Harbo Assay Counting Tray

 Knowing is half the battle! Proper genetic selection is essential to raising great queens. 

The Harbo Assay, developed from the work of Dr. John Harbo, evaluates a colony by examining naturally Varroa-infested capped worker brood. Individual pupae are removed from their cells and the mites inside are examined to determine whether the foundress mite has successfully reproduced. The assay focuses particularly on the proportion of non-reproductive versus reproductive mite families found in the sampled brood.

A high proportion of non-reproductive mites is evidence of Varroa Sensitive Hygiene (VSH)—the colony has preferentially detected and removed brood containing reproducing mites, leaving a greater proportion of cells containing mites that failed to reproduce. The Harbo Assay therefore provides breeders with a practical way to identify and select colonies expressing Varroa resistance. Unlike freeze-killed or pin-killed brood assays, it measures a response specifically associated with Varroa reproduction, rather than general hygienic behavior.

Full instructions can be found here: https://extension.psu.edu/varroa-mite-resistance-testing-for-varroa-sensitive-hygiene 

and here: https://www.lloydstbees.com/post/vsh-selection-and-breeding-in-a-northern-climate 

Do you need this tray to perform the assay? No. Will it make your life easier? Yes! It is compact and sturdy with good stability. It will keep your pupa count organized and on track. It was developed with the help of an expert queen breeder from Missouri who performs the Harbo Assay regularly as part of his breeding program.