This pdf file contains pages excerpted from Technical Bulletin 61 that relate to Angiostrongylus cantonensis, the rat lungworm, its rat host (p. 80–84), its intermediate mollusk hosts (p. 24–26), and information on angiostrongylosis disease in humans (p. 31–36). The entire 138-page bulletin is available as a pdf file (~37 MB) at the community home page of the College of Tropical Agricul-ture and Human Resources, University of Hawaii at Manoa, on ScholarSpace:http://scholarspace.manoa.hawaii.edu/handle/10125/1877

24 HAWAII AGRI C ULT URAL E XPERIMENT STATION

MOLLUSKS OF PARASITOLOGICAL IMPORTANCE IN HAWAII

M O LLUS K

( NAT URAL SIZE)

SNA ILS

A ctiatina [utica

Bradv boeno: similaris

Fassar ia oll ula

LO CA TION FO UN D

On land

O n land

On ba nks of fresh­wa ter strea msa nd swamps

Ii\IPORT A j\;C E

Intermedi a te host for th e ratlungworm , Angiosirongy luscan tonensis, which produ cescerebra l ang iostrongy losis(pa rasitic eosin oph ilic m en ­ingoen cephali ti s) in m an (seepp, 31- 36).

In term ediate host for : (a) th ecat lungworm s, Anali laroidesros tro tus a nd A elurostrongy lusabslrusus ; (b) the ch icke ncecal nuke, Pos tharmostomurngallini nn; (c) the rat lung­wor m, Angiosirongyluscan tone nsis, which produ cescere bral ang iostro ngylosis(paras itic eosinophilic men­ingoen cephali tis) in m an (secpp. 31-36).

Intermed iate host for theca tt le liver nukes, Fasciolagigan tic a a nd F. hepatica.

I' AR ASIT IC INF ECTI O '\iS O F M A N A ND A'\i I MALS IN H A WA I I 25

MOLLUSKS OF PAR ASITOLOGICAL IMPORTANCE IN HAWAII

~ IOLLUSK

(N ATU RAL SIZE)

L itt orina p in tado

Opeas [auanicum

Pseudosucciueo.columella

St enomelanian ewcornbi

Subulina oct ona

LO CATI O N F O UN D

On mari ne roc ks

O n Jan d

O n banks of fr esh­water strea msand swa m ps

1n Iresh-wa tel'st rea ms

On land

I MPORTA N C E

In terrn ediate ho st for thebloo d fluk e, Austvo bilhavziauariglan dis, of certa in fish­ea ting b irds. T he larvae(cerca ri ae) emerging from th esn ai ls are po ten ti a ll y ab le toprod uce derma titis in man .

In termediate hos t fo r th e ra tlu ngworm, Angiosirongyluscan to nensis (see A chai ina[u licay.

(Same as Fossaria oll u la)

In ter med iate host for thefo llowin g intest in al fluk es:(a) Ccntrocestu s form osan usin th e night heron and ra t;(b) H aplorchis ),olwgaw ai inthe n igh t heron ; (c) Stellan t­cha smus [alcatus in the ca t,dog, ma n , and ra t. Also in ter ­medi a te host for th e eye-fluke,Pliil oplit tialmus gra lli , in theHa wa iian coo t, a nd a lsocapa ble of develo pi ng inmamm al s.

(Same as B radybaen asimilariss

26 H A W AII AGRIC UL T URAL E X PERI MENT ST ATI O N

MOLLUSKS OF PARASITOLOGICAL IMPORTANCE IN HAWAII

M OLLUS K

(NATURA L SIZE)

T'h iara gU/'ll i[em

S I .lIe S

Devo re ms 10em:

