|Fassbinder Orth, Carol|
Submitted to: American Bee Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/6/2005
Publication Date: 8/1/2005
Citation: Fassbinder Orth, C.A., Rinderer, T.E. 2005. A study of chalkbrood susceptibility in russian and domestic honey bees. American Bee Journal 145(8):669-671 Interpretive Summary: Chalkbrood is a fungal disease of larval honey bees which was imported to the United States about 25 years ago. When it was first introduced many colonies were highly susceptible to the fungus and died. Since that time natural and artificial selection has reduced the incidence of the disease. However, many colonies of commercial honey bees are still substantially debilitated by the disease. Chalkbrood is the third most important health hazard for honey bees after those posed by two parasitic mites. Since no chemical control has been found for this fungal disease, the development of genetically resistant stock is highly desirable. This study identified colonies from a diverse population of colonies which appeared to be relatively resistant and susceptible to chalkbrood. These colonies are being used to conduct experiments which will determine to what degree resistance to the disease is genetic.
Technical Abstract: Chalkbrood susceptibility levels were determined in selected Russian and domestic honey bee lines. A baseline chalkbrood infection level was first determined for each colony, followed by three chalkbrood inoculations, each one week apart. Chalkbrood mummies were counted one week after each inoculation and removed. Both Russian and domestic post-inoculation chalkbrood infection means increased an average of five fold when compared to the baseline infection level. However, the pre and post inoculation levels were not significantly different (P=0.13), probably due to the high number of colonies exhibiting 0% chalkbrood infection throughout the entire study. No significant differences in chalkbrood susceptibility were found between the two stocks (P=0.31), or between any lines (P=0.60). However, colonies showing extreme chalkbrood resistance or susceptibility were identified. They will be used as parents in a breeding study designed to study the genetic control of chalkbrood susceptibility.