Data from: Efficacy of deltamethrin and pirimiphos-methyl in layer-treated maize against the larger grain borer and the maize weevil

Two grain surface treatment insecticides (deltamethrin and pirimiphos-methyl were evaluated in laboratory assays as a surface treatment for maize to control adult Prostephanus truncatus and Sitophilus zeamais. Both insecticides were applied to 20 g of maize placed in a vial or to the upper one half, one fourth, or one-eighth layer of the maize. Insects were either added to the vials before or after the maize. Mortality, progeny production, and insect damaged kernels (IDK) were then evaluated for each vial. Introduction method (before or after) did not have any impact on any of the variables. Mortality was nearly 100% for all treatments for both insecticides for P. truncatus. Subsequently, progeny production and the number of insect damaged kernels was very low or zero for P. truncatus. Mortality for S. zeamais remained low across layer treatments for deltamethrin. However, S. zeamais was easily controlled by primiphos-methyl. The results of this laboratory study show that while deltamethrin and pirimiphos-methyl has some effectiveness as a layer treatment on a column of maize, efficacy will be dependent on the target species, and the depth of the treated layer, as well as the location on which the insects are present.Resources in this dataset:Resource Title: Grain Layer Experiment with P. truncatus & Sitophilus zeamais.File Name: quellhorst_etal_layer_experiment.csvResource Description: Insect Mortality on Treated Maize and Progeny Production. For each replicate, 500 g of maize were treated with each insecticide or H2O (e.g., control) as described above. Before proceeding with the experiments, the grain moisture content (m.c.) was assessed, using a moisture meter (mini GAC plus, Dickey-John Europe S.A.S., Colombes, France). The standard plastic cylindrical vials of the Laboratory of Entomology and Agricultural Zoology (LEAZ) were used (3 × 8 cm in diameter by height, Rotilabo Sample tins Snap on lid, Carl Roth, Germany). These were filled with 20g of maize. In each vial, we treated either all the grain (1/1), 1/2, 1/4 or 1/8 of the maize with one of the two insecticides (deltamethrin or pirimiphos-methyl) at the labeled rate. We also either placed the insects at the bottom of the vial (before the maize has been added) or at the top (after the maize has been added). Sets A, B, and C were treated with insecticide on separate days. Insects were given 14 days before mortality counts were performed. After this interval, the mortality was assessed. It is difficult to estimate the upper 1/8 etc. of maize, therefore we based our experiments on ratios of 20 g treated, 20 g untreated, 10 g treated with 10 g untreated, 5 g treated with 15 g untreated and 2 g treated with 18 g untreated. The exact quantities of the samples were weighed with a Precisa XB3200D compact balance (Alpha Analytical Instruments, Gerakas, Greece). The