However, neonate larvae produce a chemical that is repellent to ants. A new species of nematode, Steinernema riobravis , offers potential control of D. abbreviatus larvae. This beneficial nematode applied to the soil enters weevil larvae releasing a plug of mutualistic bacteria which multiples in the larva s body cavity causing septicemia. The nematodes feed upon the decomposing host cadaver. Weevil larvae die within 24 to 48 hours following infection by nematodes, while nematodes continue to grow and mate.
Female nematodes release infective juveniles which go out and find other host larvae in the soil.
However, this product is no longer recommended due to poor quality control. Even though biological control agents may reduce the weevil populations, the remaining weevils can cause serious damage. Biologicals do fit into management of D. abbreviatus , but they appear to be the only part of the management arsenal needed. During the 1960 s, chlorinated hydrocarbons such as aldrin and chlordane were used in Puerto Rico as the primary method of D. abbreviatus control. These compounds were applied to the soil prior to egg hatch to intercept neonate larvae as they entered the soil.