Insect and Bug Guide: Aphids

APHIDS attack most garden vegetables.

Aphids are small, soft-bodied insects with piercing-sucking mouthparts. There are many different species, and color can vary from green to red, pink, or black. . Aphids remove plant sap and kill developing plant cells.

They also carry many diseases. Heavy infestations can cause leaf curl, yellowing, poor growth, and failure to set blooms. Aphids also excrete large amounts of undigested plant sap (honeydew). This sugary liquid builds up on leaves where it supports the growth of sooty mold fungi. Although sooty mold does not invade plant tissue, the black, crusty mat it produces on the surface of the leaf is unsightly and can reduce photosynthesis.

Host Plants

What do aphids love the most? The answer: depending upon the plant, there is an aphid that loves its. Let's take a look at the most common aphids and the plants they love to attack.

Green Peach Aphid

Green peach aphids feed on hundreds of different plants including:

potato
pepper
cabbage
spinach
asparagus
aster
dahlia
iris
verbena

They are commonly found on cabbage but do not cause serious damage. They are yellowish-green and have long cornicles. The eggs can live through the winter.

Cabbage Aphid

Cabbage aphids feed only on cruciferous plants like:

cabbage
kale
mustards
collards
brussels sprouts
bok choi
broccoli
radish
rutabaga
kohlrabi

They are green with a waxy covering that gives them a grayish-white appearance. They have short cornicles and feed on the underside of leaves in large clusters, in the center of cabbage heads or on the youngest leaves. Adults are present in both wingless and winged form. You are most likely to see wingless females that produce live young (nymphs).

Potato Aphid

These aphids commonly infest solanaceous crops:

potatoes,
tomatoes
peppers
eggplant
morning glory

Melon aphids

Melon aphids feed on a variety of plants, especially cucurbits such as:

watermelons
cucumbers
asparagus
pepper
eggplant
aster
hollyhock
lily

Brown ambrosia aphids

Brown ambrosia aphids are common on:

coneflower

sunflower

Orleander Aphid

Ladybug doing what she does best....eating Oleander aphids!

Oleander aphids feed on milkweed throughout the spring and summer but do not cause any damage to plants.They are 1/8 inch long, pear-shaped and bright yellow with black legs, long antennae and two black tail pipes at the end of the abdomen.

Damaged Caused By Aphids:

Aphids possess slender, needle-like mouths designed to extract sap from plants. They thrive in areas where they can feed on fresh, succulent growth such as unopened flower buds, the undersides of young leaves, and new stems, twigs, bark, and roots.

Often, their feeding goes unnoticed. However, if they have been particularly active or you have a large infestation causing a lot of feeding, you will see symptoms such as:

Twisted and curled leaves
Yellowing leaves
Stunted or dead shoots
Overall poor plant growth

Aphids can also carry many virus' from plant to plant. Common viruses they can transmit include the cucumber mosaic virus. This virus can affect the following crops:

squash
cucumber
pumpkin
melon
beans
spinach
tomato
lettuce
beets

Prevention and Management of Aphids

Biological Control: Lacewing lava eating an aphid

Biological Controls:

Lady bugs, Green Lacewings, parasitic wasps, assassin bugs, big eyed bugs, damsel bugs, hover flies, minute pirate bugs, Aphidius wasps, praying mantis, spiders.

Mechanical Controls:

Water spray from garden hose will dislodge concentrations of aphids
Yellow sticky trap with have pheromones that will attract aphids. Just remember, sticky traps get the good guys too!
Hand picking. Just admit it, hand picking and squishing is becoming your favorite way to mechanically control bugs!

Block access to susceptable plants by using a lightweight fabric row to cover the crop. These will need to be removed in time for pollination.

Cultural Controls:

Keep your plants healthy. With a complete soil food web in place, your plants will put out all kinds of pheromones that will keep the bugs away. Prevention is better than cure.
Keep the ground covered with mulch. This will help the ground stay moist.

Keeping the soil food web healthy and robust is our preferred cultural method of dealing all pests include aphids. We believe this to be a fundamental principle that serves as the foundation for successful plant growth and soil cultivation. Healthy soil, rich in organic matter, nutrients, and beneficial microorganisms, all contribute to the overall vitality of the plants that grow in it. When the soil is well-aerated and has good drainage, it allows roots to penetrate deeply, accessing water and nutrients more effectively. Since we have been dong this we have noticed the pressure from pests including aphids has reduced considerably or we have not found them in our garden at all.

Harnessing Beneficial Microorganisms for Aphid Resistant Gardens

When you think about it, a rainforest thrives without using chemicals or treatments for pests. It just handles things naturally, with decomposing pests taking care of the occasional sick plant. Microorganisms like bacteria and fungi form a protective barrier around plant roots, creating a microscopic layer that combats harmful pests such as aphids while strengthening the plants' natural defenses.

Prioritizing soil health is crucial for cultivating a resilient garden that can resist pest challenges. Healthy soil is rich in organic matter and teeming with beneficial microorganisms, which boost plant vitality. By enhancing your soil with beneficial biology, you support nature's defense force in protecting your plants and reducing their vulnerability to aphid pest damage.

Ultimately, by prioritizing soil health and fostering a diverse ecosystem filled with natural predators, and using a combination of other control mechanisms as necessary, you can create an environment where aphids are no longer a problem pest you need to deal with.

Happy Gardening!