April Varroa Monitoring: First Count of the New Season

Your first April mite count is not just a data point. It's a reset of your understanding of each colony after winter. Colonies that came through winter in good condition can still carry a surprising mite load if late-season treatment wasn't effective or if reinfestation occurred. An April count of 0.5% is not safe without follow-up: it can reach threshold by mid-May in a strong colony that's building rapidly.

VarroaVault sends your April count prompt when temperatures exceed 50 degrees Fahrenheit for 3 consecutive days at your location. That temperature trigger matters because it corresponds to when colonies are actively building brood and when an alcohol wash won't chill the colony into distress. A count done on a 38-degree April morning is both harder on the colony and less reliable because bee cluster behavior in cold conditions can lead to an inaccurate sample.

TL;DR

• April treatment decisions should be based on a current mite count, not calendar date alone
• Temperature constraints in April may limit which treatments are effective in your climate zone
• PHI timing for April treatments affects when honey supers can be added or must be removed
• Log a mite count before starting any April treatment to calculate efficacy post-treatment
• VarroaVault's treatment reminders for April account for regional temperature and flow calendars
• Recording April treatment dates creates the audit trail needed for state inspection compliance

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Reading an April Count Correctly

April counts require different interpretation than summer counts. The 2% active-season threshold is calibrated for a colony at full population. April colonies are coming out of winter with reduced populations, which means the math works differently.

A colony with 8,000 bees in April has far less dilution capacity than a colony with 40,000 bees in July. A 1% April count on a small colony represents a mite load that will compound more quickly than the same percentage in a large summer colony. Pay attention to colony size when you interpret April numbers.

The other April-specific factor is the timing of spring treatment decisions. Many beekeepers apply an oxalic acid dribble in late winter or early spring before brood begins. If you did this in February or March, your April count reflects your post-treatment starting point. If you didn't, your April count tells you where you're starting the season untreated.

When April Requires Immediate Treatment

Treat immediately in April if your count is:

• Above 2% on any colony, regardless of size
• Above 1% on a small or developing colony with rapid buildup
• Trending upward from a late-winter OA dribble that shows the dribble didn't fully work

For April treatment, OA vaporization is the most practical option when there's still limited brood. A single vaporization on a lightly brooded April colony achieves higher efficacy than the same treatment in July when brood area is at its maximum. If you're not sure whether there's brood, look: even small amounts of capped brood mean you'll need an extended vaporization protocol to catch mites emerging from cells.

Avoid Apivar in April unless you have a clear plan for strip removal before honey supers go on. With 42-56 days of required application time, April Apivar means strip removal in late May or early June. That's tight but workable if your honey flow doesn't start until June.

Building From Your April Count

Your April count is the starting point for your spring buildup mite checks calendar. Log it in your records with the date, sample size (aim for 300 bees), and method. If you're using VarroaVault for the first time this season, the April count prompt walks you through setting up your colony list and logging your first count in under 5 minutes.

Plan your May follow-up count when you log your April count. Even a 0.3% April count deserves a May recount because spring buildup can accelerate mite growth faster than expected. The first-year beekeeper varroa guide covers the April-May-June monitoring cadence in detail for beekeepers who are new to this process.

Frequently Asked Questions

When should I do my first April mite count?

Do your first April count as soon as your colony has 3+ frames of brood and temperatures reliably exceed 50F during the day. In most of the US, this is mid to late April, though it can be late March in zone 7 and warmer. Don't rush the count if temperatures are still borderline: a cold alcohol wash is harder on bees and provides a less reliable sample. VarroaVault triggers the April count reminder based on your location's temperature data, so you don't have to track the timing manually.

What April count level requires immediate action?

Treat immediately if your April count exceeds 2%. At 1-2%, treatment depends on colony size and trend: a small April colony at 1.5% may need treatment because the relative mite load is high for its population. Below 1% is generally safe to monitor, but schedule a May recount within 30 days. Even 0.5% in April can become 2%+ by late May in a colony building rapidly with lots of drone brood and warm temperatures. The rule is: low counts in April earn you more monitoring, not permission to relax until fall.

Does VarroaVault send an April monitoring reminder?

Yes. VarroaVault's April monitoring reminder fires based on your location's weather data, specifically when 3 consecutive days above 50F are forecast or recorded. This is more useful than a fixed calendar date because spring timing varies by 4-6 weeks between zone 4 and zone 8 climates. The reminder links directly to your colony list so you can log your April count immediately, and the app calculates your infestation rate automatically from the bees counted and mites found. After you log the count, VarroaVault sets your next reminder for 30 days out.

How do I know if my varroa treatment is working?

Run a mite count 2-4 weeks after the treatment ends and compare it to your pre-treatment count. The efficacy formula is: ((pre-count - post-count) / pre-count) x 100. A result above 90% indicates effective treatment. Results below 80% should trigger investigation for possible resistance, application error, or reinfestation. Log both counts in VarroaVault to track efficacy trends across treatment cycles.

How often should I check mite levels in my hives?

At minimum, once per month (every 3-4 weeks) during the active season. Increase to every 2 weeks when counts are near threshold or after a treatment to verify it worked. In fall, monitoring frequency matters most because the window to treat before winter bees are raised is narrow. VarroaVault's monitoring reminders can be set to your preferred interval for each apiary.

What records should I keep for varroa management?

Each record should include: date of count or treatment, hive identifier, monitoring method used, number of bees sampled, mites counted, infestation percentage, treatment product name and EPA registration number, dose applied, treatment start and end dates, and PHI end date. State apiarists typically expect this level of detail during inspections. VarroaVault captures all of these fields in a single log entry.

Sources

• American Beekeeping Federation (ABF)
• USDA ARS Bee Research Laboratory
• Honey Bee Health Coalition
• Penn State Extension Apiculture Program
• Project Apis m.

Get Started with VarroaVault

The information in this guide is most useful when you have your own mite count data to apply it to. VarroaVault stores every count, flags threshold crossings automatically, and builds the treatment history you need for state inspections and effective management decisions. Start your free trial at varroavault.com.