A second species of the genus Mexico Spilman, Mexico morrisoni n.sp, (Limnichidae, Thaumastodinae) is described from the Bahama Islands

Skelley, Paul E.

English

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119 INSECTA MUNDI, Vol. 19, No. 1-2, March-June, 2005IntroductionWhile studying arthropod diversity and alloch-thonous-based food webs in the Bahamas, Dr. LloydMorrison ran yellow pan traps on small, unnamedislets between the Harvey Cays and Staniel Cay inthe central Exuma Cays (Morrison, in prep.). Theseislets consist primarily of marine limestone, withlittle or no sand, and most were less than 200 m2 insize. Most of these islets had no naturally occurringplants, but a few had one or two species of vascularplants.  Although all of the islets had emergentareas, all could be inundated by heavy wave actionduring storms or at very high tides. Few insects areable to withstand submergence or quickly recolo-nize recently submerged areas. In this study, theonly insects found in abundance were collembo-lans, a ceratopogonid dipteran (W. Grogan, unpub-lished manuscript), and the limnichid beetle de-scribed here. This limnichid was found on a major-ity of the islets, of all sizes and emergent typesstudied.Materials and MethodsSpecimens are deposited in the following collec-tions: (EMEC) Essig Museum of Entomology, Uni-versity of California, Berkeley CA; (FSCA) FloridaState Collection of Arthropods, Gainesville FL;(MAIC) Mike Ivie, Montana State University, Boze-man MT; (USNM) United States National Muse-um, Smithsonian Institution, Washington DC.THAUMASTODINAE Champion 1924Diagnosis. Thaumastodine limnichids can be rec-ognized by their hypognathous head with large,narrowly separated, dorsally placed eyes; enlargedmesocoxae; heavily spined hind legs; and a tarsalformula of 4-4-4 or 4-5-5. See Spilman (1959) for alengthy description.Remarks. The subfamily Thaumastodinae con-sists of 5 genera and 15 species (Spangler 1995,Spangler et al. 2001, Hernando and Ribera 2003):Acontosceles Champion with 3 species from Japanto the Philippines and west to India, Babalimni-chus Satô with 3 species in Japan and Taiwan,Martinius Spilman with 3 species from the Ameri-cas, Mexico Spilman now with 2 species from Mex-ico and the Bahamas, and Pseudeucinetus Hellerwith 4 species widespread in Asia.Spilman (1972) gives a key to the world’s gen-era of Thaumastodinae. Wooldridge (1975) over-looked Mexico in his key to the New World generaof the Limnichidae. Shepard (2002) presents a keyto genera north of Mexico: Mexico is not presentlyknown to occur there. Babalimnichus, only recent-ly described from eastern Asia, does not appear inany of these keys (see note under Remarks below).Mexico Spilman 1972Type species: Mexico litoralis Spilman 1972, bymonotypy.Diagnosis. Length 1.6-2.0 mm.  Eyes widely sep-arated, distance half or more of eye length. Anten-nal groove of gena with 2 parts; a dorsal setose anddensely punctate part distinctly separated from aventral glabrous, shining, impunctate  (Fig. 4-5).Antenna 11 segmented, antennomere III tightlyfitting on apex of antennomere II; antennal club of4 segments. Elytral apex with margin bearingabout 10 small teeth. Male genitalia with parameresshortened, length less than median lobe; medianlobe with 3 sclerotized parts. Tarsal formula 4-4-4.A new species of ‘jumping shore beetle’ in the genus Mexico Spilmanfrom the Bahamas (Coleoptera: Limnichidae: Thaumastodinae)Paul E. SkelleyFlorida State Collection of ArthropodsFlorida Department of Agriculture and Consumer ServicesP.O. Box 7100Gainesville, FL 32614-7100, USAskellep@doacs.state.fl.usAbstract.  A second species of the genus Mexico Spilman, Mexico morrisoni n.sp, (Limnichidae, Thaumastodinae)is described from the Bahama Islands.120 Volume 19, No. 1-2, March-June, 2005, INSECTA MUNDIRemarks. Martinius, the only other New Worldthaumastodine, differs from Mexico by having 7segmented antenna; a one part, broad, setose an-tennal groove; and an untoothed, rounded elytralapex. The 3 species of Martinius occur in Cuba,Panama, and Ecuador (Spilman 1959, 1966; Wool-dridge 1988).Babalimnichus (Satô 1994) appears closely re-lated to Mexico, sharing all of the generic charac-ters outlined above, except for the possible develop-ment of the antennal groove on the gena. Thisstructure was not mentioned by Satô, but it seemslikely that the two genera are congeneric.Mexico morrisoni Skelley, n.sp.