Automated technology for in vivo mass production of entomopathogenic nematodes

As the only biocontrol agent available for many soil insects, entomopathogenic nematodes should be poised for wider use, as regulatory scrutiny in the USA continues to restrict or ban important chemical insecticides. One component of nematode production in the USA is a cottage industry of low volume producers using in vivo technology, based on a method devised in 1927: the White trap. We report the first scalable system for in vivo nematode mass production. Unlike the White trap, there is no requirement for nematode migration to a water reservoir. The LOTEK system of tools and procedures provides process technology for low-cost, high-efficiency mass production. The system consists of: (1) perforated holding trays to secure insect hosts during inoculation, conditioning (synchronizing nematode emergence), and harvesting, (2) an automated, self-cleaning harvester with misting nozzles that trigger infective juvenile emergence and rinse the nematodes through the holding trays to a central bulk storage tank, and (3) a continuous deflection separator for washing and concentrating nematodes. The harvester collects 97% of Heterorhabditis bacteriophora Poinar that emerged from Galleria mellonella (L.) cadavers in 48 h. The separator removes 97.5% of the wastewater in three passes, while nematode concentration increased 81-fold. The rearing system offers an increase in efficiency relative to the conventional White trap method with reduced labor and space.