Last week’s column discussed those unpleasant and damaging grubs, the larval stage of the Junebug. As grubs feed on root systems of garden plants and turfgrass they are destructive and can cause serious damage to lawns and crop plants when left unchecked.
Symptoms of grub infestations in turfgrass are large brown, spongy patches of dead or dying grass. Birds expose serious infestations as they scratch the soil of gardens and lawns as they hunt the grubs.
Affected areas can be treated with commercial products lethal to the grub. Timely applications of chemicals can be highly effective when following the manufacturer’s instructions. The downside to chemical treatments is that most are broad spectrum, killing a broad range of pests, beneficial as well as targeted harmful pests.
A biological remedy is to take advantage of a naturally-occurring predator, the beneficial nematode Heterorhabditis bacteriophora. This nematode is marketed by ARBICO under the name NemaSeek™ – Hb Beneficial Nematodes.
Nematodes are microscopic organisms belonging to the animal kingdom. Nematodes are sometimes called eelworms, but they are not a worm; they are eel-shaped and legless, with smooth, unsegmented bodies. The word nematode comes from Greek nema, meaning ‘thread’ and odes, meaning ‘like’. They are threadlike, miniscule organisms found in fresh and salt water and in soils throughout the world. Many are harmful to plants and animals; others are beneficial, parasitizing larval or pupal stages of soil-dwelling insect pests. They have a wide range of prey that makes them exceptional for general pest control in chemical-free growing environments.
The parasitizing mode of action is not for the squeamish reader. The nematode enters larva via openings in larva body or directly through the body wall. Once inside the larva the nematode ejects bacteria into the larva cavity. Bacteria multiply, causing blood poisoning, resulting in death of the larva. Once the beneficial bacteria have been released inside the insect, insects die within 24 to 48 hours. Before death, nematodes use host tissue for nutrition, allowing nematodes to multiply. When their food source has been depleted, nematodes exit the larva and search for a new host.
Texas Spur reader Mary S. of Tijeras, N.M., wrote that she is a believer in beneficial nematodes as she has used them for several years with positive results.
Contact information for ARBICO: email arbico-organics.com, by phone (800) 827-2847.
- Log in or Subscribe to post comments.
