The Hows and Whys of Sticky Boarding

Screened bottom boards are a popular option with beekeepers looking to improve hive ventilation, but there’s more to this useful hive component than ventilation alone: Inspecting the debris that filters through and lands on sticky board can help diagnose hive issues and let you know if your bees are on the right track. Explore this guide to learn how to use screened bottom boards for sticky boarding.

What is sticky boarding?

Before anyone was thinking about their ventilation properties, screened bottom boards were promoted as a method of controlling varroa mites. Early on, it was noted that mites that fall off (or are perhaps groomed off) the bees are sometimes able to jump onto a new host. Although they cannot fly or travel long distances on their own, mites are agile enough to swap one bee for another.

The idea behind using screened bottom boards was to separate the fallen mites from the space where the bees are moving about, holding them safely away from the bees. And thus, the sticky board, or mite tray, was born. Early versions of the boards used all kinds of goopy stuff to immobilize the mites, from petroleum jelly to vegetable shortening to specialized glues.

Unfortunately, as a mite control method, sticky boards turned out to be mostly a bust. There are simply not enough mites falling off the bees to make screened boards and mite trays effective for controlling the total mite population. If only it was that easy!

Sticky boarding for mite monitoring

Eventually, mite trapping evolved into using sticky boards for mite monitoring: Using a sticky surface to catch and collect all the mites that drop over a 72-hour period provides a low-effort way to assess a colony's overall mite population. It's an excellent starting point for beginning beekeepers who understand how important regular mite monitoring is, but are not yet confident in their bee handling skills to try some of the more involved tests. And of course, during cold weather, sticky boards are the only way to assess mite levels, since you can’t open your hive for direct sampling.

Other ways to use sticky boards

Simply counting the hapless mites that tumble down is not all you can do with sticky boards. Much of the hive's waste falls down through the screen, and looking through it will give you new insight into what's happening upstairs in the bees' living quarters. Like a detective sorting through a suspect's garbage can, it's amazing what you can deduce from trash.

When to examine sticky boards

Winter is a fine time to begin studying the board, especially when counting mites. You’ll be less pressed for time, and the smaller bee population reduces the total amount of junk on the board.

Sticky board checks are usually done over at least three days, which provides a more representative average daily mite fall. It can be done over five or six days, but in a bustling summer hive there is simply too much going on, and the large volume of debris would obscure the mites. Winter sticky boards have far less falling on them, and can be left in for a week or more and still be perfectly "readable."

What you may spot on your bottom board

A hand lens or a pocket microscope helps you identify what’s on the bottom board. There hasn't been much scientific attention to the debris on sticky boards, so there's a good opportunity for a curious-minded beekeeper to pioneer the identification of the components of the hive's trash. Here’s an overview of what you might see, what it means if you find it, and what to do if you spot a problem.

General debris

The first thing you'll notice are the stripes of the debris pattern. Each stripe corresponds to the space, or "seam" between the frames overhead, so they tell you where and how large the cluster of bees is. Over time during the winter, the location of the stripes will migrate and gradually expand as the bees' spring build-up gathers steam. A good way to make a record of the pattern on the board is to snap a picture each time you peek, which allows you to compare the boards in a sequential fashion.

Mites

When you first pull the board out, count the mites. If you have done a good job of mite control in the late summer, fall, and early broodless period, you may be gratified to find very few of them. If you have recently treated with oxalic acid, you may find an alarming flush of dead mites — but this is not representative of the natural daily mite fall.

Wax scales

Wax scales are particularly fascinating: Worker bees have eight glands on the underside of their abdomen (two rows of four) that secrete wax flakes in small, oval, usually concave scales. If you hold a sticky board in the sun and tilt it just right, these flakes will sparkle and catch your eye, even though they are nearly transparent.

Young worker bees in the 8th through the 12th days of their lives are the most prolific wax secretors. Older bees sometimes revert back to wax making, if the colony really needs that capacity, but the appearance of these flakes on a sticky board probably indicates a small, but growing population of newly maturing bees whose bodies are making wax right on schedule.

In the winter, there isn't much need for comb-making so the new wax flakes may be more likely to fall to the bottom as a form of hive waste. This is a hopeful sign of the coming spring and summer, and a promise that all is proceeding normally in the hive above. It's unusual to see the flakes in the late fall and early winter. During the warmer months, the demand for new comb and honey capping sucks up as much wax as the bees can generate, so seeing the flakes then is less common too.

Wax bits and bigger pieces

The very fine, brown, granular particles are bits of wax where cappings over honey cells were briefly pierced to allow a small amount to be consumed. The darker the wax, the older it is. The bees must be able to seal up these tiny punctures to keep honey from leaking out.

Larger, irregular crumbs of wax may indicate a history of smash and grab robbing. This is frequently seen when a hive that appears to be very active on warm winter days, unexpectedly turns out to be a deadout. The activity seen was just robbers removing what they could snatch. 

Large chunks of wax may indicate a mouse is, or was, living in the colony. Keep a sharp eye out for evidence of mice droppings and bits of grass, and if confirmed, choose a warm day and separate the boxes to find and remove the mouse — then add a mouse guard.

Pollen

Since adult wintering bees live almost exclusively on honey, evidence that pollen cells are being opened indicates that nurse bees are in search of the proteins and fats contained in pollen in order to manufacture brood food for larvae. And that is presumptive proof that you have a live, laying queen in the cluster above!

Various bee parts

You may see parts of bees on your bottom board. While seeing bee parts is common, the parts you spot may reveal important information about the health of the colony.

• Finding bee legs is very common. These were separated from the dead bodies of bees that may be sitting just on top of the screen. They do not necessarily indicate an urgent problem, since there is an inevitable pile-up of corpses when the undertaker bees don't want to fly out during very cold weather.
• Finding many headless bee bodies usually indicates a shrew has been able to get into the hive. Unlike mice (who are just looking for a warm home with some honey to eat) shrews are bee and brood predators with especially voracious appetites.

This video provides an example of what you may see on your sticky boards — what can you see?

How to clean a sticky bottom board

When you've looked over the board carefully, it’s time to clean and replace the screened board. Follow these easy steps to clean off debris and prep your bottom board for further use:

1. Scrape the debris off onto the ground. In the warmer months, scrape debris into the trash, instead, to prevent small hive beetle larvae from reaching the soil to pupate.
2. Open the front entrance of the hive and clean off the upper surface of the screen using a flat stick, bent metal crook, or a Bee Smart Bottom Board Cleaner.
3. Re-oil your sticky board using petroleum jelly, olive oil, or other sticky substance, and insert it in the slot.
4. Close the slot off — we like to use blue painters' tape.

Come back in a week or so, pull the board again, and read the latest story of what's happening in the hive. There’s always something to learn about your hives, and practice makes spotting the differences and changes even easier. Explore our Beekeeping Guide for more tips and information.

Wax flakes collected on a winter sticky board