White Moth with three brown spots on wings/ light-green caterpillars need type and how to remove them.?

Question

I work on a small farm and need to remove them soon, they are eating crops and laying eggsevery where

forgot to mention we are located in MA.

forgot to mention we are located in MA.

Answer 1

Imported Cabbageworm (Pieris rapae): Adult moths are white, have 3 or 4 black spots on the wings, and the wingspread is around 2 inches. Larvae are small, velvety green with a slender orange stripe down the middle of the back, and around 1 1/4 inches long
--- http://www.uga.edu/vegetable/caterpillars.html
http://en.wikipedia.org/wiki/Small_White

Introduced accidentally near Montreal in the 1860s, this species has become an important pest. Bacterial and viral diseases now provide some biological control.
http://bugguide.net/node/view/3259

High temperatures can inhibit larval development (Muggeridge, 1942) and heavy rainfall can cause high mortality in early instars (Harcourt, 1966). Therefore, larval populations are small during hot and wet seasons, and large in dry and cool seasons.

Harcourt (1966) showed three preadult periods where extensive mortality may occur: 1) between hatching and the second molt, 2) larval stages three to five and 3) during the pupal stage. Control is most effective when it is directed towards the young to half-grown worms (Fullaway and Krauss, 1945; Harcourt, 1966). During these stages the worms are more susceptible to control measures and damage is still relatively low. Rainfall is a major mortality factor on the first two larval stages and parasites are more significant on the more developed larvae (Harcourt, 1966).

Cultural Control

After harvest, crop plants should be destroyed and the field plowed. Weeds such as wild mustard and shepherd's purse should be destroyed in nearby areas since the first larval stage of the imported cabbageworm may develop on these alternative weed hosts.

Biological Control

A number of natural enemies prey on and parasitize the imported cabbageworm in Hawaii. The tachnid fly Frontina glomeratus does much to reduce cabbageworm populations (Fullaway and Krauss, 1945). In 1934, the parasitic wasp Apanteles glomeraus was introduced from Japan and also helps to control this pest (Fullaway and Krauss, 1945).

The microsporidian pathogen, Nosema mesilini, is an internal parasite that causes chronic infections with long debilitating effects, sometimes fatal, and reduces the fecundity of female adults. In Hawaii, this pathogen is present throughout the year and has a depressive effect on cabbageworm populations (Haji-Mamat and Tamashiro, 1988). This pathogen is most effective on larvae and has moderate control on adults (Haji-Mamat, 1984). Bacterial diseases, such as Chalcis obscurata, are common amongst these worms (Fullaway and Krauss, 1945). Diseases are more effected in controlling the last three larval stages (Harcourt, 1966). The effects of bacterial and virus diseases are most prevalent when densities of the pest are high.

CHEMICAL CONTROL

This pest can easily be controlled using chemical insecticides and certain Bacillus thuringiensis products. Growers greatly benefit from applying sprays when larvae are in early developmental stages.

Because many chemical insecticides have harmful residues, larvae can be controlled with Bacillus thuringiensis products. This application controls larvae without leaving hazardous residues.

--- http://www.extento.hawaii.edu/kbase/crop/Type/pieris.htm

Answer 2

Sounds like it might be fall webworm moths:
http://www.forestry.ubc.ca/fetch21/FRST308/lab5/hyphantria_cunea/webworm.html

Will try to find "control" page for you.
"The fall webworm moth emerges from it's cocoon in late spring and deposits white, "cottony" egg masses on the undersides of leaves. Fall webworms in South Texas prefer pecan trees over most other trees but will munch on mulberry, hickory, oak, willow or redbud just as readily.

The caterpillar, or webworm, is pale yellow or greenish in color, and is covered with long white hairs. The webs are made by groups of caterpillars hatched from the same egg mass. In South Texas, webworms may produce up to three generations per year. Webworm caterpillars and moths are active at night when most of their predators (wasps, birds) are inactive. The caterpillars feed on leaf material and leave the stems and veins behind. Although these caterpillars are hairy, they do not sting; however, they can cause an irritating rash if their hairs come in contact with human skin. "

Control help is also on this site:
http://bexar-tx.tamu.edu/IPM/Landscape/F2/nFalWebw.htm