upper rings of the vials were treated with Fluon (Northern Products Inc., Woonsocket, USA) to prevent insects from moving away from the grain and or escaping. The top of each vial also had small holes punched to allow ventilation. Each vial then received 10 P. truncatus adults of mixed sex and age from the Tanzania strain or 10 S. zeamais from Brazil. The vials were placed inside incubators set at 30°C and 65% R.H. After the parental mortality count, all adults were removed, and the vials with maize were returned to the incubator at the conditions indicated above. Sixty days later, the vials were opened again to check progeny production and the number of insect damaged kernels (IDK). For each combination, e.g., insecticide × insect species, there were three replicates with three subreplicates (total 3 × 3 = 9 vials or replicates per combination). There were 2 insecticides × 2 insect species × 4 grain treatments (1/1, 1/2, 1/4, 1/8) × 2 insect introduction methods (before or after) × 9 replicates/subreplicates = 288 vials total, 5760 g of maize, 10 insects per vial × 288 = 2880 total (1440 per LAGB and MW). We also had a separate set of vials for the control with no insecticide= 9 × 2 insect species = 18 vials, 360 g of maize, and 180 insects (90 per species).Resource Software Recommended: Microsoft Excel,url: https://www.microsoft.com/en-us/microsoft-365/excel

对两种谷物表面处理杀虫剂（即高效氯氰菊酯和毒死蜱）进行了实验室试验，以评估其对玉米表面处理的效果，以控制Prostephanus truncatus和Sitophilus zeamais成虫。这两种杀虫剂均应用于20克玉米，放置于试管中或玉米的上半部、四分之一或八分之一层。昆虫或是在添加玉米之前或之后加入试管中。随后，对每个试管的死亡率、后代产量和虫害玉米粒（IDK）进行了评估。引入方法（前后）对任何变量均无影响。对于P. truncatus，两种杀虫剂的所有处理的死亡率几乎均为100%。随后，对于P. truncatus，后代产量和虫害玉米粒的数量非常低或为零。对于deltamethrin，S. zeamais的死亡率在层处理中保持较低。然而，S. zeamais很容易被毒死蜱控制。本实验室研究结果指出，尽管高效氯氰菊酯和毒死蜱作为玉米柱层处理的杀虫剂具有一定的有效性，但其效果将取决于目标物种、处理层的深度以及昆虫存在的位置。资源标题：P. truncatus与Sitophilus zeamais的谷物层实验。文件名：quellhorst_etal_layer_experiment.csv。资源描述：经处理的玉米上的昆虫死亡率及后代产量。对于每个重复，500克玉米分别用每种杀虫剂或H2O（例如，对照组）进行上述处理。在进行实验之前，使用湿度计（mini GAC plus，Dickey-John Europe S.A.S.，法国科隆贝）对谷物水分含量（m.c.）进行了评估。采用了昆虫学及农业动物学实验室的标准塑料圆柱形试管（直径和高度均为3×8厘米，Rotilabo Sample tins Snap on lid，Carl Roth，德国）。这些试管被填充了20克玉米。在每个试管中，我们使用标记的剂量将两种杀虫剂之一（高效氯氰菊酯或毒死蜱）处理全部谷物（1/1）、一半、四分之一或八分之一。我们还将昆虫放置在试管的底部（在添加玉米之前）或顶部（在添加玉米之后）。A组、B组和C组分别在不同天进行杀虫剂处理。在死亡率计数之前，昆虫被放置了14天。在此间隔后，对死亡率进行了评估。由于难以估计玉米的上部1/8等，因此我们的实验基于20克处理、20克未处理、10克处理与10克未处理、5克处理与15克未处理以及2克处理与18克未处理的比率。样品的精确量使用Precisa XB3200D紧凑型天平（Alpha Analytical Instruments，希腊Gerakas）称重。试管的顶部环用Fluon（Northern Products Inc.，美国伍斯特克特）处理，以防止昆虫离开谷物或逃逸。每个试管的顶部还打有小孔，以允许通风。每个试管接着接收10只来自坦桑尼亚菌株的混合性别和年龄的P. truncatus成虫或10只来自巴西的S. zeamais。试管被放置在设定为30°C和65%相对湿度的恒温箱中。在父母代死亡率计数后，所有成虫被移除，装有玉米的试管被返回到上述条件下。60天后，再次打开试管以检查后代产量和虫害玉米粒的数量。对于每种组合，例如，杀虫剂×昆虫物种，有3个重复和3个子重复（总共3×3=9个试管或重复/每个组合）。总共有2种杀虫剂×2种昆虫物种×4种谷物处理（1/1、1/2、1/4、1/8）×2种昆虫引入方法（之前或之后）×9个重复/子重复=288个试管，总共5760克玉米，每个试管10只昆虫×288=2880只昆虫（每个LAGB和MW为1440只）。我们还单独设置了一组无杀虫剂的对照试管=9×2种昆虫物种=18个试管，360克玉米，180只昆虫（每种90只）。推荐的资源软件：Microsoft Excel，url：https://www.microsoft.com/en-us/microsoft-365/excel