Chiba Prefectural Agriculture and Forestry Research Center, 180-1 Okanezawa-cho, Midori-ku, Chiba, 266-0014, Japan.
Chiba Prefecture Sanbu Agriculture Office, 1-11 Higashi-shinshuku, Togane, Chiba, 283-0006, Japan.
Exp Appl Acarol. 2021 May;84(1):135-147. doi: 10.1007/s10493-021-00617-3. Epub 2021 Apr 23.
Gynaeseius liturivorus (Ehara) (Acari: Phytoseiidae) is a promising biological control agent for tiny arthropod pests, including Thrips tabaci Lindeman (Thysanoptera: Thripidae) known as a major pest of Welsh onion. In fields during summer, G. liturivorus is observed on soybean, but not on Welsh onion, even when numerous T. tabaci are present. To elucidate G. liturivorus's occurrence on soybean and Welsh onion in relation to relative humidity (RH), we examined its egg hatching on their seedlings under low RH conditions. Then we estimated the moisture transpiration from both plants. Egg hatching occurred only on soybean plants exhibiting greater moisture transpiration. Aiming at utilizing G. liturivorus as a biological control agent for Welsh onion production in summer, evaluation of its relative tolerance and compensation potential for drought injury is necessary. Therefore, we used five phytoseiid species including G. liturivorus and Neoseiulus californicus to estimate the RH and vapor pressure deficit (VPD) at which 50% of eggs hatch (RH and VPD). Furthermore, we examined G. liturivorus and N. californicus egg hatching under different RH oscillation conditions. Results show G. liturivorus as the most drought-sensitive among the five species tested, but G. liturivorus is able to compensate for lethal low-RH effects on egg hatching in part by periodic exposure to high RH conditions, as observed for N. californicus.
智利小植绥螨（Gynaeseius liturivorus）（蜱螨目：植绥螨科）是一种很有前途的生物防治剂，可用于防治微小节肢动物害虫，包括烟粉虱（Thrips tabaci Lindeman），其被认为是大葱的主要害虫。在夏季的田间，虽然有大量烟粉虱存在，但智利小植绥螨仅见于大豆而不见于大葱。为了阐明与相对湿度（RH）相关的智利小植绥螨在大豆和大葱上的发生情况，我们在低 RH 条件下，检查了其在这两种作物幼苗上的卵孵化情况。然后，我们估计了这两种植物的水分蒸腾量。仅在大豆植株上观察到卵孵化，而这些大豆植株具有更大的水分蒸腾量。为了在夏季利用智利小植绥螨作为大葱生产的生物防治剂，有必要评估其对干旱伤害的相对耐受和补偿潜力。因此，我们使用了包括智利小植绥螨和加州新小绥螨（Neoseiulus californicus）在内的 5 种植绥螨来估计 50%卵孵化时的 RH 和蒸气压亏缺（VPD）（RH 和 VPD）。此外，我们还检查了不同 RH 振荡条件下智利小植绥螨和加州新小绥螨的卵孵化情况。结果表明，在所测试的 5 种物种中，智利小植绥螨对干旱最敏感，但智利小植绥螨能够通过周期性暴露于高 RH 条件来部分补偿低 RH 对卵孵化的致死影响，这与加州新小绥螨的情况类似。
