.1. E ~ Tml()J . SoC'. BRIT COLlJ MBI A 74 119771. D F:G. 31.1977 27 MORPHOLOGY OF ALIMENTARY AND REPRODUCTIVE TRACTS OF THE RODENT BOT FLY, CUTEREBRA TENEBROSA (DIPTERA: CUTEREBRIDAE)! CRAIG R. B A IRD' and ROGER D. AKHE ' ABSTRACT The internal reproductive and alimentary structures of Cut" rebra teneiJro sa Coquillett were studied and compared to other calyptera te fli es. Well defin ed mouth parts a re present. Paired lingual sali vary g lands extend horizontally almost to the ahdomen: however. labial sali vary glands were not found . The alimenta ry canal is complete in female fli es. whereas males lack a crop. Females have three spherical spermathecae opening in to t he upper portion of the genital chamber. Male reproduct ive structures are similar to those in other flie s. Tracheal air sacs fill one-third to one-half of the abdomen. I N TRODlCTIO~ OBSERV.\TIO\'S AND DISn;SS ION Little is known concerning the internal The use of Kahle 's solu tion to kill adult fli es structure of Cuterebra bot fli es. Townsend proved a very useful technique sinc(' the 11935) provided the earliest descriptions of solution perpealed a ll body areas and preserved ('uterebra alimentary and reproductive tracts t he internal organs very well. but did not include illustrations. Alim ental''' Trac t In 1963. Calls descrihed and illustrated t he No att ~ mpt was made to describe t he mouth alimenta ry and reproductivE' tract s of parts of l. tenebrosa. The mouth parts are Cuterebra latifrons Coquillett. A comparative typica lly muscoid in both sexes as described for studv of t he alimentary canal of several flies C. em asculato r IBennett 1955 ) and C latifmn s in clu'ding r. latifron s was made by Sing h a nd ICalts 1963). Judd in 1966_ Various authors have descrihed The paired racemose sali vary gla nds are and illustrated the external genitalia of connected anteriorly by a common sali vary Cuterebra IBennett 1955 : Haas & Dicke 1958 : duct which extends to t he oral s tructures Cates 1963: Graham and Capell e 1970: and I Figure I ). Posteriorly. the glands a re situated Baird and Graham 1973 ). The purpose of the -horizontall v in the lower thora x and extend presen t paper is t.o report findings from almost to 't he abdomen. CaLts 11963 ) reported dissections of Cut erebra /e l1 eiJro sa Coquillett the sali vary gla nds extending only in to the specimens a nd t.o provide illu stra tions of the prothorax of C. la t i (run s. Singh and Judd structures. 11966 ). also working with C. la t i (rull s found sa li varv glands extending into the a bdomen. METHODS A\,D \lA TEIU", LS Townsend 11935 ) described salivar.v glands of Adult fli es were obtained by rearing larvae Cut erehra as being atrophied or absent. These in captive bus hy tailed wood rats (Nf'o toma discrepancies may be due to age or to preser­ cinerea Orrl.!. Within fiv e days a fter emergence. vation method. fli es were inj ected with Kahle's solu tion to kill Lowne 11 890) and Hewitt 11914) indicated and fix th e ~1 in a n extended position. They that paired lingual salivary glands of Calliphora were s tored in t he same preservative for several and Mu sca_ respectively , were of a simple days and then transferred to 70 % alcohol for tubula r type which ultimately te rminated in the pe~man e n t s torage. Dissections were performed posterior of t he abdomen. Hori 11972) al so with standard insect di ssection tools under a found tubular sali vary glands extending into binocular microscope. the abdomen of fli es belonging to eight caly pterate muscoid families_ An additional ISeit'lllific Papf'r No . ·J.lH9, C( )ll eg(' of Agrkult urr' Hp."C'aJ"ch difference between Cuierpbra and other Ct'nlf'r. \\"a" hi ngton S tatl' lJl1in~ r " il .\ · . Pull man. Projt'ct !J9.J:I mu scoid fli es was that the labial sali vary glands present in Callip hora and M usca I Lowne IR90: 1914) C uterebra. -' De partment o f En loll1olog.v. lIn i\"f·r<.>it.\· o f Id aho, \lnsrow. Hewitt were absent in Idaho A d dn~s ~: P. O. Box 10:")1'\ Cill d w\·11. Irla lHI R:JG();-) The alimentar v canal in C. tell eiJrosa is complete a nd basically simila r to that in other muscoid families. An important difference is 'DqJ<1rt mellt o f Elllorn o l og-~· . \ \'a shing!oll Statl.' lInin·t"sily. Pullman. \Yashingtn n 99 1(~: l the apparent absence of a crop in male r. E CS CV 'YJ" / v ! I '''.,~',:--/ -"-- - / " ~/ ,/ .,"/ .... /;;;:-~~:;;~:! ,/~U / ' / ,. ! / ; i I //:.,f' / / ' // // '·ii /:I i ;# If / { .' //i . /~.:~~ ;I ! i / ~~ . I ~,I/ ' \\ "/~. ii i c... ..:...... / .~=-~~ / \.. \~ ::IJ •c':l ..... " / , - C ' • ; ::: ~ : I / .