JJl 'c ro n i cc lla altc

LOCAT IO N FO UND

In fre sh-wa te rstrea ms

On land a ndvegeta tio n

On land a nd you ngo nes occas iona llyon vegeta tio n

1~ I PORTA i'\ CE

In termedi a te host fo r th efollo wing intestinal fluk es:(a) Cen iro cestus [orrnosan usin th e ni ght heron and ra t;(b) Ha plorch is taicliu i a ndH . yo lwgawai in th e nigh theron ; (c) Stellantchasrnus[alcatus in the ca t, dog, ma n,and ra t. Also in termedi atehost tor th e eye-fluke,Philopht ha lmus gralh , in theHawaii an coo t, a nd alsoca pa ble of developing inmamm als. Potential host forth e lung fluk e, Paragonim usioestermon i, in m an .

l n termed ia te host tor th e ra tlun gworm , A ngiostrongyluscantonensis (see Aehatinafu lica) .

Intermedia te h ost lor th e ratlungworm, A ng iostrongyluscanionensis (see A cha tina[ 'IIlica).

PAR ASITI C I:-lF ECTI O NS OF M A l': AN D AN I ~ rALS I N H AWA II 31

in a child in the cont ine n tal U nited States (De n t et al ., 1956); conse q uen tly ,th erefo re , cere bral toxocarosis m ay gi ve ri se to eosinoph ilic meningoen ­ceph ali tis.

In 1961, the ra t lungworm, A ngiostrongy lus can tonen sis , was recovered inHawai i at an a utopsy on the bra in o f a Filipino with a hi story of eosino­phi li c m en ingoen cephaliti s (Rosen et a!., 1961, 1962). Th is finding fo l­lowed the d iscover y by Ash (1962b; see Parasi tes of R at ) of the ad ult stage ofA . cantonensis (fig. 3 1d) in th e lu ngs of loca l rats, a nd confirme d the specu ­lati on orig inall y m ad e by Alica ta (1961, 1962a) th a t th is p ar asite m ay bei he ca usat ive age nt o f eosinoph ilic meni ngoencepha litis in th e Pacific (seealso Alica ta and McCarthy, 1964). A case of th is di sease, also referred to aspar asiti c meningoenceph alit is and cere bra l angiostrongy losis, occurred in aJ ap an ese la borer in H awaii following ingesti on o f two ga rde n slugs, Veron i­

eel/a ali e (see H orio and Alica ta, 1961).A . cau to nens is is no rmall y a pa rasi te of ra ts a nd util izes mollusks (p p. 2cl ­

26) as in term ed iat e hos ts (see Par asit es of R at). Land planaria ns (C eo-p lanascp tc m li n eata s in H awa ii, and fre sh -water p rawns (M acrobracl,,'u m sp.) a ndland cra bs in o ther Pa cific areas, h ave been fou nd to serve as parateni c ortran sport h osts far th e inf ectiv e lar vae (Alica ta and j\JlcCa rth y, 1964); exp eri­mentall y, p igs and calves h ave a lso been foun d to serve in th at cap aci ty(Alica ta , 1964b ).

H um an in fecti on with A, cau tonensis most lik el y occurs as a resul t of ea t­ing uncook ed food (fig. 3) con ta in ing in fecti ve larvae of the parasite. Ea tingha bi ts and customs o f people may p lay an impor ta n t pa rt. In Ta h it i, th ecommon occurre nce of eosinop h i lic meningoen cep haliti s h as been traced tothe customary h ab it o f ea ting raw prawns, incl ud ing, p ossibl y, "taio ro .' Thelatter consists o f gra ted cocon ut to wh ich is added p rawn jui ce, prepa redby grind ing th e stomach and surro und ing port ions of the p raw ns in fr eshwa tel' (AIica ta and Brown , 1962). 1n T h a ila nd, the d isease is beli eved to beacq u ired as a resu l t of ea t ing the la rge a mph ibio us snail , Pila am -p u llacca

