Neave,S. A.

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BITING FLIES IN BRITISH EAST AFRICA 87
waterwhichhasremainedirtyandunchangedfor months;
but,undertheseconditions,theydonotgrowsorapidly,and
if thedirtywaterbetoo prolonged,theyareliableto the
attacksofa diseasecalledpesterougein France.
Thecultivatedcarpof Germanyis,of course,anexcellent
eatingfish. Attachedtoalltheoldmonasterieswerethecarp
ponds,or stews,forFriday'sdipner,andfor thebanquetsof
themoreluxuriousnobleswho,at thattime,wereunableto
getsuppliesoffishfromthesea. A Germancarpthathasbeen
properlyfattenedandwellcookedhasan entirelydifferent
flavourfromthelittle,muddy-tasting,degeneratecarpofBritish
waters.Carpthrivebestin a somewhatwa.rmersummer
climatethanEngland;andbeforebeingeatenshouldbeput
in a smallfatteningpondandfattened,likea pig,onmeal.
In theold days,verygreatcarewastakenin thebreeding
andfatteningoffish,castrationevenbeingpraotisedtoha.sten
thefatteningprocess.Thosewhooareto oultivatethefish
onalargescaleshouldreadtheparticularlyinteresting.French.
workwhichhaslatelyappearedonthissubject-'Pilieioulture,'
by G.Guenaux(Bailliere:Paris).
PRETORIA May 16,1911.
NOTES ON SOME OF THE PRINCIPAL BITING
FLIES lN BRITISH EAST AFRICA
By S. A. NEAvE, M.A., B.Sc.aXON.
Beforediscussingthemethodsof collectingbitingfliesit
will be 80S wellto givea shortsynopsisof thegeneramost
likelyto bemetwithby theordinaryresidentor travellerin
thisProtectorate.
Thegreatmajorityofbloodsuokingfliesin TropicalAfrioa.
belongto thefamilyTabanidae,of whichtheprincipalgenera.
areTabanus,Haematopota,Pangonia,andChrysops.
Mostof the speciesbelongto thesefourgenera,andto
simplifymattersI donotproposetogointodetailsconcerning
88 BITING FLIES IN BRITISH EAST AFRICA
severalothergenerawith comparativelyfew and mostlyun-
Commonspecies.
The genusTabanusconsistsof a largenumberof species
of, for themostpart,stoutlybuilt flies,manyof thembeingof
largesize. Usuallyknownin Englandas•Gadflies'or •Horse-
flies,'theyareoftencalledin Africa •Hippo flies,'•Mangrove
flies,' or on the Nile •Sernt.' The following local native
namesappearto becorrectsofar asI havebeenableto ascer-
tain. TheWakambacallthelargerspecies'Njoo,'thesmaller
'Madzunzuma,'the Wakikuyu •19i, Ngikuvwa orZigayi'
(thelatternamebeingsometimesalsoappliedto Haematopota,
thenextgenus),the Nandi•Kiptololet,'the Jaluo Kavirondo
•Maugo,' the Jamwa Kavirondo •Ruuko,' but thesetwo
last namesareprobablyappliedto all biting flies. The flies
of the genus.Tabanusare·characterisedby the possessionof
ratherstoutantennae,the secondjoint beingvery shortand
the thirdor tip beingfroma.lateralviewsomewhatscimitar-
shaped. The proboscisis short,stout,anddirectedvertica.lly
downwardsothatit cannotbe seenfromabove. Exceptin
a fewspecies uchas the red and greenT.africomusandits
allies,thespotted-wingedT. maculatissimus,andthebig black
T. biguttatus,thesefliesseldomhavedefineddark markings
in theirwingsthoughthewholewingis sometimesinfuscated.
Thewingsarecarriedwhentheinsectis at restmuchasin the
house-fly.
The genusHaematopotais representedin Africa by a very
largenumberof species. The fliesof this genusarecompara-
tivelyfragileinsects,with a moreslenderbodyandlongerand
thinner antennaethan in Tabanus,the proboscis,however,
beingdirecteddownwardsas in that genus. The wingsare
mottledand spottedand havedark margins. When the fly
is at restthewingsaresaidto betectiformbecausetheangle
they makewith eachotherresemblesthat of the ridgeof a
roof. The Wakikuyu call them' MbogoorZigayi,' and the
Nandi•Sogoriet.' The majorityof nativetribesdo not seem
to havea distinctnamefor thembut classthemwith Tabanus
or otherbiting flies.
Thenexttwogenera,PangoniaandChrysops,areplacedin a
separatesub-familyof theTabanidaecalledPangoninae.They
BITING FLIES IN BRITISH EAST AFRICA 89
arecharacterisedbythepossessionf a spurat thetip of the
tibiaof thehindleg.
