Table Of ContentTThhee  LLeepipdiopdteorpoltoegircaollSoocgieitycal Society  ooff  JJaapapnan
ueLva Trans.Iqi.)iSdo,c.Japan 59(1):23-28,January2008
                     
A preliminary study  on  the overwintering  of Pelqpitla msathias  (Fabricius)
(Lepidopt eHreasp,eriidae )in the northern  Kanto region,  central  Japan
[IleLkenaIrNiotJ・E
 
Department of Furest Entomology, Forestr> a,nd  Forest Products Research Institute,
]t・{atsunos a1t,o Tsukuba, Ibaraki ,305-8687 japan; e-mail: [email protected]
Abstract  I  observed   everwintering   larva eol' the  sinal]  brundcd  swift,  Petopida smathias   in
Tsukuba, Ibara kPirefectu rdeurin gthe winter  of 2006-2007.  Larval density was  highest in a sunny
grassla nsdituated  by the wa]1  of a buildin gI.n thi senvironment.  the larva lfood plant ,Imperata c.vlin-
dric amaintaincd  green leave tshroughout  the winter,  and  1arva wecre  active on warm  days.  Even in
Fcbruar.v ,at an overwintering  site thal was  exposed  to the direc trays  of the sun. the daily maximum
temperature  sometiines  reached  approximately  30tC whereas  the minimurn  fe] 1to near  OeC,  r.arvae
thaL were  collected in thc fiel din early  Apri land  kcpt in an outdoor  cage  successful]y  dcveloped
and  emerged  in mid  May-early June as adults.  Thesc larva meolted  zero to threc tirne sbefore pupa-
tion.  Thepupal period was  22-35 and  16-21 days when  the pupation took place in Apri land May,
respectLvely.   Moreover ,one adult  femulc was  caught  by a ]vCalai sterap set in the grasstand near  the
buildin ign mid  Muy.  From the results  of thc present study, larvae of P, niathias  seem  to bc able  to
pass the winter  in inland field sof the northern  Kante region,  at ]eas twhen  the winter  is inild.
Key "'ords   Petopidas mathias,  1arva o,veru,intcring,  inu]erat ac.ytindriea.  diurnal range  of temper-
uture, Ibaraki prefectur eeme,rgence  season,  pupal period,
Introduction
The small  branded swift, fetopidas niathias  (Fabrici uiss )a ,multivoltine  skipper, with  hi-
bcrnation occurring  durin gthe Iarva lstage.  In Japan, the species  is resident  in southern
Honshu,  Shikoku ,Kyushu and  the Nansei-Shot oIslands ,and   migrants   reach  northern
Honshu  in autumn.   It is assumed  that P. maihias  larvae can  pass the winter  in the warm
temperate regions  of southern  Kanto and  southward  along  the Pacifi cOcean (Fukud eat al.,
1984; Shir6zu ,2006).  I observed  a lot of overwintering  larvae during the winter  of 2006-
2007 in Tsukuba, an inland city of Ibarak iPrefectur eno,rthern  Kanto.  Adult emergence
was  confirmed  by two methods,  rearing  of larva eand  trapping of adult  skippers,   This paper
reports  on the results  of these studies.
Materials Methods
 and  
Laival densit >i'n the.field
I  observed  everwintering   larva eof P.  mathias  in the fiel dof the  Forestry  and  Forest
Product sResearch Institut e(FFPRI) T,sukuba, Ibaraki Prefecture ,central  Japan (36COO'N,
l40008'E ,25 m  a.s.1.), from December, 2006 until May, 2007.  This fieJ ids ca 45 km  away
i]rom thc nearest  coast,   I chose  three sunny  grassland ass the study  sites.  Site A was  located
on  the south  gide of a concrete  buildin gand  include dtwo  quadrat s,The quadrat A-1  (18.5
by O.8 m)  abutted the wall  and  A-2 (18, b5y 4.0 m)  was  adjacent  to A-1.  A strip of concrete
(ca i2 cm  in width)  formed the boundary between A-1 and  A-2.  There was  no  pent roof,
but metal  tubes existed  above  quadra tA-1 (Fig s1 and  2) .Sit eB was  located between a
pond and a thin pine fores tand  include done quadra t(quadr Ba; t18.5 by 4.0 m; Fig. 3).
Sit eC was  located on a south  slope  of a small hil land  include done  quadra t(quadr aCt;
1 8.5 by 4.0 m; Fig. 4).
NNIII-IE-leEcltreoncitcronic  LMbirabrryary  Service
TThhee  LLeepipdiopdteorpoltoegircaollSoocgieitycal Society  oofJfap anJapan
24 TakenariINouE
 
