Their Parasites at Three Locations

Transcription

1 Vol., November, 55 Present Status of Oriental and Mediterranean Fruit Flies and Their Parasites at Three Locations on Oahu, Hawaii MUHAMMAD M.K. CHAUDHRY -' ABSTRACT To establish present stains of the oriental fruit fly (OFF). Dana dorsalis Hendel. and the Mediterranean fruit fly (MED). Oralilisrapilata (Wiedemann), and their parasitoids on Oalm, Hawaii, a study was tarried out from August to December 7. by collecting guava fruit and trapping adult males with hues at three locations; Mt. Tantalus, l.yon Arboretum and Waimanalo. Mean weights of individual guava fruit collected from Ml. Tantalus, l.yon Arboretum, and Waimanalo were found to be 74. g. 7.2 g..7 g respectively. Only OFF emerged from fruit which were held in the laboratory, although adult males of MED were trapped ai Waimanalo. Populations of OFF were most abundant at the highest elevation. Ml. Tantalus, where ihe mean number of flies trapped with a methyl eugenol lure in 5 minutes was Numbers trapped al the middle elevation, l.yon Arboretum, and lower elevation. Waimanalo, were.7,. respectively. The number of puparia per kg fruit sampled was highest (72.) at the lowest deration. Waimanalo. The numbers or puparia per kg fruit from the middle and highest elevations were.5,. respectively. Mean parasitism by the opiine wasp ISimlrrn arisnnus (Sonan) was 4.%. 7.7%. % respectively for Mt. Tantalus, l.yon Arboretum and Waimanalo. Fruit flies of the family Tephritidae are well-known pests. Their attack on fruit reduces both yield and quality. Four species of this family have been ac cidentally introduced into Hawaii (Gilmore ). The melon fly (MEL), Dams cucurbitae Coquillet, first found in Hawaii during 5, has caused serious losses to melons, vegetables, papayas, passion fruit and beans. The second introduction in was the Mediterranean fruit fly (MED), Oratitis capitata (Wiedemann). Its host range includes more than 25 fruits, vegetables and nuts. The oriental fruit fly (OFF), Dams dorsalis Hendel, was the third introduction, in 4. This species attacks more than kinds of fruit and vegetables. The most recent introduction, in, was the solanaceous fruit fly (SFF), Dams latifmns (Hendel), which infests eggplant, chili pepper and tomatoes (Vargas and Nishida 5). Presence of these species in Hawaii has an adverse effect on fruit production and poses a con stant threat of introduction into the U.S. mainland. 'FAO Fellow from Pakistan. Hawaii Institute of Tropical Agriculture and Human Resources. Department of Entomology. University oltiawaii. Honolulu, Hawaii 22. -Present Address: Pest Warning and Quality Control of Pesticides Unit. Department of Agricul ture (Plant Protection), Murree Road, Rawalpindi. Pakistan.

2 5 Proceedings, Hawaiian Entomological Society In the past, many efforts have been made to suppress populations of the MED, OFF and MEL fly through import of exotic parasitoids from different parts of the world (Bess 5; Clausen et al. 5; Haramoto and Bess 7), and the biological control agents have achieved much success. Levels of parasitixation fluctuate with season of the year, type of host and ripeness of fruit. Bess (5) observed 5 percent parasitization in MED and OFF by a braconid, Opius oojihilus (Fullaway) [ = Biosteres arisanus (Sonan)]. According to Kaya (), the level of parasitism by this parasitoid on OFF increased with increased superparasilism. Parasitism of both MED and OFF due to O. oophilus was determined by various authors to be from 5 to 7 percent (Haramoto and Bess 7), percent (Wong et al. 4) and 74 percent (Wong and Ramadan 7). Although both Mediterranean fruit fly and oriental fruit fly infest the same hosts, the former was found to be more abundant in upland areas and latter in lowland areas (Bess 5). Wong el al. () found that in peach fruit larger numbers of MED were recorded than OFF at higher elevations. Eclosion data of these authors further revealed that both of the species could develop successfully together in peach fruit. Hewlett (2) reported that the OFF and the peach fruit fly, Dams zonalus (Saunders), are attracted to methyl eugenol. This lure is known to be extremely attractive to the OFF (Steiner 52), and male populations of this species were eradicated up to percent with the use of methyl eugenol combined with three percent naled (Sleiner et al. 5). Populations of adult males of MED fly (Vargas et al. ; Wong et al. 5; Harris and Lee ) and OFF (Wong et al. 5) were monitored with traps baited with appropriate lures and toxicant. The present study was undertaken to determine the level of" parasitism and occurrence of MED and OFF at three locations on Oahu. The results of field and laboratory investigations are presented below. MATERIALS AND METHODS Sampling of host guava fruit was carried out on Oahu where it is season ally abundant. Three sampling sites were established, ranging from 2 me ters to 474 meters elevations. The Mt. Tantalus site is located at 474 meters on the leeward side of the Koolau Range near Honolulu where guava trees grow wild on hillsides. Lyon Arboretum is on the plateau at the head of Manoa Valley at an deration of 5 meters. In this area guava trees are scat tered around Paradise Park, which is surrounded by thick forest. Waimanalo is at 2 meters elevation on windward side of Oahu at the foot of the Koolau Range, where cultivated varieties of guavas are grown at the Waimanalo Experiment Station, University of Hawaii. Rainfall and tempera ture data for each sampling area during the period of study (August 25 to November, 7) were obtained from the respective offices (Tables and ). Sampling was initiated on August 25, 7 and continued at weekly in tervals throughout the study period. On each sampling day, to 2 mature

