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By the djrection of DASG a medical entov.olo:icalsun’eywas conducted .i on selcctcd coral islets of the LncwetakAtoll to determineall real and potential entomologicalproblems to be encounteredduring cleanup Biologicallyand ecologicallythe islets arc still ~ d-represent p a fragile and unstablebiologicalcommunist}’.Tk introductionof higher animal life forms has been artifici~.1.T’nissituationhas i allo,,’eda nunber of species to inhabit the j’.letsuncheckedby natural . A variety of factorshave successfullylimitedthe t!tc:establishment of various pests. 1) Limited acceskabilityof the islets. 3) Limited land area, breeding sites, appropriatefood sources and These factors have, for the most part, restrictedthe establishment of medically importantarthropocla-onthe islets. a. A total of 12 isletswere selected for surveillance.Selectionwas based on the followingcriteria: 3) Operationalaspects related to cleanupmission, civilians and natives...
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insect nets and collec’tineequipmnt was conduct;cl.All possible in areas where wj.ndshelter\\’asprovided to samplenocturnalactivity. Rodent surveillancewas vis!d and with traps. lIave-a-Hearttraps were set in associationI:it’n‘ourrows,nests, high activi~~areas and equipment indigenow to the survey teams providedample work and scopicallywith the NSC of appropriatekeys. d. The followingisletswere surveyed: Two sp;cies of rats were noted.
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population to soar and-be limited only by populationpressure, :,:’....-p the exceptionof the islet of Enel~stakthe rat populationreached the ““.; Mice, though not taken in traps, are presenton the islets.‘“Evidence.~:~~~~ used to determine their presencewas the collectionof frass and . .,.,., ~ Ectoparasitesfound on rats were limitedto mites of undetermined ; I species. No ticks or fleas were found. Three methods were used to .: ., Lack of higher ectoparasiticpopulationis attributedto extremely. ,“; limited contactwith other mamnalian species. Various species of stinging (aculeatc)wasps are prestnt on all of the islets. Polist.es L ti~miclent~pecies in the familyVespi&ie arc also present. parasiticwasps of the family Sph:cidaehere also collected. “F 1) In all cases the wasp populationsper islet is low. However, where present the wasps tend to be concentratedin small areas. For example, on the islet of Jedrol (Rex) a ~. fuscatus colony .. was located in a refrigeratorbuilding. The colony was olclbut - viable and nests varied in size from the diameter of a quarter to the size of a football. About 2S wasps were present in the refrigeratorbuilding and a “~ number were observed foraging in the area. The estimated living populationof the colony is between 100 and 150 wasps. I Limited natural food sources ~nd high winds have severly restricted the numbers of wssps capable of survivingon the islets. Normal fdoclssuch as lepidopterouslarvae,nectar etc, are extremely t limited. Coloniesare thereforesmall anclfocal. They may ustMll]’ be located in dense foliage,v..ellshieldedfrom the wind and C1OSC to the ground. Some R, marginatawere observed nesting up tosix feet above ground on–th=l=e of the foliage. .b
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4) The wasps normnll.yare not aggressiveand do not seek out or . attack pc!oplc.Ihc sting is in accordancewith most polistene ,. type stings with a wheel-flairreactionand pain lasti?g from although some people recalledbeing stung 4 or S times. One .. - report of 20 stin~s could not be confirmedand is considered ‘ only no;iced when the integrityand safety of the colony or ?!’ nest was directly threatened. .,. nesting stationswere I:secl.Furthermore,interviewsindicatedno one has been bitten by a mosqllito.flighwjnds are the major factor ~“ Spiders are present throughoutthe atoll’s islets. Specimensof what appears to be the b]ack widow have been collectedby personnelof the M+lL though none \(ercfo~mclduring this survey. The only island have been sent to the Bishop-hhxtwm,l[awaiifor confirmation. No “ other venomous spiders have been reportedfrom or collectedfrom the i. Flies affectingman zppear Iimi.teclto severalspecies of the genus b-ding areas arc in and arounti~~’astcdisposalsites. populationsare small and of nuisancevalue. Some transmissionof enteri.cdiseases is possible though not li.kely.d~leto gooclsanitarypracticesand The rodent populationsrequire control of the earliestpossible date. Baiting with hosphide is the most acceptableto this writer. However other baits a A special ‘annexto this report will be prepared with specificguidelineson baiting requirements. , Bait stations containingzinc phosphide in a formulationacceptableto ! the rats should be used. Several prebaitsshoulclbe testedwithout the presence’of zinc phosphide to determinewhich is the most acceptable to the rats. Upon completionof prebaitingthe actual zinc phospllicle bait should be emplo}wd. Each islet should be prebaited immediately + prior to baiting.
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Prebait and bait stations should be placed”fi the exact “s&e Iocatiohs.~ F=’-Placement of prebait ahclbait should be directlyassociatcdwith ... : hours of their placement to limit contactwith non targetorgmisms. ‘,. The process of cleaningup the islets by engineerswill itself h~ve”-””..’,,t and food sources. ‘H~iscombined integratedcontrol should significantly reduce, but not eradicatethe rodent population. Continuedsurveillance under the direct supervisionof a professionalentomologist. Thereafter Manpower and time requirementswill be directly~Jroportionalto thci ~ number and size of the islets selecteclfor control. If control is required for the base camps of Lojwa and Enewetakonly, then approximately~ seven - fourteendays will be requireclutilizingseven pest conprol , personnel and one Entomologist, L (20, 91’s, 1 Entomologist)and a period of 3- 4 weeks. Accessibility., p:: to the islets by helicopter\;ouldreduce the time requirements. .! No specific control is required for the wasps. However, certainprecauti( are wananted for personnelworking in thick foliage. . . I 3) NO bright coloredor pastel coloredcloth’ingsuch as reds, yellows, 4) c Insect repellentsare of no value in protectingagainstwvsps and bet A;estsmay be destroyedwith Wasp Kill or similar registeredinsecti-” tides as they are located. Persomel known to be all~rgicto insectvenoms should not be pexm.itted.towork in risk areas as dcscribccl. “.kmmm
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7) While caution is advised be repeated’that”theover~l”l.’{,,”-;,.. ...,- to work as a comparativelysmall numoer of insectshave,beensuccessfully~ ..% i.n~roclucedon the atoll. It would be helpful if incomingcargo were,”i..~ “’b, Pest control on any large,, . .. other than the rodents as scale is not
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the bOCiy Ot a host organism such as a rat. Entomology: The study of insects. ...$,.. Have-.~-Heart Traps: A brand name of a rodent trap which. . catches the animal alive and without Injury. The black wiclow spider. Lepidopterous Larvae: Moth and butterfly catterpillers. ?Dlusca: The genus of flies to which house fli,es belong. Polistes fuscatus Var. aurifcr: A common variety of paper Polistene type Sting: Typical sting of the paper wasp prebaitin~: Positioning a bait without the presence of a poison to=measure the acceptability and consumption by the rodent to be controlled. Furthermore, it indicates if other non-target organisms will be attracted to it. predator: Usually an a~imal which specifically seeks-out and destroys .another animal; I.e. , cats to rats and mice. R. niarginata: See 15 below. Rop?lidia iiarginata: A common paper wasp similar to the A mud wasp which is predacious against spiders.. lt does not sting man but 1s capable.. A large taxonomic group Vespidae: of wasps which include the ~
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...anywasp.i. one typically has a raised blanched center [. about 1/2 to 1 centimeter across surrounded by a large red “ P