GROOMING BEHAVIOR IN VAROOSIS RESISTANCE IN TWO HONEYBEE ECOGEOGRAPHIC VARIETIES (APIS MELLIFERA CARNICA) FROM SERBIA

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1 GROOMING BEHAVIOR IN VAROOSIS RESISTANCE IN TWO HONEYBEE ECOGEOGRAPHIC VARIETIES (APIS MELLIFERA CARNICA) FROM SERBIA Dejan Pejovic, Marijana Vucicevic and Zoran Stanimirovic Department of Biology, Faculty of Veterinary Medicine, University of Beograd, P O Box 370, Beograd, Bulevar JNA 18, Yugoslavia Tel: , Fax: , biolog@vet.bg.ac.yu Introduction Grooming behaviour, or hygienic behaviour in a narrow sense, is a specific form of hygienic behaviour. It is a very complex feature whose purpose is the removal and extermination of the mite Varroa destructor, and implies the clearance of mites by honeybees themselves, the so called clearance dance, the cleaning of open infested brood cells, and the group, i.e. mutual cleaning of infested honeybee workers. The grooming behaviour is of special interest for scientists involved in the research on the behavioural characteristics of the honeybee populations, and of, an even greater importance for those whose duty it is to control honeybee infectious diseases, not to mention bee keepers for whom the grooming behaviour means much more than simple resistance. In this work the investigations of grooming behaviour were carried out in order to determine the level of grooming behaviour of the two honeybee ecogeographic varieties from Serbia yellow bees from Machva region and grey bees from Rudnik region, and in order to answer the question: do intra- and interpopulation differences exist between the investigated ecogeographic varieties (ecogenotypes) with reference to this important characteristic of honeybee colonies, especially from the point of its resistence to some parasitic diseases, with a view of improving selection and rearing of quality queens. Materials and Methods The grooming behaviour of honeybees was monitored on 800 honeybee colonies sampled at 20 localities from Machva and Rudnik regions: 10 potent honeybee colonies with one-year old queens, 10 potent colonies with two-year old queens, 10 medium potent colonies and 10 weak colonies were analysed on each locality, i.e. 40 honeybee colonies per locality. The analysis and evaluation of grooming honeybee behaviour were done according to the procedure of Hoffman (1993) modified by Stanimirovic et al. (2000). Results The results of our investigations of the grooming behaviour of the honeybee colonies in Machva region are presented on graph 1. The potent honeybee colonies (regardless queen age) from 9 localities, were able to demage more than 36% Varroa mites in analysed sample, so according Hoffman (1993), were qualified as colonies with expressed grooming behaviour. All investigated medium potent and weak colonies from Machva region and potent colonies (regardless queen age) from locality Schevarice pertained to category of honeybee colonies without expressed grooming behaviour, with percentage of damaged Varroa mites from 29,74 to 35,05% (less than 36%), Proceedings of the 37 th International Apicultural Congress, 28 October 1 November 2001, Durban, South Africa APIMONDIA 2001 To be referenced as: Proc. 37 th Int. Apic. Congr., 28 Oct 1 Nov 2001, Durban, South Africa ISBN: Produced by: Document Transformation Technologies Organised by: Conference Planners

