We’ve had some wonderful weather. I can hear the clicking of cicadas building with each day. As a result the sun is warming the earth and as though on cue, seasonal changes are occurring.
Last night just on sunset I noticed the air filling with Diamondback Moths – Plutella xylostella. I’ve never really had a problem with them in our backyard. They are ever-present during the season but don’t cause too much damage to any plants. According to the Dept. Of Primary Industries and Regional Development website some individual moths can become naturally resistant to specific or even multiple insecticides.
For insecticides that are used frequently, any surviving Diamondback Moths can go on to breed, potentially passing on the trait of resistance to offspring. Continued use of the same insecticide can lead to populations of resistant moths building up in an area. In Western Australia, Victoria, NSW, Queensland and Tasmania, such populations currently exist for resistance to pyrethroid permethrin. Some populations with resistance to higher strength insecticides also exist.