Stings of Ants of the Tribe Pheidologetini (Myrmicinae)
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University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Center for Systematic Entomology, Gainesville, Insecta Mundi Florida December 1986 STINGS OF ANTS OF THE TRIBE PHEIDOLOGETINI (MYRMICINAE) Charles Kugler Radford University, Radford, VA Follow this and additional works at: https://digitalcommons.unl.edu/insectamundi Part of the Entomology Commons Kugler, Charles, "STINGS OF ANTS OF THE TRIBE PHEIDOLOGETINI (MYRMICINAE)" (1986). Insecta Mundi. 514. https://digitalcommons.unl.edu/insectamundi/514 This Article is brought to you for free and open access by the Center for Systematic Entomology, Gainesville, Florida at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Insecta Mundi by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Vol. 1, no. 4, December 1986 INSECTA MUNDI 22 1 STINGS OF ANTS OF THE TRIBE PHEIDOLOGETINI (MYRMICINAE) Charles Kugler Biology Department, Radford University, Radford, VA 24142 USA The definition of the Tribe Pheidologe- ted in Canada balsam. For more details, see tini in the ant subfamily Myrmicinae has Kugler (1978a). Preparations were examined always been problematic. Emery (1922) erec- with a Zeiss KF-2 phase contrast microscope ted the tribe to contain the genera Pheido- at 400X magnification. Drawings and meas- logeton, Oligomyrmex, Aneleus, Lophomyrmex, urements were made using a grid eyepiece, Trigonogaster, Ekebomyrma, Carebara and Pa- with estimated accuracy of +0.001mm. In dalgus, but Wheeler (1922) put all these measurement of regions of sting, the bound- genera in the Solenopsidini. Neither Emery ary between the sting shaft and valve cham- nor Wheeler satisfactorily defined either ber is the point of closest approximation of tribe. More recently, Ettershank (1966) outer and innner walls at the~posteriorend proposed the "Pheidologeton genus group" of the valve chamber; the boundary between composed of Pheidologeton, Oligomyrmex (in- valve chamber and sting bulb is the anterior cluding most Aneleus), Lophomyrmex, Care- end of the internal apophysis. In Oligomyr- bara, Paedalgus and Anisopheidole, but still mex, I could not discern precisely the end uncertainty remains as to relationships of of the apophysis, so used instead the middle these genera and even the definitions of the of the transverse ridge, which is near the genera themselves. New characters and new end of the apophysis in other genera. The means of analysis are needed to help resolve Index of Reduction (IR) is a measure of the this problem. length of the sting relative to the size of In earlier studies of the myrmicine the ant: (pronotal Wlsting L) X 100. Sen- sting apparatus (Kugler, 1978a. 1978b), I silla counts on gonostyli include the dorso- found that the eight sclerites constituting terminal chaeta and companion seta. Scale the sting apparatus are a rich source of lines in all figures are 0.05mm. characters that vary between genera. More- Species examined: Anisopheidole anti- over, the sting apparatus was generally podum(1 major, 1 minor) Australia: W. Aus- uniform within those genera for which sev- tralia, Manjimup, W. S. Brooks, leg. Lopho- eral species were examined. Thus, the sting myrmex bedoti (5 workers) Indonesia: Rali- apparatus holds promise for helping define mantan, Pleihari-Martapura Reserve, 3 July myrmicine genera and analyzing phyletic 1983, M. W. Moffett, leg. Lophomyrmex opa- relationships among them. ciceps (2 workers) Indonesia, W. Java, Ujung In this paper I describe and compare Kulon National Park, 1 Sept. 1983, M. W. the sting apparatuses of Pheidologeton, Moffett, leg. Pheidologeton diversus (1 Oligomyrmex, Trigonogaster, Lophomyrmex, and major, 1 media, 3 minors) Malaysia, Singa- Anisopheidole. The first three were de- pore, Botanic .Gardens, 31 Oct. 82, M. W. scribed in Kugler (1978a), but only on the Moffett and D. A. Fletcher, leg.; and N. basis of single species and few specimens. Celebes, Tangkoko-Batuangus Res., W. L. Here their descriptions are extended to Brown, leg. Pheidologeton nanus (1 major, 1 better see how the sting apparatus varies media, 2 minors) India, Kerala State, Peri- between castes and between species within yar Tiger Preserve, 8 Mar. 82, M. W. Mof- genera. f ett, leg. Pheidologeton pygmaeus (2 ma- jors, 3 minors) Malaysia, Penang, Penang Hill, colony #08-83, M. W. Moffett, leg. Each sting apparatus was removed from Pheidologeton silenus (1 major, 1 minor) the ant, cleared in hot lactophenol solu- Malaysia, Sarawak (1st Division) Samunsam tion, and usually dissected further into Wildlife Sanct., May 28, 1983, M. W. Mof- two halves and a sting. Stings and some- fett, leg. Oligomyrmex corniger? (near times whole apparatuses were mounted in sodalis) (1 major, 1 minor) New Caledonia, glycerin jelly for ease of positioning and Mt. Mou, Dec. 10, 1954, #109, E. 0. Wilson, repositioning in exact lateral, dorsal and leg. Oligomyrmex overbecki (2 major, 2 other views. The other sclerites were moun- minor workers) Singapore, Botanic gardens, 222 INSECTA MUNDI Vol. 1, no. 4, December 1986 December, 1983, M. W.Moffett, leg. Oligo- abruptly narrowed midlength. No segmenta- nyrnex sp. 2 (1 major, 1 minor) Australia, tion. Dorsoterminal chaeta and companion N. Queensland, Eungella, B. Hblldobler , leg. seta may be sparated from other sensilla by Oligomyrmex (Erebomyrma) urichi (1 minor) a gap, but generally not. Sensilla: 7-12 Trinidad, Oropouche Cave near Cumaca, 18 trichodea, 6-7 chaetica, 0-2 basiconica. June 1961, E. 0. Wilson, leg. Oligonyrmex Triangular plate: (Fig. 1) Moderately (Nimbanyrnex) villiersi (?) (1 minor) Bel- wide-bodied; not elongate; no dorsal or gian Congo, Ituri Forest vic., Epulu, July, medial tubercles. 