Eurytoma tylodermatis Ashm. was found to be parasitic on Acanthoscelides perforatus (Horn) in seed pods of Canada milk- vetch {Astragalus canadensis L.). Observations on larval behavior and frequency of parasitism are discussed. Male and female genitalia of E. tylodermatis are illustrated

Boe, Arvid A.

McDaniel, Burruss

English

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South Dakota State University Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange Native Plant Focused Publications Department of Agronomy, Horticulture, and Plant Science 1991 Life History Studies, Host Records, and Morphological Description of Genitalia of Eurytoma tylodermatis Ashm. (Hymenoptera : Eurytomidae) from South Dakota Burruss McDaniel Arvid A. Boe Follow this and additional works at: https://openprairie.sdstate.edu/nativeplant_pubs  Part of the Ecology and Evolutionary Biology Commons, Entomology Commons, and the Plant Sciences Commons PROC. ENTOMOL. SOC. WASH.93(1), 1991, pp. 96-100LIFE  HISTORY  STUDIES,  HOST  RECORDS,  ANDMORPHOLOGICAL  DESCRIPTION  OF  GENITALIA  OFEURYTOMA  TYLODERMATIS  ASUM.(HYMENOPTERA:  EURYTOMIDAE)  FROM  SOUTH  DAKOTAB.  McDaniel  and  a.  BoePlant  Science  Department,  South  Dakota  State  University,  Brookings,  South  Dakota57007.Abstract.  —Eurytoma  tylodermatis  Ashm.  was  found  to  be  parasitic  on  Acanthoscelidesperforatus  (Horn)  in  seed  pods  of  Canada  milk-  vetch  {Astragalus  canadensis  L.).  Obser-vations  on  larval  behavior  and  frequency  of  parasitism  are  discussed.  Male  and  femalegenitalia  of  E.  tylodermatis  are  illustrated.Key  Words:  Acanthoscelides  perforatus,  Dinarmus  acutus,  Astragalus  canadensisEurytoma  tylodermatis  Ashm.  parasitizesbruchid  beetles  and  numerous  other  Cole-optera  throughout  the  eastern  and  centralUnited  States  (Burks  1979).  Bugbee  (1967)listed  56  host  species  for  E.  tylodermatis,many  of  which  are  of  economic  importance,but  cautioned  that  more  exact  determina-tions  of  host  relationships  are  needed.  Hestated  that  the  species  can  act  as  either  aprimary  or  secondary  parasite  on  beetles  andmoths.  Pierce  (1908)  regarded  it  as  an  im-portant  parasite  of  the  cotton  boll  weevil{Anthonomus  grandis  Boheman)  in  Texas,and  Ritcher  (1936)  recorded  its  parasitismof  the  larger  apple  curculio  {Tachypterellusquadrigibbus  magnus  List)  in  Wisconsin.This  paper  records  a  new  host  for  E.  ty-lodermatis,  presents  descriptions  of  E.  ty-lodermatis  male  and  female  genitalia,  anddescribes  observations  and  data  regardinglarvae  and  adults  of  E.  tylodermatis  asso-ciated  with  Canada  milk-vetch  in  easternSouth  Dakota.Materials  and  MethodsIn  August  1988  and  1989  mature  seedpods  (Fig.  1)  of  Canada  milk-vetch  werecollected  from  a  field  nursery  at  Brookings,South  Dakota  and  placed  in  0.9-liter  glassjars  (five  to  ten  racemes  per  jar  in  ten  jars)in  1988  and  1.8-liter  paper  cartons  (ten  totwenty  racemes  per  carton  in  five  cartons)in  1989.  Jars  were  sealed  and  maintainedat  room  temperature.  Cartons  were  wrappedwith  aluminum  foil  and  fitted  with  a  5-mlvial  to  serve  as  a  trap  (Fig.  2).  Cartons  wereplaced  on  a  shaded  bench  in  a  greenhouse.Chalcids  that  emerged  from  pods  in  the  jarsduring  fall  of  1988  and  bruchids  thatemerged  during  spring  of  1989  were  re-moved,  identified,  and  counted  in  July  1  989.Cartons  were  checked  daily  through  Octo-ber  1989  and  chalcids  trapped  in  the  vialswere  identified  and  counted.In  June  1989,  green  pods  containing  de-veloping  seeds  were  dissected  in  order  tomake  observations  on  chalcids  parasitizingA.  