@article { author = {Kakavand, I. and ahmadi, A. and Hassanvad, I. and Danaye-Tous, A. H.}, title = {The comparison of toxicity of four wheat herbicides on the wheat aphid, Schizaphis graminum (Rondani), and its predator, Hippodamia variegate (Coleoptera: Coccinellidae), under laboratory conditions}, journal = {Plant Protection (Scientific Journal of Agriculture)}, volume = {45}, number = {1}, pages = {45-57}, year = {2022}, publisher = {Shahid Chamran University of Ahvaz}, issn = {2588-5936}, eissn = {2588-5421}, doi = {10.22055/ppr.2021.17259}, abstract = {Background and ObjectivesThe wheat aphid, Schizaphis graminum Rondani, is one of the most important pests of wheat that damages this crop by feeding on vegetable sap. Among its natural enemies, ladybug Hippodamia variegata (Goeze) is the most active predator of this pest. The application of wheat fields may affect the population of these insects. The present study investigates the effect of common wheat herbicides on wheat aphids and their predator (i.e., ladybug H. variegata).Material and methodsIn the present study, the lethal effects of four herbicides (i.e., Clodinafop-propargyl, Tribenuron-methyl, 2,4-D plus MCPA, and Mesosulfuron-methyl+ Iodosulfuron-methyl-sodium) versus untreated types(control) was examined on the green wheat aphid S. graminum and its predator H. variegata using a completely randomized design under laboratory conditions at 25±1oC, 60±10% RH, and 16:8 hours (L: D). The individuals were transferred from infested wheat to fresh plants every week to keep an appropriate aphid colony. After reproducing several generations on the potted plants, the adults were considered for experiments. Adult specimens of H. variegate were directly collected from the same aphid colony using an aspirator and transported to the laboratory.The leaf-dip method was employed to evaluate the herbicide’s lethal effects. Besides, the mortality rates were recorded 24, 48, and 72 hours after the treatment process. Experiments were replicated for each herbicide four times. In this case, each replication included ten adult insects as subjects.ResultsThe results showed that using Mesosulfuron-methyl+ Iodosulfuron-methyl-sodium on aphids killed all insects in the first 24 hours of the experiment. Clodinafop-propargyl plus Tribenuron-methyl caused mortality rates of 55, 70, and 92.5% at 24, 48, and 72 hours post-treatment, respectively. In the case of 2,4-D plus MCPA, the mortality rates were 20, 37.5, and 57.5% after 24, 48, and 72 hours of the experiment. Mesosulfuron-methyl+ Iodosulfuron-methyl-sodium causes lady bug mortality rates of 45, 52.5, and 57.5% after 24, 48, and 72 hours, respectively. These valuesfor Clodinafop-propargyl plus Tribenuron-methyl were 17.5, 37.5 and 45%, while 2,4-D + MCPA caused 12.5, 15, and 27.5% mortality rates on ladybugs. Therefore, the present study recommends Mesosulfuron-methyl+ Iodosulfuron-methyl-sodiumto implement weed control in wheat fields and control S. graminum. Also, it is suggested to utilize Clodinafop-propargyl + Tribenuron-methyl and 2,4-D + MCPA in combination with biocontrol (using H. variegata) to perform the relative control of wheat aphids.DiscussionAgricultural herbicides can affect various insects such as pests and natural enemies. This procedure occurs through their direct toxicity or their effects on the population and diversity of their plant hosts. The present study is one of the few studies that simultaneously investigate the influence of herbicides on a pest and its natural enemy. The findings demonstrated that herbicides could directly affect insect populations. The principal purpose of the present study was to determine whether common and widely used herbicides in the cultivation of wheat in Iran can directly cause death in adults of aphids and their main predator (H. variegata). Since both of them have a high population in most wheat fields, their adults were simultaneously established and activated in the wheat farms during herbicides. Based on the recommended concentrations and direct application, four herbicides caused death in adults of green wheat aphids and ladybugs.}, keywords = {Herbicides,Side effects,Schizaphis graminum,Hippodamia variegate}, title_fa = {مقایسه سمیت چهار علفکش روی شته معمولی گندم Schizaphis graminum (Hom.: Aphididae) و شکارگر آن، کفشدوزک Hippodamia variegata (Coleoptera: Coccinellidae) در شرایط آزمایشگاهی}, abstract_fa = {شته معمولی گندم، Schizaphis graminum، یکی از آفات مهم گندم است که با تغذیه از شیره نباتی موجب خسارت به این محصول می‌شود، از بین دشمنان طبیعی آن، کفشدوزک Hippodamia variegate فعال‌ترین شکارگر این آفت است. کاربرد علف‌کش‌ها در مزارع گندم ممکن است روی جمعیت این حشرات تأثیر بگذارد. این پژوهش با هدف بررسی تأثیر علف‌کش‌های توفوردی‌+ ام‌ث‌پ‌آ®، آگرانتیس®، و مخلوط تاپیک®+گرانستار®روی شته معمولی گندم به‌عنوان آفت و کفشدوزک شکارگر آن انجام شد. میزان تلفات حشرات در 24، 48 و 72 ساعت پس از آزمایش محاسبه گردید. تیمار آگرانتیس در 24 ساعت اول آزمایش تمام شته‌ها را از بین برد. تیمار مخلوط تاپیک+گرانستار در 24، 48 و 72 ساعت پس از شروع آزمایش به ترتیب 55، 70 و 5/92 درصد تلفات و تیمار توفوردی‌+ ام‌ث‌پ‌آ، نیز به‌ترتیب 20، 5/37 و 5/57 درصد تلفات ایجاد کردند. علف‌کش‌ها در غلظت یکسان به‌طور متوسط روی کفشدوزک تلفات کمتری نسبت به شته بود، به‌صورتی که در زمان‌های 24، 48 و 72 ساعت پس از شروع آزمایش تیمار آگرانتیس® به ترتیب 45، 5/52 و 5/57،تاپیک®+گرانستار® 5/17، 15و 45 و توفوردی‌+ ام‌ث‌پ‌آ®،  5/12، 5/37 و 5/2 درصد تلفات روی افراد بالغ کفشدوزک داشت. با توجه به نتایج به نظر می‌رسد شته معمولی گندم نسبت به علف‌کش آگرانتیس® و در مرحله بعد تاپیک®+گرانستار® حساسیت زیادی دارد. براساس اصول سازمان بین‌المللی کنترل بیولوژیک (IOBC)، برای کفشدوزک H. variegata علف‌کش آگرانتیس در دسته کمی خطرناک و مخلوط تاپیک®+گرانستار® در زمان 24 ساعت در دسته بی‌خطر ولی در 48 و 72 ساعت در دستۀ کمی خطرناک و علف‌کش توفوردی‌+ام‌ث‌پ‌آ® در دسته بی‌خطر قرار گرفت؛ بنابراین برای کنترل علف‌های هرز مزارع گندم و شته معمولی گندم علف‌کش‌ آگرانتیس و جهت کنترل نسبی و پایدار شته معمولی گندم با حفظ کفشدوزک H. variegata، علف‌کش‌های تاپیک®+گرانستار و توفوردی+ ام‌ث‌پ‌آ® قابل توصیه است.}, keywords_fa = {علف‌کش‌ها,اثرات جانبی,شته معمولی گندم,Hippodamia variegate}, url = {https://plantprotection.scu.ac.ir/article_17259.html}, eprint = {https://plantprotection.scu.ac.ir/article_17259_39f717e146cea564f0d19cf7f82e1a65.pdf} }