Pangonia hasnowbeensubdividedinto severalgenera,
but for ourpurposeit will besufficientto treatit as one.
The fliesof thisgenusareusuallyratherlargeinsects,some
of them,especiallysomeof thesmallerspecies,beingrather
likeabeeingeneralppearance.Theyareeasilydistinguished
by theirlong(sometimesverylong)proboscistickingout
horizontallyin frontofthehead. Thewingsaredarkorclear
butnotmottledorspottedandarecarriedsomewhatextended
evenwhentheflyis at rest. Theabdomenis notspotted,as
in a fewspeciesof Tabanus andmanyof Baematopota,but
frequentlybearsa numberof transversebandsof different
colours.
ThegenusChrysopscomprisesrathersmall,oftenbrightly
colouredflies. Theirproboscisis directed ownwardsas in
Haematopota,andtheirwings,thoughnot spotted,generally
haveoneor morebroaddarkbandson them,thetip being
usuallyalsodark. Theirwingsarecarriedas in Tabanus
notasin Haematopota,i.e.nottectiform.Theireyesarevery
beautiful,beingin mostspeciespurplewithzigzagsof golden
green.Indeedthe eyesof mostTaban4daearewellworth
examination,andastheylosetheircolourafterdeathcareful
noteof thecolourandmarkingshouldbemadeaBBoonas
possibleaftercapture.Twootherveryimportantgeneraof
bitingflies,GlossinaandStomoxys,belongtoanentirelydifferent
familyof Dipt.era,theMuscidae, towhichthehouse-fliesand
bluebottlesalso belong.Theydiffercompletelyfrom the
abovedescribedgenerain theformof theirantennae.These
aremuchlessconspicuousthanin anyof theabove,andthe
mostprominentpartof theantennaeis somewhatfeatherlike
insteadof beingsingleandratherstiffasin Tabanus, &c.
ThegenusGloss1lnacomprisesthewell-knownTsetseflies.
Thesearesmallor medium-sizedflies,varyingfroma trifle
largerthana house-flyto aboutwice·thatsize. Theyareof
varioushadesofbrownorblackwithoutverydistinctmarkings.
Theyarecharacterisedby thefactthatwhenat resttheir
wingsoverlaplikethebladesofapairofscissorsas well asby
thepossessionof a bitingproboscis,theprotectingsheathat
90 BITING FLIES IN BRITISH EAST AFRICA
least of which projectshorizontallyfrom the head. It is
importantto rememberthecombinationof thesetwocharacters
as thereareharmlessnon-bitingflieswhichcarrytheir wings
in thesamewayasthe Tsetse.
Being very local in their distribution in British East
Africa thesefliesareunknownto manytribesof natives,but
at Kibwezi,wherethereare threespecies,the Wakambacall
them' Chitangua.'
Thereareat leastfourspeciesof Tsetsein theProtectorate.
Two largespeciesG. brevipalpis,Newstead(formerlyknown
in EastAfrica as G.fusoo),andG. longipennis.G. brevipalpis
is oneof the largestspeciesandof a dark browncolour; it is
onlyonthewingin themorningandlateeveningandis seldom
seenduringthe heatof the day exceptin dull weather. It
frequentsthebanksof rivers,especiallywherethereisa certain
amountof cover.
G. longipennisis anotherlargeinsect,only a little smaller
than brevipalpis,but is muchpaler. It bitesfreelyduringthe
heatof thedayandseemSto beentirelyindependentof water,
ohiefly frequentingbarren desertlocalities. Neither of the
abovespeciesis definitelyknownto carry diseaseto manor
animalsin nature.
G. pallidipesis a markedlysmaller,brownishfly, also fre-
quentingrivervalleys,thoughit is probablylessdependenton
waterthan brevipalpis.It bitesat all hoursof thedayandis
believedto carrydiseaseto domesticanimals.
G. palpalisis thesmallestof all theabovedescribedspecies
&nd is very much blacker. It only occursin British East
Africa, so far as is known,in the Nyanza Province,and is
confinedto thebeltsof timberonlakeshoresandriver banks.
As is wellknownto all,it carriessleepingsicknessto man.
The fliesof the genusStomoxysare small,blackishflies,
verymuchlikehouse-fliesin appearance,indeedarefrequently
mistakenfor them. A closeexaminationwill, however,reveal
a rather long, stiff, somewhatcurvedbiting proboscisquite
differentfromtheshortsoftmouthpartsof thecommonhouse·
fly andits allies.