2 The results of our investigations of the grooming behaviour of the honeybee colonies in Rudnik region are presented on graph 2. All investigated potent honeybee colonies (regardless queen age) pertained to category of honeybee colonies with expressed grooming behaviour, because of ability to demage more than 36% Varroa mites in analysed sample. All investigated medium potent and weak colonies from Rudnik region pertained to category of honeybee colonies without expressed grooming behaviour, with percentage of damaged Varroa mites from 29,43 to 35,34% (less than 36%). The results of comparision of percentage values of damaged Varroa mites between honeybee colonies from Rudnik and Machva regions are presented on graph 3. Discussion and Conclusion The obtained results concerning the grooming behaviour in the honeybee from the investigated localities of Machva and the Rudnik show that grooming behaviour potentially exists, but its significance cannot be discussed as, on the whole, the ability to eliminate damaged mites in the total number of eliminated mites from all the investigated colonies amounted to 36%. Namely, the colonies from Machva (yelow bees) had grooming behaviour with a potential of 34,78%, whereas those from the Rudnik (grey bees) had a potential of 34,8l% (graph 3). However, the results point to the existence of a relationship between the grooming behaviour and the strength (potential) of the colony. Thus, in the honeybee colonies belonging to the category of potent ones, at all l0 localities from the regions of the Rudnik and 9 from Machva an expressed grooming behaviour was registered. At the localities from the Rudnik they ranged from 36,41% to 38,68%, and at the localities of Machva from 36,7% to 42,14%. We concluded that the grooming behaviour of the investigated yellow bees from Machva and grey bees from Rudnik, is a reality and a special potential, being more expressed at the population level, supported by the observed high intra- and interpopulation variabilities of the studied feature. Those results are in agreement with those of Stanimirovic et al. (2000). The potent honeybee colonies (regardless queen age) with expressed grooming behaviour at 9 localities from the regions of the Machva and l0 from Rudnik could be used as breeding colonies for rearing of quality queens. The obtained data concerning grooming behavioursof yelow and grey bees in Serbia, especially the fact that variability is higher at population level (intra- and interpopulation variability) compared with global expression of this feature in bees from investigated regions, indicate that investigated behaviour is genetically unfixed and poligenic feature. Therefore, the level of grooming behaviour do not obligatory inherit from parents to offsprings. Our interpretations of results are in agreement with those of Hoffman (1993) and Stanimirovic et al. (2000). References 1. Hoffman S. (1993): The occurrence of damaged mites in cage test and under field conditions in hybrids of different carniolan lines. Apidologie, 24, Stanimirovic Z., Mladjan V., Vucicevic Marijana and Todorović Dajana (2000): Biological potency of honeybee hygienic behavior and diseases resistance. Clinica Veterinaria '2000, , pp Budva, YU.

3 1. Graph 1. Comparision of honeybee grooming behaviour from 10 different localities in Machva region, in accordance to colony strength Potent (P1+P2)/2 Med. Potent Weak Percentage of demaged mites (grooming behaviour) Schevarice Tabanovic Majur Crna Bara Klenje 1-Limit line for grooming behaviour

4 Graph 2. Comparision of honeybee grooming behaviour region, in accordance to colony strength from 10 different localities in Rudnik Potent (P1+P2)/2 Med. Potent Weak Percentage of demaged mites (grooming behaviour) Semedraz Jablanica Brusnica Majdan G.Branetic Nakucani G. Crnuca Klaticevo Grabovica Takovo 1-Limit line for grooming behaviour

5 Graph 3. Comparision between grooming behaviour of honeybee colonies from Machva and Rudnik regions Percentage of demaged mites Limit line for grooming behaviour 34.78% 34.81% Machva Rudnik

6 GROOMING BEHAVIOR IN VAROOSIS RESISTANCE IN TWO HONEYBEE ECOGEOGRAPHIC VARIETIES (APIS MELLIFERA CARNICA) FROM SERBIA Dejan Pejovic, Marijana Vucicevic and Zoran Stanimirovic Department of Biology, Faculty of Veterinary Medicine, University of Beograd, P O Box 370, Beograd, Bulevar JNA 18, Yugoslavia Tel: , Fax: , biolog@vet.bg.ac.yu CURRICULUM VITAE Name: Zoran Stanimirovic, associate professor Code number: Date and place of birth: Ševarice, YU Speaking languages: Russian, German, English Professional career: - Graduated from the Department of Biology, Faculty of Natural Science, Belgrade University, in MSc from the Faculty of Biology in The title of the thesis: Chromosomal polymorphism of natural populations Mus musculus, Linne (1758) in Yugoslavia. - PhD from the Faculty of Biology in The title of the thesis: Comparative analyses of natural and induced polymorphism of chromosomes in the species Mus musculus, Linne (1758). - Finished PCR school at the Faculty of Biology, Belgrade University in In 1988 was elected junior asssistant at the Department of Biology, Faculty of Veterinary Medicine, Belgrade University. - In 1993 promoted to Assistant at the same Department. - In 1996 became an Assistant Professor at the same Department. - From 1993 to 1997 was engaged to teach at the Department of Biology, Faculty of Medicine and Dental Faculty, Sarajevo University. - In 1999/2000 engaged in postgraduated studies at the Faculty of Medicine, Prishtina University. - Until now has been a mentor for 3 MSc theses; a member of the commissions for 3 specializations, 5 MSc theses and 2 PhD theses. - In 2001 became an Associated professor at Department of Biology, Belgrade University he published 77 papers, one monography, one textbook and one manual for practical classes.