(see Pu nyagupta, I96·l). The flesh y h ead-foot part 01' the sna ils is cu t a ndthen eithe r d ip ped in boiling wa ter or sto red in an icebox to keep it fr esh .It is th en ea ten after being chop pe d int o small p ieces, seaso ned wi th lim ej uice, a nd mi xed with vegeta bles. I n New Caledo nia a nd Hawai i, whe re

eosinoph i lic meningoen ceph ali tis occ urs sporad ica lly, it is p ro babl y acq u iredthrou gh the acciden ta l in gest ion of a n in Iected smaII garden slug, or a carrierhost such as a la nd plan arian, wit h con ta mina ted salad gree ns (Alica ta ,I963a; M ead , 1963). F ur thermore, in som e are as, human in fection m ay pos­sibly tak e place from ea ting raw land cra bs (Alica ta, 19640) and impro perlycooked li ver or o the r in tern al org ans of swine or ca lves (Alica ta, 1964b).T hese a nimals in th eir fo raging habi ts ar e believed to in gest live mo ll usks.

F IGURE 3. Life cycle of the ra t l ungworm , Angiostron gylu s can tonensis, and possible aven ues of hum an infection. (O rigina l.)

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PA RA SITIC INFECTIO~S OF :\I A N A~D AN D'fALS 11\ H AW AII 33

Experimentall y, livin g lar vae of A. can ionensis h ave been found in th e stom ­ach wall, li ver, lungs, and sp lee n of pigs a nd calves 2 weeks after infect ion .In th e pi g, however , th e lar vae were found enca ps ula ted and dead in th eabove organs 5 weeks after in fection. The com pa ratively ea rl y encapsula tionof th e lar vae, th erefore, appears to m in imize th e importan ce of th e pi g as acarrier h ost. Experimenta lly, th ese larvae h ave no t been found to mig ra teto the volun ta ry m uscles of pigs or calves (Alica ta , 1963c) 1964b) . To wh atex ten t p igs and calves are infected with lar vae of A . can tone nsis undernatural cond itio ns and thus serve as sources of human in fecti on rem ains tobe determined.

Eos inoph ilic men ingoencepha lit is is a syndrome ch aracterized by th epresen ce of eosinoph ils in the cere brospina l fluid . In m an this syndrome h asat times been no ted in conn ect ion wit h cases of no nh elmin th ic and h el­minthic infections involving the cen tral n erv ou s system . N onhelminthicinfecti on s h ave been obs erved in some cases of cere bra l tumors, ep ide m iccerebrosp inal me ning itis, neurosyphilis, purulent m eningitis, an d tubercularmeningitis (Kaczynski, 1936). H elminthic infecti ons in clude cer ebral angio­strong ylos is (H orio a nd Alica ta , 1961; R osen e t a l ., 1962; Alica ta, 1963a),cere b ra l cysticercos is (Kulkov, 1930), cere bra l ech inococcosis (App leb au mand Wex berg, ]9'14), cerebral paragonim ias is (U ema tsu and Shi ozaki, 1935;N ono rn u ra, 1941), and cere bra I sch istosomias is (Cas ta igne e t al., ]959).

In the Pacific Basin , cases o f eos inoph ilic men ingoencep hali tis h ave beenrep orted from Micro nes ia, Pol ynesia, and Me lanesia . A few add it ion a l casesha ve bee n reported from J apan ( onomura, ]941) an d the Philippines(Sison et al ., 1951). In South eas t Asia , cases h ave occurred in T haila nd(Pu nyagup ta, 1964) and Su ma tra (Sm it, 1962). Labora tory and field evi­den ce suggests that A . can tone nsis is in m ost cases th e causat ive age n tof eosino p hilic men ingoencepha li tis in H awaii a nd o the r Pacific islands.T h is evidence includes: (a) recover y of young ad ult A. can tonensis fr omman in two cases of eos ino p hi lic m eningoen cephaliti s (N om ura a nd Lin,1945; R osen et al ., 1962); (b) capabi li ty of th e lar vae of A . can ionensis totr a vel to th e centra l n ervou s system of simia n primates a nd to give rise toeosinop h ilic meningoen cephalitis (Alica ta, 1962a; Alica ta , Loiso n, and Ca­vallo, ]963; Weinstein et al., 1963); (c) record of two hum an cases o f eosino ­philic meningoen cephalitis fo llow ing th e willful in gesti on of raw slugs fr omendemic areas (H orio and Alica ta, 1961; Ali ca ta , 1963a ); (d ) record of ahuman case of the di sease in Hono l ulu foll owing th e in gesti on of six rawg iant Afr ica n sna ils, A chat ina [utica (see Mookini, ]96-J.); (e) presence oflungworm s amo ng rats in all the P acific islands (fig. 4; see also Parasit es ofR at ) in whi ch eosinoph ilic men ingo encep halitis has been re corded, namel y,Cook Islan ds (Alica ta and :McCar th y, 1964), Fo r mosa (Nomura and Lin ,1945), G uam (Lo ison, 1963), H a wai i (Horio an d Alica ta , 196] ; R osen et al.,

