Beating Pests with Plant Chemicals

Beating Pests with Plant Chemicals

It would seem that landscapes are filled with pests ready to devour our favorite plants. We can often see evidence of pest damage in the form of leaf curls, stippled leaves, or chewed holes in foliage. How do plants survive with all the pest threats without intervention from people?

Many plants have their own alert system to help manage a plant-feeding insect attack. When tissues are damaged by plant feeders, the plant releases volatile chemicals that serve as signals for many beneficial insects. Predators such as lady beetles, lacewings, and predatory bugs ‘pick up’ the chemical signals and fly to the injured plants to find their prey.

Ladybeetle larvae will eat many soft-bodied pests.

Ladybeetle larvae will eat many soft-bodied pests.

An interesting part of this occurrence is that the release of chemicals by one plant can stimulate other surrounding plants to build up their chemical defenses against future pest feeding.

The key lesson for all gardeners is that there are many natural processes going on without our knowledge. Instead of immediately applying a broad-spectrum insecticide at the earliest sign of pest feeding on a plant, give the predators a chance to provide you with a free and environmentally sound form of pest control.

Green Lynx Spider

Green Lynx Spider

Take a walk through the garden or woods this fall and you are sure to pass by a Green lynx spider. Unless you are very observant though, you will probably not realize that this common spider is perched upon flowers and low shrubs, ready to catch an insect meal.

Lynx spider bbolles

An adult spider blends in well with plants. Photo by Beth Bolles, Escambia County Extension

Even though Green lynx spiders are very large, they are often well camouflaged in plant material. Spiders are bright green with a lighter color on the abdomen including some small red markings. The legs have distinctive black spines.

This spider does not spin a web but actively hunts insects using a dragline as it quickly moves or jumps over plants. It is an opportunistic feeder catching many types of insects that are visiting flowers. It has been noted as an important predator of some crop damaging insects.

Females will normally lay one egg sac in the fall and guard it from predators. It is constructed in the upper portions of branches and has webbing connecting it to nearby plant leaves. This webbing becomes a protective area for the emerged spiderlings until they are able to take care of themselves.

Lynx spiders pose no harm to people and should be considered one of many beneficial arthropods that we see in Florida.

 

Young spiderlings on a blackberry guarded by the adult. Photo by Beth Bolles, Escambia Extension