28 March 2006 PROC. ENTOMOL. SOc. WASH. 108(2), 2006, pp. 253-260
TAXONOMIC AND BEHAVIORAL STUDIES OF A NEW DANCING BELTHECA BUSCK (LEPIDOPTERA: GELECHIIDAE) FROM COSTA RICA
AKlTO Y. KAWAHARA AND DAVID ADAMSKl
(AYK) Maryland Center for Systematic Entomology, University of Maryland, 4112 Plant Sciences Building, College Park, MD 20742-4454, U.S.A. (e-mail: kawahara@ umd.edu); (DA) Department of Entomology, National Museum of Natural History, Smith sonian Institution, Washington, D.C. 20013-7012, U.S.A. (e-mail: [email protected]. usda.gov)
Abstract.-Beltheca oni, new species, is described from the Atlantic lowlands of Costa Rica. The adult female is similar to that of B. picolella Busck, but the former lacks a signum. The male can be distinguished from that of Beltheca phosphoropa (Meyrick) by its longer vinculum and larger aedeagus. Adults of both sexes "dance" on leaves of different plants by anchoring one of their forelegs to a substrate and rotating around this pivot point. The anchored leg shifts slightly when the moth dances in large circles, moves to another region of the leaf, or changes the direction of rotation. There is no preference for rotating clockwise or counterclockwise. Dancing occurs all over the adaxial leaf sur face, but it can be localized. An adult was observed dancing around a water droplet and drinking from it. We hypothesize that dancing is a courtship behavior or a predator avoid ance tactic. A photograph of the adult and illustrations of the head, wing venation, and genitalia of both sexes are included along with a diagram of a dancing path. Key Words: Anacampsinae, behavior, Beltheca, Commatica, courtship dance, microlep idoptera, morphology, predator avoidance, taxonomy
The genus Beltheca Busck is represented theca, but it has been documented in three by two Neotropical species, B. picolella other gelechiid genera. In the United States, Busck, and B. phosphoropa (Meyrick). Clemens (1860) reported Strobisia dancing Busck (1914) proposed Beltheca based on on the surface of shaded leaves, and Forbes the type species, B. picolella, which he de (1923) observed dancing Anacampsis agri scribed from Cabima, Panama. Clarke moniella (Clemens) and A. levipedella (1969) synonymized Anterethista heteractis (Clemens). Aiello and Becker (2004) re (Meyrick) with B. picolella and transferred ported Commatica falcatella (Walker) and Anterethista phosphoropa (Meyrick) to Bel Commatica cryptina (Walsingham) dancing theca. Beltheca phosphoropa is known in Mexico, Costa Rica, and Panama. from Jurimaguas, Peru, and Para, Brazil There have been many reports of dancing (Meyrick 1922). Nothing is known about in microlepidoptera, but few studies de dancing or the life history of either species. scribe the behavior in detail. Most detailed "Dancing" in microlepidoptera has been studies focus on the jerky display behavior defined as "running in tight circles with a of choreutids (e.g., Rota 2003, Aiello and crab like sideways gait" (Robinson 1988: Becker 2004), which is different from the 73). Dancing has not been reported in Bel- rotating dance of other microlepidopteran 254 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
families (e.g., Gelechiidae, Cosmopterigi TAXONOMY dae, Momphidae, and Tineidae). Despite Beltheca oni Kawahara and Adamski, the numerous reports of dancing in Gele new species chioidea (e.g., Forbes 1923, Plant 1980, (Figs. 1-10) Robinson 1988, Aiello and Becker 2004), there has never been a detailed description Diagnosis.-The female of Beltheca oni of dancing for any species in the superfam is similar to that of B. picolella but lacks a ily. The purpose of our study is to describe signum. The male of B. oni has a longer the morphology and dancing behavior of a vinculum and larger aedeagus than that of new species of Beltheca from Costa Rica, B. phosphoropa. The male of B. picolella and to hypothesize the ecological signifi and female of B. phosphoropa are un cance of its dance. known, and therefore could not be com pared with B. oni. MATERJALS AND METHODS Description.