Annual Population Dynamics and Daily Activity Rhythm of Adult Oriental Hornets (Vespa orientalis), an Important Pest of Iranian Honeybee in Ahvaz, Iran

The Oriental hornet, Vespa orientalis L. (Hymenoptera: Vespidae), is one of the most important and serious enemies of honeybees. In this study, the annual population dynamics and daily activity rhythm of Oriental hornet were examined, based on the number of adults trapped in an apiary located in Ahvaz (southwest of Iran) during a period of two years (January ۲۰۲۱ to December ۲۰۲۲). Samplings were performed using the box traps available in the market. The bait used in the traps was fresh chicken liver, with the traps checked daily in four time periods. The results revealed that the first overwintering queens (gynes) emerged in March and two population peaks of newly emerged hornet workers occurred during the year, one in July and the other in October. In late November and early December, no adult hornet was trapped. The daily activity rhythm of adult hornets was observed mostly during ۹ – ۱۲ hr, almost twice as much as in the afternoon period (۱۲ – ۱۵ hr). The lowest activity was recorded in the evening period and night (۶ pm - ۹ am). During both sampling years, the seasonal abundance of adult hornets displayed a significant positive correlation with air temperature and a significant negative correlation with relative humidity. By comparing the results of our findings with other studies performed in the same and different climate zones, it can be hoped to present effective methods to control the population of V. orientalis, especially in areas that have extensive beekeeping.

کلیدواژه ها:

Apis mellifera meda ، Bait trap ، Khuzestan Province ، Population fluctuations ، Vespidae.