3 Vol., November, 57 and firm ripe guava fruits were picked from trees in each sampling area and promptly taken in polyethylene bags to the laboratory. In the laboratory, live fruits which had fruit fly ovipositional punctures were selected, weighed, transferred singly to paper cups containing sand and covered with paper lids or nylon organdy cloth. Sand in holding cups was sifted at week ly intervals, and pupae were removed and held in glass vials (2 cm diameter and cm high), plugged with cotton wool, for emergence of fruit flies and parasitoids. In the laboratory, paper cups and glass vials were held separate ly for pupation and eclosion at room temperature and humidity (Table 2). On emergence, the numbers of fruit flies and parasitoids were recorded. The parasitoids were identified to species with the key of Wharian and Gilstrap(). For trapping adult males of MKD and OFF, Moroccan vertical traps (Hafraoui et al. ) made from plastic food containers ( cm diameter, 2 cm high with four holes 2.5 cm diameter on sides) and baited with ap propriate lures, were set up on non-host trees 2 meters apart in each sam pling area. Medfiy traps contained a wick treated with 2 ml tri-mcd lure on a 2.5 cm cotton dental roll having % dichlorvos as a toxicant (Harris el al. ), and were allowed to remain exposed throughout the period of study. In addition, each trap contained 2 cm piece of Sergeant's flea and tick col lar impregnated with 5% naled. This was to kill ants that might enter the trap and feed on the flies. Oriental fruit fly traps, baited with 5 ml of a mix ture of methyl eugenol (%) and naled (2%) in a cotton wick 4 cm long, and 2 cm diameter (Wong et al ), were set up at each site for 5 min utes on each sampling day. The numbers of fruit flies trapped during each trapping period were recorded for each location. The lures were replen ished twice during the study period. RESULTS Trap Data. Trap catches of the two tephritid species are presented in Table. OFF was detected in all the sampling areas. Although, tri-med lure traps remained in the field throughout the experimental period in each sampling area, MKD were trapped only at Waimanalo (Table ) where sterile flies of this species had been released for a scientific study. This indi cated that the lure was effective. At Mt. Tantalus, I.yon Arboretum and Waimanalo, the mean numbers of OFF caught in traps were 55.5,.7,. per 5 minutes, respectively. The density of this species was much higher at Mt. Tantalus, which had a mean temperature of 25.2C and rainfall of 4. mm, than at Lyon Arboretum and Waimanalo, where mean temperature and rainfall were 2.C and.4c, and. mm and 5.7 mm, respectively (Tables I and ). At Lyon Arboretum and Waimanalo, the numbers of flies trapped were almost the same. Guava trees are abundant around Mt. Tantalus, which may explain why larger numbers of fruit flies were caught there, compared with Lyon Arboretum, and Waimanalo, where there are fewer guava trees.

