Loss of Attractiveness to Bessa harveyi (Tns.) (Diptera: Tachinidae) of Host Larvae During Cold Storage

Abstract

A study of factors that influence host references of the parasitic tachinids Drino bohemica Mesn. and Bessa harveyi (Tns.) (Monteith, 1955, 1958a, 1958b, 1962) included tests with successive generations of the parasites. Large numbers of the sawfly larvae used as hosts were collected each summer and, when they had spun their cocoons, were put into cold storage until required. In some seasons sufficient larvae of a particular species were not available to conduct experiments for a twelve-month period though a supply of larvae of the same species collected in the previous year was in storage. If larvae stored for one year or longer did not change in their attractiveness to the parasites they could be used in tests together with larvae stored for less than one year. This is a report of an investigation to determine if changes occur during cold storage in the attractiveness of sawfly larvae to B. harveyi.