Mechanical impedance of adult pecan weevil (Coleoptera: Curculionidae) emergence related to soil moisture and penetration resistance

Emergence of adult pecan weevils (Curculio caryae ) from orchard soils in Texas and South Carolina was delayed and reduced at low soil moistures. Regression models relating soil moisture and penetration resistance readings (kg/cm super(2)) at 10- to 13-cm soil depths showed that impeded emergence was related to the resistance of dry soils to penetration by adult weevils. Adult emergence at various levels of penetration resistance induced by water treatment was strikingly similar for both locations.