Treated my two hives with Oxalic acid on January 10th- 55 degrees day. It was so warm early that my main hive was overcrowded by March. I did a split on April 2 and added a queen cell from a local breeder. Doing well as of April 27th Captured 2 swarms on: April 1st, 2016-viable and doing well as of April 27th, 2016 April 10th, 2016-added mature swarm cells on April 20th from main hive to this queenless swarm. Still active but watching for signs that the cell formed a viable queen and she mated. I have not checked since we have had cold rain for the last 3 days with plunging nighttime temperatures. Feeding syrup
RESPONSE – Mid April for queen mating is iffy some years. With queen cell requeening we should have positive signs (eggs at least) within two weeks, three at most. If beyond that then it might be best to combine (if there are enough bees to make it worthwhile). Thanks for sharing – hope that requeening event went well like the earlier one.
I treated only 1 hive with oxalic acid. They absconded 2 weeks later. The others had very high mite levels and lots of DWV. 2 queens from — heading splits died with their colonies during cold snap in Dec. with lots of food on the next bar (both TBH). Langstroth hive from a nuc from —– died between Jan and Feb. The only hive that survived well was headed by a swarm queen from another beekeeper. The other surviving hive is alive but puny.
RESPONSE: I am unsure that the Oxalic acid or the high mite numbers caused the bees to abscond in your hive. Oxalic acid ONLY kills mites on the adult bee bodies – if there was a lot of brood when you used the oxalic, all those mites would have survived since it does not penetrate cell cappings. Splits (see report from last year) have heavy losses – depends on the time of year the splits were taken and what was done to try to get them up to speed to survive winter. It is a good idea to try different stocks. You may have had a colony that was a “mite bomb,” a colony with lots of mites and they spread to your other colonies and thus you did not have good survival, despite the different stocks. I hope you small survivor colony is progressing well.
In March I discovered a virgin queen with the workers looking healthy and a good sized cluster. I may have killed the queen with Oxalic Acid (drip) and they created a queen before she could do a mating flight.
Response: Bees replacing their queen that early in season often means poor replacement chances. We do what we can for them. Thanks for your comment.
How was the oxalic acid applied and how often?
Response: Oxalic acid is our newest material (tool) for varroa control. You are correct that this question on the survey needs further definition as to drip or fumigation – we do ask when applied – but it is lumped with the other acids now in the survey. I will separate these questions in future surveys. Thanks for your feedback.
Q-For future surveys ask when people are using oxalic acid are they vaporizing or dribbling. What were their results? Another semi-related question. Were their any ill effects on the beekeeper with either dribble or vaporizing?
A-Thanks for sending a survey. Yes as Oxalic Acid is now going to be registered with both drizzle and fumigation techniques we will want to check how individuals are using it and key that to success overwintering. I am not able to include the medical consequences question you suggested – I am not a MD so I don’t know what I would do with the information. Thanks for suggesting however.