Zhang Minling, Spaulding Nathan R, Reddy Gadi V P, Shapiro-Ilan David I
Southern Insect Management Research Unit, United States Department of Agriculture Agricultural Research Service, 141 Experiment Station Rd., P.O. Box 346, Stoneville, MS 38776.
Southeastern Fruit and Tree Nut Research Station, United States Department of Agriculture Agricultural Research Service, 21 Dunbar Rd., Byron, GA 31008.
J Nematol. 2025 Sep 17;57(1):20250034. doi: 10.2478/jofnem-2025-0034. eCollection 2025 Feb.
(Lepidoptera: Noctuidae) is a significant soybean pest in the southern United States. As it has developed resistance to many commonly used insecticides, alternative control measures are necessary. Entomopathogenic nematodes (EPNs) may be one such alternative. Our previous study found that a surfactant Southern Ag Surfactant (SAg Surfactant), significantly increased the mortality caused by on the first instars of in corn plants. In this study, SAg Surfactant and two more adjuvants - dish soap and vegetable oil - were tested for efficacy of on larvae under laboratory and greenhouse conditions. The three adjuvant treatments tested were 0.125% dish soap (Soap), dish soap combined with 0.25% vegetable oil (Soap & Oil), and 0.066% SAg Surfactant. In laboratory conditions, insect mortality caused by 72 hr after application was significantly higher with the Soap & Oil treatment than with the no-adjuvant treatment at 1 and 4 hr of exposure, as well as with the Soap treatment at 4 hr of exposure. No significant difference was observed among the EPN with and without adjuvant treatments when the exposure times were extended to 8 and 24 hr. However, compared to the no-adjuvant treatment, insect mortality 24 hr after application was significantly higher for all EPN adjuvant treatments at 8 hr of exposure and for the Soap & Oil treatment at 4 and 24 hr of exposure. These results suggest that these adjuvants shortened the time needed for EPNs to kill larvae. In the first trial, under greenhouse conditions, insect mortality 72 hr after application was not affected by the adjuvant treatments. In the second trial, all the adjuvant treatments increased insect mortality. However, in the third trial, only the Soap & Oil treatment caused higher mortality compared to the no-adjuvant treatment. Additionally, the Soap & Oil treatment yielded the highest number of viable EPNs in most of the three trials, although this result was statistically significant only at one sampling point. Overall, our results showed that the adjuvants could enhance the efficacy of on larvae.
（鳞翅目：夜蛾科）是美国南部一种重要的大豆害虫。由于它已对许多常用杀虫剂产生抗性，因此需要采取替代控制措施。昆虫病原线虫（EPNs）可能是这样一种替代方法。我们之前的研究发现，一种表面活性剂南方农业表面活性剂（SAg表面活性剂）显著提高了EPNs对玉米植株中[某种昆虫]一龄幼虫的致死率。在本研究中，在实验室和温室条件下，对SAg表面活性剂以及另外两种助剂——洗洁精和植物油——对[某种昆虫]幼虫的防治效果进行了测试。所测试的三种助剂处理分别是0.125%洗洁精（洗洁精）、洗洁精与0.25%植物油混合（洗洁精&植物油）以及0.066% SAg表面活性剂。在实验室条件下，施用EPNs 72小时后，洗洁精&植物油处理组导致的昆虫死亡率在暴露1小时和4小时时显著高于无助剂处理组，在暴露4小时时也显著高于洗洁精处理组。当暴露时间延长至8小时和24小时时，有助剂处理和无助剂处理的EPNs之间未观察到显著差异。然而，与无助剂处理相比，施用EPNs 24小时后，在暴露8小时时所有EPN助剂处理组的昆虫死亡率显著更高，在暴露4小时和24小时时洗洁精&植物油处理组的昆虫死亡率也显著更高。这些结果表明，这些助剂缩短了EPNs杀死[某种昆虫]幼虫所需的时间。在第一次试验中，在温室条件下，施用EPNs 72小时后的昆虫死亡率不受助剂处理的影响。在第二次试验中，所有助剂处理均提高了昆虫死亡率。然而，在第三次试验中，只有洗洁精&植物油处理组与无助剂处理相比导致了更高的死亡率。此外，在三项试验中的大多数情况下，洗洁精&植物油处理组产生的存活EPNs数量最多，尽管这一结果仅在一个采样点具有统计学意义。总体而言，我们的结果表明，这些助剂可以提高EPNs对[某种昆虫]幼虫的防治效果。
