Willden Samantha A, Evans Edward W
Department of Biology, Utah State University, Logan, UT.
Environ Entomol. 2018 Feb 8;47(1):1-7. doi: 10.1093/ee/nvx174.
The phenology of the stem-mining weevil Mecinus janthiniformis Toševski and Caldara (Coleoptera: Curculionidae) as adults attacking Dalmatian toadflax, Linaria dalmatica (L.) Miller (Plantaginaceae), was studied in 2014-2015 at two low elevation sites in northern Utah. The seasonal pattern of adult weevil abundance on the host plant at the two sites was most similar between years when described by degree-day accumulation, versus calendar date. Repeated censusing over the growing season revealed that males appeared first and subsequently peaked in abundance on the host plant earlier than females did, such that the adult population was dominated by males early in the season and by females late in the season. Peak female abundance on the host plant occurred at the time when Dalmatian toadflax stems reached their maximum height and density and when they began flowering widely. Maximum toadflax stem heights and densities, and flowering activity, were markedly reduced in 2015 compared to 2014. In contrast to these host plant parameters that vary between years, degree-day accumulation can be used readily for timing collection and survey efforts for adult weevils and female adult weevils in particular. Use of degree-day accumulation can thereby facilitate implementation of redistribution and monitoring programs for M. janthiniformis as a biological control agent of Dalmatian toadflax.
2014 - 2015年，在犹他州北部的两个低海拔地点，对蛀茎象鼻虫Mecinus janthiniformis Toševski和Caldara（鞘翅目：象甲科）成虫侵害亚麻叶柳穿鱼（Linaria dalmatica (L.) Miller，车前科）的物候进行了研究。当按度日积累而非日历日期来描述时，两个地点寄主植物上成年象鼻虫数量的季节性模式在不同年份间最为相似。在生长季节进行的多次普查显示，雄性象鼻虫先出现，且在寄主植物上数量达到峰值的时间早于雌性，因此在季节早期成虫种群以雄性为主，而在季节后期以雌性为主。寄主植物上雌性象鼻虫数量的峰值出现在亚麻叶柳穿鱼茎达到最大高度和密度且开始大量开花之时。与2014年相比，2015年柳穿鱼茎的最大高度、密度以及开花活动都显著降低。与这些随年份变化的寄主植物参数不同，度日积累可轻易用于确定尤其是成年象鼻虫和成年雌性象鼻虫的采集和调查时间。因此，使用度日积累有助于实施针对作为亚麻叶柳穿鱼生物防治剂的janthiniformis象鼻虫的重新分布和监测计划。
