Dwight Wells Slide Deck from the March 2016 Meeting

Contributed by Jerry Rinehart

SIBA wishes to thank Dwight Wells for visiting us in March and sharing information on mite management and and ideas on how to populate our area with better bees. Here are some brief talking points from his presentation, but you can find this and much more in the included PDF that is linked below. Thanks again Dwight!

Biology, Anatomy and Behavior of mites

  • Life Cycle of the Mite vs.The Honey Bee Life Cycle
  • How Mites killhoney bees; How Bees KillMites
  • How Mite populations grow in the colony
  • What Beekeepers need to know
  • How Beekeepers cansuccessfullymanage Varroa Mites

Mite growth potential

  • Mite numbers increase from 1 mite to 11 in 50 days
  • One mite results in a population of 1456 mites in 150 days on worker brood
  • The population would be 6000 mites in 150 days if they reproduced only in drone brood
  • Two mites invading a colony per day can result in a growth of 1000 mites a month earlier.
  • Invasion rates can be low in the spring, 1.6 to 13.7 mites per day in summer, 75 mites per day in the fall
  • Varroa stay on adult bees between 5 to 11 days before entering an uncapped cell with larvae
  • Mites can survive away from brood or bees for 2-3 days
  • Mites are introduced to colonies by beekeepers exchanging equipment between hives, drifting of bees and bees robbing colonies weakened by varroa.
  • Mites can only reproduce on honey bee brood
    –Enter cell with 5 day old larvae before cell is sealed
  • Adult mites leave adult bees and invade worker brood cells 20 hours before they are capped or 40 hours in drone brood cells
  • Drone cells are 6 to 12 times more likely to contain varroa than worker cells
  • Usually 4-5 eggs are laid, 1stis a male, then 3-4 females
  • The male mates with the females before the host bee emerges.
  • Reproduction rate is ~1.3 in worker cells, 2.6 in drone cells

Effects on colony production

  • Spring: Bees population will grow quicker than mite population and will produce a good honey crop
  • Summer: Mite population rapidly grows, infecting larva and young bees (late summer bee population is decreasing).
  • Fall: Infected bees and brood develop Parasitic Mite Syndrome, plus invasion of mites will prevent the colony to perform normal activities, the colony fails
  • Winter: Colony is dead

Why sample Colonies for Varroa

  • Surveillance
    –April –July 1st-September 1st–Oct 15 to Nov 15
  • When to treat for Varroa Mites (Thresholds)
  • To determine the effectiveness of treatments
  • To locate mite resistant strains of bees
    –Check mites for chewed legs with microscope
    –% of total mites on sticky board

Download Dwight's full slide deck

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