Use of Gelgard M and an Evaporation Retardant to Facilitate Control of Larch Sawfly by a Nematode-Bacterium Complex1

Abstract

A manipulation of the microenvironment to increase the period of viability of the insect-parasitic nematode, DD-136 strain of Neoaplectana carpocapsae Weiser, 1955 and its associated bacterium Achromobacter nematophilus Poinar and Thomas, sprayed onto larch foliage infested with larch sawfly, Pristiphora erichsonii (Hartig), was successful in laboratory tests. By adding to the aqueous suspension of nematodes, the water thickener Gelgard M® (0.13%), an evaporation retardant, Folicote 351® (0.2%), and a surfactant, Arlatone T® (0.1%), the average mortality of the larch sawfly larvae was increased from 24 to 90%.