Figs 1-4.  Photographs of the site A, B and  C on early Febn[ary 2,e07.  1: Site A (quadr Aa-t1 and
     A-2) ,PA and  PB indica ttehe points where  the temperaturcs  were  recorded.   PA (Poin At):
     insid tehe grasses growing by the wal1  of a building .PB (Poi nBt): in thc shade  of a rree at
     1.5 m  above  the ground .2: A close-up  picture of quadra tA-1.  3: Site B (quadr aB)t.  4:
     Sit eC (quadra Ct).
Figs 5-6 .A Iai'v naeslt  and  an overwintering  1arv aof Petopidas mathias  found near  the building in
     early  February, 2007.  5: A nest made  by an old larvn ,6: A mid  insta ]rarva.
At all three of the sites, the gras swas  mowed  in September of 2006, and  after that ,regrowth
appeared.   Cogon grass impevata cytindrica   (Graminea  oene), of the major  larva lfbod
plants d,ominated these sites during the winter.   I counted  the number  of P. mathias  1aryae
on grasse sin these quadrat sto determin ethe larva ldensitie sin February ,March, April and
May, 2007,  I recorded  the daily maximum  and  minimum  temperatures at two point sat site
A (poin At sand  B; Fig. 1) from early  February unti1 early  April ,2007.
Development  oflarv aine the spring
[Ib detemine whether  overwintered  larva ecan  complete  their developmen tunder  outdoor
NII-Electronic Library Service
TThhee  LLeepipdiopdteorpoltoegircaollSoocgieitycal Society  ooff  JJaapapnan
Overwintering Petopidas 25
 of   mathias
conditions,  I collected 20 larvae in the fiel dof FFPRI outside  the above  mentioned  quadrats
in early  April ,2007.  They were  reared  individual ]iyn transparen tcups (125×125 mm  at the
base ,57 mm  height )Nfp'hich were  placed in a wire-me・sh  cage  (4 m2×2.5 m  in height) in the
fiel d.I ,cylindrica   leave swere  provide das  food . The development of immatures  was
2-3days.
checked  every    
Monitoringofadulit.snthefield
     
Tb determin ethe adult  emergence  season  of the overwintering  generation under  natural
conditions,  thre eMalaise traps were  set along the wall  of the buildin gin the grassland near
site A on April 1O, 2007. The traps were  checked  every  week  through  July 2, 2007,
Results
I found about  ten small  larva ein early  December  of 2006 for the fir sttime in quadra tA-1.
On  that occasion,  the lanJa ldensit ywas  unknovLrn.   In early  Februar yof 2007, 24 larvae of
various  sizes  were  found in quadrat A-1  ([fa b1l, eFigs 5 and  6) ,Most of the larva lnests
were  fbund on  grasse sgrowing within  10 cm  from the building wali,  A few larva lnests
were  even  attached  to the walI.
During warm  daytimes ,some  laiva eemerged  from their nests  and  actively crawled  on  the
grasse s.In early  March and early April ,37 and  nine  larvae were  found in quadrat A-1, re-
spectively.  In quadrat sA-2 and  B, only a few larvae were  fbund in February, March and
April .No  larva ewere  fOund in quadra tC.  In early May, I could  not find any  larva ein any
of the quadrats .In quadra tA-1, many  green regrowths  of I. cylindrica  live dthroughou tthe
winter  (Fi g2,), but in the other  quadrat sm,ogt  of them  died and  only  a few discolored
leave ssurvived.
The temperatures  were  higher at poin tA (overwinter siitneg) than at poin tB (ai trempera-
tures: Fig. 7),  Even in February ,the dail ymaximum  temperature  at point A reached  ap-
proximatel y300C on  sunny  days whereas  the minimum  fel lto near  OOC,  On cloudy  and
rainy  days, the difference sin temperature  between the two  point swere  smaller  than on
sunny  days .No  snowfall  was  observed  throughout  the winter  in and  around  the present
field.
Table 1.  Stat eof food plant sand  densiLy of overwintering  larvae of P, mathias  in each  qudrat.
Quadra[ A-l A-2 B C
Area censused  (m)18.5xO.8 18.5×4.0 18.5x4.0 18.5x4.0
Season when  gras s lat cSeptember.   lateSeptembcr,
was  inowed  in 2006  grass was  carriedateSeptemgbrera,s swas  carricdmidScptegmbrear,ss was  lef tin the  grass was  lef tin the
outofthgglgEE!lggg-ggLgL!dgtg.fgtllhggs!gng-g !ggE!gug1d   1d   -m ptassland
Statc of L cylindrica 20-25 crn in height , 1O-15 cm  in heigh t,70-Se cm  in height,  40-50 cm  in height,
in early  February, high densit ym,any   high density ,inost highdensity,most  lowdensity,most
2007 green regrowths   of the regrowths uf thc regrowths   of the regrowths
lived  died andafew died andafew   died andafew
                discoloredleaves discolore dleave s discolor eldeaves
                suryived survived   survivcd
2-9,Feb,24 (1.62) o (o) 2<O.03) O(o)a)
No.1arvae        
found(densit1y, ;Mur. 37 (2.50)i・) 1<O.O1) 1 (0,Ol) o (o)
2, Apr, 9 (O.61) 1 (O.Ol) 2 (O,03) o (o)
per m:') 7, May o (o) o (o) o (o) o (o)
:'' One dead larva was  found.
o, Two  dead larvae were  found.
NII-Electronic Library Service
TThhee  LLeepipdiopdteorpoltoegircaollSoocgieitycal Society  oofJfap anJapan
26 TakenariINouE
 