\ I '!? i ;:s \ ! i '- :0 :0:: Fig, \. i- (') o } .:~">~' c ::: :>­ SG ...., v MT R "" m m -.J 5.0 ~========= '"...., ~ :- Fig, 2, / ~ / / 9 ro w Pig. 1. Alimentar,Y t raCL of CUIl'rehra Il'llebr .. ,,!' E , esopha gus: CS, cardiac sac: CV, crop vestige: 1.0mm ;- SG. sa li va r.v gland: V. ventriculus: MT. '\lalphighia n t ubules: H. rectum -.J Pig. 2. En larged view or cardiac sac. CS. cardiac sac: CD. crop duel: CV. vestig ial crop c·s CD cv '"-.J e> '" .y .. .. v .•. ·_f :~ . ~ : ,. .,., 0 ~ C) .. :,.;;,; ""':\; ,, '" .... '"'" en c C loLl .)~." c:s: J';).:J. > ~ ,iI"." ...... " "· ~·~"r.' I: ~ .:~ ' ;~~ .•." . .ii ~.~, I , """1\-, -,:3 ~ ~ '~$~: .> <,~ .•,~ .• ;.. .."'- to; / ~\ 1-.. _...." " , ' )- - - -' ~" "" .. ,.. \, I- .~ . t, "~~, ~ ~ ~ ~ .... c: '- ,'""'-' "\ '-~', ~ r-~,~ :~ .. ":-1--';"., _ y. ;.7" M ... // ~'{"" . ~~- 'l': ," ~:~ :. 'I .;-l -j\ 1 V .,." 't" .•.. • ..c": . ~:..-. , , ~ -.'" ~ .~J / ' '. I ~- <~l$ ' /=- ... :-::=-..... ,<,..... ~.- . "_ ':7" '- ;I: · ~ ;.-t :";··· ./ ''~ ' c5 -' ~'. J''''.' 1"0 -... ~ .-: '<i" -, c-­ " ":;' z. ~ " -:.,~~' E l­ " e> .,,1'-. ,. ' E , "~" ..; " -""""";~' - , " t ' <.:-.: t.;~ .. ~....,... I-"'" • ''''T':- '- E .". « " E (/~' ~ ,:; , :v' I o ' > I':'::' .' \. .... .. ' :""' '' ~' ,=.i; • c: , 0 ,"-" ;:.. ~. '..,. .' ' " • ... ..1 11-,·,... .~ ...: I " r~~·J. ::0 _.. ' . ...: :.,.• .......... 't' . I './' ." . ;. ,:-" , '~~. - ;" " o -\~ ., '::' "' _., U !f ~ .. .~ . - -'~ ~ ;'~~ , f ·~ 0:: a:l cc.., (/) .§ is ;:.. ~. Fig. 3, Female reproductive organs. 0, ovary; AG, accessory gland; S, spermatheca; Ge, genital z2 chamber w Fig. 4. Male reproductive organs. T , testis ; YD, vas deferens: AG, accessory glands; ED, ejacula· -, tory duct; A , aedeagus 30 J . ENTOMOL. Soc. BRIT. COI.UMBIA 74 (1977). D EC. 3 1, 1977 ' tellebrusa specimens. Only one of fiv e males from zero to four. C. tell ebrosa specimens have had a crop, whereas all fo ur females had small spermat hecae arranged one on the upper left crops (Figure I, Figure 2). Studies with side of the genital cha mber, one on top, and one C. latifrons present co nflicting results : Catts on the upper right side of the chamber ( I: 1: 1) . (19631 reported a vestigal crop, whereas Singh I n contrast, most other muscoid genera have and Judd (1966) described a crop proportional two left and one right 12: I) or one left and two in size to that of other muscoid Diptera. rig ht 11: 2) ILowne 1890; H ewitt 1914; Hori The ventriculus begins with a typical 1972) . A variety of spermathecal shapes were cardiac sac. This organ is termed t he proventri­ illustrated by Hori (1972) for muscoid fli es; culus by Lowne (1890), Hewitt ( 1914), however, within genera the shapes were fairly Hori 11972), and the cardia by Singh and consistent. Judd ( 1966). The remainder of the C. tell ebrusa C. tellebrosa males are basically similar to ventriculus is tubular and of the same diameter other muscoid flies in the internal reproductive t hroughout. T hi s agrees with findings for structures. One difference between C. t f'lIebrosa C. lati/i'olls by Catts (1963) and Singh and and C. latifrolls ICatts 1963) is that t he Judd 11966). Food remnants were found in the accessory glands are s maller in relation to t he ventriculus and in testines of three male C. testes in C. tenebrusa. This may be a function tCllebrusa specimens. This must certainly be of t he age of the fly, however, as Hori 11972) material held over from larval feed ing sin ce the stated the shape of the testes of male muscoid flies had no opportunity to feed as adults. At fli es correlated closely to the age. the ventriculus-i ntestine junction, two Malpighian ducts are present. Each duct g iv es CONC LLSIO NS rise to two moniliform Malpig hian tubules The a li mentary tract of Cuterebra tenebrosa which extend among t he organs of the is basically sim ilar to other muscoid Diptera. abdomen. The rectum is simi la r in shape to that The two main differences are the reduced or of other fli es; four rectal pads are present on absent crop in males and the racemose salivary the an terior portion. Catts (19631 and Singh glands in C. tellebrosa. Judd 11966) reported similar observations fo r [n early Cuterebra li terature, these bot fli es C. latifruns. Large tracheal ai r sacs extend from we re described as being without mouth parts. one-third to one-half of the length of the Alt hough more recent work has shown the true abdomen of C. tenebrosa. Townsend 11935) nature of their mouth parts and alimentary made no mention of air sacs in his studies of svstem, no one has reported Cuterebra fli es Cu ler"hra specimens. feeding or drinking, Apparently there is no fo od requiremenl for oviposition. In rearing several R eproductive Tract hundred ('lI t('l'{dl/,(/ fli es in recent years, we have Figures 3 and 4 illustrate the in ternal maintained them from eclosion to oviposition reproductive system of femal" and male 1usua ll y fi ve daysl with nO opportunity to feed.