Description of the preimaginal stages of the golden native dronefly from Australia, Eristalinus punctulatus (Macquart, 1847) (Diptera: Syrphidae)

Abstract

Eristalinus punctulatus (Macquart, 1847) is a hoverfly (Syrphidae) that is native to Australia. Eristalinus belongs within tribe Eristalini, which is well known for its pollination efficiency. Although there is not much information available about this species, the abundance and floral constancy of this group of flies make E. punctulatus an appropriate candidate for use as pollinating agent. However, like most other eristalines, there is a lack of information regarding basic aspects of its biological cycle, as well as the morphology of the preimaginal stages. In this paper, the morphology of the egg, the first and third larval instars and the puparium of E. punctulatus are described for the first time. A description of the head skeleton is also given to improve understanding of the larval feeding habits of this species. Additionally, a diagnostic key of the third larval instar is provided together with an update of the pupal stage key, including all the Eristalinus species whose preimaginal morphology has already been described. The most noteworthy morphological features of the larva of E. punctulatus are the presence of lappets, the proportions of the anterior spiracles and the number and size of the facets.