A comparative insight into Bombyliid's biodiversity indexes in grasslands in the north of Iran

The Bombyliidae family with around 5382 described species is one of the most important families in order Diptera considering their remarkable roles in biological pest control. Species of the family Bombyliidae were monitored in Guilan province in 2019 and 2020. We aimed to evaluate their biodiversity in the grasslands along with the determining Simpson and Margalef indexes. Totally 20 species from 11 genera in 2019 and 17 species from 10 genera in 2020 were identified in eight selected stations. The highest numbers of Bombyliids individuals were observed in Heiran pass station in 2019. Surprisingly the lowest number of individuals also was present in Heiran pass station in 2020. The results of ecological indices also showed the highest Margalef index in Darestan station (2.18) in 2019 and the lowest observed in Bivazen station (0) and Rudbar- Loockhee (0) in 2019 and 2020 respectively. Also, the highest values for the Simpson index were recorded in Bivazen (1) in 2019 and Rudbar- Loockhee (1) in 2020. The lowest values of the Simpson index have been recorded for Amlash (0.13) stations as well. It seems that climate and ecological condition changes in different years clearly affect the insect biodiversity indexes via making changes in their population dynamics.