Sunday, February 12, 2006
The Aphids Are Coming! The Aphids Are . . .
Oops I blinked; they're already here, the squishy plant sucking bugs gardeners love to hate. These are a sampling of the aphids present in a garden in Tustin on a warm February day.
Here's a group of green peach aphids, myzus persicae, sucking the life out of this pelargonium leaf. This is the same plant featured in this post. A lot of aphid species specialize in one host plant; this one is more opportunistic and feeds on a wide range of your favorite garden plants.
Aphids always go for the tender new growth when colonizing a plant. Here is a fresh group, possibly melon aphids, aphis gosspii, on salvia clevelandii. Aphids produce many generations of offspring per year, some from fertilized eggs, some from unfertilized eggs, some by live birth. Some are winged. The winged individuals are able to fly to new plants to colonize them.
This rose aphid is unusual in that she (most aphids are shes . . . they reproduce most of the time asexually) is almost alone. You will most commonly see rose aphids shoulder to shoulder coating the first fat rose buds of spring. No worries, there's sure to be more of her kind when the roses do bud.
Oleander aphids (aphis nerii) also feed on milkweed as they are in this photo. Both of these plants have poisonous sap, which the aphids concentrate in their bodies as a deterrent to predation. They display the bright coloration typical of species that do this.
In a balanced environment, you can expect the predators to start showing up to cut down the aphid population just about the time you start to despair. If they don't, a very good way to reduce aphid infestatons on a smaller scale is to blast them off the plants with a stream of water.