Wednesday, May 20, 2009
Aphids the Overrated Pest
Behold, Aphids and all of their evil. Here we see them sucking the life force out of flower buds to some of the most heavenly smelling roses ever. While many gardeners will be quick to get the insecticide, leaving them there also has it's benefits.
When it comes to roses aphids can prevent the buds from flowering. Thankfully most plants produce way more flowers than they actually need. If you are angered at the fact you have aphids on your plants though now would be the time to act. Simply remove them with a cloth and go after the winged forms as much as possible. Stopping them now will help slow their communicative reproduction.
Another tricky issue is the presence of ants. Yes they are protecting the aphids which are harming the plant. But the aphids are only on the new growth which usually isn't very much of the plant for a given season. Some species of ants are actually providing a service to the plant by guarding the aphids. The older growth maybe free of aphids but not herbaceous insects. The presence of ants can help discourage grazing by such bugs, or at the very least the ants will be removing the eggs to these insects from the plant.
Even when ants are not around to protect the aphids they are still in danger. Here you see flower buds to a native honeysuckle loaded with aphids. But on the other side of the leaf are some ladybug eggs. When the eggs hatch the resulting grubs will feast on the aphids.
Even when ants are protecting the aphids they are not necessarily out of harm. Right under the leaf is a hoverfly larva. These are predators of aphids that somehow go undetected by the ants. In this case I believe the hoverfly larva was producing nectar itself from consuming all the sweet aphids. When the hoverfly reaches adulthood it turns into a colorful fly. Some mimic bees but all the same they're a beneficial pollinator.
These ants weren't doing a particularly good job of protecting them either. Not in the photo is a ladybug feasting on the aphids right next to some ants. And also under a leaf is another clutch of ladybug eggs.
In conclusion aphids never really pose any threat to the plant and the problem will usually fix itself.