The relationships of the clicking Elateroidea beetles were studied with the help of parsimony analysis using Hennig86. The character matrix included 70 characters and 27 taxa. The results demonstrate the monophyly of the group Throscidae sensu Crowson, contrary to views presented in other papers. Methods for solving this problem were sought. When several minimum length solutions were obtained, successive weighting and a search for a strict consensus tree identical with one of the original trees appeared to be acceptable ways for trying to identify the preferred solution. When conflicting trees from separate data sets were compared, a combined global analysis turned out to be impossible to perform because the data sets used different terminal taxa. In this case, the incongruence and total support tests provided by Farris' programs RNA and KON proved indispensable. The conflict found between the results obtained here and those presented by other workers using a large suite of larval characters were shown to be caused by an incongruent data matrix used in the latter study-the larval data set resulted in a polyphyletic ingroup and suggests relationships quite different from adult data alone. Directed large scale homoplasy due to repeated re-invasion of two major habitats by separate clades may be the factor causing difficulties in coding the larval characters.