perforatus  larvae.  Chalcid  larvae  foundparasitizing  beetle  larvae  were  placed  in  5-mlvials  and  observed  daily  until  adultsemerged.Genitalia  were  removed  from  ten  femalesand  ten  males  of  E.  tylodermatis.  Illustra-tions  were  made  for  both  sexes  and  dataVOLUME 93, NUMBER 1 97Fig. 1 . Pods of Canada milk-vetch {Astragalus can-adensis L.).were  recorded  for  number  of  rami  spinesand  eighth  tergite  setae  of  the  females.  Mor-phological  terminology  is  that  of  Snodgrass(1941).Results  and  DiscussionThe  following  is  a  description  of  femaleand  male  reproductive  structures  based  onthe  20  adults  obtained  from  laboratory  rear-ings.Fetnale  (Fig.  3):  2nd  Valvifers  (Vf2)(semicircular  sheaths)  with  two  setae  nearapodemes  of  laminated  bridge  (Lam.  Br.);ramus  spines  (Ra.Sp.)  range  from  23  to  35on  right  valvifer  (mean  of  29.6  for  10  spec-imens),  and  from  25  to  36  on  left  valviferFig. 2. Paper carton rearing container.(mean  of  30.5  for  10  specimens);  spineswidely  spaced  in  laminated  bridge  region,close  together  near  fulcral  plate  region;  ful-cral  plate  (Ful.Pl.)  attachment  near  notchedarea  (Ful.Pl.  Not.)  of  fulcral  plate;  outer  ovi-positor  plate  (Ops.Ot.Pl.)  fused  with  8th  ter-gite  (8-Teg.);  8th  tergite  with  row  of  setae(8-Teg.Set.)  ranging  from  41  to  51  (meanof  46.  3  for  10  specimens),  setae  count  beginswith  first  seta  anterior  to  cercus  (Ce.);  setaesingle  adjacent  to  cercus  becoming  pairedtoward  attachment  of  outer  ovipositor  plateand  fulcral  plate;  selal  region  plated,  bor-dered  by  dark  line  that  divides  fused  outerovipositor  plate  into  light  and  dark  pig-mented  areas;  apex  of  8th  tergite  with  seriesof  long  setae  similar  in  structure  to  other8th  tergite  setae  [these  setae  associated  withepipygium  (Ep.)];  cercus  with  5  setae  of  dif-ferent  sizes  and  shapes.  Inner  ovipositorplate  (Ops.  In.  PI.)  separated  from  2nd  val-vifers  (Vf2)  by  darkened  region  that  con-nects  apodemes  of  outer  and  inner  rami  andthe  groove  in  which  the  fulcral  plate  fitsalong  with  monitoring  spines  (rul.Pl.Sp.);inner  ovipositor  plate  with  plated  region  ex-tending  to  region  of  fused  ovipositor  sheaths(Ops.Sh.);  ovipositor  sheath  not  articulated,containing  the  ovipositor  sheath  ligament(Ops.Sh.  Lg.)  which  connects  sheaths  inwhich  the  ovipositor  is  held;  ovipositorsheaths  lightly  striated  with  typical  series  ofeurytomid  setae  at  apex.98 PROCEEDINGS  OF  THE  ENTOMOLOGICAL  SOCIETY  OF  WASHINGTONFig. 3. Ovipositor of Eurytoma tylodermatis Ashm.Abbreviations: (Lam. Br.) Laminated bridge; (Ra.) Ra-mus; (Ra.Sp.) Ramus spines; (Vf2) 2nd Valvifer (Semi-circular  sheet);  (FuLPLSp.)  Fulcral  plate  spines;(Ful.Pl.Not.) Fulcral plate notch; (Ful.Pl.) Fulcral plate;(Ops.In.Pl.) Ovipositor inner plate; (Ops.Ot.Pl.) Ovi-positor outer plate; (Ops.Sh.Lg.) Ovipositor sheath lig-ament; (8-Teg.) 8th tergite; (8-Teg.Set.) 8th tergite se-tae; (Ops.Sh.) Ovipositor sheath; (Ce.) Cercus; (Ep.)Epipygium.Male  (Figs.  4,  5):  reproductive  apparatuswith  4  dorsal  aedeagal  sensory  pores(Aeg.S.Por.);  aedeagal  striae  (Aeg.Str.)  ex-tend  from  posterior  aedeagal  sensory  poresto  beyond  anterior  aedeagal  sensory  pores;aedeagal  sensory  pores  may  be  paired  orstaggered  on  dorsal  surface  of  aedeagus  (Fig.4);  ventrally  apex  of  aedeagus  with  five  sen-sory  pores  on  each  side;  these  smaller  thandorsal  pores;  aedeagus  (Aed.)  elongated  ca-pable  of  extending  beyond  digiti  (Dgi.);  par-ameres  with  three  setae;  apex  setae  normallyhidden  between  digiti  and  aedeagus;  para-mere  plate  setae  (Par.Pl.Set.)  located  on  out-er  margin  of  curved  paramere  plate  (Par.Pl.);posterior  paramere  plate  setae  longer  andlarger  than  anterior  paramere  plate  setae;anterior  paramere  plate  setae  located  adja-cent  to  digiti  apodemes  (Dig.  