Fruit flies (Diptera, Tephritidae) cause economic damages in many fruit orchards. To know the population fluctuation of these flies in Citrus orchards in the west of Santa Catarina, Brazil, and to study the environmental factor interferences on these insects, five traps with 25% vinegar were weekly installed in two orange Valência variety orchards, in Águas de Chapecó and Chapecó, from October of 1999 to September of 2001. The samples of flies trap captured were counted at Epagri Fitossanity Laboratory in Chapecó. A correlation and regression polynomial analyses between flies monthly captured of genus Anastrepha and monthly datas of rain precipitation, isolation, air humidity, wind speed and environmental temperature were executed. Maximum and minimum temperature had more interference on these pests than the other environmental factors. Analysis of non-linear regression were applied with monthly accumulate number of these flies and showed top of captured flies in March to June. Anastrepha fraterculus (Wiedemann, 1830) was the predominant fruit fly.
Citrus; Tephritidae; Anastrepha fraterculus; environmental factors
