N. W. Earle

Storage and excretion of steroids in the adult boll weevil.

Abstract Adult boll weevils (Anthonomus grandis Boheman) required about 20 mg of cholesterol/100 g of diet for sustained egg production and normal longevity. Nutritional and radiotracer experiments indicated a high rate of replacement of body cholesterol. 1. 1. The mean lifespan for adult weevils on sterol-deficient diets was 14 days as compared with the normal range of 55–89 days for laboratory-reared weevils. 2. 2. Sterol-deficient females laid almost no eggs. 3. 3. Significant amounts of sterol were carried over from the larval to the adult stage. 4. 4. A high percentage of the cholesterol in newly emerged adults was replaced within 15 days by 4-C14-cholesterol given in the diet. 5. 5. Fat weevils contained more sterol esters than lean weevils, but about the same quantity of free sterols.

Effect of Release Time on Recovery of Tagged Irradiated Boll Weevils

Irradiated Anthonomus grandis Boheman, tagged with 32P, were hand-released in cotton fields during the morning, noon, and evening. Equal numbers of boll weevils were recovered irrespective of release time. Within 1 day after release, ca. ⅓ of all released weevils had disappeared from the field; by the 4th day, only 38.0% live weevils were recovered. Tagging did not reduce survival of irradiated weevils.