The establishment and spread of the stem-boring weevil, Listronotus setosipennis (Coleoptera: Curculionidae) released in 2017 for the control of the invasive weed, Parthenium hysterophorus (L.) (Asteraceae) at four locations in northeastern Ethiopia were assessed over a 4-year period. The number of L. setosipennis eggs on parthenium in 0.5 m × 0.5 m quadrats was recorded at each location where the weevil was originally released and where it spread later. The weevil damage to parthenium and the distance it spread were also recorded. At all release locations, the number of L. setosipennis eggs detected increased over the 4-year assessment period indicating the build-up of the weevil population where it was released. At one of these locations, Chorisa, the number of eggs increased from 2.7 ± 1.3 m⁻² in 2017 to 92 ± 6.1 m⁻² in 2020. Similarly, at the site where the weevil spread (dispersal site), the number of L. setosipennis eggs detected on parthenium rose over the 4-year period. L. setosipennis larvae damage to parthenium was evident at all release locations ranging from 13.3 ± 3.3% to 36.7 ± 6.7%. Similar level of damage (36.7 ± 5% to 66.7 ± 8.3%) was also recorded at the dispersal sites. After 4 years, the maximum distance L. setosipennis spread from its original release spots was 185.3 ± 12.0 m. The establishment and spread of the weevil were slow but was steady at all locations in northeastern Ethiopia.

中文翻译：

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埃塞俄比亚针对入侵杂草 Parthenium hysterophorus L. (Asteraceae) 释放的螟螟象鼻虫 Listronotus setosipennis (Coleoptera: Curculionidae) 的建立和传播

2017 年为控制入侵性杂草Parthenium hysterophorus (L.) (Asteraceae)于 2017 年发布的钻茎象鼻虫Listronotus setosipennis (Coleoptera: Curculionidae)的建立和传播经过了 4-年期间。在象鼻虫最初被释放和后来传播的每个位置记录了在 0.5 m × 0.5 m 的象限中在帕特尼姆上的L. setosipennis卵的数量。象鼻虫对parthenium的破坏及其传播距离也被记录下来。在所有释放地点，L. setosipennis的数量检测到的卵在 4 年评估期内有所增加，表明象鼻虫在其被释放的地方集结。在这些地点之一，Chorisa，鸡蛋的数量从2017 年的2.7 ± 1.3 m ^-2增加到2020 年的92 ± 6.1 m ^-2。同样，在象鼻虫传播的地点（扩散地点），L .在 4 年期间，在 parthenium 上检测到的setosipennis卵上升。L. setosipennis幼虫在所有释放位置对 parthenium 的损害都很明显，范围从 13.3 ± 3.3% 到 36.7 ± 6.7%。在扩散地点也记录到类似的损害水平（36.7 ± 5% 至 66.7 ± 8.3%）。4年后，最大距离L. setosipennis距其原始释放点的距离为 185.3 ± 12.0 m。象鼻虫的建立和传播缓慢，但在埃塞俄比亚东北部的所有地点都保持稳定。