-Adult (Fig. 1). Head (Fig. Adults of Beltheca oni were collected on 2): Scales on head teardrop shaped, dark plants growing along the edge of a pasture brown with bronze iridescence. Antenna fi at the EI Ceibo Research Station (500 m), liform, 2.1-2.2 nun in length, with 58-60 west side of Rio Peje, Heredia, Costa Rica, flagellomeres (n = 4 antennae). Labial pal in February 2003 and March 2004. All pus upcurved, 2.2-2.3 mm in length (n = specimens were collected using a killing jar 14), approximately two times horizontal containing potassium cyanide after obser length of head; labial palpus with second vations of dancing were recorded. Adult be segment dorsoventrally wider than third, havior was documented, and video footage with long raised scales on dorsal surface. of 24 adults was taken using a Nikon Cool Proboscis approximately two-thirds length pix 4500 digital camera. A number was as of body. Thorax: 1.3 mm in length, dorsal signed to each specimen corresponding to surface covered with small bronze oval the appropriate video file. Each video was scales, ventral and lateral surfaces covered played frame-by-frame and the dancing with longer scales. Forewing (Figs. 1, 3): path sketched. QuickTime® video files are Elliptic, 3.5-4.6 mm in length (n = 25), in the possession of the primary author. dark bronze, ventral surface similar but pal The illustration of the head was made er. Forewing with short, narrow scales with a camera lucida attached to a WILD along swollen base of subcosta and radius, M5 microscope, and genitalia drawings female with more scales at base of subcosta
were made with a Jena Pictoval Microslide than male. Rs absent, M J closer to R 4 than
Projector. Wing and genital dissections to M 2 in both sexes. Hindwing (Figs. 1,4): were permanently mounted on glass micro Dark brown, Rs straight to pointed apex,
scope slides and deposited in the National M 2 arising from approximately midpoint of Museum of Natural History, Smithsonian distal margin of discal cell, slightly arched Institution, Washington, D.C., USA broadly toward MI' Frenulum approximate (USNM), along with the holotype and 12 ly one third length of Sc+RI; male with one paratypes. Twenty additional paratypes are acanthus, female with two acanthi. Abdo deposited in the Instituto Nacional de Bio men: Dark brown, approximately 2.2 mm diversidad (INBio) collection in Santo Do in length. Male genitalia (Figs. 5,6): Uncus mingo de Heredia, Costa Rica. Nomencla elongate, broadly curved apically, with nu ture for genitalia follows Klots (1970), and merous peglike setae on ventral surface; terminology for wing venation follows gnathos elongate, enlarged basally; tegu Comstock (1918). Wing length is defined men with several setae along ventral mar by the distance from the wing base to the gin; valva broadly curved from base, distal apical margin. half of inner surface setose, transtilla C- VOLUME 108. NUMBER 2 255
Fig. I. Beltheca ani, hololype male. Scale = l.O nun.
shaped; vinculum elongate and sharply pointed medioventrally; aedeagus ovate and apically hooked. Female genitalia (Figs. 7, 8): Papilla analis setose, apophysis poste rior extending nearly to anterior margin of eighth tergum, apophysis anterior very short. Lamella antevaginalis semicircular, medially notched; ductus bursae long and narrow; corpus bursae oviform with an ac cessory lobe at posterior end, lobe pointed and sclerotized at base of ductus seminalis. Type material.-Holotype: 0, COSTA RICA: Heredia Province: II km southeast of La Virgen, west side of Rio Peje, El Cei bo Station. 21 February 2003, A. Y. Ka wahara. The specimen bears the following labels: printed white label: COSTA RICA: Heredia Province: II km Southeast of La Virgen, El Ceibo Station, lOo20'N 84°04'W, 450-500 m, INBio-OET-ALAS transect, 21-11-2003; Akito Y. Kawahara leg.; printed red label: HOLOTYPE, Beltheca ani Ka- Fig. 2. Head of Beltheca ani. lateral view of male. wahara and Adamski 2006 (USNM). Scale = 0.1 nun. Paratypes (30 0, 2 ~): Same data as for 256 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON holotype, 20 male paratypes deposited in as differing from Commatica in having INBio, each INBio paratype with a unique three forewing radial veins. After re-ex Project ALAS white label with INBIO bar amining the wing venation of all species of code numbers: 003226769 to 003226775, Beltheca, we conclude that Beltheca and 00322686 to 003226828. Twelve paratypes Commatica eremna, the type species of (10 c3', 2