/4035so6
  2sove
  2ojNg
15Ee
 
  lo5o,-5
                             
  i t                X. g.e .errToNoN  ti  tti  ttsi  ol2i 22Ee6lE  ES-ctruSti  {{{k. S.g.{t <s ptt  s eTc- cl prt - ormr  .・   eoc.v  ・ eclut lE ccua  Tm- o
                                    .L   2'  2               .  e                 t t t            tttt 1
Fig .7.  Dail ymaximum  and  miniinum  temperatures  at points A and  B from early  February to early
     April ,2007.
         H
       N
     H
  NHN
/
    H
    NHN-N
-N
NH-
/
Nk</ma<1tT-tsf9a<rtNts<1aec
'tuE1"zaasEfm>asE1! tstuE1e $coE1tov MdiE1ge c]"1co:7co
Fig. 8.Pupal periods of Pelopidah 'mathias  larvae collected  ip carly  April 2007 under  quusi-naturaL
conditions  (fie clagde),   Each lin ewith  symbols  denotes an individua] ,Black and  white  eir-
cles rnean  male and  female ,respectively.   Two  larvae which  died or escaped  wcre  excluded.
Tiwent y]arva ecollectcd  in the fiel din early  April includc dvarious  instar s.Eighteen of
them pupatcd in Lhe fiel cdage,   Seventee nof them  mDlted  once  or not at all before pupation
and  one  larv amolted  three times ,Pupatio nand  adult  emergence  occurred  in early  April-
lat cMay  and  mid  May-early June, respectively  (Fig 8,) .When the larva epupated in April,
the pupal pcrio dwas  22-35 days, but i twas  16-21 days when  the pupatien took place in
May,  Males emerged  carlie rin the season  than females .One female adult  was  caught  in
mid  May  in the fiel dwith  a Malaise trap.
Discussion
In Ibarak iPrefecture ,we  can usually  observe  P, mathias  adults  from June-Jul >t,o October-
Noyember  (Ibara Skhiinbun Co,, 1985; Inoue, 2001, 2007), but the detai losf overwintering
NII-Electronic Library Service
TThhee  LLeepipdiopdteorpoltoegircaollSoocgieitycal Society  ooff  JJaapapnan
27
Overwintering of Pelepidas mathias
Table 2.  Monthly mean  air temperatures  (OC )from Oetobe rto April in Mito and  Tsukuba (Tateno )I,baraki
     Profccture, cenU'al  Japan.
OctoberNoi,ember DecemberJanuaryFebruaryMarch April
 
