RELATION BETWEEN STYLET AND BODY LENGTH IN APHELENCHUS AVENAE WITH OBSERVATIONS ON PARATYLENCHUS NANUS

The body length and breadth of adult Aphelenchus avenae increased or decreased with food supply but stylet length remained unchanged. Correlations between stylet and body length were slight except in newly-moulted specimens and depended on the extent to which body length had changed after moulting. Initial body length of adults depended partly on the duration of feeding in the fourth-stage larvae. Correlations between body length and breadth were greater and varied less with changes in size of the body than did correlations between stylet length and body length (or breadth). In Paratylenchus nanus, the relation between stylet and body length in adult females was similar to that in Aphelenchus avenae so that there was little dependence of stylet length on body length. Therefore any classification of Paratylenchus, which relies on stylet length and body length being correlated would be unsatisfactory as it is partly based on invalid criteria. © 1969 BRILL.