Apd.);  apex  se-tae  similar  in  size  to  latter  paramere  setae;digiti  with  two  finger-like  teeth  and  a  round-ed  projection;  each  digitus  with  two  poreson  base;  digital  apodemes  short  (Fig.  5),fused  to  aedeagal  apodemes  (Aeg.Apd.);  ae-deagal  apodemes  protrude  from  caulis  (Ca.);paramere  plates  (Par.Pl.)  and  Volsellar  plates(Vos.Pl.)  fused  to  caulis  with  pigmentationbeing  darker  on  the  sides  of  reproductiveapparatus  and  lighter  in  the  center;  caulisforms  opening  below  digiti  in  which  aedea-gal  apodemes  are  connected  to  muscles  ofthe  8th  tergite.  There  is  a  narrow  nonpig-mented  membrane  connecting  the  aedeagusto  the  epipygium  and  8th  tergite.  This  mem-brane  is  beset  with  small  spine-like  setae.The  membranous  portion  of  this  structuresurrounds  the  aedeagus  and  contains  twoacorn-like  setae.  This  structure  is  attachedto  the  aedeagus  and  apparently  plays  a  rolein  exsertion  and  retrieval  of  the  entire  malereproductive  apparatus  as  well  as  the  ae-deagus.Parasitic  BehaviorInformation  on  behavior  of  E.  tyloder-matis  larvae  was  obtained  by  splitting  green,well-developed  seed  pods  along  their  septato  expose  seeds  in  the  chambers  of  each  ofthe  two  locules.  On  July  18,  1988,  weobserved  a  pinkish-white  larva  that  wasfeeding  on  an  /I.  perforatus  larva.  A  grayish-black,  pubescent  hatched  egg,  which  resem-bled  E.  tylodermatis  eggs  (Pierce  1  908),  wasattached  to  the  bruchid  larva.  The  pod  loc-ule  containing  the  parasitic  larva  and  its  hostwas  placed  in  a  5  -ml  vial  and  stored  atroom  temperature.  Daily  observations  weremade  and  on  July  22  the  parasitic  larvacrawled  out  of  the  locule,  defecated,  andpupated.  By  July  26  the  pupa  had  becomesolid  black  except  for  prominent  reddish-VOLUME 93, NUMBER 1 99_Aeg SPorAeg__ParPI SetDgiPar PI SetDgi ApdF Par PI.Vos PIAeg ApdFigs. 4, 5. Male reproductive apparatus of Eurytoma tylodermatis Ashm., dorsal and ventral, respectively.Abbreviations: (Aeg.) Aedeagus; (Par.Pl.Set.) Paramere plate setae; (Par.Pl.) Paramere plate; (Aeg.S.Por.) Ae-deagal sensory pores; (Aeg.Str.) Aedeagal striae; (F.Par.Pl.) Fused paramere plate; (Ca.) Caulis; (Vos.Pl.) Volsellarplate; (Aeg.Apd.) Aedeagal apodemes; (Dgi.) Digiti; (Dgi. Apd.) Digiti apodemes.brown  compound  eyes.  On  July  30  an  adultfemale  oi  E.  tylodermatis  emerged  and  wasone  of  the  ten  females  studied  for  the  struc-ture  of  the  genitalia.  These  observationsmade  it  possible  to  recognize  E.  tyloder-matis  larvae  in  subsequent  pod  dissections.Numbers  of  adult  E.  tylodermatis  and  thepteromalid  Dinarmus  acutus  Thomsonreared  from  inflorescences  of  Canada  milk-vetch  in  1988  and  1989  are  presented  inTable  1  .  Total  numbers  recorded  of  eachspecies  were  68  and  1  12  for  E.  tylodermatisand  D.  acutus,  respectively.  Male  D.  acutusoutnumbered  females  by  67%  while  femalesof  E.  tylodermatis  outnumbered  males  by52%.  The  number  of  A.  perforatus  adultsreared  in  1988  was  70,  indicating  that  ap-proximately  35  and  24%  of  the  beetles  wereparasitized  by  D.  acutus  and  E.  tyloder-matis,  respectively.  