ebook img

Body weight as related to wing measure in hawkmoths (Sphingidae) PDF

2 Pages·1997·0.94 MB·English
Save to my drive
Quick download
Download
Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.

Preview Body weight as related to wing measure in hawkmoths (Sphingidae)

GENERAL NOTES JournaloftheLepidopterists'Society 51(1), 1997,91-92 BODYWEIGHTAS RELATEDTOWING MEASURE IN HAWKMOTHS (SPHINGIDAE) Forewingorhindwinglength(L)andforewingspan(S)areoftenusedasspeciesbody- sizeindicesin Lepidoptera,butthebodyweights (W) actuallyrepresentedarenotusually known. Establishing mathematical relations between totalbodyweight or mass andwing measure among species ofataxon not onlyvalidates the use ofwing measure as abody size surrogate (Miller 1996), but also enables estimation ofbodyweight from wing mea- sureforphysiologicalandecologicalpurposes. Indetail, suchrelationsWarespecificfordif- ferentgroups; in form, theyare usuallyallometricpowerfunctions of = a (Lbor Sb) or the logarithmic equivalent (Miller 1977). Winglength is defined here as the distance be- tween the wing base (excluding tegula) and the farthest extending wing tip (including fringe);wingspanis definedas the farthestdistancebetweenthewingtips on specimens spreadinthe usual manner. IntheirstudiesoffliWghtmechanics, BartholomewandCasey(1978) andCasey(1976) as- sembledandtabulated and Lvalues for 15 and38ideWntifiedhawkmoth species, respec- tively. Although theydid not derive relations between and L in the foregWoingpapers, Casey (1989) presented such a relationlater. This relation had L ratherthan as thede- pendentvariable,wasbasedononlythesmalleroftheabovedatasets,andwasdisplayedon Live body wt. (W) (g) W 206 6.0 = 0.000548 (L ) Raw r 2 = 0.90 ° Macroglossinae • Sphinginae 4.0 2.0 " ^P*" 0.0 20 40 60 80 100 Forewing length (mm) (L) FlG. 1. Livebodyweightas relatedto forewinglengthinhawkmoths. Eachpointrep- resents from one to several individuals ofeither or both sexes ofa species. Data from BartholomewandCasey(1978) andCasey(1976). — 92 Journal of the Lepidopterists' Society W adouble-logarithmicscale. HereIrecharacterizetherelationwith asthedependentvari- ableusingbothoftheabovedatasetsanddisplayingresultsonanarithmeticscale. Study data here are 70 observations on live weight (W), forewing length (L), and forewing span (S) offield-caught individuals of48 identified species (Bartholomew & Casey 1978, Casey 1976). These species include 33 Macroglossinae and 15 Sp—hinginae the sole subfamilies recognized in Sphingidae (Hodges 1971, Pittaway 1993) andthere are29 NewWorldand 19OldWorldspecies.Thesexesarepooledbecausemanyindivid- uals originallywere not sexed. Species liveweights range from 0.18 to 6.25 g, essentially the full range forthe family. Fordisplay, two or more observations forthe same species were averaged. In analysis, species meanswereweightedbythe numberofobservations. Where only S was originallygiven fora species, as in the data set ofCasey (1976), I de- rived Laftermeasuring L and S on D'AbreWra's (1986) life-size illustrations such that L = S(LD-Abrera/SD-Abrera). Tosolvethe equation = a (Lb), I usedthe quasi-Newtonloss func- tionforordinaryleast-squaresnonlinearregression (SYSTAT 1992). Iderivedproportion- alityfunctions forinterconverting Land S bysimpleordinaryleast-squares regression. The recharWacterized family-level relation between live bodyweight (W) and forewing length (L) is = 0.000548 (L206) (Fig. 1). Itis evidentfrom Fig. 1 thatsample speciesof SphinginaearelargerinmeansizethanthoseofMacroglossinae, anoutcomethatmayrWe- flect areal condition amonghawkmoths. The subfamilies do not seem to differin the versus L relation, however. Theproportionalityfunctionswhich servetoestimate Lfrom Sandviceversawhenoneortheothermeasurementisavailablebuttheotherdesiredare L = -1.09 + 0.467 S, and S = 4.46 + 2.094 L (r2= 0.98). Thisstudyreconfirmsthathawkmothbodyweightisindexedbywingmeasure. Livebody weightincreasesasthesquareofforewinglengthin Sphingidae,whereasitincreasesasthe cubeinTortricidae (Miller 1977). The differenceis fundamental, andreflects theempirical natureofsuch relations andtheirdependenceon morphometries andphysiology Liveweights estimated from the nonlinearequationwith forewinglength (Fig. 1) are not intended for rigorous use. Rigorous usewould require not onlyconfidence intervals forthe equation, but also body-weight controls in the original sources for sex, eggload, andcropcontent. I thank L. S. Fink, T. M. Caseyand an anonymous readerforuseful reviewcomments onthe manuscript. Literature Cited Bartholomew, G. A. & T. M. Casey. 1978. Oxygen consumption ofmoths duringrest, pre-flightwarm-up, and flight in relation to body size andwing morphology. Exp. J. Biol. 76:11-25. Casey,T. M. 1976. Flightenergeticsofsphinxmoths: powerinputduringhoveringflight. Exp. Biol. 64:529-543. JC.. .H.19W89h.eeOlxeyrge(endsc.)o,nsInusmepcttifolnighdtu.rCinRgCflPirgehsts,,ppB.oc2a57R-a2t7o2n., IFnlorGiodlad.sworthy, G. J. & D'Abrera, B. 1986. Sphingidae mundi: hawk moths oftheworld. E. W. Classey Faring- don, UniWted Kingdom. 226pp. HODGES, R. 1971. Sphingoidea: hawkmoths. Moths ofAmerica NorthofMexicoFasc. 21. E.WW. Classey& R. B. D. Publications, London. 158pp. MILLER, E. 1977. Wing measure as a size indexin Lepidoptera: the familyOlethreu- tidae. Ann. Entomol. Soc. Am. 70:253-256. 1997. Diversity and evolution oftongue length in hawkmoths (Sphingidae). . J. Lepid. Soc. 51:9-31. Pittaway, A. R. 1993. The hawkmoths ofthe western Palaearctic. Harley Books, Col- chester, Essex, England. 240pp. SYSTAT. 1992. Statistics,version5.2edition. SYSTAT Inc., Evanston, Illinois. 724pp. William E. Miller, Entomology Department, University ofMinnesota, Saint Paul, Minnesota 55108, USA. Receivedforpublication 10May 1995; revisedandaccepted6January 1996.

See more

The list of books you might like

Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.