The importance of larval characters in determining the affinities and systematic position of Diptera has been emphasized by Dufour, Brauer, Mik, Osten-Sacken, and Keilin. Osten-Sacken considered that the desideratum of dipterology was “ to establish the natural character of each family in its larval form as well as the natural characters of at least the principal genera within each family during the same stage of existence” . As Edwards says, “ The question as to whether the larval or adult characters are of greater value for classification has often been raised. In more than one case the larval characters have been shown to be more important (Culicidae,
Mycetobia
), and in some cases the classification of adults has been based on Secondary Characters, and only further examination revealed the characters of real taxonomic value ”. The position of
Mycetobia
provides a good example of the importance of larval characters. Winnertz and J ohannsen included it in the Mycetophilidae. Keilin (1919, a),from a detailed larval study of
Mycetobia
and
Rhyphus
, concluded that they are closely related. Further investigations by E dwards based on adult characters confirmed Keilin’s view that it should be transferred to the Rhyphidae.* In our present state of knowledge, however, classification based on larval characters could not supersede classification by adults, as only a small proportion of the immature stages of insects is known in comparison to the number of adults. However, as Edwards points out, “ Any attempt to base a classification on adults only without reference to the other stages is an unnatural proceeding and likely to produce unnatural results, owing to the ease with which striking but really superficial characters can be confused with those of more fundamental importance from the point of view of phylogeny ”.
Immature stages and phylogenetic importance of Astrapaeus, a rove beetle genus of puzzling systematic position (Coleoptera, Staphylinidae, Staphylinini)