On the Larval Development ofDacnusa areolarisNees (Braconidae), a Parasite of Phytomyzinae (Diptera), with a Note on certain Chalcid Parasites on Phytomyzids

Abstract

1. Dacnusa areolaris Nees is a parasite of the fly Phytomyza angelicae Zett.2. The egg is laid and development takes place within the body of the host.3. A membrane of trophic cells is formed, within which the embryonic and first larval stages are passed.4. The further growth and development of the parasite are delayed until after metamorphosis of the host, probably to ensure sufficient food in the later stages.5. The length of the larval and pupal life of the parasite is intimately correlated with the puparial period of the host.6. It is suggested that this is an adaptation to ensure that an adequate supply of host larvae shall be hatched by the time that the parasites are ready to oviposit.7. Certain Chalcididae of the genera Eulophus and Chrysocharis are ectoparasites of Ph. angelicae, and a summary of observations on their life cycle is given.