About a month ago Chile’s Agriculture and Livestock Service (SAG) found eight specimens of spotted wing Drosophila (SWD), also known as ‘Drosophila suzukii‘) in traps between Pucon and Villarica – an area well-known as a tourism hotspot and agricultural zone.
Since then the pest has spread rapidly. Late last week a SAG spokesperson confirmed with PBUK that 162 examples of the pest had been trapped in that same region, as well as a further 454 specimens in the Los Lagos region further south, predominantly between Puerto Varas and Puerto Octay.
To date the detections have been in traps associated with wild fruit collection areas, but in a statement the spokesperson said the pest’s presence was a “threat to the phytosanitary status of the country”.
“Of course, in this case, as the pest is present in the main buying countries for Chilean fresh fruit, it should not be a limitation to trade for quarantine reasons,” she said.
“Basically, at this moment we are in the diagnosis stage of verifying the real distribution of the insect in our territory. In parallel, public-private roundtables are being developed where representatives of SAG and more directly involved grower associations participate.
“In times like this it’s very important that growers are attentive and coordinate with SAG, whether it be through their grower associations or through another channel (like the service’s webpage), to get to know the results of the diagnostic efforts that SAG is doing in the country, while also being very attentive to allow SAG to enter to take fruit samples (if they are there) or set up pest traps.”
She said that given it was currently winter, a period when insect populations are in survival mode rather than reproducing, it would not be convenient to apply pesticides to control them.
“This is clearer if you consider that to date the pest has mainly been detected in wild vegetation areas or gardens not associated with commercial orchards,” she said.
“It has been considered, according to experience overseas, that cultural control measures are fundamental in orchards, emphasizing the management in terms of eliminating remaining fruit after the commercial harvest.”
Apart from being a potential hazard for blueberry growers, SWD is also known to affect stonefruit, including cherries, and other berries such as raspberries and blackberries.