Since  D.  acutus  out-numbered  E.  tylodermatis  by  approximate-ly  50%  in  1989  rearings,  the  pteromalid  wasthe  more  predominant  parasite  of  A.  per-foratus  in  this  study.  These  data  agree  close-ly  with  a  previous  study  on  the  effects  ofparasitism  by  D.  acutus  on  Canada  milk-100 PROCEEDINGS  OF  THE  ENTOMOLOGICAL  SOCIETY  OF  WASHINGTONTable 1 . Numbers of parasitic chalcids reared fromCanada milk-vetch pods infested with the bruchidAcanthoscelides perforatus.vetch  seed  predation  by  Acanthoscelidesperforatus  (Horn)  (Boe  et  al.  1989).  In  thatstudy,  D.  acutus  parasitized  over  45%  of  ^.perforatus  larvae.We  have  reared  E.  tylodermatis  from  seedpods  of  American  licorice  (Glycyrrhiza  lep-idota  Pursh)  and  false  indigo  (Amorphafru-ticosa  L.)  QonXdiining  Acanthoscelides  aureo-lus  (Horn)  and  A.  submuticus  (Sharp),respectively.  It  is  likely  that  E.  tylodermatisalso  parasitizes  bruchid  beetles  in  seeds  ofthese  two  legumes.  However,  we  have  notdissected  pods  to  observe  E.  tylodermatislarvae  feeding  behavior  in  these  species.AcknowledgmentsThe  authors  extend  their  gratitude  to  Dr.E.  E.  Grissell,  Systematic  Entomology  Lab-oratory,  ARS-USDA  for  providing  identi-fication  of  Eurytoma  tylodermatis  and  toKathy  Robbins  for  assistance  in  data  ac-quisition.  This  research  was  supported  bythe  South  Dakota  Agricultural  ExperimentStation,  SDSU,  Brookings,  project  numbersH-277  and  H-388,  contribution  no.  2457.Literature  CitedBoe, A., B. McDaniel. and K. Robbins. 1989. Directeffect of parasitism by Dinannus acutus Thomsonon seed predation by Acanthoscelides perforatus(Horn) in Canada milk- vetch. J. Range Manage.42: 514-515.Bugbee, R. E. 1 967. Revision of chalcid wasps of thegenus Eurytoma in America north of Mexico. Proc.U.S. Nat. Mus. 118: 433-552.Burks, B. D. 1979. Eurytomidae. In Krombein, K.v.. P. D. Hurd, Jr., D. R. Smith, and B. D. Burks,eds.. Catalog of Hymenoptera in America northof Mexico. Vol. 1. Symphyta and Apocrita (Para-sitica). Smithsonian Institution Press, Washing-ton, D.C. 1198 pp.Pierce, W. D. 1908. The economic bearing of recentstudies of the parasites of the cotton boll weevil.J. Econ. Entomol. 1: 119-121.Ritcher, P. O. 1936. Larger apple curculio in Wis-consin. J. Econ. Entomol. 29: 698-703.Snodgrass, R. E. 1941. The male genitalia of Hy-menoptera. Smithsonian Miscellaneous Collec-tion 99(14): 36-37.McDaniel, Burruss and Boe, Arvid A. 1991. "Life history studies, host records,and morphological description of genitalia of Eurytoma tylodermatis Ashm.(Hymenoptera : Eurytomidae) from South Dakota." Proceedings of theEntomological Society of Washington 93, 96–100. View This Item Online: https://www.biodiversitylibrary.org/item/54815Permalink: https://www.biodiversitylibrary.org/partpdf/55488Holding Institution Smithsonian LibrariesSponsored by SmithsonianCopyright & Reuse Copyright Status: In copyright. Digitized with the permission of the rights holder.License: http://creativecommons.org/licenses/by-nc-sa/3.0/Rights: https://biodiversitylibrary.org/permissionsThis document was created from content at the Biodiversity Heritage Library, the world'slargest open access digital library for biodiversity literature and archives. Visit BHL at https://www.biodiversitylibrary.org.This file was generated 16 April 2022 at 19:14 UTC

Life History Studies, Host Records, and Morphological Description of Genitalia of Eurytoma tylodermatis Ashm. (Hymenoptera : Eurytomidae) from South Dakota

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Life History Studies, Host Records, and Morphological Description of Genitalia of Eurytoma tylodermatis Ashm. (Hymenoptera : Eurytomidae) from South Dakota

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