With regardto collectingthe abovedescribedflies it is
difficulttolaydownanydefiniterules. It mustberemembered
BITING FLIES IN BRITISH EAST AFRICA 91
that the femalesof all the speciesbite, and in the caseof
Glossinaand Stomoxysthe malesalso. The result of this is
that theyare frequentlyseekingthe collectorquite 80S much
as he is seekingthem!
Thefollowinghintsmay,however,proveuseful. All fliesof
the family Tabanidae,so far as is known,spendtheir larval
statein wateror at leastdampmudor sand,so that thereis
alwaysagreaterprobabilityoffindingthemnearrivera,swamps,
or suchdamplocalities. ThemaleTabanidaearedistinguished
at a glancefromthefemalesby theirhugeeyeswhichoccupy
the entirehead,therebeingno distinctdivisionbetweenthe
two eyesas thereis in the female. Sincetheydo not bite,
specialmethodsmustbeadoptedforcollectingthemales,which
aremuchlesswell knownthanthe femalesandarecompara·
tively rare in collections.
The genusTabanus,in British East Africa at least,seems
to bemuchbetterrepresentedon thelow groundthanon the
higherplateaux.
Thefemalestravelcomparativelylongdistancesfromwater,
followingcattle,&c., in searchof food. Canvas,especiallyif
damp,is curiouslyattractiveto them,sothatif atall numerous
somearenearlycertainto find their-way into the traveller's
tent. Herds of cattle or other domestioanimals in the
neighbourhoodare also well wo1th&xamining. These flies
areusuallyto beobtainedonlyduringtheheatof thedayand
soomto prefer bright sunshine. The beginningand again
towardstheendof therainsareusuallythebesttimesfor this
genus. The malesshouldbe soughitfor ohieflyat the end01
thedryseasonor duringanearlybreakin therains. Theywill
thenbe founddrinkingat dampsandor mudin streambeds.
Much dependson locality,as 80 runningstreamaffordsa less
chanceof looatingthemthanwhenthereareonly 80 fewpools
in the river bed. The malescanalsobe sometimesobtained
bycarefulsearchonthereedsatthewater'sedgeoroccasionally
sunningthemselveson the boughsof treesoverhangingthe
stream. I havenevermyselfoundthemalesanygreatdistance
fromwater.
ThegenusHaematopotasomewhatresemblesTabanusin its
habits, but during the rains at least is almost universa.lly
92 BITING FLmS IN BRITISH EAST AFRICA
distributed. In the forestareasof cool high districtsthese
fliesareprobablyto befoundthroughoutheyear. Themales
maybeobtainedin thesamewayasthoseof Tabanusbut are
alsooccasionallyto be foundin largenumbersin swampsor
grasslandnearrivers. Theyareverysluggishinsectscompared
with the malesof Tabanus,thesameapplyingto the females
thoughto a lessextent. The fliesof this genusaregenerally
mostnoticeablein the morningsand evenings,and are not
muchin evidenceat middayexceptin dull,dampweather.
The fliesof the genusPangoniafrequentforestor at least
well-woodedareas. They are not, so far as my experience
goes,verycommonin BritishEastAfrica. Theyflywithadeep
hummingnote,thefemalesusuallybitingnativeson the shins
or ankles. The malesarealsosometimesto beseenat flowers.
The genusChrysops alsoseemsto be confinedto wooded
localitiesand the rainy season. They areusuallyonly found
at comparativelylow elevations,andseldomin largenumbers.
The Tsetsefliesareusually,whenpresentat all, verymuch
in evidence,but as explainedabovetheydiffera gooddealin
their habitsasregardsthetimeof daywhentheyaremainly
on thewing.
The fliesof the genusStomoxysoccurmoreor lessevery·
where,butaremuchcommonerin theneighbourhoodof human
habitationsanddomesticanimalsthanin thebush. Sofar as
my experiencegoesthey are moreabundantat the higher
elevationsthan in the low country. They seemto prefer
domesticanimalsto man,andareoftena seriouspestto dogs,
the earsof whichtheyattack,causingsoreswhicharedifficult
to heal.
Theabovedoesnotpretendto bemorethana verysketchy
surveyof someof the principalflies likely to be met with.
To anyonewho wishesseriouslyto take up the important
subjectof biting fliesI wouldrecommendMr. E. E. Austen's
recentbook' AfricanBlood-suckingFlies,'whichcontainssome
fineillustrationsof manyof themoreimportantof them.
In conclusionI would ask the indulgenceof my readers
in respectof this ratherscantypaper,but it ha.'beenwritten
out in the bushunderconsiderablestressof otherwork and
with very little literatureat my command.


Notes on some of the principal biting flies in B. E. A.

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Notes on some of the principal biting flies in B. E. A.

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