تغییرات جمعیت و پراکنش فضایی تریپس‌‌های مزارع لوبیا (phaseolus vulgaris l.) در استان لرستان، غرب ایران

با توجه به خسارت شایان توجه تریپس‌ها در مزارع لوبیا‌‌، تغییرات جمعیت، تنوع گونه‌‌ای و پراکنش فضایی تریپس‌‌ها همزمان با مراحل رشدی لوبیا (phaseolus vulgaris l.) در مزارع لوبیای شهرستان سلسله (استان لرستان) بررسی شد. نمونه‌‌برداری‌‌ها همزمان با دوبرگی‌‌شدن لوبیا تا زمان خشکیدگی برگ‌‌ها در دو مزرعه واقع در روستاهای چم‌‌تکله و درتنگ در سال 1400 انجام شد. نمونه‌‌برداری در مزارع با حرکت به شکل w صورت گرفت. در هر بار نمونه‌‌برداری، تعداد 20 برگ انتخاب و سپس با تکاندن برگ‌‌ها روی سینی سفید لعابی، تریپس‌‌های موجود جمع‌‌آوری شد. در این مطالعه، 12 گونه تریپس شناسایی شد که در بین آنها، بیشترین درصد فراوانی مربوط به تریپس پیاز (thrips tabaci lindeman.) با فراوانی 69.43 درصد بود. تغییرات جمعیت نشان داد بیشترین تراکم تریپس پیاز و تریپس گل frankliniella intonsa (trybom) در روستای چم‌‌تکله به ترتیب 4.99 ± 166.35 و 1.38 ± 16.85 و در روستای درتنگ به ترتیب 3.61 ± 159.3 و 1.32 ± 22.6 تریپس در واحد نمونه‌‌برداری بود؛ همچنین در هر دو مکان مطالعه‌‌شده بیشترین مقادیر شاخص‌‌های تنوع زیستی در مرحلۀ زایشی لوبیا مشاهده شد؛ به طوری که بیشترین مقادیر شاخص تنوع شانون - وینر، سیمپسون، یکنواختی پیلو و غنای مارگالف در روستای چم‌‌تکله به ترتیب برابر با مقادیر 2.94، 0.93، 0.95 و 2.98 و در روستای درتنگ به ترتیب برابر با مقادیر 2.89، 0.91، 0.94 و 2.74 به دست آمد. به‌طور کلی براساس نتایج این مطالعه، پیک جمعیتی تریپس پیاز و تریپس گل به ترتیب در مراحل زایشی و غلاف‌‌بندی لوبیا در مزرعه مشاهده شد. با توجه به اینکه در این مراحل رشدی از گیاه لوبیا، تریپس‌‌ها خسارت زیادی به محصول وارد می‌‌کنند، باید اقدامات مدیریتی مناسبی برای کشاورزان منطقه ارائه شود.

population fluctuation and spatial distribution of thrips in bean farms (phaseolus vulgaris l.) in lorestan province, west of iran

