Roots: root feeding pests

In Mexico there exist two major insect pests of corn, an armyworm Laphygma frugiperda (A. S.), which breeds and feeds in the leaf whorls of young corn, and the larvae of certain coleoptera which inhabit the soil and feed upon the roots of the corn plants. Of these two the armyworm is the most important. Its attack is particularly severe on corn grown during the summer but, as it is able to breed continuously, it is a problem in corn grown throughout the year in the tropics. 

Rice Water Weevil (Lissorhoptrus simplex). Isely and Schwardt (16) who worked with this insect from 1930 to 1933, inclusive, state, The rice water weevil is the most important insect pest of rice in Arkansas. It seems likely that this statement also applies to most of the other rice-producing areas of the southern states. Although the adult weevils feed to a considerable extent on rice leaves, the principal injury is caused by the larvae feeding on the rice roots. Under conditions of heavy infestations practically all the roots are destroyed approximately 4 to 5 weeks from the time of the first flooding of the fields. Normally, even under such conditions, the rice is not killed and when the larvae have matured and ceased feeding, the plants produce a new set of roots and will still produce a crop. The severe setback given the plants during this period naturally results in a marked reduction in yield. 

Pests are often classified according to where and how they feed on the plant (see facing page). Although this is convenient, these categories are not mutually exclusive. Many leaf-feeders also feed on stems some sapsucking aphids also feed on roots and flowers. 

Larvae of the carrot rust fly will feed on the roots of all members of this family, but it is only a major pest of carrots. Barriers and crop... 

Species of the genus Melaleuca were transferred to Horida for development purposes. People wanted to use the strong invasive roots of this tree to turn swampland into firm ground for building. However, in the swamps of Rori-da, Melaleuca has proven to be an invasive pest that has displaced many native species from the swamps. Melaleuca reproduces so quickly and so thickly that attempts to eliminate it from the swamps by cutting have met with little success. Efforts are being made to remove Melaleuca by introducing an insect which feeds on it. A similar phenomenon has occurred in New Caledonia, where when native trees have burned, solid stands of Melaleuca replaced them. 

Cause Grape phylloxeras. Feeding of this aphidlike pest causes root tips to die, decompose also forms harmless leaf galls. 

Plant yellow and stunted, wilts during bright, hot days roots have swollen galls. Cause Root knot nematodes. These microscopic, wormlike creatures invade and feed on plant roots. Pull and destroy infected plants. Control pest nematodes by adding chitin or parasitic nematodes to the soil, polarizing problem areas also reduces futur problems. 

Crowns blacken and die leaves notched. Cause Strawberry root weevils. The grubs of A", black snout beetles feed on alumroots crowns starting in early spring. Adults feed at night on foliage. Remove and destroy infested plants clean up debris where pests overwinter. Drench soil around roots with parasitic nematodes spray pyrethrin on leaves at night to kill adults. 

C-shaped, white beetle 1 iPests eat blades bugs. Pests give. - larvae feed on roots, which Ipromoted by off an offensive... 

Turf has irregular streaks of brown grass. Cause Mole crickets. These 1 A", light brown insects have short forelegs and shovel-like feet. They are serious lawn pests in the South. The crickets tunnel under the lawn and feed on grass roots. Infested grass wilts and turns brown, so irregular dark streaks appear on lawns. Apply parasitic nematodes and water the soil well before and after application, or apply milky disease spores. 

Leaves with notched edges. Cause Black vine weevils. The wingless. Vs", brownish black adults feed on the leaves and bark and can kill branches. See the opposite page for an illustration of this pest. To control them, try spreading a dropcloth around your plants, then shaking the plants the adults will drop and can be removed and destroyed. Spray leaves several times with pyrethrin for major infestations. The small, curved, white grubs of these weevils feed on the roots drench the soil around... 

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