Optimizing Italian honey bee (Apis mellifera ligustica Spin.) density in caged laboratory trials
Author(s)
Date Issued
2023
Type
conferenceObject
Abstract
Laboratory trials (LT) with honey bee (Apis mellifera L., HB) can avoid the environmental factors affecting the in-field trials. Among the experimental conditions, for practical and scientifical reasons the HBs’ density (HBD) per unity of cage volume can be considered relevant in LTs. To try optimizing the HBD in LTs, a test under controlled conditions (34.3 ± 1.0 C°; 72.0 ± 1.5 % RH) with increased HBD was performed.
A four bees’ densities trial, in triplicate, was set up with 20 (D1), 30 (D2), 40 (D3) and 50 (D4) 0-24h post-emergence A. m. ligustica Spin. workers (11.9, 17.8, 23.8, 29.7 bees/100 cm3) by using 168 cm3 plastic cages. Bees were supplied ad libitum with 50% w/w sugar syrup (SS50), tap water and Haydak solid diet. Daily, for 15 days, deceased HBs were recorded, and daily individual consumption of water and SS50 (μg/HB) as well as solid diet intake (mg DM/HB) were calculated. D2 showed the lowest (p<0.001) mean mortality (19.9 ± 3.9 %) compared to other densities; in addition, it showed the slowest (p<0.01) daily mortality rate if compared to D3 and D4. The D2 individual consumption of SS50 was lower (15.0 ± 6.7 μg/HB) compared to D3 (p<0.05) only. The individual consumption of Haydak diet was density-dependent, with a significant difference (p<0.01) between D4 and D1. D2 and D4 consumption of water results lower (p<0.01) than D1 and D3. Our test suggests, also for the easier management, that D2 (17,8 bee/100 cm3) can be the optimal density for LTs.
Conference(s)
ECE 2023 - European Congress of Entomology