Av.i,  2006  Av.  2006   Av.  2006  Av.  2007  AN・.  2007  Av,  2007  Av.  2eCL7-..
Mito  15.7  17.I  102  11. 4 S. 1 6.6  2.8  4,6  3.3  5.8  6.3  8.1  1].8  1].6
Tsukuba  15.6  17.3  9.8  11.6  4.5  6.4  2.3  4.S  3.2  6,O  6.5  8.6  12.3  11.9
'' Averas,e of 197I-2000,
of the species in this prefectu rheave not  been clarified.  In [[bchi gPirefecture ,it is assumed
that migrants  lay eggs  in June-July and  that new  generatio nasre produced in summcr-au-
tumn,  but that they cannot  pass the winter  there (Kuzuy a2,000) .From the prescn tobserva-
tions, it seems  that larva eof P, mathias  are able to pass the winter  in inlan dfield s(away
from coastal  areas)  of northern  Kanto, and  the emergence  of adults  successfu11y  takes place
in May-June,  at leas twhcn  the winter  is mi'ld.
Larval diapause of P. niathias  is terminated  by eurly  December  (Ish i]i98,0),  The survival
rate ofP.  mathias  during winter  is lower than that of P. gtttlat aa,nd  P. mathias  is morc  sen-
sitive to low temperature than P, gtttta t(aNakas vate iaL,  1981) .The mean  air temperature
at Ibaraki (Mit oand  Tsukuba  (Taten odu)r)ing the presen tstudy  is approximately  2-3 de-
gree sCelsiu shighe rthan the averagc  (Mit olocal meteorological  observatory;  http:!/www,
tokyojma.go.jplhome!mitol)  (T.a b2l) e.The mild  willter  may  contribute  to successfu1  over-
wintering  after termination  of diapause .Furthe rstudies  are needed  to investiga twheether
larva ccan  survive normal  or cooler  winters.
Fukuda  et al. (1984 s)peculated  that overwintering  larvae might  be the middle  (,th iarndd
fourth) instar sR.esult sof the presen tstudy  suggest  that the insta rstage  of overwintering
larvae is more  variable,  because iarvae collected  in early  April molted  zero  to three times
beforepupation,
 
Larvae may  pass the winter  morc  easily  on  grasscs growing near  buildings than on  those
growing in open  land bccause host leaxie skeep a bette rcondition  during the winter  and  the
temperature  is higher in such an envirenment.   Omeri (1933 p)ointed out a similar  result
with  the hibernation of the rjce skipper, I'tirnar aguttat a.In lat eautumn  and winter,  pupae
of the ladybird ,Coccinetla sev)te"ny,ttnctatct bruck ifreguentl yattaches  to substances  such as
stones or woQd  that have been discarde din sunny  plaees ,and  the heat from warmed  sub-
stances  makes  it possibl efor adults  to emerge  from pupae even  in winter  (Sakura teat nali.,
1991; Sakuratan iand  Miwa, 2005).  Larvae of P. niathias  may  also develop by receiyins,
heat from warmed  substances  such  as a concrete  wall even  in mid-winter.
Beck (1 98.3) showed  that devclopmenta lresponses  to thermopcriods  <dai lcyycles  of tem-
perature )vary  among  differe nitnsec tspecies, Jn  some  cases,  developrnenta lperiods are
shortened  by thermoperiods  (e .  Yamashiro et al., 1998),  For example,  in butterfli ethse,
.o.
dcvelopmenta lperiod (eg gto adult  emergence)  of IVttratht b{aiznattt sreared  under  fiuctuat-
ing temperatures  was  significantly shorter  than that under  constant  temperatures,  especially
when  the rearing  tempcrature conditions  were  relatively  low (As oet al., 2006).
The temperatures recorded  in the present study at point A may  have been highe rthan those
insid ethe  larva lnests which  werc  made  of livin ggras sleaves ,At the overuJintering   site
that was  exposed  to the direc trays  of the sun, ho"ieve rP,. mathias  Iarvae may  have been
exposed  to a rather  wide  range  of diurnal temperatures  which  occasionally reached  30 de-
grees Celsius .In order to understand  physiologic aaslpects  during hibernation .we  must
study  the efR]ct of thermoperiods on the Iarva ldevelopmen tof P. mathias  in the future,
NII-Electronic Library Service
TThhee  LLeepipdiopdteorpoltoegiroaollogical  SSoooiceityety  ooff  JJaapapnan
28 TakenariINOUE
 
