SourwoodGrace · North Carolina, US · Pests & Disease · Aug 4, 2026

Apiguard vs Formic Pro when it's 33-35C every day — are the temperature limits real or cautious lawyering?

Third year in North Carolina, four hives, mite counts creeping up (6-9 per 300) and I need to pick a treatment. Our forecast is 33-35C for the foreseeable. Formic Pro says max 29.5C for the first three days. Apiguard says it works from 15C up but everything I read says thymol gets brutal on the bees at high temps too — evaporates too fast, bees beard like crazy, sometimes they chuck brood out. So which label do I trust less? Half the forum threads I find say 'I used formic at 33 and it was fine', the other half are queen-loss stories. Is there a real difference between the two in genuine heat, or am I choosing between two bad options and should look elsewhere entirely?

#formic-pro#apiguard#thymol#treatment#heat

▲ 13 votes 💬 4 replies

4 replies

muglabalci · Aug 4, 2026

Muğla summers are exactly this and I'll tell you what 15 years taught me: both labels are real. Formic above 30C kills brood and sometimes the queen — the 'it was fine' posts are survivorship. Thymol at 35C doesn't kill queens but the colony hates it: heavy bearding, brood pulled, and in a dearth the smell invites robbing. If you must use thymol in heat, half doses more often, and shade the hives. But honestly? Neither is my choice in that forecast.

CorkBeeRon · Aug 4, 2026

The formic limit is chemistry, not lawyering — vapour release rate scales with temperature, so at 34C you're delivering an overdose on day one. People get away with it when a cool front lands the same week. That's luck, not a method. If supers are off, amitraz strips don't care about temperature. If supers are on, wait for a 3-day cool window and then formic.

AlpineCarnica · Aug 5, 2026

Agree with both. One more angle: timing beats product choice. Watch your 10-day forecast like a hawk — most places get one dip under 29C even in a hot spell, and Formic Pro only needs the first 3 days cool-ish. If no window appears by mid-August, strips. What you cannot do at 6-9 per 300 is wait for September.

SourwoodGrace · Aug 5, 2026

This is exactly the reality check I needed. Supers come off this weekend anyway (dearth, they're not filling anything) so I think it's strips now, and I'll keep formic for spring when the weather cooperates. Thanks all.

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