Sunday, August 23, 2009

Cabbage Disease Due to Cabbage Maggots, Caterpillars & Moths



The cabbage family is inclusive of a number of different kinds of plants including plants such as watercress and cauliflower. In a normal garden they are under the threat of a number of cabbage pests such as the cabbage maggot, the cabbage worm, cabbage caterpillar etc. These cabbage pests damage the crops and cause cabbage disease.

What Are Cabbage Maggots?

The cabbage maggot is a bright milky white and is soft-bodied. They are usually found in clusters at the roots of the plant. Each cabbage worm grows to be about 1/3 inches long. The cabbage maggot attacks the root of the plant causing channels to from in them. A plant that has been damaged by a cabbage caterpillar will slimy or brown in the damaged area. The plant will slowly start to wilt? and will eventually die.

Cabbage maggots prefer moist weather and presently thrive in the United States due to optimal weather conditions. The adult cabbage caterpillar is a fly and closely resembles a common house fly. However like in most other cabbage pests, it is the cabbage worm rather than the cabbage fly that causes damage to the plants.

Other Commonly Found Cabbage Pests

Other cabbage pests that may damage crops are the cabbage looper, the imported cabbage worm, cross striped cabbage worm, the cabbage moth.

  • The cabbage looper is light green in color and moves in a looping motion. These particular cabbage pests are found on the under side of the leaves and feed mostly on the leaf veins. They slowly chew their way to the centre causing great damage to the plant.
  • The imported cabbage worm has larvae that are velvety green with a thin white stripe. The imported cabbage worm causes similar damage to the loopers but feed closer to the centre of the plant. Larger larva can cause great damage to the plant.
  • The larva of the cross striped cabbage worm is bluish grey in color with black stripes across its back. In addition it has yellow and black stripe running across on each side of its body. The cross striped cabbage worm feeds on all tender parts of the plant but prefer terminal buds. These cabbage pests are also found in clusters.
  • The cabbage moth has larvae that are lime green, small, spindle-shaped and have a forked tail. The adult cabbage moth has a small grayish brown body with folded wings. The larvae cause damage to buds

It should be kept in mind that at most of times it is the cabbage caterpillar that causes more damage than the adult cabbage moth. Thus it is important to start damage control at an early stage.

Cabbage Disease Caused By Cabbage Pests

The presence of cabbage pests can lead to a number of cabbage diseases that can be very harmful for the crop. The cabbage caterpillar and the looper cause holes in the leaves that lead to the plant starving and eventually dying. Cabbage maggots that affect the roots of the plant cause the leaves to wilt.

The plants of the cabbage family are affected by other cabbage diseases as well, that may not be caused by cabbage pests. These are:

  • damping- of ( where the seedling dies)
  • bacterial soft rot ( leaves turn yellow starting at the edges)
  • leaf spots ( brown lesions appear on the leaves)
  • black rot ( leaves turn yellow or brown)

Control of Cabbage Pests and Cabbage Disease

It is important to pick off the larvae of cabbage worms as soon as they appear as it is the larvae that cause the most amount of damage to the plant. In-furrow application of insecticides may give some respite from cabbage maggots. Soil insecticides may also be used to prevent and control the spread of cabbage worms and caterpillars.

Plant disease and garden pests are despised by every gardener so whether it is cabbage worms that worry you or pests in the form of garden weeds, control them actively before they start taking over your garden.

Reference:

  1. Cabbage Insects - University of Kentucky Entomology
  2. Cabbage Maggot - Government of Alberta, Agriculture and Rural Development