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F IGURE 4. Geogra phical d ist ribu tion of th e rat lungworm . A ngiost ron gylus can ton ensis, in th e Pacific islan ds and Southeast Asia (indicatedbv slars) . and its rela tionsh ip to the d istr ibut ion of eosino ph ilic me ningoen ceph alitis in man (underscored). (See text , pp . 31- 36.)

PAR ASIT IC I :>I F ECTI O i\:S OF M A N AN Il A N Ii\ IALS 1:\ HA W A II 35

1962), l\ew Caled onia (T r uben, ]952), N ew H eb rides (Loison, ]963), Po­nape (Ba ile y, 1948), Saipan (All ison, 1962), an d T ahi ti (Fran co et al., 1960 );(f) absence of the di sease in areas o f the Paci fi c wh ere th e ra t lu ngwormis not known to occur, namel y, Fi ji, Samo a, Tonga, and W allis (Lo ison,]963); (g) h igh incid en ce of eosino p hil ic meningoenceph ali tis in Tahiticorrela ted with th e freq ue nt cons umption of raw prawn s, 4 percen t o f whichhave been found in fected wit h th e lar vae of A. cau tonensis (see Alica ta andBrown, 1962); and (h) wides pread in cid en ce of the d isease in parts of T ha i­land correlated wit h cons umptio n of in suffi cien tl y coo ked amph ibiou s sna ils,Pi la am.pu llacea (see Pun yagupta, 196'1).

The cause of eosinophilic m en ingoen cephalitis reported from J ap an andposs ibly from th e Philip pines, wh ere A . can tonensis is not kn own to occu r,in a ll p robability is d ue to cerebral paragon imiasis. In J apan, Uerna tsu andSh ioza ki ( 1935) rep orted a pl eocytosis of 1,44 1 cells per cub ic mi llimet er ,consist ing of practi call y all eosino ph ils, in th e cerebrosp ina l fluid of an indi­vid ua l wh o showed meningeal irritation s, cloud iness of both lu ngs in theX-ra y ex ami nat ion, a nd numerous Paragon imus eggs in th e sp u tu m. I n thesame wa y, N ono mu ra (194 1) reported a pl eocytosis wit h 98 percen t eosino ­phi ls in th e cerebros p ina l fluid of a no ther patient in J apan . Alt hough nofluke eggs wer e found in th e sp u tum of th is pa tie n t, Nono mura conclude dthat th e p leocytosis was most likel y produced by cerebral paragonimiasis.Furthermore, the sporadic cases o f eosinoph il ic meningoen ceph alitis, whichhave been rep orted from E urop e and N or th and Sou th Ame r ica, wh er e A,caritonensis is not kn own to occ ur, ar e poss ibly ca used by one or more spe­cies of h elminths whi ch occasiona lly in vad e the cen tra l n er vo us system (Smi t,1962). Of importa nce in this connec tion is th e findin g of eosino ph ilic infil ­tration of th e meninges, resulting fr om lar val in fect ion of T ox ocara can is)wh ich ha s been observed in a ch ild in the con tine n ta l U ni ted States (De ntet al., 1956). E tio log icall y, however , infect ion wit h larvae of T ox ocara occu rsmost commo nly in young ch ild ren, wh ereas eosinoph il ic meningoencepha­litis in the Pacific area occ urs ch iefly am on g adult s.

