Oligonychus yothersi (McGregor) (Acari: Tetranychidae), known as yerba mate red mite, is typically found on the abaxial face of leaves, feeding on mesophyll cell contents in yerba mate crops. Euseius concordis (Chant) is a generalist mite, feeding on other mites, pollen, and nectar, and can be a promising control agent of O. yothersi. This study aimed to evaluate development time, reproduction, survival, and sex ratio of this predatory mite when feeding on O. yothersi on yerba mate leaves. A life-cycle study was performed in a climate chamber at 22 ± 1 °C and 12 hours of photophase, 19 ± 1 °C during scotophase, and 70 ± 10% relative humidity. The study started with 36 experimental units, which were examined three times a day during immature development and once during the adult stage to evaluate reproductive parameters. Mean developmental times of egg, larva, protonymph, deutonymph, and egg-adult stages were the following: for females, 2.14 ± 0.15, 1.59 ± 0.12, 1.97 ± 0.11, 2.18 ± 0.13, and 7.88 ± 0.21, respectively; for males, 2.00 ± 0.67, 1.77 ± 0.52, 1.94 ± 0.52, 2.05 ± 0.69, and 7.75 ± 1.08. Mean pre-oviposition, oviposition, and post-oviposition periods were 3.31 ± 0.33, 10.4 ± 0.74, and 1.50 ± 0.28, respectively. Sex ratio was 0.67 and mean life expectancy was 15.22 days for females and 12.51 ± 1.91 days for males. Mean daily oviposition was 1.67 ± 0.08 eggs per female, with a mean value of 20.14 ± 1.42 eggs per female. T, R_o, r_m, λ, and DT values were: 16.33, 10.03, 0.14, 1.15, and 4.91, respectively. This study demonstrated that E. concordis is a predator with potential to be used in biological control programs, successfully developing and reproducing when feeding on O. yothersi under laboratory conditions.

称为Yerba mate red mite的Oligonychus yothersi（McGregor）（Acari：Tetranychidae）通常在叶片的背面上觅食，以Yerba mate作物中的叶肉细胞含量为食。Euseius concordis（Chant）是一种普通螨，以其他螨，花粉和花蜜为食，并且可能是O. yothersi的有希望的防治剂。这项研究旨在评估以捕食O. yothersi为食的这种捕食性螨的发育时间，繁殖，存活和性别比。在yerba伴侣叶子上。在气候室中于22±1°C和12小时的光相，在暗相期间为19±1°C和70±10％的相对湿度下进行了生命周期研究。这项研究从36个实验单位开始，在未成熟发育期间每天进行3次检查，在成年阶段进行一次检查，以评估生殖参数。卵，幼虫，质子虫，申命鱼和成虫卵的平均发育时间如下：雌性分别为2.14±0.15、1.59±0.12、1.97±0.11、2.18±0.13和7.88±0.21；男性为2.00±0.67、1.77±0.52、1.94±0.52、2.05±0.69和7.75±1.08。产卵前，产卵期和产后平均周期分别为3.31±0.33、10.4±0.74和1.50±0.28。性别比为0.67，女性平均寿命为15.22天，平均寿命为12.51±1。男性91天。平均每日产卵为每只雌性1.67±0.08卵，平均每只雌性为20.14±1.42卵。T，R_o，r _m，λ和DT值分别为：16.33、10.03、0.14、1.15和4.91。这项研究表明，Con。concordis是一种捕食者，具有被用于生物防治计划的潜力，当在实验室条件下饲喂y。oothersi时成功开发和繁殖。