4 5 Proceedings, Hawaiian Entomological Society Host Fruit Data. The weight (Table 4) of individual guava fruit col lected from Waimanalo was the greatest, followed by Lyon Arboretum and Mt. Tantalus. The largest number of pupae per kg fruit (72.) was recov ered from collections from Waimanalo. The numbers of pupae per kg fruit from collections from Lyon Arboretum and Mt. Tantalus were.5 and 4.4, respectively. No MED emerged from the puparia from fruit collections from any of the three sampling sites. Only OFF and its opiine parasitoid, Biosteres arisnmis (Sonan), were recovered. Total numbers of OFF and parasitoids which emerged from fruit collections from Mt. Tantalus, Lyon Arboretum and Waimanalo were 2,,, and 5, 7, respectively. Eclosion percentage was highest (5.) in the collections from Mt. Tantalus, and the lowest (47.) from Lyon Arboretum. Parasitism by B. ari.umus was higher (4.%) at the highest elevation, Mt. Tantalus, followed by Lyon Arboretum (7.7%) and Waimanalo (.%). DISCUSSION These results clearly show that the most dominant species of fruit fly in the sampling areas was the oriental fruit fly. Mediterranean fruit fly was not reared from guava fruit during this study. The results presented here differ from those of previous authors (Bess 5; Haramoto and Bess 7; Vargas et al. and 5) as they recovered both species from guava fruit, while we reared only the oriental fruit fly. Use of the Morocco vertical traps was effective for catching both species of fruit flies. Temperature, rainfall and host plants (Wong et al. ) affected population levels of fruit flies. In this study the highest numbers of male adults of the OFF were caught with traps at Mt. Tantalus, the highest eleva tion site, which also had abundant wild guava trees in the immediate vicinity. But the recovery of puparia per kg fruit was greatest from Waima nalo, which is the lowest elevation with the lowest rainfall. The number of puparia recovered was lowest at Mt. Tantalus. Our data are not in agree ment with Vargas et al. () who captured low numbers of fruit flies from upland forest areas on Kauai. However, Vargas referred to captures of OFF above m in native forests, above most of the guava. Nevertheless, our results are in line with the findings of Wong et al. () and Wong et al. (5) who caught larger numbers of mixed populations of both species from higher elevations. ACKNOWLEDGMENTS I am indebted to Professor Wallace C Mitchell, Department of Entomol ogy, University of Hawaii, for his help and guidance for carrying out this study. Many thanks to him for extending me his expertise and allowing me to use his equipment and literature. My job would not have been fruitful without his help.

5 Vol., November, 5 Thanks are also due to Professor John W. Bcarclsley, Chairman, Depart ment of Entomology, University of Hawaii, Honolulu, for providing facilities in the laboratory; Dr. Ernest J. Harris, Mr. James E. Gilmore, and Mr. Clifford Y. I.. Lee, of the USDA, ARS, Tropical Fruit and Vegetable Re search Laboratory, Honolulu, for help and assistance in the collection of fruit and field data. I am also thankful to Dr. Harold J. McArthur, Jr., Coor dinator for International Programs, Hawaii Institute oftropical Agriculture and Human Resources, University of Hawaii, Honolulu, for his kind cooperation. The study was made possible through the generous support of the Food and Agriculture Organization of the United Nations and the Pakistan Agri culture Research Council, Islamabad (award no. UTF/Pak/7). Financial support by the FAO is gratefully acknowledged. REFERENCES CITED Bess, H. A. 5. Status of Otatitii cupitata in Hawaii following the introduction of Dunn dotsnlh and its parasites. I'roc. Hawaii. Kntomol. Soc. 5 ( ):22l-4. Clausen, C. P., D. W. Clancy and Q. C. Chock. 5. Biological control of tin- oriental fruit fly (Dams dorsali\hcnc\v\) and other fruit flies in Hawaii.ARS. I'SDA, Tech. Bull. No. 2*2, IO2pp. Gilmore, J. E.. Research in tri-fly eradication. Tropical Kruii and Vegetable Research laboratory, ARS. USDA, Hawaii; 57to!4. (In Intern. Symp. Fruit Flies. -2 Sept.,. Crete, Greece). Hafraoui, A., E. J. Harris and A. Chakir..'lastic traps for detection and survey of Mediter ranean fruit fly. Oralili\ capilala (l)iptera: Tephritidae) in Morocco. I'roc. Hawaii. Entomol. Soc. (2): -. Haramoto, F. H. and H. A. Bess. 7. Recent studies on the abundance of the Oriental and Mediterranean fruit flies and the status of'their parasites. I'roc. Hawaii. Entomol. Soc. 2<):55-5fi. Harris, E. J. and C. Y. L. Lee.. Seasonal and annual occurrences of Mediterranean fruit Hies (Diplera: Tcphrilidae) in Makaha and Waianae Valleys, Oahii, Hawaii, Knviron. Kntomol. 5: Harris, E. J., R. T. Cunningham, N. Tanaka, K. Ohinata and W. J. Schroeder.. Develop ment of the sterile insect technique on the island of Lauai. Hawaii, for suppression of the Mediterranean fruit fly. Proc. Hawaii. Entomol. Soc. 2:77-. Howlelt, F. M. 2. The effect of oil of citronella on two species ot'oarus. Trans. Em. Soc. Lon don, Part II: Kaya, H. K.. Superparasiiism by Ofiius oophilus Kullaway, an egg-larval parasite of some tephritid fruit flies. M.Sc. Thesis, L'niv. Hawaii. 4pp. Steiner, L. F. 52. Methyl eugenol as an atlractanl for oriental fruit fly. J. Econ. Enlomol 45(I):24-2I. Steiner, _ F., W. C. Mitchell, E. J. Harris, T. T. Kozuma and M. S. Fujimolo. 5. Oriental fruit fly eradication by male annihilation. J. Econ. Enlomol. 5:-. Vargas, R. I. and T. Nishida. 5. Survey of Dams liili/wns (Diplera: Tephritidae). I. Econ. En tomol. 7:-4. Vargas, R. I., E. J. Harris and T. Nishida.. Distribution and seasonal occurrence of Ornlilis capilala (Wiedemann) (Diplera: Tephritidae) on the island of Kauai in the Hawaiian Islands. Environ. Enlomol. 2:-. Vargas, R. I., T. Nishida and J. W. Beardsley.. Distribution and abundance at Dams doruitis (Diptera: Tephritidae) in native and exotic forest areas on Kauai. Environ. En lomol. 2:5-.