(Figs. 1-6)Description. Holotype male, length 1.9 mm, width1.0 mm. Fitting the description of M. litoralis asgiven by Spilman (1972), except for the followingcharacters.Body slightly more elongate (Fig. 3, 6). Coarsedorsal punctures prominent, 3-4 times wider thanfine punctures, separated by one puncture diame-ter. Dorsal surface covered with dense, mixed coarseand fine, setiferous punctures; setal coloration cre-ates a pattern of prominent color bands (Fig. 6),white bands wider than brown bands. Legs andassociated spines entirely black. Dorsal separationof eyes equal to 0.6 length of eye in lateral view.Male genitalia (Figs 1-2) with parameres halflength of median lobe; median lobe (= penis,  Spilman1972) with 3 distinct sclerotized parts, 2 lateralparts and a dorsal part; dorsal part club shape withconstricted tip and middle; parts of median lobenarrowly separated, not fused and slightly mov-able.Variation. Length 1.6-2.0 mm, width 0.8-1.0  mm.No notable variation nor external sexual dimor-phism was observed.Remarks: The only other species known in thegenus, M. litoralis (Fig. 7), differs from M. morriso-ni in being slightly broader, having dark brown legswith contrasting black spines, less prominent coarsedorsal punctures separated by 2 puncture diame-ters, eyes separated by about 0.8 times eye length,and the color pattern not as prominent, with brownbands much wider than the white bands. In addi-tion, the parameres of M. litoralis are 0.75 timesthe length of the median lobe, and the median lobeis not narrowed at the middle, nor separated into 3distinct parts. However, the median lobe of M.litoralis has 3 sclerotized areas that are moretightly connected and appear to act as a single unit.Mexico litoralis is found on the west coast of Mex-ico, while M. morrisoni is found in the BahamaIslands.Material examined. Holotype male with follow-ing label data: “BAHAMAS: Central Exuma Cays,24°12.6’N-76°29.4’W, Dec.-2002, pan traps, L. Mor-rison, BR-11" (FSCA).Paratypes (22 total in EMEC, FSCA, MAIC, USNM):(3) same data as holotype; (4) same data except,24°12.1’N-76°28.7’W, May-2003, BR-16; (3) samedata except, 24°12.0’N-76°28.5’W, Dec.-2002, BR-17; (9) same data except, 24°09.8’N-76°28.6’W, May-2003, BR-37; (3) same data except, 24°09.0’N-76°27.9’W, 17. The number at the end of each set ofdata, “BR-...,” are codes referring to Dr. Morrison’sstudy.CommentsThaumastodines are known to jump (Spilman1966, 1972), having been called the ‘jumping shorebeetles’ (Hernando and Ribera 2003), and are diffi-cult to catch. This behavior could explain the un-usual development of the metacoxa and hind legs.Intertidal areas, especially on isolated islets,are not the usual places entomologists think to lookfor specimens. At least one limnichid is reported tofeed on algae (Paulus 1970), and given the scarcityof plants in intertidal areas, that may be their foodsource in this niche.Some limnichids (e.g.Throscinus LeConte, Hy-phalus Britton, and the Cephalobyrrhinae) are knownto occur in intertidal zones or tidal mud flats (Shepard2002, Hernando and Ribera 2004, Shepard 1979respectively). In the Thausmastodinae, Acontosceles(Champion 1924) and Pseudeucinetus (Spangler 1995)in Asia is found in riparian areas. However, othermembers of the Thaumastodinae appear to preferintertidal or brackish waters. Members of the generaMartinius, Babalimnichus, and Mexico are known tooccur in “high and mid-tide rock crevices” (Spilman1972), “brackish lagoon” (Wooldridge 1988),  “moistsand among the mangroves and ‘dog-teeth’ limestonein the intertidal zone” (Spilman 1966), “tide pools ona rocky seashore, though they may have jumped inthe pools from rocky walls” (Satô 1994), “coral reefs at121 INSECTA MUNDI, Vol. 19, No. 1-2, March-June, 2005low tide” (Satô 1994), and “coral cliff by sea” (Hernan-do and Ribera 2003).  