Of interest is the a ppa re nt ab sence o f A . can ton ensis amo ng rats in Fij i,the Phi lippines, Samo a, Tonga , an d "Va ll is Islands, whose cl ima tic cond i­tion s and fau na are ge ne ra lly sim ilar to those of o ther Pacific isla nds inwh ich th e parasite occu rs. In a ll probability, th is cond it ion poin ts o ut thatth e pa ras ite is a recen t immigrant to th e Pacific islands an d one wh ich asyet h as not becom e more wid ely di str ibuted . Its origina l sou rce of dispersala ppea rs to be Eas te rn As ia. It was first re corde d fr om Ca n to n, C hi na , by Chenin 1935, a nd in 1937 it was repor ted by Matsumoto an d Yokogawa fr om For­mosa. It a ppea rs to h ave gra d ua lly spread to variou s Pacific isla nds eithe rthrou gh im portation of infected mo llusks or in fected rat s. This has probablybeen bro ught about by recen t increased commerc ia l and mi litary ship ping

36 HAWA II AGRIC ULT URA L E X PER IMENT ST ATION

operatio ns, esp ecially d uring World W ar II, fr om Eastern Asia to variousPacific ports. Further evidence of th e recent di sp er sal of th e rat lungwormin the Paci fic r egion appears to be th e recent occ urrence of eosinop hilicmeningoencephalitis in the P aci fic islands. T his syndrom e was first noted inFormosa in 1944 (Nom ura a nd Lin, 1945), Ponape in 1947 (Bailey, 1948),New Cal edonia in 1951 (Tru bert, 1952), an d T ahiti in 1958 (F ranco et al.,1960).

As indicated above, A. can tonensis was first dis covered in East Asia in1935. Furthermore, the firs t case of eos inop hi lic meningoence p halitis in th ePacific was reported fr om Form osa in 1944. In this connectio n, it is of im­po rtan ce to note that th ese findings followed shor tly after the in troductionof th e gia n t Africa n snail, A chat ina [ul ica, in th e areas . A . [ulica is an idealintermediate h ost of A. can tone nsis. According to Me ad (1961), du ring th eninet eenth cen tury, th e ach a tini d snails became di spersed from th eir EastAfr ican home to Sou the as t As ia and from there to East Asia a nd the Pacificislands. T hey were first found in Ma lay a in 1911, Indonesia in abou t 1930,Ch ina in 1931, Form osa in 1932, the Maria na and Hawaiian Islands in1936. T hese data point out that A. [utica mi ght have imported or assisted inth e spread of the ra t lu ngworm in Asia a nd in th e P acific is la nds . If this istrue, it is possible that th e origina l habitat of th e parasi te is East Afri ca, th esame as tha t of A . [ulica. Altho ug h A . [utica is not known to occ ur in Aus­tr alia, New Ca led on ia , or Tah it i, where A . can lonensis is now fou nd, it isposs ib le th at th e paras ite was im ported in th ese areas th rou gh infected lan dmollusks or in fected rats from Southe ast As ia 0 1' ] nd o nesia af te r it had be­come establ ishe d th er e. T he p rob ability tha t A. can tonensis mi ght haveoriginated from East Africa o r nea rby areas is being further in vestiga ted bythe au tho r. *

The geog rap hical area in whi ch A. canionensis is presently known tooccu r in man and ro dents is li mi ted to th e tropica l belt wh ich ex te nds ap­prox im a tely from th e Tropic of Cancer (230 N or th la ti tu de) to th e Tropicof Caprico rn (230 Sout h latitude) (fig. 4), and from T hailand (1000 Eastlon gi tude) to th e island of Tahiti (1500 W est lon gitu de). T h is a rea is char­acte rized by tro pical and subtropical clim ate, rnodera te to h eavy ra infa ll ,and considerable veget a tion . All th ese factors are hi ghl y con d uc ive for th epropagation and sp read of mo ll usk s and roden ts.

