Proctacanthus brevipennis, pattern of dorsal abdominal spines and D S Dennis Collector”. Associated adults spurs. Abdominal segment 1 typically were identified using the key and de- has a dorsal transverse row of spurs, scription presented by Hine (1911) and, and abdominal segments 2–7 have a dor- by comparing specimens with those in sal transverse row of spines alternating the Smithsonian Institution, National with spurs, sometimes with 2–3 spines Museum of Natural History (NMNH), between spurs. On some pupal cases the Washington,D.C.Thespecimenswill spines are short, stout extensions of the be deposited in the NMNH. The description format follows that of cuticle, and the longer, often thinner, spurs Dennis and Barnes (2012) and Dennis emanate from areas of this cuticle. Pupal et al. (2008a, b). There are three tagmata: cases of known species of Laphriinae have head, thorax, and abdomen (Fig. 1–3). rows of spines, but lack discernible spurs. Proctacanthus brevipennis The head has ventral mouthpart sheaths has a unique and lateral eye sheaths. There is a terminal arrangement of ventral callosities and tu- anterior antennal process and three pos- bercles on abdominal segment 9. These terior antennal processes on each side are defined below with a callosity being of the head. There is a prothoracic spi- a thick, swollen lump and a tubercle a racle, anterior mesothoracic spines, and little, solid pimple: a posterior mesothoracic callosity with a spine on each side of the thorax. The Male Pupal Cases abdomen has nine abdominal segments Lateroventral Callosities.—callosities with lateral spiracles on segments 1–8 between the midventral tubercles and the and processes consisting of spines and posteroventral tubercles. spurs; the ninth abdominal segment has Midventral Tubercles.—tubercles mid- dorsal and ventral posterolateral pro- way between the anterior end of abdom- cesses. A spine is a rigid, immovable, inal segment 9 and the posteroventral thornlike, outgrowth of the cuticle that is tubercles. not separated from it by a joint and lacks Posteroventral Tubercles.—tubercles be- a socket area of integumental weakness tween or slightly anterior to the ventral around its base. A spur is a moveable posterolateral processes. process of the cuticle that is connected tothebodywallbyajointandhasa Female Pupal Cases socket or integumental weakness or con- striction around its base (Comstock 1925; Median Tubercle.—small tubercle on Daly et al. 1998). Some spines, such as abdominal segment 9 between the mid- those on the dorsolateral, lateral and ventral callosities and the posteroventral ventral abdominal segments, are bristle- tubercles. like, but a bristle is defined as a unicellu- Midventral Callosities.—four callos- lar macrotrichium or seta connected with ities very close together just posterior 318 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON Figs. 1–3. Proctacanthus brevipennis pupal case, female, St. Johns County, Florida. 1, Dorsal view, showing abdominal segments 1–9; 2, Lateral view; 3, Ventral view. aap = anterior antennal process, absr = abdominal spiracles, absr 8 = abdominalspiracle8,amsp= anterior mesothoracic spine, dpp = dorsal posterolateral process, lesh 1 = fore leg sheath, lesh 2 = mid leg sheath, lesh 3 = hind leg sheath, pap = posterior antennal process, pmc = posterior mesothoracic callosity, pthsr = prothoracic spiracle, vpp = ventral posterolateral process, wsh = wing sheath. to or at the anterior end of abdominal abdominal segments 3–6. Greatest length, segment 9. including anterior antennal processes, Posteroventral Tubercles.—tubercles 20.5–22.5 mm; greatest width of thorax slightly anterior to the ventral postero- 4.0–5.0 mm; greatest width of abdomen lateral processes. 4.0–4.5 mm tapering to 1.0 mm at greatest width of abdominal segment 8. Sub- RESULTS AND DISCUSSION shining golden brown, variably rugose Description.—Pupal cases straight to (wrinkled), rugulose (minutely wrinkled), slightly curved ventrally, starting with or smooth. Spurs, spines and processes VOLUME 115, NUMBER 4 319 glistening reddish brown, often darker leg sheaths on raised, rugose area, each apically (Figs. 1–3). spine long, subequal, round to broadly Head with pair of basally rugose, re- flattened in cross section, posteriorly curved, dorsally rounded to flattened, curved, apically pointed. Posterior meso- ventral wedge-shaped anterior antennal thoracic callosity at base of wing sheath processes with straight to concave sides; medium to large, rugose, with slight pro- anterior antennal processes not joined tuberance toward dorsum of pupal case; at base; also with group of 3 fused, ba- callosity with apically rounded to acute, sally rugose, mostly equidistant, posterior posteriorly curved, posterior mesotho- antennal processes; posterior processes racic spine with sclerotized edge. Wing subequal, dorsally rounded to flattened, sheath smooth anteriorly, otherwise ru-