4 -'1'1::=------.::::::... Rs
Figs. 3-8. Wing venation and genitalia of Be/theca ani. 3, Forewing of male. 4, Hindwing of male. 5, Male genitalia, ventral view. 6, Male genitalia, enlargement of uncus and gnathos. 7, Female genitalia, ventral view. 8, Female genitalia, enlargement of eighth abdominal tergum. Scale bar = 1.0 mm in all figures except 6 and 8 where scale bar = 0.5 mm. 258 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
out laterally while the moth dances, and in one case, a moth was seen rotating slowly around a water droplet with its proboscis extended to the droplet (Fig. 10). When dis turbed, the moth either stops dancing or flies from the leaf. The average time spent dancing was 71.14 seconds (SD = 36.7, n = 24) and dancing speed varied. The behavioral significance of dancing in Beltheca oni and other microlepidoptera largely remains unknown. The adult of some Brenthia sp. (Choreutidae) move in a jerky fashion after alighting (Fletcher 1920, Forbes 1923, Rota 2003, Aiello and Becker 2004), and the display behavior may mimic the movement of salticid jumping spiders (Robinson et al. 1994, Rota 2003, Aiello and Becker 2004). Dancing in Gelechiidae, Momphidae, Cosmopterigidae, and Tinei dae is quite different, as the moth typically rotates rapidly without jerky movements. Observations of B. oni suggest that the adult dances during courtship. Typically only one moth was seen on a leaf, but there were three instances where two moths were dancing on the same leaf, two of which in volved a male and a female. In one case, as soon as one of the sexes began dancing, the other danced also, and several seconds after one stopped, the other also stopped. This "dance-stop" scenario was repeated four times, and in each instance, dancing lasted Fig. 9. A dancing path of Beltheca ani. S = start 4-5 seconds before one of the moths point, E = end point. stopped. Morrison (1968) described a sim ilar scenario in Dryadaula pactoila Meyrick clockwise and 1,217 counterclockwise (Tineidae). He observed a male in captivity quarter-turns; rotating in a given direction running around in circles beside a female was statistically insignificant (X 2 = 0.049, while fanning his wings, and repeatedly df = I, P > 0.2). When the moth rotates dancing and stopping until the pair mated. clockwise, it anchors its right foreleg, and Unfortunately we were able to witness when it rotates counterclockwise, it anchors dance-stop behavior between only two in its left foreleg. The leg that is used as an dividuals, and the pair flew away before the anchor moves very little compared to the outcome of the scenario could be observed. other legs, only shifting it slightly when the Additional observations are necessary to moth makes large circles, changes direc conclusively determine that this dance-stop tion, or moves to another region of the leaf. behavior is associated with courtship in mi In general, dancing takes place over the en crolepidoptera. tire leaf, but at times can be localized to The moth also may dance to confuse a certain areas (Fig. 9). Each antenna is held predator that uses visual cues for hunting. VOLUME 108, NUMBER 2 259
/'
\
F Fig. 10. Illustration showing how Beltheca ani dances while drinking from a drop of water. The moth shuffles its legs and rotates from point A to point F and back to point A to make one dancing rotation. Rotation can be clockwise or counterclockwise.