6 Proceedings, Hawaiian Entomological Society Wharton, R. A. ;m<l F. E. Gilslrap.. Key to and the status of opiiue hracouid (I lymenoplera) parasiloids used in biological control of (lemlilii and Dacits s. I. (Diplera: IVphi itidac). Ann. Entomol. Soc. Am. 75: Wong, T. T. Y. and M. M. Ramadan. 7. Parasiti/ation of the Mediterranean and oriental fruit Hies (Diplera: Tephritidae) in the Knla area of Mani. Hawaii. ) F.ron. Kntomol. :77-. Wong, T. T. Y.,J. I. Nishimolo and N. Mochizuki.. Infi-stalion patterns of Mediterranean fniil fly and the oriental fruit llv (Diptcra: Tephrilidae) in the Kula area of Mani. Hawaii. Environ. Kntomol. 2:: Seasonal abundance of parasitoids of the Mediterranean and oriental Irnii flies (I)iptera: Tephritidae) in the Kula area of Mani. Hawaii. Environ. Kntomol. :-45. Wong, T. T. Y., D. O. Mclnnis and N. Mochizuki. 5. Seasonal distribution and abundance of adult male- oriental fruit flies (Diplera: Tephritidae) in Kula, Mani, Hawaii. J. Econ. Knloinol.7:l2fi7-I. Wong, T. T. Y., D. O. Mclnnis, R. M. Kobayashi and J. I. Nishimoto. 5. Distribution and seasonal abundance of adult male Mediterranean fruit flies (Diplera: Tephritidae) in Kula. Maui. Hawaii.). Kcon. Kutoinol. 7:5">2-;i.:>7. TABLE I. Temperature and rainfall data for the three sampling sites from August lo November, 7. Temperature Location Elevation <m) Max Min "C C (Range) (Range) Rainfall (mm) Mt. Tantalus l.yon Arboretum Waimanalo <J lh.y-.. (ill. 5.7 TABLE 2. Monthly mean temperatures and relative humidity maintained in the lalx>ralory, September to NovemlK-r. UI7. Month September October Noveml)er Mean Temperature CC).y ±..fi ±.. ±. Mean Relative Humidity 75. ± y ± ± 2.

7 is TABLE. Numbers of.uliili mali Numbers oladult males (if the oriental fruit fly (OFF), I). f/«n/j/j.t ami the Mediterranean fruit fly (MKl». C. capitobt i'mi%hi in plaslit traps bain*'! with birrs ;it three elevations on Osihu. Hawaii, September to November, 7. CO Date of Ml Tantalus (474 m) Lyon Arboretum (5 m) Waimanalo (2m) B ( Collection MED OFF Temperature ( C) MED OFF Temperature < C) MED OFF Temperature ( C> Septemlx-r October November 5 2 ( 2f» 2 I'i 72 :i:t (> *)*} < Mean Mcdlly lure: Tri-mcd lure 2 ml + naled in field during the whole experimental pcruxl. OriciiLiI fruit fly lure: methyl cugcuol 5 ml + naled. exposed for 5 minim* on each date.

8 TABLE 4. Percent paras! ti/at ion of the oriental fruu fly (OFF), Dacus donalis infested guava sampled at three different elevations mi Oahu, Hawaii, August to November, 7. Location Date of collection Weight of fruit (gm) puparia OFF emerged Percent eclosion parasitoids* Percent parasitism Mt. Tantalus {474 m) August September October November l.von Arboretum {5 in) August September , October November , , I J 4, S\ CQ CO fi> I m O c7 CQ 'A sample of five tree fruit with ovipositional punctures. * Moistens amanus (Sonan) {= Opixts oophilus), a braconid egg-larval parasiloid. $ O

9 z o TABLE 4. Percent par.isiti/ation of the oriental fruit fly (OFF), Darns thnafis infested guava sampled at three different elevations on Oahu. Hawaii, August to November, )7. (Omtimird) I Location Date of collection Weight of fruit (gin) puparia OFF emerged Percent eclosion parasitoids Percent parasitism Waimanalo (2 m) August September October November I ( II , 'A sample of five tree ftnil with nviposilional punrtures. -Boistem arimnm (Sonun) ( = Optus (ntyhilus), a bi aeon id egg-laival

10 4 Proceedings, Hawaiian Entomological Society