Suspected larvae of Babalimni-chus masamii Satô were collected in an intertidalarea (Yoshitomi and Satô 2001). It seems likely thatthis overlooked niche may hold many more taxa inother places around the world.Figures 1-7. Mexico species. 1-6) Mexico morrisoni; 1) Male genitalia, dorsal view; 2) Male genitalia, lateral view; 3) Ventral habitus; 4)Lateral habitus; 5) Head, anterior view; 6) Dorsal habitus; 7) Mexico litoralis, dorsal habitus.122 Volume 19, No. 1-2, March-June, 2005, INSECTA MUNDIAcknowledgementsI thank Dr. Lloyd W. Morrison, Missouri StateUniversity, Springfield, MO-USA,  for bringingthese interesting specimens to my attention andallowing me to describe them. These specimenswere collected as part of a National GeographicSociety grant (#7447-03) to Dr. Morrison.I thank Warren Steiner, Smithsonian Institu-tion, Washington DC-USA, for assistance obtain-ing literature and loans of specimens, and PaulSpangler, retired, Smithsonian Institution, for hiscomments on the new species.For reviews of the manuscript, I thank W.Steiner and C. Staines, Smithsonian Institution,Washington DC-USA; W. Shepard, Essig Museumof Entomology, University of California, BerkeleyCA-USA; M. Thomas and W. Dixon, FDACS-DPI,Gainesville FL-USA.  This is Florida Department ofAgriculture and Consumer Services, Division ofPlant Industry, Entomology Contribution No. 1005.Literature citedChampion, G. C. 1924. On a new subfamily ofClavicorn Coleoptera. Entomologist’s MonthlyMagazine 60(717): 25-29.Hernando, C. and I. Ribera. 2003. Babalimni-chus slendens sp.n., a new jumping shore beetlefrom the Tonga Islands (Polynesia) (Coleoptera:Limnichidae, Thaumastodinae). Koleopterolo-gische Rundschau 73: 269-273.Hernando, C. and I. Ribera. 2004. Hyphalusmadli sp.n., a new intertidal limnichid beetlefrom the Seychelles (Coleoptera: Limnichidae:Hyphalinae). Koleopterologische Rundschau 74:413-417.Morrison, L. [in prep.]. Arthropod diversity andallochthonous-based food webs on tiny oceanicislands.Paulus, H. F. 1970. Zur morphologie und biologieder larven vond Pelochares und Limnichus.Senckenbergiana Biologia 51: 77-87.Satô, M. 1994. Notes on the genus PseudeucinetusHeller and its new relative (Coleoptera, Lim-nichidae). Special Bulletin of the Essa Entomo-logical Society, Niigata 2: 173-177.Shepard, W. D. 1979. Co-occurrence of a marineand a freshwater species of Limnichidae (Co-leoptera). Entomological News 90(2): 88.Shepard, W. D. 2002. Family 46. Limnichidae. Pp.125-126.  In: R. H. Arnett, Jr., M. C. Thomas, P.E. Skelley and J. H. Frank (eds.). AmericanBeetles. Volume 2. CRC Press LLC, Boca Ra-ton, FL, 861 pp.Spangler, P. J. 1995. A review and two newspecies of the genus Pseudeucinetus Hellerfrom southeast Asia and a world checklist of theThaumastodinae (Coleoptera, Limnichidae).Special Bulletin of the Japanese Society ofColeopterology, Tokyo, 4: 395-405.Spangler, P.J., C. L. Staines, P. M. Spangler,and S. L. Staines. 2001. A checklist of theLimnichidae and the Lutrochidae (Coleoptera)of the world. Insecta Mundi 15(3): 151-165Spilman, T. J. 1959. A study of the Thaumastod-inae, with one new genus and two new species(Limnichidae). Coleopterists Bulletin 13(4): 111-122.Spilman, T. J. 1966. A new species of Martiniusfrom Cuba (Coleoptera: Liminichidae). Coleop-terists Bulletin 20(4): 123-125.Spilman, T. J. 1972. A new genus and species ofjumping shore beetle from Mexico (Coleoptera:Limnichidae). Pan-Pacific Entomologist 48(2):108-115.Wooldridge, D. P. 1975. A key to the New Worldgenera of the beetle family Limnichidae. Ento-mological News 86(1&2): 1-4.Wooldridge, D. P.  1988. Martinius temporalis, anew species from Ecuador (Coleoptera: Lim-nichidae: Thaumastodinae). Journal of the NewYork Entomological Society 96(3): 314-315.Yoshitomi, H. and M. Satô. 2001. Description ofthe larva of Babalimnichus masamii M. Satô(Coleoptera: Limnichidae, Thaumastodinae).Coleopterists Bulletin 55(4): 471-474.

A new species of ‘jumping shore beetle’ in the genus Mexico Spilman from the Bahamas (Coleoptera: Limnichidae: Thaumastodinae)

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