Is it going to storm? Check for flying beetles

It’s a lot of work for one insect species, but the dung beetle aphodius distinctus is thought by some to be a weather forecaster as well as a manure handler.

H.L. Seamans of the Dominion Entomological Laboratory in Lethbridge studied flights of the dung beetle in the early 1920s. In a 1934 paper published in a report to the Quebec Society for the Protection of Plants, he noted a correlation between beetle flights and the weather that followed those flights.

“The first flight in the spring is usually followed by a cold period with snow, but this cold period is the last one before spring growing conditions arrive,” wrote Seamans.

“This cold period may be from one week to a month long, but it seldom is as severe cold as that previous to the flight. Only once has the minimum temperature dropped below zero after a spring flight of Aphodius, and that was in 1926 when there were two spring flights.”

Seamans also concluded that the autumn flight of the beetle immediately preceded the first snow or severe frost, suggesting Aphodius successfully forecast the true end of seasonal growing conditions.

“Gardeners and growers of root crops in the Lethbridge district are beginning to govern their activities by the beetle flights,” Seamans wrote.

Agriculture Canada entomologist Kevin Floate acknowledged the connection between beetle activity and weather, although he is not convinced that Aphodius is as reliable as Seamans suggested in his paper 80 years ago.

“It’s certainly true that these clouds (of flying dung beetles) occur in the late season,” said Floate, who has researched the species.

“When we get hard frost, the big flights stop. If it’s a light frost, they might be flying then but if you get a light one, you will get a hard frost shortly after.”

Seamans documented weather conditions and beetle flights over several years, as recorded with hand-drawn graphs within his paper. He concluded that beetle flights were important indicators of when to expect seasonal insect activity to begin or end.

He also noted that some southern Albertans ignored dung beetle activity to their detriment. One example occurred in the fall of 1930.

“The flight occurred in the midst of very warm weather and was ignored. One or two gardeners dug their gladioli bulbs before the snow, which arrived two days later.”

Unfortunately, many gardeners ignored the warning provided by Aphodius and its second flight, said Seamans.

“The result was that over 80 percent of the gladioli bulbs in Lethbridge were frozen by the cold period which followed and many tons of potatoes which were left too long were frozen in the ground.”


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