1955, No. 6, T. Gregg, leg. Trigonogaster Lancet: (Fig. 1) Short, weak; apex sp. 1 (2 workers) Indonesia, Central Sula- acute, flexible, lacking barbs. Two small wesi, Lore Lindu N. P. at Toro, 14 July, valves per lancet; posterior valve highly 1983, M. W. Moffett and D. A. Fletcher, reduced. leg. Trigonogaster sp. 2 (1 worker) and Trigonogaster recurvispinosa (1 worker) In- Sting: (Figs. 2,3) Sting shaft reduced donesia, Bali, Monkey forest at Ubud, 18 in length (38-41% of sting length), weak, August, 1983, M. W. Moffett and D. A. Flet- lacking campaniform sensilla; apex laterally cher, leg. Trigonogaster sp. 3 (2 workers) compressed to form a flexible, spatulate Malaysia, Gombak field station, November, flange. Flange larger in P. diversus and 1983, M. W. Moffett and D. A. Fletcher, leg. especially P. nanus (Fig. 3). Valve chamber Vouchers of all species will be de- 19-25% of sting L; profile distinct from posited in the Museum of Comparative Zoolo- sting bulb, but not from sting shaft; inter- gy, Harvard University with the label nal apophysis touches dorsal wall of sting. ''VOUCHER Sting Dissection, Kugler 1984;' Sting wall at boundary between sting bulb and valve chamber thickened into a wide, transverse, internal ridge. Sting bulb 34- 42% of sting L, very wide, but sharply ta- Majors of P. silenus; majors and medias of pered to narrow, weakly arched sting base P. diversus and P. nanus. with thick basal ridge. Bulb more vaulted in P. diversus major, approaching the shape Spiracular plate: (Fig. 1) Nearly of minors (Fig. 5) Basal notch very wide square, larger than quadrate plate. An- dorsoventrally. IR = 11-15. terior apodeme not extending onto partially Furcula: (Figs. 2.3) Reduced to a membranous medial connection. No postero- thick, subtriangular sclerite tightly fused dorsal lobe or dorsal notch. Posteroventral to top of sting base. No dorsal arm. corner not elongate. Spiracle not enlarged. Apodeme wider in P. nanus. Posterodorsal Minors of P. silenus, P. diversus, and P. corner of P. diversus media reduced and nanus . approaching condition in minors (Fig. 4). Quadrate plate: (Fig. 1) Body wider Spiracular plate: (Fig. 4) More trian- than apodeme; anterior and dorsal ridges gular than in major, due to reduction of thick, forming a prominent, well sclerotized pos terodorsal corner. anterodorsal corner with lateral and medial Quadrate plate: (Fig. 4) Anterior edge lobes. In P. silenus and P. nanus, pos- concave. Body wider than apodeme, with terior edge of body with a concave notch in notched posterior margin. Anterodorsal cor- dorsal half; P. diversus not notched. ner without lobes; pollicate in P. diversus, Anal plate: Much wider than long, with more elongate in P. silenus (Fig. 4) and P. ill defined edges. Setae arranged as in nanus . minors (Fig. 4) along posterior margin in Anal plate: (Fig. 4) Posterior margin two lateral patches; 9 setae in P. silenus more convex than in major; with fewer (3-5) and P. diversus; 5-6 in P. nanus. setae. Oblong plate: (Fig. 1) Not divided Oblong plate: (Fig. 4) Shape like that into posterior and ventral arms by a postin- of major. Sensilla: 2 intervalvifer, 1 cision. Dorsal ridge with subterminal tu- ramal, 0 fulcral. bercle and long posterior apodeme. Anterior Gonostylus: (Fig. 4) Same basic shape apodeme not especially elongate. Fulcra1 as in major, but narrow distal portion shor- arm weakly sclerotized, 'oval. Sensilla: 3- ter. Fewer sensilla than in major: 5-7 6 intervalvifer, 3-9 ramal, 2-6 fulcral. trichodea, 2-3 chaetica, 0 basiconica. Numbers can vary between two halves of same Triangular plate: (Fig. 4) Body more apparatus, and are generally larger in lar- slender than in major. ger individuals. Lancet: (Fig. 4) As in major, but with Gonostylus: (Fig. 1) Wide basally, but single, highly reduced valve. Vol. 1, no. 4, December 1986 INSECTA MUNDI 223 Sting: (Fig. 5) Sting shaft short; Sting bulb short (14% of sting L); not high- seems to retain small apical flange, but er than valve chamber. Sting base in ven- possibly not (see Kugler 1978a, Fig. 235). tral view convex, without anterolateral Valve chamber even less distinguishable from processes. Basal ridge present, weakly sting shaft than in majors. Sting bulb more arched in anterior view. Relative to body vaulted in lateral view; without internal size, sting longer in minors than in majors ridge.