TAP EWORM S

Most cases of tap eworm infect ion th a t h a ve occurred in Hawaii probablyrepresen t in fection s acqu ired elsewh ere . In a survey carrie d o u t b y Powers

" Afte r thi s manuscr ipt was submitted for p ub lication , Dr. Kenich i Nish im ura and Dr.Ma ria no G. Yogor e rep orted to the wr ite r o f find ing Angiostro ngylus can tone nsis am ongra ts in Ma nila. T he writer has a lso found A . can ton ens is in th e lun gs o f rats on th e isla nd sof Maurit iu s, Ma dagascar, and Ceylo n.

80 H A W AII AG R IC ULTU RA L £ XPER I;vI E:-lT STATION

ARTH ROPOD S

T he m ite, Psoro p tes eq u i cu niculi, which ca uses ear man ge, is th e mostim port a n t ex te rna l pa ra site a ffect ing dom estic ra bb its. It is as troublesom ein H awa ii as in ot he r areas . T he in flammatory reacti on prod uced by themite ca uses a b rown ish di sch a rge which ca kes inside of the ea rs. Affectedan ima ls freq uen tl v sha ke their h ead and tr y to scra tch th eir ears wi th th ei rh ind feet. T he m ite, 'volocd res cati cun ic uli . has a lso been collec ted fromth e face of' the rabbi t ( Hara moto, 196 1). M ires are tra nsm itte d by con tact.

R AT

P ROTOZOA

The blood fl agell a te, T rypmlOsnrna. leioisi , has been re ported fr om wildrats inha bi ti ng a gu lch in the H umakua D istr ict of th e islan d of H awaii(Ka r tma n, 1954). T he in cidence of in fection among the fi e ld rat, R attus ex u­lans, was sa id to be almost four t imes that of R . noroegicus a nd abou t twoti mes th a t o f R . rat tus and i ts subspecies. On th e bas is of epizoot iologicalevide nce, it was suggested tha t the ra t fl ea , X en op svl! a uexo bilis hn ioai ien sis,is the principa l in term ed ia te host. TrY/Jal/ oso." w conorh ini, a blood parasi teof a n unknown vert ebra te, h as been reported from th e red uviid b ug, T ri­at om a rub rolasciaia, co llected under a ch icken coo p on the island of Oa hu(Wood, 1946). T h is par asite has bee n gro wll ex pe r ime nta lly in ra ts a nd mice,and in cu iture med ia (Joh nson, 1947).

RO UND W ORM S

.ln a survey of parasites of rats in H on olu lu, the foll owin g spec ies a ndper ce n tages of roundworms were fou nd (Ash, .l962b) : sto ma ch worm s, Con­p,y lonema u eoplasticum (fig. 3 1a) , 53; Pliysalop tera muris-braziliensis (fi g .31c), 37; in test ina l worms, H eteraki s spurnosa, 46; Nip post ro ngyl us brasili­ensis, 17; Strongy lo id es raui, 17; Syp ha cia ob uelata, 44; urinary bladder­worm , T'rich osomoides crassicau da (fig. 31b) , 17; Iun gworm , A ngiost rongyluscantonensis (fig. 3 1d ), 12; li ver cap illa rid , Capi llaria hepat ica (fl g . 3Ie), 28,T he intesti na l capi lla rid , Capillar ia. tra uera e, a nd th e aca nthocepha la n,M onili iorm is mon ili !armis, were also rep orted. A fa ta l case of C. h epat icainfection h as also been reported from a ch ild in H awaii (see Parasit es ofMa n).

I n add it ion to th e a bove, T viclnn cll a sp ira lis ( fig. 32a) occ urred in 2.7percen t of the ra ts exam ined [rom the isla nd of H awa ii, a nd in 0.09 per cent[rom th e islan d of M au i (Alica ta, 1938e). No tri chin ae have been fou ndamong rats on the isla nds of Oah u a nd Ka ua i , T h is par asite occurs in ma na nd swine in Hawa ii (see Par asit es of Ma n, and Swine ).

