The chestnut weevils are probably the weevils best known to most of you. E. R. VanLeeuwen, of the Bureau of Entomology and Plant Quarantine, has added much to our knowledge of these weevils in recent years. Two species, the small chestnut weevil[8] and the large chestnut weevil,[9] are commonly present together and cause similar injury. The small chestnut weevil appears as an adult over a period of about 6 weeks beginning near the first of May in the vicinity of Beltsville, Md., but it does not lay eggs until about the middle of August. The larger species does not emerge until about the middle of August and begins to lay eggs soon thereafter. Eggs are laid in the developing nuts, and injury is caused by the feeding of the larvae therein. Most of the small weevils require two years to complete development, and most of the larger weevils but one year. Some control of these weevils can be obtained by collecting and destroying the infested nuts before the larvae leave them to enter the soil. Better control can be obtained by spraying the trees with DDT. Apply a spray containing 4 pounds of 50-percent DDT wettable powder per 100 gallons of water (3 level tablespoonfuls per gallon) 30 days before the first mature nuts are expected to drop, and make two additional applications at intervals of 7 days. If you are not equipped to spray, you may obtain some control by treating the soil under the trees with ethylene dibromide at a depth of 5 inches. Make injections at intervals of 1 foot in each direction and also in the center of each square formed by these injection holes. Place 1 milliliter of 40-percent ethylene dibromide or an equivalent quantity of another dilution in each hole. Make the application in the fall immediately after the nuts are harvested and close the injection holes by pressing with the foot. The soil should preferably be loose to a depth of 5 inches. The pecan weevil,[10] also known as the hickory nut weevil, often causes heavy losses of pecans and most species of hickory. Two or three years are required for the insect to complete its life cycle, but some specimens reach maturity every year. Adults emerge from the ground from the middle of July until early in September, according to locality and seasonal conditions. Injury is of two types--(1) that resulting from attack before the shell-hardening period in July and August, causing the young nuts to drop, and (2) that resulting from attack after kernel formation, the kernel being destroyed by the developing larvae, or grubs. Egg deposition in the nuts usually begins late in August.