Department of Biology, Utah State University, Logan, UT.
J Econ Entomol. 2021 Feb 9;114(1):187-196. doi: 10.1093/jee/toaa269.
Spider mite (Acari: Tetranychidae) outbreaks are common on corn grown in the arid West. Hot and dry conditions reduce mite development time, increase fecundity, and accelerate egg hatch. Climate change is predicted to increase drought incidents and produce more intense temperature patterns. Together, these environmental shifts may cause more frequent and severe spider mite infestations. Spider mite management is difficult as many commercially available acaricides are ineffective due to the development of resistance traits in field mite populations. Therefore, alternative approaches to suppress outbreaks are critically needed. Drought-tolerant plant hybrids alleviate the challenges of growing crops in water-limited environments; yet, it is unclear if drought-tolerant hybrids exposed to water stress affect mite outbreaks under these conditions. We conducted a greenhouse experiment to evaluate the effect of drought-tolerant corn hybrids on Banks grass mite [Oligonychus pratensis Banks (Acari: Tetranychidae)], a primary pest of corn, under optimal irrigation and water-stress irrigation. This was followed by a 2-yr field study investigating the effect of drought-tolerant corn hybrids exposed to the same irrigation treatments on Banks grass mite artificially infested on hybrids and resident spider mite populations. Results showed that water-stressed drought-tolerant hybrids had significantly lower Banks grass mite and resident spider mite populations than water-stressed drought-susceptible hybrids. Interestingly, water-stressed drought-tolerant hybrids had equal Banks grass mite populations to drought-susceptible and drought-tolerant hybrids under optimal irrigation. We posit that planting drought-tolerant hybrids may suppress spider mite outbreaks in water-challenged areas.
叶螨（蜱螨目：植绥螨科）在干旱的西部种植的玉米上经常爆发。炎热和干燥的条件减少了螨虫的发育时间，增加了繁殖力，并加速了卵的孵化。气候变化预计会增加干旱事件，并产生更强烈的温度模式。这些环境变化的共同作用可能导致更频繁和更严重的叶螨虫害。由于田间螨虫种群中抗性性状的发展，许多市售杀螨剂的效果不佳，因此叶螨管理非常困难。因此，迫切需要替代方法来抑制爆发。耐旱植物杂种缓解了在水资源有限的环境中种植作物的挑战；然而，目前尚不清楚在这些条件下，耐旱杂种在受到水分胁迫时是否会影响螨虫爆发。我们进行了一项温室实验，以评估耐旱玉米杂种对斑须蝽[Oligonychus pratensis Banks（蜱螨目：植绥螨科）]的影响，斑须蝽是玉米的主要害虫，在最佳灌溉和水分胁迫灌溉下。随后进行了为期两年的田间研究，调查了在相同灌溉处理下暴露于耐旱玉米杂种的斑须蝽和驻留蜘蛛螨种群的耐旱玉米杂种对斑须蝽的影响。结果表明，与耐旱敏感杂种相比，受水分胁迫的耐旱杂种的斑须蝽和驻留蜘蛛螨种群显著降低。有趣的是，在最佳灌溉条件下，受水分胁迫的耐旱杂种的斑须蝽种群与耐旱和耐旱敏感杂种相当。我们假设种植耐旱杂种可能会抑制水资源匮乏地区的叶螨爆发。