P ARASIT IC I NF ECTI O NS OF MAN A;\ID Ai\ L\-IA LS 1;\1 H A W A I I 81

f lC UR E 31. Pa rasi tes of the rat : a, ad u lt Gongylo llema neoplasticurn; b, ad ult bladder­worms, T ricn osom oides crassicauda; c, ad u lt sto ma ch worms, Ph vsalopterr: mu ris-brasili­ensis; d, ad u lt l un gworms, Angiostrongyll.l s can ionensis; e, l iver sho wing clu st ers (an· ow )of eggs a nd ad u lts of Capi llaria hepatica; f , liver sho wing (an ow ) encys ted in fect ive la rva lstage (st ro b ilocerclIs) of th e ca t ta peworm . f-fyda tigera taen iaelormis. All na t u ra l size.( Or igina L)

82 H AWAII AG RICULTURAL EXPER IMENT STATION

FIGURE 32. 0, I nfecti ve la rvae ot T richinella spi ralis en cysted in the d iaphragm of rat ,hi gh ly m agni fi ed : b, ad u lt ta peworm , H ym en ole-p is n ana, na tu ra l size; c, ad u lt tapewor m,Hym enolepis diminu ta, na t ura l size. (O rig inal.)

Of th e above rou ndworms , Gon gy lon ema neop lastic uni uti li zes cert aincoc kroach es and beet les as interm edi a te hos ts. T h ese in cl ude Blate lla gel"­

monica, Peri p lan eta ameri cana, and T'en cb rio m olitor (see H all , 1929), allof which occur in H awa ii. Accord ing to O 'Dea ( 1964), th e stoma ch wo rm ,Plrysa loptera muris-brasilieusis , h as been exp erime n ta lly det ermin ed to

u til ize the following arthropods as in tcrmed iate hosts: (O rder : Co leoptera )Dcrmestes uu lpinus, T'en ebro ides ncrui , and T'rib ol ium castane urn; (O rde r :Orth o p tera) N au .phoeta cinerea a nd Pe rip lan eta am ericana.

T h e lungworm, Angiosirongylus can ione nsis, u ti li zes a mollusk as in ter me­diate host (pp. 24, 26 a nd fi g. 3). T he developm ent of th is parasi te to the in ­fecti ve or th ird-larval stage (fig. 33e) in th e garden slug , D eroceras laeue, was[i rst described by Mackerras a nd Sanda rs ( l 955) . These wr iters a lso traced thedevelop men t of the paras ite in th e rat host a nd determined th a t du r ing larva ldevelopmen t i t in vad ed th e brain and p rodu ced d ilation of the m en ingea lvessels and leucocytic infi ltrat ion . T h e rat lu ngworm was first round in Ha ­wa ii b y Ash in Novem be r, 1960 (Ash , 19620). Subseq uently the g ia n t Africansna il, Achatina [utica, the gard en snails, B rady baena similaris and Subu linao Ct011O , an d th e ga rden sl ug, Veronicella alte, were fou nd to be su itable ex-

r lC UR E 33. Larvae of A ngiostrongylu s can ion ensis: a, first-st age la rva recovered fro mfeccs of ra t, X300; b, full-grow n first-st age la rva from sna il, X300; c, second -stag e larvaenc losed within cu t icle of first mo l t from sna il, X300; d, third -stage larva enclose d withincast cu ticles of th e firs t and second molt from snail. X300; e, third -st age la rva co iled in th em usculature of sna il, X300; f, a ntcr ior end of third -stage lar va showing th e cha racte r ist icsclero tized sto ma torha bd ions in b ucca l cavi ty, X640. (n- e, Or igin al; f, af ter Alica ta , 1962,co urtesy of Canadian Journ al of Zoology. ;

