Swedish Cloth Strips - A Game Changer in the USA!

ADVERTORIAL: BEEQUIP NZ

By Russell Smith, managing director Beequip NZ

The Swedish cloth strips continue to impress us the more we trial them, and from the feedback received from many clients.

One such client is Mr. Sennett who runs 3500 hives in the USA states of Georgia and Maine. He has been using the Swedish cloth strips for four years as the main treatment for varroa. He says they give him 10 weeks of very good efficacy which corresponds with research trials done in New Zealand. His hive losses last winter were no different to usual and a big contrast to the high losses experienced by many other beekeepers in the USA. He occasionally uses some formic acid treatments but uses no synthetic miticide strips.

Swedish Cloth strips, new to New Zealand beekeeping and proving impressive in their results.

Each of the four cloth strips is soaked with 25 grams of 1:1 oxalic acid (OA)/glycerine solution and placed horizontally directly on top of the bottom brood box.

Mr. Greg Rogers, Beekeeper and researcher from North Carolina, USA, has conducted extensive field trials with the Swedish Cloth and states in his video with Bob Binnie that they are “A game Changing Treatment”.

Size Counts

A question for many beekeepers has been what size of Swedish cloth to use.

It was determined very early on that two half-size pads worked more effectively than a full-size pad. Mr Greg Rogers then conducted field trials to compare results between half-size pads and four strips.

For the full report, you can view his video here. From 11 minutes to 25 minutes shows how four strips are more effective than two half-size pads. A tip - Set the playback speed to 1.5 if short of time.

Summaries of the results are shown in figures 1 and 2.

Another trial was conducted in 2024 to see if the same results could be obtained with four strips as previously.

It was conducted over 90 days and not 75 days. There were just 2 hives out of 31 that had a mite count at the end of the trial over the economic threshold of 9.

One comment from Mr. Greg Rogers: “I can tell you what I saw going through the hives that have this treatment in them. Typically in August (in USA) you see some strong hives and some medium-strength hives and some weaker hives. Probably those hives are starting to run into virus problems. With this treatment, what I saw literally looked like the bees of 30 years ago.”

Making them Work in Singles

Mr Sennett said the four Swedish Cloth strips worked extremely well in his double brood box colonies but were not successful on long term varroa control in the single brood box colonies. He uses the Beequip cardboard strips as staples in his single brood box colonies. When asked why the cloth strips were not effective on the single brood colonies, he suggested it was because there wasn’t enough nurse bee travel on the strips.

We were concerned in New Zealand that the strips could get cold. No OAE (oxalic acid extended-release) strips work very well if they get below 30°C. They need to be at brood temperature.

In the face of this evidence, two commercial beekeepers in New Zealand used the strips on their single brood box hives right through the 2024-25 summer honey flow. They placed the strips horizontal over the single brood box, then added a rimmed queen excluder so there was a bee space. Then added lots of honey supers on top. Both beekeepers said they were very impressed with the results, and plan to repeat the process next season.

A bin with 50 freshly soaked Swedish Cloth strips, ready for packing and sealing into bags.

Regarding the 2 perceived issues:

Temperature

The process was used over summer in very strong colonies, so the strips stayed above 32°C.

The glycerine stayed liquid to keep bringing OA to the surface as it is used up.

Bee travel

The strips were used when the colonies had a peak population of bees with a huge amount of bee travel up and down in the hive, so the OA got very well distributed.

Important factors when choosing Swedish Cloth to use in beehives for OAE applications.

1.        To be made from just Cellulose and Cotton.

2.        To have no colour additives.

3.        To have no flame retardant additives.

4.        To have no plastic membranes or micro plastics.

5.        To be 100% biodegradable.

6.        To be approx. 200mm x 43mm x 2mm thick.

7.        To be supplied as dry strips, not premoistened.

Based on all the information available, the Swedish Cloth strips are an excellent product for summer OAE treatments and when the beehive has enough bee population to keep the strips warm above the brood nest and to spread the OA around the brood nest.

We conducted a trial over winter on one hive and were impressed with the results (see Fig 3) This is not a recommendation, but very interesting all the same.