Ashe-Jepson Esme, Bladon Andrew J, Herbert Greg, Hitchcock Gwen E, Knock Richard, Lucas Colin B H, Luke Sarah H, Turner Edgar C
Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK.
Bedfordshire and Northamptonshire branch of Butterfly Conservation, Registered office: Manor Yard, East Lulworth, Wareham, Dorset, BH20 5QP UK.
J Insect Conserv. 2022;26(1):43-58. doi: 10.1007/s10841-021-00360-5. Epub 2021 Dec 6.
Climate change affects butterflies in many ways, influencing the timing of emergence and reproduction, habitat preferences, and behaviour. The small blue ( Fuessley, 1775) is highly specialised in its host plant requirements, feeding on the seeds of a single species, kidney vetch (), on which the larvae occur singly to avoid cannibalism. The butterfly is likely to be vulnerable to temperature-related changes in oviposition, adult emergence, and host plant flowering times, and is, therefore, a good model species for investigating climate change-related impacts. Using 26 years of data from the national UK Butterfly Monitoring Scheme (1993-2019) from one nature reserve, and 4 years of targeted egg searches (2006, 2007, 2008, 2020) from three reserves in Bedfordshire, UK, we investigated the effects of local temperature on small blue emergence date and total abundance, whether flowerhead or local environmental characteristics predicted small blue oviposition behaviour, and whether this changed between years. Small blue adults emerged on earlier dates over time, and earlier in years with higher maximum February temperatures. Total adult abundance was not predicted by monthly temperatures or total abundance in the previous year. Oviposition behaviour was broadly consistent across years, with egg presence more likely and egg abundance higher on kidney vetch flowerheads that were taller than the surrounding vegetation, and surrounded by taller vegetation and fewer mature flowerheads. The effect of solar radiation differed between years, with a negative effect on the probability of egg presence in 2007 and 2008, but a positive effect in 2020. Egg abundance per flowerhead was highly variable between years, with 2006 having four times more eggs per flowerhead than other years. This was likely driven by high adult abundance in 2006, which could have increased competition for flowerheads.
Our results indicate that management for greater availability of taller kidney vetch amongst taller vegetation would encourage small blue oviposition on a greater number of flowerheads, providing a possible means of reducing competition and increasing larval survival, and that this would be effective despite variation in adult abundance between years. The high level of competition we observed in the year with the highest adult abundance indicates that higher numbers of host plants should be encouraged to reduce competition and larval cannibalism in peak years, increasing the likelihood of long-term population persistence and growth.
The online version contains supplementary material available at 10.1007/s10841-021-00360-5.
气候变化在许多方面影响着蝴蝶，包括影响其羽化和繁殖的时间、栖息地偏好及行为。蓝灰蝶（Fuessley，1775）对其寄主植物有高度特定的要求，以单一物种肾叶天剑的种子为食，幼虫单独生活以避免同类相食。这种蝴蝶很可能易受产卵、成虫羽化和寄主植物开花时间与温度相关变化的影响，因此是研究气候变化相关影响的良好模式物种。利用来自英国一个自然保护区的26年（1993 - 2019年）英国蝴蝶监测计划的数据，以及来自英国贝德福德郡三个保护区的4年（2006年、2007年、2008年、2020年）有针对性的卵搜索数据，我们研究了当地温度对蓝灰蝶羽化日期和总数量的影响，花头或当地环境特征是否能预测蓝灰蝶的产卵行为，以及这种情况在不同年份是否发生变化。随着时间推移，蓝灰蝶成虫羽化日期提前，在2月最高温度较高的年份羽化更早。月温度或上一年的总数量无法预测成虫的总数量。多年来产卵行为大致一致，在高于周围植被且被较高植被包围且成熟花头较少的肾叶天剑花头上，出现卵的可能性更大且卵的数量更多。太阳辐射的影响在不同年份有所不同，2007年和2008年对卵出现概率有负面影响，但在2020年有正面影响。每个花头的卵数量在不同年份变化很大，2006年每个花头的卵数量是其他年份的四倍。这可能是由2006年成虫数量多导致的，这可能增加了对花头的竞争。
我们的结果表明，在较高植被中增加较高肾叶天剑的可获得性进行管理，将鼓励蓝灰蝶在更多花头上产卵，这可能是减少竞争和提高幼虫存活率的一种方法，并且尽管不同年份成虫数量有所变化，这种方法仍将有效。我们在成虫数量最多的年份观察到的高水平竞争表明，应鼓励增加寄主植物数量，以减少高峰年份的竞争和幼虫同类相食，增加种群长期持续和增长的可能性。
在线版本包含可在10.1007/s10841 - 021 - 00360 - 5获取的补充材料。
