Formic Pro: single-strip 10-day dosing vs the full 2-strip hit — heat ceiling and queen risk
Perthshire, 9 hives, mite loads creeping to where I want formic on before the heather. Deciding between the two label options for Formic Pro: both strips at once for 14 days, or one strip for 10 days then the second strip for another 10.
What I understand so far: the temperature window matters a lot — label says apply when daytime highs are between about 10 and 29.5C, and the first 3 days are when most of the vapor releases, so a heat spike early is the danger window. Queen losses and brood kill seem mostly tied to the 2-strip dose in warm weather.
Scottish "heat" rarely troubles 29.5C, so in theory I could do either. But I've heard the staggered single-strip method is meaningfully gentler on the queen for only slightly slower knockdown. Those of you who've run both — real-world queen losses? Is the 2-strip hit worth it when I'm not in a rush?
#formic-pro#varroa#treatment-timing#queen-loss
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4 replies
ImkerinLena · Jul 18, 2026
Our association tracked this informally over three seasons: queen problems (loss or a 2-3 week laying pause) in roughly 1 of 10 colonies with the full double dose in warm weather, versus almost none with the staggered single strips when temperatures stayed moderate. The double dose earns its risk when you need mites down FAST — visible DWV, pre-winter panic. You are pre-heather with moderate loads and a cool climate. Stagger it.
TexasBeeSam · Jul 18, 2026
I'll be the cautionary tale: ran the 2-strip dose two Junes ago with a forecast high of 28C, got an unforecast 33C day two, and lost 2 queens out of 8 plus a stripe of cooked brood in most hives. It kills mites under the cappings like nothing else, but respect that ceiling — check the ACTUAL forecast for the first 3 days, not the average. Your Scottish summer is honestly the ideal formic climate and I'm jealous.
MendozaMiel · Jul 19, 2026
Southern-hemisphere footnote: it's winter in Mendoza so my formic season is months away — this is my oxalic window, broodless colonies, dribble done last week. But when I do run formic in our hot spring, staggered single strips only. The double dose and 30C+ afternoons is a combination I tried exactly once.
PerthshireBees · Jul 19, 2026
Consensus is clear then — staggered strips it is, going on Monday with a boring 19C forecast. ImkerinLena, that 1-in-10 figure matches the horror stories at our association meetings almost exactly. Will do a wash 3 weeks after to check knockdown.