PERFORMANCE AND Nosema spp. SPORE LEVEL IN YOUNG HONEYBEE (Apis mellifera carnica, Pollmann 1879) COLONIES SUPPLEMENTED WITH CANDIES

Abstract

We evaluated the efficacy of supplementation with protein, yeast, or sugar candies of young honeybee colonies origi- nated from artificial swarms, by measuring strength and determining Nosema spp. spore level in adult bees in summer period. At the same time, we aimed to assess longevity of adult worker bees after feeding the same type of candies in controlled laboratory condition. The highest survival was found in Yeast and Protein candy group. On the contrary, the field study showed that artificial swarms produced significantly more pupae (2510.4 cm 2 , p=0.0001) in the 1 st period of measurement, and more larvae (964.8 cm 2 , p=0.003) and frames with bees (5.6, p=0.008) in the 2 nd period by feeding non-protein candy. In the 3rd period of evaluation of young colonies, the Sugar candy group had the highest number of frames covered by adult bees and honey stores, respectively (5.6, p=0.0009; 3432.0 cm 2, p=0.015). Sugar candy group produced the largest area of wax cells, however, the differences were not statistically significant. Nosema spp. spore level was checked quantitatively in adult bees. The lowest infection was statistically significant in Yeast candy group in June (4.35 million spores per bee, p=0.02), but insignificant in September. Supplementing artificial swarms Sugar candy offers the most promising potential for development of productive young colony. The findings of our study could help beekeepers to choose the effective candy supplement for optimal development of artificial swarms. Key words: Apis mellifera; artificial swarms; young colonies; supplements; candies; development; Nosema spp.; longevity RAZVOJ DRUŽIN IN ŠTEVILO SPOR Nosema spp. PRI MLADIH DRUŽINAH MEDONOSNE ČEBELE (Apis mellifera carnica, Pollmann 1879), KRMLJENIH S POGAČAMI Izvleček: Mlade čebelje družine iz umetnih rojev smo krmili z različnimi pogačami z dodatkom beljakovin, kvasa ali sladkorja. Ocenjevali smo razvoj družin in določali število spor Nosema spp. pri odraslih čebelah v poletnem obdobju. V laboratorijskih pogojih smo krmili čebele delavke z isto vrsto pogač. Najboljše preživetje smo ugotovili v skupinah, ki so prejele pogačo s kvasom oziroma beljakovinami. Nasprotno pa je poskus v družinah pokazal, da je bilo v 1. obdobju merjenja bistveno več bub (2510,4 cm 2 , p = 0,0001), v 2. obdobju pa več ličink (964,8 cm 2 , p = 0,003) in okvirjev s čebelami (5,6, p = 0,008) pri krmljenju s sladkorno pogačo. V 3. obdobju ocenjevanja mladih družin je imela skupina s sladkorno pogačo največ pokritih okvirjev z odraslimi čebelami in zalog medu (5,6, p = 0,0009; 3432,0 cm 2 , p = 0,015). Skupina s sladkorno pogačo je zgradila največjo površino satja, vendar razlike niso bile statistično značilne. Število spor Nosema spp. je bilo kvantitativno preverjeno pri odraslih čebelah. Najnižja okužba je bila statistično značilna v skupini s pogačo s kvasom v juniju (4,35 milijona spor na čebelo, p = 0,02), septembra pa spremembe niso bile signifikantne. Dodajanje sladkorne pogače umetnim rojem se je pokazalo kot najbolj obetavno za razvoj produktivnih mladih čebeljih družin. Ugotovitve naše študije bi lahko pomagale čebelarjem pri izbiri učinkovitega dodatka pogač za optimalen razvoj umetnih rojev. Ključne besede: Apis mellifera; umetni roji; mlade družine; dodatki; pogače; razvoj; Nosema spp.; dolgoživost