Data obtained from observations in the laboratory on the morphology and biology of immatures of Dasyhelea necrophila Spinelli & Rodriguez are provided. Eggs and larvae were collected from containers with rain water and organic matter in Gonnet, La Plata, Argentina. The C-shaped eggs were able to resist desiccations of approximately 48 hours. Hydrated eggs developed in 7–10 days and the emerging larvae (instar I) remained immobile during 30 minutes. The first molt took place inside the eggs exposed to drought periods. These eggs started to break when rehydrated and after 24 hours larvae II were born. Larva I showed positive phototropism and due to the fact that the processes of the last segment are still internal, it hardly moved. The pupa did not show any changes when placed under artifical light and remained immobile for short periods at the bottom of the glass tube. The larva in their different instars and the pupa increased mobility with the increase of temperature.