ABSTRACT

Dioscorea bulbifera has invaded, smothered, and disrupted ecological functions of native plant communities in Florida. Vines senesce in late fall, then overwinter as tubers and aerial bulbils which sprout in spring and repeat the growth cycle. A foliage-feeding beetle Lilioceris cheni, introduced from Asia as a biocontrol agent has established throughout D. bulbifera's range in Florida. Synchronies among the growth phenology of the weed, life stages of biocontrol agents and weather conditions, are considered essential for the successful suppression of an introduced weed. We conducted a common garden study that encompassed pre-biocontrol release attributes of D. bulbifera followed by a 5-yr post-L. cheni release impacts study on its natural infestations in four sites. We gathered monthly data on D. bulbifera and L. cheni and assessed possible synchronies between their life stages and with local weather variables. Air and soil temperatures and total rainfall showed positive correlation with timing of D. bulbifera vine emergence/senescence, vine coverage, adult beetle emergence from diapause, and their life stages (egg clutches, larvae, and adults). Vine sprouting and beetle emergence in two southern sites began in February and April, and in the remaining two northern sites in March and May, respectively. Vine sprouting and beetle emergence was initiated at 15 and 20°C, respectively. All sites achieved maximum vine coverage in July. Bulbil development, oviposition by overwintering adults, and vine damage by adult and larval feeding began in June. These sequences of events indicated phenological synchrony of the beetle and air potato life stages in Florida.

摘要

薯蓣已入侵、扼杀并破坏了佛罗里达州本土植物群落的生态功能。葡萄藤在晚秋衰老，然后作为块茎和气生球茎越冬，春季发芽并重复生长周期。从亚洲作为生物防治剂引入的食叶甲虫Lilioceris cheni已在佛罗里达州D.bulbifera的整个范围内建立起来。杂草的生长物候、生物防治剂的生命阶段和天气条件之间的同步被认为对于成功抑制引入的杂草至关重要。我们进行了一个公共花园的研究，所涵盖的预发布生物防治属性D.黄药子，随后5年后L. cheni释放影响研究其在四个地点的自然侵染。我们收集了关于D.bulbifera和L. cheni 的月度数据，并评估了它们生命阶段和当地天气变量之间可能的同步性。空气和土壤温度和总降雨量与D.bulbifera 的时间呈正相关藤蔓出现/衰老、藤蔓覆盖、滞育成虫的出现及其生命阶段（卵窝、幼虫和成虫）。两个南部地点的藤蔓发芽和甲虫出现在 2 月和 4 月，其余两个北部地点分别在 3 月和 5 月开始发芽。藤蔓发芽和甲虫出现分别在 15 和 20°C 下开始。所有地点在 7 月份都实现了最大的葡萄藤覆盖率。球茎的发育、越冬成虫的产卵以及成虫和幼虫取食对葡萄藤的损害始于 6 月。这些事件序列表明佛罗里达州甲虫和空气马铃薯生命阶段的物候同步。