Acknow
且edgment
lthank Ms K. Takano f{)r helping the experimen1 ,
References
 As o 比bl, uIe, nNoauei,’ atThu, raand  bTa.z aKh(》‘ysa(mHaew,i20〔s0o6l1. )E(L仔eepcti dofQ pttheemr:laoLpyecriaoedni odna )e,im」rゆna」t.u ar pdepclv.e Elnotpm. eZnoto ’o.f5 p0o:w2d4e1−r2e4d 6oak(in−
  Jαpanes ewi [h English summary ).
Beck, S.D,,1983. Insect ther皿 opcri 〔〕dism. A. Rev. E班.28:91−108.
 Fu kudaand,  HY.,・ HWaamtaan, aEbe, ,K1u9z8u4y・a, TTJi,,e  TLaikfae hHaisshtior, iAe・岡., Tプa8ka確haεs赧hi榔, M’1,,z T,1砂an衄aka4, .B.3, 7T3a nPaPk, a,H oHi,k, uWsahkaab, aOysaaskhai., M(ln.
  Japanese with  EngHsh sulnlna 巧り.
lbaraki Shinbun Co.,1985.β配∫‘召が廓 ρズ乃αrακ1[Jbarak ino  Cho ].180 pp. Ibaraki Shinbun Co,, Mito.(In
  Japanese).
Illoue, T,,2001. Records of adul しbutterfli eisdentifie fdrom lbarak PireffectL Lirnc the las tfive years of the 20th
  century (1996−2000)・Retribos(h2i6):2−63(ir Jlapalles)e.
    ,2007.Records of adult  butter伍es idcntifie fdrom Ibaraki Pref¢cture il lthe丘rst fiv eyears of the
  21st century 〔2001−2005). Ruribosh i〔35):2−109(il lJapanese),
 Is hii, (M6):り117−92800,〜 2D6i(aipn aJuasp eaannde so)e.>erwi 皿tering of Pa.rnara  guttαta and  Pc.topidas,mathias . Nature insec t1s5
 Ku zuy(Nae,w T ,E.d2n〔}0):09. 2P−e9l3op, iIdcntsse cmat tLhoiavsers.  ’IAns Ssh〔}icin atTioonch, iUtg−sikmelnc }mnioya Ch.u( lHne nJsahpuane[isnek).ai〔Ed.), Buttenyfl ioefTsochigi
N  ak  asPJtaairl丿nja,ai nrFa ,1, 8 lg:sluhlti9t,i− aM1t2a. 5(HL.ieupriado,p1l, .carnad: HHe. sHpoenrdiaid,ae1)918. LS urPvoipvuall aratteis od noyfn aovlernwiinc toesf t而hen gmi glraar皿vta , sckiPphpe.ソrsi obtu. tEtceortH,y
OmQri, N.,1933. Life cycle  of Parnara guttat waith  special reference  to it sos・erwintering . Dobutsu8aたu.
  記α∫3’45:303−326(in亅apanese ).
S ak urtaattaa nbi JY−i・i.c』ki ceiunc hrie】 aKti. oann dto  Ts.o Ilaork aa,lt1it9L9[dLe .S血easPooユl1agl ecrh, aLng.e, C ihna amllbgeler so,f R p. upJ.a, tDiioxn oonf , CAoc. cFi、 nG〃e. a asnedpt eImp. uHncodek−
  (Eds)、 Belrabio uanrd  lmpact ofAphidophaga :259−264. SPB Academic Publishin bgv, The Hague 、
S ak urAa「attatntir, e Yln. saendct  sY40. M(5i)w:a40,−24030(5i. nJPauppaan eosfc )C.occine〃a septem ρunctala  bnlck iutilizing  the solar mdiaUol1 .
Sllir6,z Tu,,2006. The Standard ofButtetfiies  in Jalアcill..336 pp. Gakken, Tokyo .(lnJapanese).
Y am asovhiiporsoit,i oCn 吟 AiIn tlhdeo,  LYea. f abnede dSc.  AtMraascahk.i1,a, m1an998.et. rieTsh〜e. mE皿notpe. rSicod・i.1 :re2d9uc9e−s30 7t.he therma !con8tant required  fbr
摘 要
関東地方北部におけるチ ャバ ネセ セ リ幼虫の 越冬に関する予備的研究(井上大成)
2006−2007年にかけての冬に,茨城県つ くば市で チャ バ ネセ セ リの 越冬幼虫を観察 した.幼虫の密度
は,建物の南1則の壁に近い草地で高かっ た.こ こではチガヤ は冬の 間緑色を保っ てお り,幼虫は暖か
い H 中には活発.に活動 して い た.直射日光の当たる.建物の南側の 越冬場所で は,2月には目最低温度
は〔〕℃ 近くまで ドがっ たが,晴れた 日の最高温度は30℃ 前後に も達した.4月に野外から採集され網
室で飼育された幼虫は.4月上旬一5月下旬に蛹化 し,5月中旬一6月上旬に羽化 した,幼虫は蛹化前に0−
3ま回た脱,皮野外したの。壁蛹際期の 問草は地4に月設に置蛹し化たしマたレ場ー合ズにトはラ2ッ2−3プ5で日はで5.5月月中に旬蛹に化雌し成た虫場1合匹にがは捕1獲6−さ21れ日ただ.っチたャ.
バ ネセセ リは北関東の 内陸で も,少な くとも暖冬の 時には野外越 冬して い るこ とが明らかになっ た.
(Accepted August 9,2007)
Published by thじLepidopterolog[iSooaciety of Japan,
5−20,MQtoyokoyama 2,Hachi ji,Tokyo ,192−0063Japan
    (’    
一
NNI工I工-EElleoetcrotniroonic  LLiibrbarryary  Service