Document text
Machine-read from the scan, so expect some errors. Lines that couldn’t be read are left out.
Page 1
By the cljrectionof DASG a medical entomologicalsun’eywas conducted on sclcctcd cor~l islets of the EnewetakAtoll to determineall real and potential entomologicalproblems to be encounteredduring cleanl]p a fragile and unstablebiologicalcomrwlity. The introductionof higher animal life forms has ken artifici~l. This sit~]ationhas allo\\’eda nwher of species to inhabit the ic’letsUT~chec~CdbY natural . A variety of factors have successfullylimitedthe t!.cestablishment 1) Limited acces>abilityof the islets. 3) Limited land area, breeding sites, appropriatefood sources and ‘IIlesefactors have, for the most part, restrictedthe establishment of medically importantarthropod on the islets. a. A total of 12 isletswere selected for surveillance.Selectionwas based on the followingcriteria: Operationalaspects related to cleanupmission, civilians and natives.
Page 2
insect nets and collectingequipr,entwas conducted. All possible breeding sites and harborages:iere sampled. Light traps were set out , were set in associationwith burrows,nests, high activityareas and scopicallywith the use of appropriatekeys. \ a. The predo,minanatproblem on the atoll is thelargepopulationof h’o spdcies of rats were notccl,
Page 3
the exceptionof the islet of Ene\:atakthe rat populationreached the “’..’ Mice, though not taken in traps, are presenton the islets. “Evibence’,~’:\~; used to cletcrminetheir presenceW?.Sthe collectionof frass and . signs of damage. The populationof mice on the individualislets is ““”.””’1 Ectoparasitcsfound on rats were limitedto mites of ~rn~ete~ine~ . species. No ticks or fleas were found. Three methods were used to”. 3) Visual examinationof the body and hair with the aid of magni&ng ~’- Lack of higher ectoparasiticpopulationis attributedto extremely. . limited contactwith other mammalian species. Various species of stinging (aculeate)wasps are present on all of the islets. Polistes ~ Parasiticwasps of the family Sphecidaewere also collected. ‘k 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 oldbut - viable and nests varied in size from the diameter of a quarter to the size of a football. About 25 wasps were present in the refrigeratorbuilding and a ‘F nuriberwere observed foragingin the area. The estimated living populationof the colony is between 100 and 150 wasps. Limited natural fooclsources and high winds have severly restricted the numbers of wasps capable of survivingon the islets. Normal fdoclssuch as lepidoptcrou-slarvae,nectar etc, are extremely ~ limited. Colonies are thereforesmall anclfocal. They may usually be located in dense foliage, v:ellshieldedfrom the wind and close to the ground. Some R, marginatawere observed nesting up
Page 4
type stings with a wheel-flairreactionand pain lasting from ‘ report OF 20 stin~s coulilnot be confirmedand is considered “ unlikely. It should be noted that aggressivereactionswere ~ . only no~iced when the integrityand safety of the colony or ;,“ nest was directly threatened. -,.. No mosquitoeswere collectedtl~oughlig?lttraps, natural and artificial nesting stationswere usecl. Furthermore,inten~iew.sindicatedno one has been bj.ttenby a mosq~lito.High w;nds are the major factor Spiders are present thro[lglm]tthe atoll’s islets. Specimensof what appears to be tileblack w.ido’whave been collectedby personnelof the MP}lLthough none were founclduring this survey. The only island have been sent to the Bisl~op-fi,tise~ml, Snakes are not present on Enev.retakAtoll. breeding areas are in and around waste disposalsites. populations The rodent populationsrequire control of the earliestpossible date. Baiting with zinc phosphi~e is the most acceptableto this writer. l{owever other baits are ava~lablc. A special ,anncxto this report will be prepared with specificguidelineson baiting requirements. Bait stationscontai.ni~zinc phosphidein a formulationacceptableto the rats should be used. Several prcbaits shoLlldbe tested without the presence’of zinc phosphideto determinewhich is the most acceptable to the rats. Upon co~letion of preba.itingthe actual zinc phosphide bait should be employed. Each islet should be prebaited immediately - prior to baiting.
Page 5
Post suneillance should be conducted immediately aft~r.”theconcl~ion ,“.”’ of the baiting cycle. Unconsumedbaits shouldbe retrievedwithin48;.72”’ hours of their placement to limit contactwith non targeto:g~ism. “::. The process of cleaningup the islets by engineerswill itselfhave’-::’.~:’: and food sources., This combined integratedcontrolshould significantly reduce, but not eradicatethe rodent population. Continuedsurveillance under the direct supervisionof a professionalentomologist. Thereafter” number and size of the islets selected for control. If control is “ ~ required for the base camps of Lojwa and Enewetakonly, then approximately seven - f~urtcendays will be requiredutilizingseven pest control personnel and one Entomologist. L,’ Control on most or all of the isletsmay requirea minimumof 21 people “t (20, 91’s, 1 Entomologist)and a period of 3- 4 weeks. Accessibility h to the islets by helicopterwould rcducc the time requirements. No specificcontrol is required for the wasps. However, certainprec&tic are warranted for personnelworking in thick foliage. . . 3) No bright colored orpastcl colored clotliingsuch as reds ”yellows,I hkts may be destroyed with ?;asp Kill or similar registered insecti-~ ci.des as they are located. Persomel known to be all~r~ic to insect~cnoms should not be pemittcdto work in risk a~eas as dcscribccl.
Page 6
While caution is advised small and not at a level to work as a comparativelysmall nunber of insectshave been successfully in~roducedon the atoll. It would be helpful if incomingcargo were,. TPest control on any large scale is not required for other than the roclents as indicated. Ist Medical Group
Page 7
body oi a host organism such as a rat. Entomology: The study of insects. Have-.A-Heart T~aps: A brand name of a Im rodent trap which . I The black wiclow spider. Lepido~terous Larvae: Moth and butterfly catterpillers. Musca: The genus of flies to which house flies belong. Polistes ;uscatus Var. aurifer: A common variety of paper Polistene type Sting: Typical sting of the paper wasp Prebaiting : Positioning a bait without the pres~nce 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. .-15: Ropalidia “rnarginata: A common paper wasp similar to the A mud wasp which is predacious against spiders.. ,,. It does not sting man but 1s capable.. ,17. Ve.spidae: A large taxonomic group of wasps which include the
Page 8
Gais .‘(jty])i~ally has a raised blanched center . about 1/2 to I centimeter across surrounded by a large r~d ‘“ circle with a common total dianeter around” the size of a :....