These little buggers (no pun intended...really) appear so fast! Y'all know I'm in my garden every day! Yet in just one overnight, look what a caterpillar did to my just-emerging-squash-seedling:
And here is the little culprit...and let's just say he didn't make it home for dinner tonight...
Something is eating my hibiscus flowers (likely a big fat caterpillar that I can't find!)
and the thrips are attacking my roses
Needless to say, I'm not happy; but I'm also not surprised. "Battling the bugs" is an ongoing challenge for home gardeners.
When I discover insect damage to my plants, I first try to decide what type of pest caused the damage. Insect damage can usually be identified in one of four primary categories:
1. Injury by chewing leaves, flowers and stems--usually caused by beetles, caterpillars, doodle bugs, snails and grasshoppers.
2. Injury by piercing and sucking plant juices--usually caused by aphids, leaf-hoppers, sharpshooters, mealybugs, mites and scale.
3. Injury by booring and feeding inside the plant--usually caused by bugs like squash vine borers (these little suckers decimated my butternut squash crop this past fall).
4. Injury by feeding on the roots--usually grubworms.
It's taken me time and research to begin to figure out what insects cause what damage, but I have a couple of good reference manuals and an online site that I refer to constantly. The online site is my favorite. It's maintained by the Texas A&M Department of Entomology and it's a great reference for identifying pests that plague us in this part of the country: Plant Pest Identification Aid.
Most agricultural extension services or local universities have a similar aid to identify and help eliminate garden pests. Or you can gather samples of the insects and/or the damage done to your plants and take them to a local nursery and they can usually assist in identifying the problem and the best solution.
OK, so I've noted the damage and identified the likely culprit...now what? Since I try really hard to maintain an organic garden, I try and use only natural/organic insecticides that have very low toxicity to humans and have a low environmental impact. My favorite is Neem Oil
Neem oil and extracts are derived from the seed kernel of the neem tree fruit, which contain a complex mixture of biologically active compounds. The neem tree is a tropical native to Southeast Asia and grows in many countries throughout the world. It is a close relative of the Chinaberry tree, a tree very common in these parts of Texas.
Neem oil and extracts can act as both an insecticide and a fungicide (double bang for the buck). Spraying neem products onto plant leaves kill a wide range of insects and pests. They work particularly well on soft-bodied insects like aphids, caterpillars, mites, thrips and whiteflies. Neem is not a quick "knockdown" insecticide; it breaks down quickly in sunlight and washes away with irrigation or rain. It must be applied often for best effectiveness. Although it is harmless to humans, pets should be kept away from the treated area until the leaves dry.
When used as a fungicide, neem is applied as a preventative measure or when disease is just beginning to appear. It's effective against blight, leaf spot, mildew, rot, rust, scale and scab. Two years ago I had a real problem with scale on my lemon tree and although it took time, persistence and elbow grease, I used high pressure water spray and neem oil to effectively and completely get rid of the scale. I really like this product and I couldn't imagine gardening without it. But as with any insecticide, always read and follow the label directions carefully.
I add 1 tablespoon of neem oil concentrate to 1/2 gallon of water in a spray bottle and simply saturate the infected areas of my plants. It's best to do this in the early morning hours and do not spray when the bees are actively pollinating your plants. Wait until they leave your garden or apply the mixture in the evening when the bees are usually not active.
Another non-toxic but effective pesticide I often go to is an insecticidal soap, which is just sodium or potassium salts combined with fatty acids. Insecticidal soap must come in direct contact with the insect and is no longer effective once it has dried. But is is one of the safest pesticides on the market and is quite effective when used regularly and properly.
Battling insects is a never ending struggle in the home garden. One must be diligent and very aware of exactly what is happening in the garden or in flower beds. I learned this a long time ago. A motto I try very hard to live by is "My garden's best friend is my shadow."