At El Ceibo, similar dancing behaviors test the ecological and evolutionary signif were observed in distantly related arthro icance of dancing in moths and other ar pods that have very different methods of thropods. courtship, suggesting that factors other than courtship may have selected independently ACKNOWLEDGMENTS for dancing in different lineages. A dancing We thank Klaus Sattler (formerly De pattern nearly identical to that of Beltheca partment of Entomology, The Natural His oni was observed in a black psycodid fly tory Museum, London, UK) for discussion and several Collembola on the surface of on Beltheca. John Brown (Systematic En leaves from which B. oni were collected. tomology Laboratory [SEL], USDA, Wash Similarly, Robinson (1988:73) reported ington D.C., USA) and Ronald Hodges that, "In Sulawesi, [a] momphid and its (formerly SEL, USDA, Washington D.C., dance are the model for, or rrtimic an iden USA) gave critical comments on an earlier tical display by a sirrtilarly coloured collem version of the manuscript which greatly im bolan-Lepidocyrtus sp. (Entomobryi proved its quality. Christian Thompson dae)." We believe that microlepidoptera (SEL, USDA, Washington D.C., USA) pro dance for courtship, but it may also be that vided nomenclatural suggestions on the moths and distantly related arthropods specific epithet. Donald Davis (Department dance to avoid capture by confusing pred of Entomology, USNM, Washington D.C., ators such as salticid spiders that use visual USA), Keitaro Eda (Shizuoka, Japan), Jerry cues to adjust for jumping distance. Future Powell (Essig Museum of Natural History, studies on dancing demand rigorous hy Berkeley, CA, USA), Gaden Robinson (De pothesis-based behavioral experiments that partment of Entomology, The Natural His- 260 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON tory Museum, London, UK), and Jadranka dopterology, No.4. Proceedings of the Academy Rota (University of Connecticut, Storrs, CT, of Natural Sciences of Philadelphia [121: 156 174. USA), provided information on dancing be Comstock, J. H. 1918. The wings of insects: an ex havior. We also thank Robert Denno, Ste position of the uniform terminology of the wing phanie Johnson, Silvana-Marten Rodriguez, veins of insects and a discussion of the more gen Jeffrey Sosa-Calvo, and Gina Wimp (Uni eral characteristics of the wings of the several or versity of Maryland, College Park, MD, ders of insects. Comstock, Ithaca, 430 pp. Fletcher, T. B. 1920. Life-histories of Indian Insects USA) who gave comments on the manu Microlepidoptera. Memoirs of the Department of script, and discussed the potential evolu Agriculture of India, Entomological Series 6: 1 tionary and ecological significance of danc 217. ing. The first author thanks David Wagner Forbes, W. T. M. 1923. The Lepidoptera of New York (University of Connecticut, Storrs, CT, and neighboring states. Cornell University Agri cultural Experiment Station, Memoir 68, 729 pp. USA) for introducing him to the microlep Klots, A.B. 1970. Lepidoptera, pp. 115-130. In Tuxen, idoptera of Costa Rica in 2002. This study S. L. ed. Taxonomist's Glossary of Genitalia in was made possible by funding provided to Insects. Munksgaard, Copenhagen, 359 pp. the first author through the Arthropods of Meyrick, E. 1922. Descriptions of South American Mi La Selva (ALAS) ATBI research expedi cro-Lepidoptera. Transactions of the Entomologi cal Society of London 1922: 65-116. tions (2002-2004), The University of Morrison, B. 1968. A further record of Dryadaula pac Maryland Graduate School, and the Orga tolia Meyrick (Lep., Tineidae) in Britain with nization for Tropical Studies (OTS) 04-01 notes on its life history. Entomologist's Gazette Tropical Ecology graduate course. 19: 181-188. Plant, C. W. 1980. Unusual behavior of Mompha nod LITERATURE CITED icolella Fuchs (Lep.: Momphidae). The Entomol ogist's Record and Journal of Variation 92: 255 Aiello, A. and V. O. Becker. 2004. Display of the 256. "Peacock Moth": Brenthia spp. (Choreutidae: Robinson, G. 1988. The systematic position of Ther Brenthiinae). Journal of the Lepidopterists' Soci mocrates epischista Meyrick (Lepidoptera: Tinei ety 58: 55-58. dae) and the biology of the Dryadaulinae. Nota Busck, A. 1914. New genera and species of microlep Lepidopterologica 11: 70-79. idoptera from Panama. Proceedings of the United Robinson, G. S., K. R. Tuck, and M. Schaffer. 1994. States National Museum 47: 1-67. A Field Guide to the Smaller Moths of South-East Clarke, J. F. G. 1969. Catalogue of the type specimens Asia. Malaysian Nature Society, Kuala Lumpur, of microlepidoptera in the British Museum (Nat 309 pp. ural History) described by Edward Meyrick, Vol. Rota, J. 2003. Choreutidae (Lepidoptera) of La Selva 6. Glyphipterigidae, Gelechiidae (A-C). Trustees Biological Station (Costa Rica): taxonomy, ultra of the British Museum (Natural History), London, structure of immature states, and life history. Mas 537 pp. ter's Thesis, University of Connecticut, Storrs, 160 Clemens, B. 1860. Contributions to American Lepi- pp.