considering the significant damage caused by thrips species to the bean crops, population fluctuation, species diversity, and spatial distribution thrips’ relationship to the growth stages of red bean (phaseolus vulgaris l.) was investigated in the bean farms of selseleh county (lorestan province, west of iran). sampling was done at the same time as the bean became two leaves until the leaves dried in two farms located in the villages of cham-takleh and dartang during the year 2021. the sampling was done in the farms by moving in a w-shape. in each sampling, 20 leaves were selected and then the thrips were collected by shaking the leaves on a white tray. in this study, 12 species of thrips were collected and identified. amongst them, the highest frequency was related to onion thrips, thrips tabaci lindeman (69.43%). the results of population fluctuation showed that in cham-takleh, the highest density of onion thrips and flower thrips was 166.35 ± 4.99 and 16.85 ± 1.38, respectively, and in dartang, the highest density was 159.3 ± 3.61 and 22.6 ± 1.32 on average. also, in both locations, the highest values of biodiversity indices were observed in the reproductive stage of the bean. the highest values of shannon-wiener, simpson, pielou evenness, and margalef richness indices in cham-takleh were 2.94, 0.93, 0.95, and 2.98, and in dartang were 2.89, 0.91, 0.94, and 2.74, respectively. in general, the results of this study showed that the population peak of onion and flower thrips was observed in the reproductive and development of pod stages of beans, and their density gradually decreased in the farms. considering that at this stage of the bean, thrips can cause a lot of damage to the bean crops, so appropriate management measures can be provided for the farmers.key words: population changes, thrips, biodiversity, beans. introductionbean (phaseolus vulgaris l.) (fabaceae) is one of the most cultivated plants of legumes in most countries. lorestan province is one of the most important bean-growing areas in iran with a cultivated area of 15,887 ha. several insects with piercing-sucking mouthparts such as thrips, leaf hoppers, aphids, and plant bugs are pests on beans. but, thrips, the most dangerous pests, are the focus of this research. thrips can attack beans from the moment the seedlings emerge from the ground through to flowering. considering the significant damage caused by thrips species in the bean crops, the present study investigates population fluctuation, species diversity, and spatial distribution thrips’ relationship to the growth stages of beans in the bean farms of selseleh county (lorestan province, west of iran). materials and methodsin this study, the sampling procedure was done as the bean became two leaves until the leaves dried in two farms located in the villages of cham-takleh and dartang during the year 2021. the sampling was done in the farms by moving in a w-shape. in each sampling, 20 leaves were selected and then the thrips were collected by shaking the leaves on a white tray. in order to accurately count thrips, using a stereomicroscope, some samples were separated and microscopic slides were prepared from some samples and finally the number of samples was recorded. the spatial distribution of immature as well as adult types of thrips was estimated using taylor’s power law and iwao’s patchiness regression methods. biodiversity indices were calculated using past software. in this study, the counting of larvae and adult insects was done. also, in order to investigate the effect of temperature and humidity on thrips population density, a multiple linear regression relationship was used between average daily temperature, average daily relative humidity, and thrips population density on each sampling date. for data analysis, excel 2016 software was used to calculate the relative frequency, and t-test was used to calculate biodiversity indices and compare diversity data between different regions. statistical tests were performed using spss version 23. results and conclusionin this study, 12 species of thrips were collected and identified. amongst them, the highest percentage of frequency was related to onion thrips, thrips tabaci lindeman (69.43%) and flower thrips, frankliniella intonsa (trybom) (12.11%). the frequency (%) of the other species are as follows: aeolothripidae: aeolothrips intermedius bagnall (6.63), a. collaris priesner (1.13); thripidae: tenothrips frici (uzel) (4.76), thrips trehernei priesner (2.8), odontothrips confusus priesner (1.5), scolothrips longicornis priesner (1.3), neohydatothrips gracilicornis (williams) (0.09), microcephalothrips abdominalis (crawford) (0.08); phlaeothripidae: haplothrips reuteri (karny) (0.1), and h. globiceps bagnall (0.07).the results of population fluctuation showed that in cham-takleh, the highest density of onion thrips and flower thrips was 166.35 ± 4.99 and 16.85 ± 1.38, respectively. in addition, in dartang the highest density was 159.3 ± 3.61 and 22.6 ± 1.32 on average. also, in both sites, the highest values of biodiversity indices were observed in the reproductive stage of beans. the highest values of shannon-wiener, simpson, pielou evenness, and margalef richness indices in cham-takleh were 2.94, 0.93, 0.95, and 2.98, and in dartang were 2.89, 0.91, 0.94 and 2.74, respectively. in general, the results of this study showed that the population peak of onion thrips and flower thrips was observed in the reproductive and development of pod stages of beans, and their density gradually decreased in the farms. appropriate management measures can be provided for farmers considering that at this stage of the bean, thrips can cause a lot of damage to the bean crops. funding funding was provided by the department of plant protection, faculty of agriculture, lorestan university, khorramabad, iran.