Dacus cucurbitae Coquillett -- Tephritidae
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Native to the Indo-Malayan region, the melon fly was first recorded in Hawaii in 1897. Prior to its invasion, cucurbit crops were widely grown for local consumption and some were exported to California. Following the introduction of the fly, growing cantaloupes became impractical and the production of other melons, cucumbers and tomatoes was seriously curtailed (Nishida & Bess 1950). Biological control of the melon fly was undertaken by introducing Biosteres fletcheri (Silv.) from India. The parasitoids were mass reared in Hawaii, and field releases made in 1916 and 1917 resulted in their establishment. Two additional species Biosteres longicaudatus watersi Full. from India and B. angeleti Full. from Borneo, were introduced during 1950 and 1951, respectively (Clausen 1978). The 1916 and 1917 releases resulted in a 50% reduction of the melon fly populations, and although the flies were still a pest, melons were again a profitable crop in Hawaii (Fullaway 1920). Later the melon fly again became a severe pest requiring multiple applications of insecticides and generating additional control related research (Nishida & Bess 1950). Studies showed that the change in parasitoid efficiency was probably associated with changes in land use and agricultural practices (Newell et al. 1952, Nishida 1955).
Because melons and other perishable crops are available in the field for only a short period, these plants form an unstable resource to which the biology and life cycle of D. cucurbitae are well adapted. Consequently, parasitoids of the fly must be able to follow the short-lived and localized fly populations throughout their range if efficient control is to be achieved. In Hawaii, control had been possible because the presence of Momordica balsamina, the fruits of which constituted a stable wild host for D. cucurbitae and its parasitoids. Changes in agricultural practices and increased land use, however, reduced the areas where M. balsamina grew abundantly, thereby reducing the reservoirs of the natural enemies and making it more difficult for the natural enemies to reach the cultivated fields. The main fly population now had its origin in culti9vated fruits where parasitization was much lower than in the fruits of M. balsamina: 1% for tomatoes, 0-16.5% for melons, and 0.2-6.5% for cucumbers vs. 20-37.8% for M. balsamina (Nishida 1955). Thus, a change in the diversity of the habitat proved detrimental to this biological control project (Kogan et al. 1999).
Please refer to the following for greater detail on biological control effort, and biologies of host and natural enemies (Back & Pemberton 1917, Willard 1920, Yashiro 1936, Hutson 1939, McBride & Tanada 1949, Nishida & Haramoto 1953, Clausen 1956, Nishida & Bess 1957, Clausen et al. 1965).
REFERENCES: [Additional references may be found at: MELVYL Library ]
Back, E. A. & C. E. Pemberton. 1917. The melon fly in Hawaii. U. S. Dept. Agric. Bull. 491. 64 p.
Clausen, C. P. 1956. Biological control of fruit flies. J. Econ. Ent. 49: 766-68.
Clausen, C. P. 1978. Introduced Parasites and Predators of Arthropod Pests and Weeds: A World Review. U. S. Dept. Agric., Agric. Handbk. 480. 545 p.
Clausen, C. P., D. W. Clancy & Q. C. Chock. 1965. Biological control of the Oriental fruit fly (Dacus dorsalis Hendel) and other fruit flies in Hawaii. U. S. Dept. Agric. Tech. Bull. 1322. 102p.
Fullaway, D. T. 1920. The melon fly: its control in Hawaii by a parasite introduced from India. Hawaii For. Agric. 17: 101-105.
Hutson, J. C. 1939a. Report on the work of the entomological division. Ceylon Dir. Agric. Admin. Rept., 1937. p. D37-D42
Hutson, J. C. 1939b. Report on the work of the entomological division. Ceylon Dir. Agric. Admin. Rept., 1938. p. D36-D41
Kogan, M., D. Gerling & J. V. Maddox. 1999. Enhancement of Biological Control in Transient Agricultural Environments. In: Bellows, T. S. & T. W. Fisher (eds.), Handbook of Biological Control: Principles and Applications. Academic Press, San Diego, New York. 1046 p.
McBride, O. C. & Y. Tanada. 1949. A revised list of host plants of the melon fly in Hawaii. Hawaii. Ent. Soc. Proc. 13: 411-21.
Newell, I. M., W. C. Mitchell & F. L. Rathburn. 1952. Infestation norms for Dacus cucurbitae in Momordica balsamina, and seasonal differences in activity of the parasite Opius fletcheri. Proc. Hawaii Ent. Soc. 14: 497-508.
Nishida, T. 1955. Natural enemies of the melon fly, Dacus cucurbitae Coq. in Hawaii. Ann. Ent. Soc. Amer. 48: 171-78.
Nishida, T. & H. A. Bess. 1950. Applied ecology in melon fly control. J. Econ. Ent. 43: 877-83.
Nishida, T. & H. A. Bess. 1957. Studies on the ecology and control of the melon fly Dacus (Strumeta) cucurbitae Coquillett (Diptera: Tephritidae). Hawaii Agric. Expt. Sta. Tech. Bull. 44 p.
Nishida, T. & F. Haramoto. 1953. Immunity of Dacus cucurbitae to attack by certain parasites of Dacus dorsalis. J. Econ. Ent. 46: 61-4.
Willard, H. F. 1920. Opius fletcheri as a parasite of the melon fly in Hawaii. J. Agric. Res. 20: 423-38.
Yashiro, H. 1936. Outline of the work of establishing Opius fletcheri Silv. in Ishigaki Island, Loochoo. Nojikairyoshiryo 109: 149-52. [in Japanese].