84 H AW AII AGR ICULTURAL EX P E Rl l\ lENT ST ATI ON

per im ental in term ed ia te hosts (A licata, 19G2a). In clud ed a lso is the garde nsna il , Opeas javaniclI1 l1 , and possibly other members of this ge n us. Accord ingto Kon do ( 196!), rna lacolog ist, B ishop M useum, seven spec ies of O!Jeas occurin H a waii as fo llow s: O. beck ian urn , O. claou linu nt, O. goodall i, O. [auan i­CII 11/., O . m auriiia nurn, O . o-parattum , and O . opella. T he fresh-wat er sna il,Fossaria ollu la, was a lso found to be a suita ble expe r ime ntal host (Alica taan d Bro wn, 1962). Of the a bove mollu sks, A. [ulica, B . simi laiis, S. octona ,o. [auanicu rn, V . al tc, a nd D . laeue have been found na tu rally infected withth e la rvae of the ra t lu ngworm. T he la nd p la nari a n, Geo p lana sep temli­

neat a, in Ha wai i a lso frequ en t ly harbors the inf ecti ve lungworm la rvae (Ali­cata, 1962n). Pl an aria ns, however, serve on ly as pa raten ic or transport hostsa nd acq uire the la rvae Irorn feedi ng on th e bod ies of natura lly infect edsna ils. A . cnu ton ensis is a ble to in vad e th e bra in of m an a nd of th e monkeyand to prod uce cere bra l ang iostrongy losis (pa rasit ic eosinop h ilic m eningo­encep halit is) (see Parasites of M an).

In addi t ion to H a wa ii, A . can ton cusis has bee n rep orted a1lI0n g ra ts fromother islands of th e Pacifi c a nd part s of Southeas t Asia, as follows (fig. 4):Esp ir itu Sa nto, N ew Hebrides (Alica ta, 1963n); Formosa (Yokoga wa, 1937):Guadalcan al , Solo mo n Islands (Loison , 1964); G uam (L indq uis t and L i,1955); L ifou , Loya lt y Islands (Alica ta , 1963a); Ma laya (Sch ache r and Ch e­ong , 1960); few Cal edonia (Alica ta , 19G3n); Mo en, Pinga la p, a nd Pori a p e,

Caro line Island s (] ackson, 1962); R ar oton ga, Cook Islands (Alic a ta and Mc­Ca rt hy, 1964); R o ta, Sa ipan, and T' in ian , Ma r ia na Islands (Al ica ta , 1961 c);T ah it i (Alicata, 1962a ); Ch ina (Ch en, 1935); and T hai lan d (P unyagup ta ,1964). In add ition to rats of the ge nus Rattus, A. can ion ensis h as also beenrepor ted from the ba ndicoot ra t, B ari dicot a indica. nemoriuaga, in Formosa(Ku n tz and M yers, 1964).

TA PEWOR~ IS

In a survey cond uc ted by Ash (1962b), H v m enolc p is uana (fi g. 3~ b) a ndH. diminu ia (fig. 32c) wer e recovered in approx im ately 50 percent of the ra tsexa m ined in H onolu lu. T he infecti ve stage (strobilocercus) of the ca t ta pe­worm , H ydat igera taeniacjormis, was lo und i n th e li ver of about 40 percentof the rats exa m ined (fig. 311). T he high in ciden ce of th is la rva l par asite inth e ra t correspo nde d wi th the frequ en cy of occ urrence of th e ad u lt pa ra sitein th e ca t (see Pa rasi tes of Cat). H . nan n a lso has been fou nd in man inH awaii (see Parasites of Ma n).

Altho ug h most tilpeworm s ha ve a n indirect lif e cycle , H . n on a ca n haveeit he r a d irect o r a n ind irect lif e cycle . I n the forme r, the eggs are in gestedby th e defin itive host a nd the yo ung larvae pene trate the in testinal wa ll tofo rm a ta illess cyst icerco id . T hese eve nt ua lly eme rge in to t he lumen o f th e