Insect cell lines and baculoviruses as effective biocontrol agents of forest pests

Abstract

Background Canada is a nation of trees. Canadian forests cover 50% of Canada’s land area and represent 10% of world’s forested area. Canada exports more processed forest products than any other country. It is also a host to a variety of forest insects both native and non native that limit the economic, recreational and wildlife habitat use. Our research focuses on initiating insect cell lines, determining nutritional requirements of cells, and developing low cost media for large scale propagation of insect pathogenic viruses as ecologically sound alternatives to chemical pesticides. Cell lines are used for bioassay and strain selection of viruses and bacterial toxins and for production of foreign gene products using baculovirusand entomopoxvirus expression vectors. They offer a cleaner, viable alternative to insect larvae for producing viral pesticides. Since 1969, over 150 continuous cell lines have been produced for forest insect pest research at GLFC. This collection represents one of largest single site repository of frozen insect cell lines in the world. Cell lines developed include tissues of the eastern spruce budworm (Choristoneura fumiferana), western spruce budworm (Choristoneura occidentalis), forest tent caterpillar (Malacosoma disstria), tobacco hornworm (Manduca sexta), white-marked tussock moth (Orgyia leucostigma), red-headed pine sawfly (Neodiprion lecontei), gypsy moth (Lymantria dispar), white pine weevel (Pissodes strobi), the tarnished plant bug (Lygus lineolaris) and the ash and privet borer (Tylonotus bimaculatus). These cell lines represent six tissues of origin, namely neonate larvae, pre-pupae, embryos, ovaries, hemocytes, and midgut and four Insect Orders namely Lepidoptera, Hymenoptera, Coleoptera and Hemiptera. Presently, cell lines developed at GLFC are being used by 41 researchers in 8 Canadian provinces, 42 researchers in 21 US States and 28 researchers in 12 countries worldwide.