Post-application Persistence of Entomopathogenic Nematodes

Behaviour and Population Dynamics of Entomopathogenic Nematodes Following Application

“…3.1). This rapid decline, with losses varying between 40 and 90 % within hours or days of application, has been attributed to inactivation of IJs by ultraviolet light and desiccation at the soil surface (Smits, 1996), but predation by collembolans and mites may also be important at this stage (Wilson & Gaugler, 2004). Those nematodes that move into soil will be protected from UV, but still vulnerable to abiotic stressors such as desiccation and temperature extremes as well predators and pathogens such as nematode trapping fungi (reviewed by Kaya, 2002 and Chap.…”

“…3.1). According to Smits (1996) the population maintains a fairly stable level of "perhaps 10,000-40,000 nematodes/m 2 ". Most species of EPN can utilise a fairly broad range of hosts, and as more than 100,000 IJs can be produced from a single large host cadaver (Dutky, Thompson, & Cantwell, 1964;Lindegren, Valero, & Mackey, 1993;Shapiro-Ilan, Gaugler, Tedders, Brown, & Lewis, 2002), a large population of susceptible insects can contribute significantly to EPN population numbers.…”

“…Later studies support these general trends. Different factors are likely to .1 Post-application persistence of entomopathogenic nematode populations, after Smits (1996), showing a rapid decline immediately after application (1) followed by a more gradual decline of the applied infective juveniles (2) and eventual maintenance of the population through recycling (3). Populations may become undetectable (4) due to low numbers of infective juveniles free in soil and recover as new hosts are infected or juveniles emerge from previously infected hosts…”

“…Smits (1996) proposed a useful model for considering the fate of the applied population, with an initial period of rapid decline, a more gradual decrease in numbers, followed by maintenance at a low level through periodic recycling ( Fig. 3.1).…”

The impact of entomopathogenic nematodes on a non-target, service-providing longhorn beetle is limited by targeted application when controlling forestry pest Hylobius abietis

“…Non-target infection and dispersal and persistence (e.g. via recycling) of inundatively applied biocontrol agents are key factors when estimating their risk and should be investigated closely when considering EPN as a potential alternative to conventional control methods (Gaugler, 1988;Bathon, 1996;Smits, 1996;van Lenteren et al, 2003).…”