Poinar G O Jr, Grewal P S (2012). History of Entomopathogenic Nematology. Journal of Nematology, Jun;44(2):153-161. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3578475/
The history of entomopathogenic nematology is briefly reviewed. Topic selections include early descriptions of members of Steinernema and Heterorhabditis, how only morphology was originally used to distinguish between the species; descriptions of the symbiotic bacteria and elucidating their role in the nematode- insect complex, including antibiotic properties, phase variants, and impeding host defense responses. Other topics include early solutions regarding production, storage, field applications and the first commercial sales of entomopathogenic nematodes in North America. Later studies centered on how the nematodes locate insect hosts, their effects on non-target organisms and susceptibility of the infective juveniles to soil microbes. While the goals of early workers was to increase the efficacy of entomopathogenic nematodes for pest control, the increasing use of Heterorhabditis and Photorhabdus as genetic models in molecular biology is noted.
Georgis R, Koppenhöfer A M, Lacey L A, Bélair G, Duncan L W , Grewal P S , Samish M, Tan L, Torr P, van Tol R W H M (2006). Successes and failures in the use of parasitic nematodes for pest control. Biological Control, 38:103-123. Retrieved from https://crec.ifas.ufl.edu/extension/diaprepes/bibliography/PDF/BioCont381.pdf
Advances in mass-production and formulation technology of entomopathogenic nematodes, the discovery of numerous isolates/ strains and the desirability of reducing pesticide usage have resulted in a surge of scientific and commercial interest in these nematodes. The lessons learned from earlier problems have encouraged scientists and leading commercial companies to increase their efforts toward improving cost efficiency and better product positioning in the market within the confines of product capabilities. The successes or failures of the nematodes against 24 arthropod pest species of agriculture and animals and against a major slug pest in agriculture are discussed in this review. Commercial successes are documented in markets such as citrus (Diaprepes root weevil), greenhouses and glasshouses (black vine weevil, fungus gnats, thrips, and certain borers), turf (white grubs, billbugs, and mole crickets), and mushrooms (sciarid flies). In addition, the successful commercialization of a nematode (Phasmarhabditis hermaphrodita) against slugs in agricultural systems is presented. Despite this progress, the reality is that nematode-based products have limited market share. Limited share is attributed to higher product cost compared to standard insecticides, low efficacy under unfavorable conditions, application timing and conditions, limited data and cost benefit in IPM programs, refrigeration requirements and limited room temperature shelf life (product quality), use of suboptimum nematode species, and lack of detail application directions. One or more of these factors affected the market introduction of the nematodes despite promising field efficacy against insects such as black cutworm in turf, sugar beet weevil in sugar beet, sweet potato weevil in sweet potato, and house fly adult in animal-rearing farms. Insects such as cabbage root maggots, carrot root weevil, and Colorado potato beetle are listed on the label of certain commercial products despite low efficacy data, due to insect susceptibility, biology, and/or behavior. To make entomopathogenic nematodes more successful, realistic strategies through genetic engineering, IPM programs, and new delivery systems and/or training programs to overcome their inherent cost, formulation instability, and limited field efficacy toward certain insects are needed.
Gaugler R (1981). Biological Control Potential of Neoaplectanid Nematodes. Journal of Nematology, Jul;13(3):241-249. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2618097/
The neoaplectanids are among the most studied of all entomogenous nematodes. Because these nematodes kill their insect hosts, they are regarded as having excellent potential as biological control agents. While the host specificity of most entontogenous nematodes tends to limit their potential usefulness, the broad host range and high virulence of neoaplectanids make them attractive candidates for industrial development. Also, recent development of economical mass rearing procedures appears to make production on a commercial basis feasible. Infective stages may be stored for years trader various laboratory conditions. Although entomogenous nematodes, as parasites, are exempt from govermnent registration requirements, the mutualistic association of neoaplectanid nematodes with a bacterium will likely necessitate a detailed safety evaluation. Studies conducted to date indicate a lack of pathogenicity to mammals. Field trial success has been limited by the intolerance of infective stages to mffavorable environmental conditions, particularly low moisture. Applications against pests on exposed plant foliage have been especially disappointing. More encouraging anti consistent results have been obtained in more favorable environments, including soil and aquatic habitats, but the most promising treatment sites ntay be cryptic habitats where infective stages are shehered from environmental extremes. Cryptic habitats also exploit the ability of neoaplectanids to actively seek out hosts in recessed places where conventional insecticide applications are intpractical.