- Author: Neil McRoberts
General outlook After a brief spike in temperatures over the last few days, with highs in the low to middle 80s F, a more unsettled and cooler pattern will return for the coming week, including a chance of localized rain showers on Saturday. Highs will likely be in the middle 70s F once Saturday's cooler front has passed through. Overall temperatures will be adequate for thrips development and we expect to see populations continue to develop.
Thrips/TSWV situation We are expecting generation 2 adults to peak in the next few days. If temperatures stay on track generation 3 will likely see its peak adult numbers in the first week of June. We have now had confirmed TSWV cases in the southern San Joaquin Valley and the Sacramento Valley, so this seems like a year when targeting generation 3 will give useful benefits. Generation 3 juveniles will be feeding and developing over the rest of May, so treatments applied in the second half of the month will have a chance to prevent infected adults from spreading the virus to new hosts. If you are considering investing in a thrips treatment this season, the second half of May appears to be a good time to make that treatment.
- Author: Lauren Fordyce
The multicolored Asian lady beetle, Harmonia axyridis, has a bad reputation. There is a common myth online that this lady beetle (ladybug) is invasive and aggressive, which can sometimes lead to people killing these beetles.
While this species of lady beetle was introduced to California from Asia in the 1990s to control aphid pests, it is not considered invasive. For an organism to be considered invasive it must be nonnative and cause harm to the environment, economy, or human health. Fortunately, the multicolored Asian lady beetle does not cause harm. Like many native lady beetle species, it feeds on pest insects like psyllids, scales, and especially aphids.
In the fall, multicolored Asian lady beetles can become a nuisance when they enter homes seeking shelter to overwinter. If you experience this problem, you can vacuum or sweep them up. Make sure windows, doors, and other openings to the outside are properly sealed to prevent the lady beetles and other insects from coming indoors. In the garden, adults may be attracted to ripening fruit when pest populations are low. In general, there is no need to control these lady beetles with pesticides.
Find out more about these predators and other beneficial insects in the UC IPM Natural Enemies Gallery.