OCR Text |
Show SPRAYING TO CONTROL PEAR LEAF WORM (Prepared by the United States Department of Agriculture.) The pear-leaf worm, an insect which docs considerable damage to pear orchards, especially on the Pacific coast, is easily controlled hy spraying. A contact spray is usually effective in controlling the insect in the larval stage, and should lie applied when the blossoming period is about over and two-thirds-of the petals have fallen. The following formula for a contact spray is given, in a new professional paper of the bureau of entomology, United States department depart-ment of agriculture: Fish-oil soap, 1 pound; water, 25 gallons; nicotine sulphate sul-phate (40 per cent concentrate), 1 to 1,200 parts of the spray. When the-infestation the-infestation is severe and promises destruction of the foliage, a poison spray: made of 4 pounds of lead arsenate to 100 gallons of water, should be used. The best time for applying this is when the holes in the leaves are not larger than one-half inch in diameter. (A) Leaf showing character of injury and egg in situ. (B) Enlarged section of leaf showing egg in tissue and manner of young larva feeding. (C) Full-grown larva. |