16th June 1947

Guernsey was invaded by Colorado beetles

The Colorado beetle can quickly destroy a tomato crop, so when they started turning up on the Channel Islands beaches in 1947, everyone was out to get them.

The following day, it was front-page news in the Daily Herald. “Hundreds of dead Colorado beetles have been washed ashore at Guernsey after falling exhausted into the sea on a 35-mile flight from France. Since May 1 seven Colorado beetles have been found on Channel boats.”

While many of those found on the boats may have fallen there, like the ones that had washed up, some were being discovered in produce exports.

Several had already been found in potato crops arriving at the mainland from Jersey. From the Coventry Evening Telegraph of 31 May, we learn that “landings [of potatoes from Jersey] ceased at noon owing to the finding of Colorado beetles in the island”. Authorities couldn’t risk the infestation spreading to mainland Britain – particularly not with the nation still subject to rationing in the early post-war years.

An ongoing problem

The infestation certainly wasn’t short-lived. On 3 July, the Dundee Evening Telegraph reported that 64 beetles had been found on Sark by an expedition sent from Guernsey.

As late as 23 August, the Cheltenham Chronicle reported,

the Colorado beetle… had been found in some numbers as near as the Channel Islands and I am informed that in the island of Jersey this pest was particularly troublesome, while on the beaches of Guernsey numbers of dead ones have been picked up by the children. These dead beetles have evidently migrated and been forced down on the sea.

Colorado beetle

The Colorado beetle is around 1cm long and 3mm wide. It is dark yellow, with 10 black stripes running along its back. It first became a problem in the 1850s when it earned itself a reputation for destroying potato crops in the American mid-west. Within 25 years it had covered almost the whole of the United States.

Two years later, it was first seen in Europe, likely having been brought over in vegetable imports. It underwent a population explosion in Europe in the years immediately following the second world war.