June 2006. From Cook Islands a request for the identification of Psocoptera species on lettuce. It was found associated with a new (?)fungal disease on lettuce. The question also asked was is this Psocoptera species beneficial feeding on the fungus or can it also act as an vector spreading the disease?

In general, insect species belong to the Psocoptera like booklice feed on the spores of fungi (such as Liposcelis spp., Liposcelidae, Psocoptera); therefore, you can consider them as beneficial, but they are not vectors spreading diseases.

However, most species of Psocoptera are a secondary pest, in the sense that they infest stored products. Some species of Liposcelis such as Liposcelis bostrychophila and L entomophila have high resistant to the fumigant phosphine and are difficult to control.

Another view was that the Psocids were feeding on the dead leaf tissue.