A Beekeeping Sensor Deep Inside a Flow Hive Detected the Death of the Queen

Hi, I have been using Flow Hives for many years and have a company that makes sensors. We recently detected a Queenless hive and saw the normal brood temperature drop. Here is the article where I wrote about it. I hope the information is useful.


Greg, did the Queen have a reaction to smoke or to the temperature drop? Do you believe that you could have prevented the queen from dying?

Thanks for the question.
I am unsure what became of the queen; the temperature drop came because the hive stopped maintaining a constant temperature for the brood. When we opened the hive up for inspection, we found no new eggs or larvae in the hive.
The recent fires in the area may have contributed, we have had heavy smoke in the past and this never caused an issue with a queen.

I used to use an Arnia hive monitor with a brood temperature probe. The temperature would also drop if the queen stopped laying for normal seasonal reasons, or if the brood nest moved a bit within the boxes (I run double deeps). Yes, it can be helpful, but it doesn’t always mean that she is dead.


Good points, thanks - I am going to add another sensor so I will have one in each box and in the roof of the hive to give me a good indication of the status

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Hi Greg,
Thanks for the info. I’ve been beekeeping for 7 yrs, still consider myself as being a newbie. I live in MA and I’ve experienced 2 springs in a row that have had abrupt freezes. Both freezes happened during the 3rd week in March 2021 and 2022. The day temps were mid-60’s and plunged down to 20 degrees after mid-night. I want to see what the temps were in the hive along with the humidity during the winter and early spring. The price of the NEO-1DP temp and humidity sensor with data logging is reasonable. Does one have to subscribe to a data app for the data logging feature?

Hi AL,

You just need to create an account to be able to use the logging functions. You can register in the App or directly on the website. https://cloud.imatrixsys.com/

Let me know if you have any other questions


Thx, I will go on the website.

Hi @greg.tahoe,

I setup bee hive monitoring using an ESP32 over 2.4ghz WiFi, with 3 Dallas DS18B20 probes and one BME280, in a Colorado Top Bar hive that had 22 frames max, 14 frames used. The BME was at hive center (7 frames in), in burlap, and the Dallas probes were hive front (2 frames in), back (12 frames in), and roof center (7 frames in and sealed from lower compartment).

Sadly I saw the temperature drop drastically at BME twice during a 10 day long 20F night time cold spell and the colony died. First time it dropped to 75F for one night, rebounded to 90F, and second time down to 55F, for three days, which never recovered.

My logs were in 1 min intervals, and then uploaded using WiFi every15 mins, which showed drastic temperature collapse.

Did you see rapid temperature collapse between sensors?
Do you think 2.4Ghz WiFi or Bluetooth frequencies are detrimental to colony health?

Hi Tinker,

Thanks for the follow-up. The sensors were pretty consistent between them.
We use Sensiron Temp/Humidity sensors; some are sealed, so we just take the temperature from those. These are connected to Bluetooth controllers that log the data, and then they advertise to the Gateway when they want to check-in. The Gateway then connects and pulls the logged data over GATT. We can change the polling/sampling and check-in times from the Cloud. The Gateway updates the BLE devices when they check in. The Gateway supports 2.4 & 5GHz Wi-Fi. Gateways can support 128 devices in a single scan cycle and rotates this list if there are hundreds of BLE devices.
I am not worried about the 2.4GHz signals and colony health.
I have used hive blankets around my hives here in the winter. We don’t usually see that long of a period of 20F temps here, maybe just for a day or two.

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Greg , Would love to know how you setup the probes and how the rest of us could utilize this?

Hi ZooBee,

The probes have a 1m/~3ft cable, and the probe is fully sealed. I mounted the probe in the middle of the super and ran the cable outside, where I mounted the sensor controller. In some Flow Hives, I mounted the controller in the roof of the hive, and in others, I cut a small bit of the super side away so the cable could come out the side between the supers.

Also look at Model H5179 on a search with Amazon.