Nematodes & Caterpillars

Vampire Nematodes

• Nematodes are nearly invisible, thread-like animals with sharp, needle-like structures in their mouths that puncture plants to release the sap they crave. In heavy numbers, these tiny animals contribute to the decline of lawns and to the failure of vegetables to grow properly. Symptoms of nematode infection that you may see aboveground include yellowing and wilting of turfgrass and the stunted growth and thinning of plants. Underground infestations present symptoms such as root knot and swellings; laboratory testing may be required. Nematode damage can prevent grass and other plants from properly absorbing water and nutrients.

Banishing Nematodes from the Garden

• Use nematode-resistant plants in areas where infestation is common. Plants and seeds certified nematode-free are available from a variety of online sources and physical stores. Allow infested areas to remain fallow for several seasons, rotating garden vegetables and flowers to a new location. When rotating plants, make sure that possible infestations are far away from established cultivated areas. Follow a fallow season with proper tilling, and make sure that new seedlings are disease-free. Add organic matter to soil to improve its structure and health and reduce nematode populations.

The Very Hungry Caterpillar -- The Real Story

• Common caterpillars are creatures in the immature or larval stage of butterflies and moths. Several species of sawflies, which are non-stinging wasps, produce larvae sometimes mistaken for caterpillars. In the larval stage, these insects are active feeders, increasing size and weight at a rapid rate. As caterpillars grow, they feed voraciously, usually on plant leaves or tress. Caterpillar bodies are cylindrical and elongated, and typically have 10 segments. Body surfaces vary and may be smooth, hairy or have spine-like projections. They shed their exoskeletons anywhere from three to nine times, and at their final molt, caterpillars transform into non-feeding, tough pupae that transforms them into butterflies and moths. The adult forms of caterpillars that eat -- some don't in their short lives - benefit gardens by pollinating.

Control and Damage Mitigation

• Destruction from caterpillars takes several forms. Depending upon the species, some fold or roll leaves to make shelters. Others feed on leaves and may severely defoliate plants. A single caterpillar rarely causes significant problems, but severe infestations can weaken or kill healthy plants, trees or shrubs. Before taking action, try to identify the type of caterpillar invading your landscape before turning to pesticides, which should be used only as a last resort.

  Controls, at their simplest, include clipping and disposing of foliage infested with eggs. Be sure to disinfect pruning tools. You can do this with a household disinfectant. Hand pick caterpillars, and along with leaves or stems with eggs, drop into a bucket of soapy water. Alternatively, spraying water with a high-pressure hose will remove small caterpillars that less than 1 inch long. Or spray organic, insecticidal soap on the caterpillars to kill them without damaging your plants.