Three microsporidian pathogens infecting Lymantria dispar larvae do not differ in their success in horizontal transmission

Abstract

We quantified horizontal transmission of three microsporidian pathogens, Endoreticulatus schubergi, Nosema lymantriae and Vairimorpha disparis that infect Lymantria dispar larvae in an experiment using caged, potted oak plants. Despite marked differences in the modes of spore release from infectious hosts, no significant differences in the transmission success to uninfected, susceptible test hosts were ascertained between the tested microsporidian species. The density of initially inoculated larvae and the exposure period, on the other hand, did influence the number of infected test larvae. Depending on the density of inoculated larvae (10%, 30% or 50%), between 0% and 26% of the test larvae became infected with one of the three tested microsporidian pathogens after an exposure period of 6 days. When the exposure period was 12 days, between 11% and 76% of the test larvae became infected.

The ecology and evolution of microsporidian parasites

“…The role of N. pyracusta in biocontrol is well established (Lewis et al 2009) but the use of microsporidia more widely has also been considered for many other pest species. Among the Lepidoptera Endoreticulatus schubergi , N. lymantriae and Vairimorpha disparis have been proposed for control of the Gypsy moth Lymantria dispar (Goetz and Hoch, 2008, 2009), Vairimorpha ephestiae for the wax moth Galleria mellonella (Vorontsova et al 2004) and Vairimorpha necatrix for the tomato moth Lacanobia oleracea (Down et al 2004). Paranosema locusta used for control of locust and other orthopteran pests (Lomer et al 2001; Tounou et al 2008) and Thelohania solenopsae has been proposed for control of the fire ant Solenopsis invicta (Fuxa et al 2005).…”

“…It is currently difficult to discriminate between ‘genetic’ and ‘environmental’ effects but evidence from experimental studies gives support to both. There clearly are intrinsic differences between microsporidian isolates as revealed by comparison of disease phenotype in a single host, such as the silkworm (Rao et al 2007) or the Gypsy moth (Solter and Maddox, 1998; Goetz and Hoch, 2009). There is also evidence that the parasite phenotype varies according to host species (Solter, 1997).…”

Within-Host Competition between Two Entomopathogenic Fungi and a Granulovirus in Diatraea saccharalis (Lepidoptera: Crambidae)

“…In nature, infections involving several different categories of invertebrate pathogens may take place in the same invertebrate host and may, through their function, regulate the host population [ 1 , 2 ]. Such interactions allow for studies of a variety of intriguing interactions [ 3 , 4 , 5 , 6 , 7 ].…”

Effects of the ant Formica fusca on the transmission of microsporidia infecting gypsy moth larvae

“…Ten days post infection, nine infected and marked L. dispar larvae and 21 uninfected newly molted third instars (= test larvae) were placed onto potted 2‐year‐old and 1‐m‐high Q. petraea saplings. This prevalence of 30% infected insects was chosen based on previous studies examining horizontal transmission (Goertz & Hoch, ). The plants were divided into five groups (Figure ).…”