Seasonal abundance of six tephritid species and the fruiting phenology of their main hosts in northern Jiangxi, China

Several tephritid species have successfully invaded northern Jiangxi, China, posing a serious threat to regional fruit and vegetable production. This study presents a detailed report on the seasonal abundance of six tephritid species and the fruiting phenology of their main hosts across Nanchang, Yongxiu and Xiushui in northern Jiangxi from 2018 to 2021, using data from methyl eugenol (ME), cuelure (CUE), and sugar-wine-vinegar-water (SWVW)-baited traps and from fruits infested by tephritid larvae. A total of 18,875 tephritid specimens were captured by traps, representing six species, <i>Bactrocera dorsalis</i> (Hendel), <i>B. scutellata</i> (Hendel), <i>B. minax</i> (Enderlein), <i>Zeugodacus tau</i> (Walker), <i>Z. cucurbitae</i> (Coquillett), and <i>Callantra trimacula</i> (Wang). Notably, <i>B. minax</i> and <i>C. trimacula</i> were discovered for the first time in northern Jiangxi. In addition to <i>B. minax</i> (captured only in Xiushui) and <i>Z. cucurbitae</i> (captured only in Nanchang), <i>B. dorsalis</i>, <i>B. scutellata</i>, <i>Z. tau</i> and <i>C. trimacula</i> were captured in all three regions. <i>Zeugodacus tau</i> exhibited the highest population density, followed by <i>B. dorsalis</i> and <i>B. scutellata</i>, and <i>C. trimacula</i> densities were markedly lower. The diversity index of captured tephritid species was similar in Nanchang, Yongxiu and Xiushui, but varied significantly across different seasons from May to December. When tephritid adults were active, <i>B. minax</i> population density reached its maximum in mid-June, whereas <i>B. scutellata</i>, <i>Z. tau</i> and <i>Z. cucurbitae</i> peaked in August-September, and <i>B. dorsalis</i> peaked in September-October. <i>Bactrocera dorsalis</i> and <i>B. minax</i> share similar hosts, primarily those from the Rutaceae family, including <i>Citrus sinensis</i> (L.) Osbeck, <i>C. reticulata</i> Blanco, <i>C. maxima</i> (Burm) Merr., and <i>C. grandis</i> Tomentosa. However, <i>B. scutellata</i>, <i>Z. tau</i> and <i>Z. cucurbitae</i> have similar hosts, especially those from the Cucurbitaceae family, such as <i>Cucurbita moschata</i> (Duch. ex Lam.) Duch.ex Poiret, <i>Luffa cylindrica</i> (L.) Roem., <i>Momordica charantia</i> L., and <i>Cucurbita pepo</i> L. The varying phenological stages of different host fruits guaranteed a continuous and adequate supply of suitable food resources for these tephritid species across different seasons. The theoretical and practical implications of the results concerning the management strategies for the six tephritid species in northern Jiangxi, China, are discussed.