بررسی نوسانات جمعیتی سوسکهای کرگدنی خرما (Scrabeidae:.Coleop) Oryctes spp. در استان بوشهر

Oryctes elegans and Oryctes agamemnon are the most important pests in date palm orchards in Bushehr province which have recently caused damage in different levels in more than 70% of orchards. The damage is very severe in more than 20% of orchards. The damage of larval stages happens in the trunk while the damage of adults occurs in both trunks and the base of young fronds and inflorescences. This research was conducted for evaluating the fluctuation of Oryctes spp. population and determining the period of activity as well as the peak of the flight of adults of Oryctes spp. in three orchards positioned in Dashtestan District (Talhe village, 240m altitude), Tangestan District (Dehmian zone, 60m altitude) and Jam District (Darreban village, 368m altitude) during 2021-2023. For this purposeو 3 light traps were installed which were illuminated by 20W white lamps and supplied by AC current for trapping (catching) the adults. The data were recorded separately in each trap and the number of trapped (caught) adults was recorded weekly. Meteorological data were collected by means of the installed dataloggers in the regions in which the research was conducted. The results showed that the emergence and flight of adults of both species in Dashtestan and Tangestan started in the second half of Esfand (first half of March) while in Jam started in the second half of Farvardin (first half of April); in all the districts the emergence continued until the end of Mehr (middle of October). The activity and monthly trapped adults of both species increased by increasing the temperature during Khordad, Tir and Mordad (May, June, july) in both years. Peak of monthly cumulative catch of adults per trap happened in Tir (June) for all Districts wich was for Dashtestan 45 and 39 adult/trap, Tangestan 46 and 40 adult/trap and Jam 41 and 35 adult/trap in 1401 and 1402 respectively. These results can be used for managing the best time for mass trapping the adults in order to reduce the population of the pest.