## 4 Discussion  
As proposed by [PERSON] [7], the fore wing length and the sum of the widths of the third and fourth tergites are measures of the worker's body size. Based on this suggestion, we found that the small-cell combs offered equally favorable conditions expressed as a lack of statistically significant changes in morphological traits describing bee body dimensions used for species identification. This is supported by the findings that the workers from the small-cell combs did not differ significantly in the fore wing length and the sum of the widths of the third and fourth tergites from worker bees reared in the standard-cell combs. It is surprising that they had a significantly longer and wider thorax. A contrasting result was reported by [PERSON] and [PERSON] [14] in workers collected from colonies in September: a significantly higher value of the thorax width was recorded in workers reared in standard-cell combs. These findings may indicate that small-cell combs provide comparable rearing conditions only in spring. Moreover, the workers reared in the small-cell combs in the present study did not differ significantly in the proboscis length from those reared in the standard-cell combs. This suggests that they can collect nectar with equal efficiency from flowers with a long and thin floral tube and deep-seated nectaries. The values of the morphometric parameters of the STComb + STColony workers compared to those reared in the smComb + smColony variant did not increase proportionally to the increase in the width of their comb cells (13%). The range of changes in the values of most traits did not exceed 3% and was equal to the range of seasonal changes [6; 7]. Similar results were obtained by [PERSON] and [PERSON] [11] and [PERSON] and [PERSON] [14]. The values of traits of the STComb + STColony workers compared to those reared in the smComb + smColony regarded by [PERSON] [6; 7] as a measure of the body size of workers, \begin{table}
\begin{tabular}{l c c} \hline \hline  & \multicolumn{2}{c}{**Groups**} \\ \cline{2-3}  & **STComb + STColony** & **STComb + smColony** \\ \hline Cell width & +13.2 & +13.0 \\ Head width & +1.3 & \(-\)0.5 \\ Head height & 0.0 & \(-\)1.3 \\ Proboscis length & +0.1 & \(-\)1.3 \\ Thorax width & \(-\)4.1 & \(-\)7.5 \\ Thorax length & \(-\)5.8 & \(-\)6.0 \\ Wing length & +1.8 & \(-\)1.0 \\ Wing width & +0.9 & \(-\)1.6 \\ Distance a of cubital vein & +3.7 & 0.0 \\ Distance b of cubital vein & +4.2 & \(+\)8.3 \\ Cubital index (Goetze) & \(-\)0.9 & \(-\)8.7 \\
3 rd tergite width & \(-\)4.3 & \(-\)4.3 \\
4 th tergite width & +1.3 & +2.5 \\ Sum of widths of the 3 rd + 4 th tergites & \(-\)1.4 & \(-\)1.0 \\ Fill factor & \(-\)13.9 & \(-\)17.0 \\ \hline \hline STComb + smColony—workers reared in standard-cell combs in colonies kept on small-cell combs; STComb + STColony—workers reared in standard-cell combs in colonies kept on standard-cell combs. & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Percentage changes in comb cell width, values of morphometric parameters, and fill factor calculated in relation to workers reared in small-cell combs in the colony kept on the small-cell combs (smComb + smColony). i.e., the fore wing length and the sum of the widths of the third and fourth tergites, increased by 1.8% (fore wing length) and declined by 1.4% (sum of tergites). We observed a similar relationship in our pervious study [15] where the fore wing length of the STComb + STColony workers compared to those reared in the smComb + smColony increased by 3.4%, which slightly exceeded the range of seasonal changes [6,7]. On the other hand, rearing bees in the STComb in STColony in summer months resulted in the increased value of the sum of the widths of the third and fourth tergites by 3.3% compared to those reared in the smComb + smColony [15]. Such a difference supports our hypothesis that the small-cell combs offered equally favorable conditions in spring for colony development by affecting the bee body dimensions as providing better brood-rearing conditions.