Almond Facts, May-June 2021

Fig. 3: The BIP Field Specialists assessed and inspected colonies across a five-week period. During those weeks, Varroa loads are compared between beekeepers from each Tech Transfer Team region. Fig. 4: Distribution of the Nosema loads of colonies sampled during almond pollination 2021. The color shows the grouping by team (origin). The dashed line represents the 1 million spores per bee threshold (331 colonies were measured). Some beekeepers reported colonies coming home with more brood (new bees in development) than last year, may be due to generally favorable weather and prolonged access to almond pollen. — Dan Wyns, Great Lakes Region Field Specialist Nosema Loads Nosema ceranae is a parasite of the honey bee gut. Often associated with the higher proportion of older forager bees, in the springtime and sometimes later in the fall, Nosema ceranae can affect a colony’s productivity. Nosema often clears up with good weather and forage, so if colonies come out of the winter with high Nosema loads, a good almond pollination season may be part of the cure. Many beekeepers do not request Nosema samples and those who do, typically have had issues with it in the past or perceive signs of its presence. This year, we had 23 beekeepers request some Nosema processing and most of them had at least some of their colonies over the standard threshold of 1 million spores per bee. Only 4 beekeepers had all colonies test below threshold. The average Nosema load for all samples (all teams) was 1.9 million spores per bee. 3 7 M A Y – J U N E 2 0 2 1