Attractants for the New Zealand grass grub, Costelytra zealandica (White)

Abstract

It has been demonstrated (Osborne and Hoyt, 1970) that male grass grub beetles are strongly attracted to the phenol/formaldehyde resin Durez 12687. In preliminary work it was shown that attractant activity was associated with the presence of residues of phenol in the resin although this latter material appeared to be far more active than phenol. The situation has now been investigated more fully. Phenol release rates from samples of resin have been measured and field trials have been carried out in which the attractancy of formulations with similar release rates have been compared. Evidence has been presented that an odour synergist is present in the resin.

The second part of this thesis has involved a study of larval attractants for the grass grub. Preliminary work (Osborne and Hoyt, 1969b) suggested that third-instar larvae C. zealandica may be attracted chemically to certain natural products including roots of carrot and parsnip. This attraction has been studied further using a choice chamber assay technique. Chemical analysis has revealed that certain of the active attractants possess terpene constituents in common and one of these (β-pinene) is active as an attractant. Routine screening of related compounds led to the discovery that ά-fenchol is a potent larval attractant for C. zealandica under laboratory conditions.