Hi Jean,

These look like aphids with many ghosts.  Aphids are soft bodied insects that are capable of multiplying rapidly. They grow by shedding their skin, which leaves a "ghost-like skeleton on the leaf.Aphids feed by sucking plant juices.  Aphids have a number of natural enemies that hold down population increases, especially lady bugs and parasitic wasps. A large number of aphid "ghosts" suggests that parasitic I insects are already at work to control the aphid population.  I would recommend spraying the plants with Water: The safest and fastest way to control aphids is to spray them off your plants with a strong stream of water from the garden hose. Aphids are easily knocked off plants and once they are knocked off a plant, they rarely climb back on.  Then monitor them about twice a week.  

Most gardens have some aphids. On healthy plants, they don't cause much harm, and beneficial insects, including ladybugs and parasitic wasps, keep them in check. Aphids can become more of a problem when the plants are stressed by drought, poor soil conditions, overwintering or overcrowding. Unfortunately, aphids can reproduce at amazing speed and a large colony that can literally suck the life out of your plants. The key to dealing with them is knowing when you need to take action, and then having the right tricks up your sleeve to keep them under control.  I would recommend using additional measures if the aphids persist after diligent spraying with water.

How to Identify Aphids: Often the first sign of an aphid infestation is twisted and curled leaves, yellowing foliage, stunted or dead shoots, and sluggish plant growth. Damage is usually most noticeable on shoot tips and new growth, along with unopened flower buds. When you take a closer look at these damaged plant parts, particularly on the undersides of young leaves and developing stems, you'll likely find lots of aphids crowded together.

Aphids range in color from green to yellow, brown, red, or even black. Aphids cause damage by sucking sap from tender plant parts. As they feast, they excrete a sugary substance called honeydew. A fungus called sooty mold grows on the honeydew and blocks light from your plant, but is otherwise harmless. You can wash your plant leaves with water to get rid of the honeydew and sooty mold.

How to Get Rid of Aphids: When an aphid population explodes and begins to cause noticeable damage to leaves, stems, and buds, it's time to act right away. The sooner you can deal with the infestation, the better chance you have of eliminating or controlling the aphids.

Spray with Water: The safest and fastest way to control aphids is to spray them off your plants with a strong stream of water from the garden hose. Aphids are easily knocked off plants and once they are knocked off a plant, they rarely climb back on.

Insecticidal Soaps and Horticultural Oils: These controls are low-risk to people and the environment and can be applied to food crops. They'll kill aphids, but must be applied on a regular basis during heavy infestations, since aphids reproduce so quickly. Insecticidal soaps and horticultural oils only kill aphids when they come in direct contact, so you'll need to spray both tops and undersides of leaves and reapply frequently until the pests are completely gone. Keep in mind that insecticidal soaps and horticultural oil will kill beneficial insects as well, so only apply it to target pests.

Crush Aphids with Your Fingers: If the infestation isn't too heavy, you can squash aphids by gently rubbing your thumb and fingertips over your plants' leaves and stems wherever you see aphids. Check back every few days to see if you need to repeat the procedure.

How to Prevent Aphids: Preventing large numbers of aphids from making themselves at home is possible. In addition to making sure your plants have the water, light, and nutrients they need, here are a few more ways to help keep aphid numbers down. Remove dead stems and weeds from around the plants. You can cover plants with a barrier to insects (like cheese cloth or row covers). You can also grow certain plants nearby to attract beneficial insects like lady bugs which eat aphids (plants like marigolds,calendula, sunflower, daisy, alyssum, or dill).

For more information about aphids and treatment I would refer you to two excellent reviews available on the web: one from the University of California and the other from Louisania State University.

http://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html

www.lsu.edu%2Fdepartments%2Fentomology%2Fassets%2Faphidparasitoids.pdf&psig=AOvVaw2f_F_9v7U87MSX7mf0kjh0&ust=<personal data hidden>41503" class="redactor-autoparser-object">https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=0CAQQw7AJahcKEwjog-bjgsP-AhUAAAAAHQAAAAAQAg&url=https%3A%2F%2F<a href="

"><a href="http://www.lsu.edu%2Fdepartments%2Fentomology%2Fassets%2Faphidparasitoids.pdf&psig=AOvVaw2f_F_9v7U87MSX7mf0kjh0&ust=<personal data hidden>41503www.lsu.edu%2Fdepartments%2Fentomology%2Fassets%2Faphidparasitoids.pdf&psig=AOvVaw2f_F_9v7U87MSX7mf0kjh0&ust=<personal data hidden>41503</p&gt;

If you have any further questions, please feel free to contact me.

Bob