The Classroom – February 2020
Q Trapping Small Hive Beetles
Enjoyed your videoed viewpoint(s) from 2015. I’m an old hand beekeeper (New England) but new to Tennessee. Never saw small hive beetles (SHB) before coming here. Will step up to perhaps 40 hives this year depending on winter losses. Limiting factor is that I am surrounded by conventional ag, viz. corn/soy/wheat rotations of which everything has some sort of systemic insecticide treatment.
I put down four acres of successional clover and planted 18 nectar-rich trees this past spring. Such planting will proceed.
My hives are screened bottom, then slatted rack, then single deep, then queen excluder, and then on up. I usually have a screened top cover replacement — the same mesh as the bottom. Each hive has a Bee Smart robbing screen at all times. I use only wax foundation.
My questions are about entry/exit: Do SHB larvae headed out to pupate drop through the hive or do they crawl? If they drop, then what mesh will ensure they hit the sticky board underneath the bottom board? If they crawl out, can they be intercepted in some way at exit, i.e., are they able to navigate the robbing screen?
Do adult SHB just fly in? Do guard bees challenge them? Is a diversion to a trap at entry possible? Lastly, does the small-cell vogue hold any promise here?
Thanks in advance,
I have numbered my answers based on how I encountered your questions while reading. I hope this makes sense.
1) SHB larvae can crawl out the colony entrance and can exit through the screened bottom board to access the soil.
2) You would have to have quite a large mesh size to ensure the larvae would fall through it while dropping. The mesh we use for Varroa control is not big enough. That said, the larvae will crawl through a screened bottom board once they hit it. So, they will get to the sticky trays themselves. Sticky traps have not been that great for use against SHB. The larvae are pretty good at crawling through various sticky substances.
3) Many people have tried various traps to capture larvae crawling out of the colony entrance or going through the screened bottom. In fact, the latter is what the West Beetle Trap is constructed to accomplish (i.e, the larvae are captured in a tray underneath the screened bottom board). My team and I have looked recently at a trap placed at the colony entrance.
4) They can navigate a robbing screen.
5) The adults can fly directly into the hive, though they usually land on the hive and walk into it.
6) Guard bees often challenge them, but not always. Nevertheless, SHB seem to have little problem getting into a hive.
7) People have worked on diversion traps, but most are somewhat complicated, cumbersome, and likely expensive to employ.
8) The use of small cells is not known to have any impact on SHB (or anything else for that matter).
For SHB control, I recommend trapping adult beetles (using a trap like the Better Beetle Blasters or something similar) and keeping strong colonies otherwise. Also, there are some really good SHB resources here: https://bee-health.extension.org/managing-small-hive-beetles/ (Google “eXtension bee health” and then look for information on small hive beetles) and here: https://entnemdept.ifas.ufl.edu/honey-bee/beekeeper-resources/pest-and-disease-resources/small-hive-beetles/ (Google “University of Florida small hive beetle”).
Q How Should I Treat?
You won’t remember, but you know me from several conversations at your Davie, Florida Bee College. I think you concluded your talk by stating: “If you don’t treat, mites will kill your bees.” Well I’m there.
Cutting to the chase, I’ve been able to stay ahead of the dirty little “spiders” by splits and brood breaks; until I didn’t. I now have hives exhibiting counts in the 90s and I expect them to crash soon. So what to do?
My first instinct is to remove all the brood, cover the bees with confectioner’s sugar and treat with oxalic acid. Would you suggest something more conventional? If so, which of the available poisons would you suggest for this part of the world?
Thank you for taking the time?
Conventional wisdom would suggest removing brood and treating with OA or something with good documented efficacy. However, you can leave the brood and treat with Apivar or remove the brood and treat with Apivar. The latter will be more effective, but it is also harder on the colony. If the counts are that high, it may be hard to fix. How are the colonies looking now? Are they very weak? Or, are they strong, but with lots of mites? If the former, it might be hard to rescue them. If the latter, a less drastic approach (i.e., without removing brood, but with using Apivar) might help. Powdered sugar is not really going to help that much (OK, not really at all).
Also, have a look at: https://honeybeehealthcoalition.org/varroa/ (Google “honey bee health coalition Varroa”). This is a wonderful resource on Varroa management. In fact, I consider it the best resource on Varroa control available. It is really important to be very proactive against Varroa. In my opinion, many beekeepers do not take Varroa seriously. These mites are incredibly bad for honey bees and their control should be one of the cornerstones of every beekeeper’s operation.
Of the big colonies (20 frames) I have one looking like it’s on the way out with lots of bees and little brood (probably queenless and maybe workers making drones). Others aren’t showing outward signs of disease while others still remain untested. I have already started reducing the space in some, choosing the best 10 frames. My nucs are doing much better (still in the 3-5% range).
I will try the Amitraz as you suggested. I suppose I should treat all the hives in this yard?
You should treat them all if it seems to be an apiary-wide problem (which it likely is). Please do have a look at the Honey Bee Health Coalition guide. It is a great resource.
Q Eucalypts, and Frame Sizes
I have a couple of very simple questions that, no doubt, Dr. Google could tell me but your answers will probably be more complete.
I am an Australian (by choice) living in Western Australia. Most of our honey is produced from Eucalypts which are native to this country. I have noticed, recently, mention of this family of trees in California and elsewhere.
My questions are: Are they n….