The Effect Of Lower Temperature 24℃ On The Development Of Capped Brood Of Honeybee Workers

Temperature is an important factor for honeybee’s development and has significant impact on the development, behavioral activity and physiological metabolism of honeybee.Under normal condition, the colony usually maintains the center temperature at 35℃ to make sure the broods can develop normally. When temperature deviates from 35℃, it will affect the development of brood. In this paper, we treated 1,2,4,5,7,8 day-old workers’ capped brood of Apis mellifera ligustica and 0,3,6,9 day-old workers’ capped brood of Apis cerana cerana at 24℃for 8～168 hours and investigated the capped brood’s mortality, developmental period, emergent weight and wing veins mutants. The results were as follows:When the worker capped broods A.m ligustica of 1,2,4,5,7,8 day-old treated at 24℃ for 8-168 hours, significant influence had happened on the development of the capped broods. Compared with the worker capped broods developed at constant optimal temperature 35 ℃, the mortality of those treated at 24℃for 8～168 hours increased and the developmental period prolonged. The longer incubated time, the higher mortality and the longer developmental period became. The emergent weight after emergency of 1,2,4,5,7,8 day-old worker capped broods decreased as the incubated time prolonged. When the worker capped broods treated at 24℃ for 8～168 hours, three dominant mutation types, including newborn vein, protrusion vein and missing vein, were observed in wing vein. The majority mutation types of wing veins appeared in adult workers of 1 day-old and 2 day-old capped broods after emergence. With the process of treated increasing, the number of mutation types increased and the variation degree was strengthened. However, there were small amount mutations and there was no significant difference in mutations in workers of 4,5,7,8 day-old capped broods as the treated time at 24℃prolonged. The 2 day-old worker capped broods were more sensitive to lower temperature, they all died when treated at 24℃ for 72 h.When the worker capped broods A.cerana cerana of 0,3,6,9 day-old treated at 24℃for 8～168 hours, the development of them are all affected. Compared with the worker capped broods developed at constant optimal temperature 35℃, the mortality of which treated at 24℃for 8℃168 hours becomes bigger, the developmental period becomes longer, and both of them increases as the incubated time increases; the emergent weight becomes lighter, and which shows a trend to increase as their old age increasing, but the emergent weight of 0,3 day-old worker capped broods decreases as the incubated time increased. When the worker capped broods treated at 24℃ for 8-168 hours, wing veins of honeybees appeared varies mutation.The most mutation types of wing veins appeared in eclosion workers of 0,3 day-old. With the process of treated increasing, the number of mutation types increased and the variation degree strengthened. However, there are little mutation types in workers of 6,9 old day worker capped brood when the treated time at 24℃ prolonged. The 3 day-old worker capped broods are more sensitive to low temperature, the mortality of which is significantly higher than 0,6,9 old day worker capped brood when they treated at 24℃ for 8-168 hours. However, the 6 day-old worker capped broods are more resistant to low temperature, the mortality has been at a lower level.