# Seasonal Dynamics and Nest Characterization of Vespa orientalis (Hymenoptera: Vespidae) in Apiaries: Insights from Bait Trap Capture Efficiency

## TL;DR

This study tracked the seasonal population of oriental hornets in Egyptian apiaries and found that grape juice is the most effective bait for capturing them.

## Contribution

The study provides new insights into the seasonal dynamics and nest composition of Vespa orientalis and identifies effective bait types for trapping.

## Key findings

- Hornet populations peaked in October and declined in December with seasonal and location-based variations.
- Grape juice was the most effective bait, capturing significantly more hornets than other tested attractants.
- Nest composition varied between seasons, with differences in the number of cells, eggs, larvae, and pupae.

## Abstract

This study examined the population changes of the oriental hornet (Vespa orientalis) in bee yards during two successive seasons (2023–2024) in three locations in Egypt. The number of hornets was highest in October and lowest in December, with noticeable differences between years and locations. We also studied the contents of hornet nests, including eggs, larvae, and pupae, which varied between the two seasons. Among the different food baits tested, grape juice attracted the most hornets, followed by black honey, while the capturing trap caught very few. These results help us to understand the seasonal behavior of V. orientalis and can assist in developing safer and more effective ways to capture it around apiaries.

This study investigated the population dynamics of Vespa orientalis L. (Hymenoptera: Vespidae) across two consecutive seasons (2023–2024) in selected apiaries, with a focus on nest composition (eggs, larvae, and pupae) and the effectiveness of various bait traps for capturing the species. Monthly monitoring revealed the highest population peaks in October and the lowest in December. Notable inter-seasonal variations in population density were observed across the studied sites. The average number of individuals per nest varied between seasons, reflecting fluctuations in colony development and environmental factors. In 2023, the mean counts of cells, eggs, larvae, and pupae per nest were 30.14, 18.77, 13.33, and 20.88, respectively, while in 2024, they were 10.55, 14.81, 18.02, and 30.43. Among the tested attractants, grape juice proved the most effective, capturing an average of 511.67 hornets, followed by black honey (422.33 hornets), whereas the capturing trap caught only 5 hornets. These findings provide insights into the seasonal activity and reproductive status of V. orientalis and support the development of environmentally friendly capture strategies.