From June to September 2020, 52 monitoring sites were set up across 23 counties in Hunan Province, then steiner-type traps with 4-(p-Acetoxyphenyl)-2-butanone(Cue) or with methyl eugenol(Me) were placed in melon vegetable orchards for the purpose of monitoring the occurrence of Zeugodacus tau(Walker) and Zeugodacus cucurbitae(Coquillett). Annual life history of the dominant species Zeugodacus tau was inferred by field investigation and room temperature transgenerational breeding. Steiner-type traps with Cue were placed in a mixed vegetable orchard in Youxian County in 2021 to record daily trapped adults, and the relationships between insect occurrence and certain meteorological factors was analyzed. The results showed that 5 fruit fly species, including Zeugodacus tau, Zeugodacus cucurbitae, Zeugodacus scutellatus(Hendel), Bactrocera dorsalis(Hendel) and a Dacus sp. were trapped, and Zeugodacus tau was distributed throughout Hunan Province and was the dominant species, while Zeugodacus cucurbitae was only collected in partial areas, but still was a key pest in some areas. There are 3-5 generations which overlap for Zeugodacus tau in Hunan every year, and the first and second adult generations(i.e., the second and third larval generations) are the dominant generations follows by the third adult generation(i.e., the fourth larval generation). The seasonal dynamics of fly adults in the mixed vegetable orchard of Youxian County was unimodal and the peak was in mid to late September. Adult activity could be initially observed when the daily maximum temperature was greater than or equal to 15 ℃, and the collection was the largest when the daily maximum temperature reached to 33.4 ℃, the farther away from which, the less the trapped flies. From July 7 to September 30, the trapped Zeugodacus tau adults on rainy days and days that a day after a rain were significantly larger than those trapped under other weather conditions, and wind speed had no significant effect on the collection.