An insecticide screening trial against grass grub (Costelytra zealandica (white))
1. Topical applications, bioassay, residue analysis and field assessment of HOE 2960 carried out against third instar larvae of grass grub. 2. HOE 2960 was found to be similar in activity to diazinon in topical test comparisons. 3. A method for bioassay was used, that failed to produce conclusive results. 4. HOE 2960 was also similar in activity to diazinon in field trials but inferior to fensulfothion.