# Relationships Between the Quantity and Quality of Pollen and the Quantity of Capped Brood in Apis mellifera carnica and Apis mellifera caucasica

## TL;DR

This study explores how two honeybee subspecies adapt to spring weather changes by analyzing pollen collection and colony development.

## Contribution

The study identifies adaptive traits in Apis mellifera carnica and caucasica subspecies under changing spring conditions.

## Key findings

- CR subspecies showed higher spring development potential despite collecting less pollen than CC later in the season.
- Pollen protein content positively correlated with capped brood weight, indicating better colony development in CR.
- Wind speed significantly influenced pollen collection, with CR being more sensitive than CC.

## Abstract

Dynamic changes in climate increasingly result in atypical patterns of early spring and spring seasons. Insects such as honeybees are highly dependent on meteorological conditions during this period. Honeybees leave their hives, and the spring development of their colonies plays a crucial role in determining colony strength in subsequent seasons. Therefore, honeybee colonies must effectively adjust their behavior to adapt to spring ecosystem conditions. In this context, it is necessary to explore solutions that can support these beneficial insects. One such approach involves identifying honeybee strains with traits that enable colonies to adapt efficiently to the dynamics of changing spring meteorological conditions. This includes studying behaviors that ultimately promote colony development. In this study, particular focus was placed on analyzing the quantity and quality of collected pollen, as a source of protein, and the amount of capped brood, as an indicator of colony development. These indicators were examined in the context of meteorological conditions from April to July. Two subspecies were selected for the study: Apis mellifera carnica (CR) and Apis mellifera caucasica (CC). The results showed that CR exhibited higher developmental potential in spring, although CC collected more pollen later in the year. Meteorological conditions, particularly wind speed, significantly affected pollen collection. CR was more sensitive to this factor than CC. The usefulness of this study lies in expanding knowledge about the adaptive capacities of the investigated honeybee subspecies to dynamic springtime meteorological conditions. The findings may help optimize beekeeping practices in response to changing climatic conditions, particularly through the selection of honeybee subspecies adapted to specific ecosystems.

An important aspect in improving the efficiency of apiary production is knowledge of factors stimulating the condition of colonies. In view of climate change, one important factor is bee behavior associated with meteorological conditions. Studying the effect of selected meteorological parameters on honeybee colony development can help enhance management of the apiary economy. The aim of the study was to evaluate the connections between the quantity and quality of collected pollen and the quantity of capped brood, as an indicator of the rate of development against the background of weather condition indicators. We studied colonies of two relatively old subspecies: Apis mellifera carnica L. (CR) and Apis mellifera caucasica L. (CC) colonies. It was hypothesized that the quantity of pollen gathered is dependent on meteorological conditions, while the amount of capped brood depends on the quality and quantity of pollen. The study was carried out from April to July. Until May, both groups collected similar amounts of pollen. In the second part of the study, CC collected more pollen (averaging 32.3 g more). CR bees, however, exhibited greater development potential, with 6.32 g more capped brood on average (p ≤ 0.05). The greatest differences were noted in the spring period, which indicates faster development in CR colonies. The capped brood weight was positively correlated (0.391, p ≤ 0.05) with the amount of protein in the pollen. Trends in capped brood mass indicate that CR colonies were stronger during spring development. To some extent, this can be explained by the dependency of this behavior on meteorological conditions, specifically wind speed. In comparison to the CC subspecies (−0.600, p ≤ 0.05), CR bees were less sensitive to this factor, as indicated by the stronger correlation between pollen collection and wind strength (−0.642, p ≤ 0.05). The results indicate that some of the features of the subspecies we studied may have some potential in improving colony strength management in the context of changes related to the course of spring weather in eastern Poland.