How do I control sucking ... - Ask Extension
How do I control sucking insects on petunias? The eggs look like narrow.white,cottony threads and little white dots on stems and leaves. My plants ar...
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How do I control sucking ... #150457
Asked September 01, 2013, 1:33 PM EDT
How do I control sucking insects on petunias? The eggs look like narrow.white,cottony threads and little white dots on stems and leaves. My plants are infested with them. I water them almost daily and have used a product called Eight on them. However, I don't seem to be making any progress. Many thanks for your help! Donna
Ramsey County Minnesota
Expert Response
We don't know of any sucking insects that exactly match those you have described. Until we know what they are, we can't recommend ways to control them.
Aphids are the sucking insects most likely to affect petunias. If they are present, the "little white dots" might be their shed skins. Although aphids are tiny, if they are present, you should be able to see them moving slowly on the stems or leaves. If the insecticide has been effective, it's possible the aphids will be gone even though the shed skins remain. Aphids sometimes remain on the plants for a while after they are killed. Lack of movement indicates they are dead.
Living aphids and shed skins:
http://agents.cirad.fr/pjjimg/<personal data hidden>/puc_1.jpg
Wooly aphids have a cotton-like appearance:
http://www4.uwm.edu/fieldstation/naturalhistory/bugoftheweek/images/homopterans4_250.jpg
Lacewing eggs vaguely resemble what you have described. Lacewings eat other insects, including aphids, and should not be disturbed. They do not damage plants.
http://www.fcps.edu/islandcreekes/ecology/Insects/Green%20Lacewing/33chrysopid-eggs.jpg
If aphids are present, but the insecticide has been ineffective, try another of the control methods mentioned in this bulletin:
Aphids in Home Gardens
http://www1.extension.umn.edu/garden/insects/find/aphids-in-home-gardens/
If none of what we have discussed fits what you are seeing on the petunias, please reply to this message with sharp close-up photos attached.
Aphids are the sucking insects most likely to affect petunias. If they are present, the "little white dots" might be their shed skins. Although aphids are tiny, if they are present, you should be able to see them moving slowly on the stems or leaves. If the insecticide has been effective, it's possible the aphids will be gone even though the shed skins remain. Aphids sometimes remain on the plants for a while after they are killed. Lack of movement indicates they are dead.
Living aphids and shed skins:
http://agents.cirad.fr/pjjimg/<personal data hidden>/puc_1.jpg
Wooly aphids have a cotton-like appearance:
http://www4.uwm.edu/fieldstation/naturalhistory/bugoftheweek/images/homopterans4_250.jpg
Lacewing eggs vaguely resemble what you have described. Lacewings eat other insects, including aphids, and should not be disturbed. They do not damage plants.
http://www.fcps.edu/islandcreekes/ecology/Insects/Green%20Lacewing/33chrysopid-eggs.jpg
If aphids are present, but the insecticide has been ineffective, try another of the control methods mentioned in this bulletin:
Aphids in Home Gardens
http://www1.extension.umn.edu/garden/insects/find/aphids-in-home-gardens/
If none of what we have discussed fits what you are seeing on the petunias, please reply to this message with sharp close-up photos attached.
