How to Check a Newly Purchased Hive for Varroa

Buying bees without checking for varroa is like buying a used car without checking the tires. The seller may have told you the mite levels are fine. They may genuinely believe that. But until you count for yourself, you do not actually know. This matters because a newly purchased hive with high mite levels will decline quickly, fail before you realize what is happening, and in the meantime spread mites to any other colonies you have.

Why Sellers Cannot Always Guarantee Mite Levels

Package bees originate from large-scale production operations in the southern US. The packages are produced quickly during spring buildup, and mite monitoring of every individual package before sale is not standard practice. A package may carry a meaningful number of mites that were present on the original colony.

Nucleus colonies (nucs) come from established colonies and are more likely to have accurate mite histories if the seller is running a serious varroa management program. But "serious varroa management" is not uniform across the industry. Some nuc producers monitor regularly and treat consistently. Others treat rarely or only when they see visible symptoms.

Established hives bought from another beekeeper carry the most uncertainty. You are getting the mite history of that colony, whether or not the seller accurately knows what that history is.

The only way to know where your newly purchased bees actually stand is to count the mites yourself.

When to Count After Purchase

For package bees: Wait 4 to 5 weeks after installation before the first count. The queen in a package begins laying within a few days of release. You need at least one round of brood development before you have a meaningful nurse bee population to sample. Mite counts done immediately after package installation, when there is no capped brood, reflect only phoretic mites and will be artificially low.

For nucleus colonies: Count within the first week of receipt. A nuc already has established brood and a nurse bee population. An alcohol wash can be done as soon as the colony is settled, ideally the day you receive it or within the first 48 hours.

For established hives: Count the day you take possession. An established hive with brood present can be sampled immediately. Do not wait.

How to Conduct the Alcohol Wash

Collect 100 bees from a brood frame (not a honey frame or the outside of the cluster). Nurse bees near capped brood carry more mites than foragers. Use a half-pint mason jar with a screen mesh lid, or a purpose-made mite wash device.

Add 70% isopropyl alcohol to cover the bees completely. Seal the container and shake for 30 to 60 seconds. Pour the wash through the screen over a white plate or tray. Discard the bees (they do not survive the wash). Count the brown oval-shaped mites that washed off into the liquid on the plate.

Divide the number of mites by 100 and express as a percentage. Three mites in 100 bees is a 3% infestation rate.

Interpreting Your Results

• Below 1%: Low. Monitor on a regular schedule. No immediate treatment needed.
• 1 to 2%: Moderate. Monitor closely. Treat before the season progresses.
• Above 2%: High. Treat now, regardless of whether you have just installed the bees.

If you find a high count in a newly installed package, contact the seller. Some sellers will provide replacement bees or partial refunds for packages with demonstrably high mite levels. Whether or not you pursue that, treat the colony regardless of the commercial resolution.

Treatment After a High Purchase Count

The treatment you choose for a newly installed package depends on whether brood is present. A package that has been installed for less than 2 weeks has minimal or no capped brood. OAV is highly effective in this quasi-broodless state. Apply one to three OAV treatments over 15 days, then monitor again.

For a nuc or established hive with full brood, Apivar strips are the most straightforward option. Apply immediately in the brood area and leave for the labeled duration. This is not ideal timing from a honey production perspective, but protecting the colony's survival takes priority over early honey harvest from a new acquisition.

Starting a Record From Day One

The mite count you do at acquisition is the founding data point for this colony's record. Log it in VarroaVault with the acquisition date, source (package, nuc, established hive, swarm), and seller if relevant. Any treatment applied after the initial count becomes the first entry in the treatment log.

Starting a clean record from the day you receive the bees gives you a complete longitudinal history of the colony. One year in, that history tells you whether this hive is a problem colony that always runs high counts or a reliable performer that stays clean between treatments. That information guides requeening decisions, placement decisions, and how much attention to allocate to the hive relative to others in your operation.