October 2009. A series of questions about the use of Chrysopa (lacewings) for the control of Banana aphid, Pentalonia nigronervosa, in Sindh-Pakistan. Is Chrysopa effective against the black aphid on banana; what is the impact of ants on Chrysopa; and have members any research papers on the topic?

It is not possible to eliminate BBTV solely by using a biological control agent. It can only be suppressed, at best; and its suppression will change over time because of the population dynamics of the pest and the predator.

As far as members were aware, there are no specific predators or parasitoids of Pentalonia nigronervosa. Most of the biological control agents that have been tested in the past have been generalist predators that have a very wide host range. The problem with this is that once a population of banana aphids has been suppressed, the predators will feed on something else. They may have preferred hosts that may also be in the area.

The difficulty is that only a few BBTV-infected aphids can cause problems once they are actively feeding.

It would probably be best to use a biological control program with systemic or registered target-specific insecticides (e.g., imidacloprid) that have low impact on beneficial insects. These can be applied through a monitoring program based on economic threshold levels. High ant populations will reduce the effectiveness of biological control programs.