Vertical transmission and overwintering of microsporidia in the gypsy moth, Lymantria dispar

Host specificity of microsporidia pathogenic to the gypsy moth, Lymantria dispar (L.): Field studies in Slovakia

“…lymantriae was recovered from one individual non-target larva in 2003 but no infections were recovered from non-target species in 2004 and 2005, despite application in 2005 at a concentration 4Â the concentration used for the previous two applications. While V. disparis causes larval or pupal mortality at dosages over 100 spores and when orally inoculated at any larval stage (Goertz and Hoch, 2008), N. lymantriae-infected larvae may survive if dosages are low or larvae are late stage when infection is acquired. This species may be transovarially transmitted to the next L. dispar generation by infected adults (Goertz and Hoch, 2008).…”

Microsporidia Biological Control Agents and Pathogens of Beneficial Insects

“…Infectivity of E. schubergi spores collected from the feces 10-25 days after inoculation was 100%, yet virulence was low with a maximum of 38% larval mortality under laboratory conditions (Goertz & Hoch 2008a). Survivorship of infected larvae to adulthood, transovum (but not transovarial) transmission, venereal transmission, and the infectivity of spores from overwintered cadavers contribute to the cross-generational persistence of E. schubergi (Goertz & Hoch 2008b). Laboratory host specificity studies indicated that E. schubergi was a generalist, with 15 of 33 nontarget species exhibiting patent infections.…”

“…The systemic infection that extends into the other tissue such as fat body also contributes to significant dissemination of spores from decaying cadavers. Transovarial transmission also occurs (Goertz & Hoch 2008b) as a likely result of gonad infection. The moderate virulence apparently permits the combination of horizontal and vertical transmission, which allows for effective transmission as well as persistence to the next generation of hosts (Goertz & Hoch 2008b).…”

“…Spores can be excreted with the feces prior to larval death, but it is a minor transmission pathway (Goertz & Hoch 2008a). There is no evidence for transovum infection with V. disparis (Goertz & Hoch 2008b). The high virulence, lack of vertical transmission, and poor overwintering viability of spores have not indicated a definitive mechanism for interseasonal or generational persistence of V. disparis.…”

Specific Detection and Localization of Microsporidian Parasites in Invertebrate Hosts by Using In Situ Hybridization

“…For example, parasites of the genus Nosema that infect crustacean hosts cause little pathogenesis; they form low-burden localized infections in the reproductive tissue, are vertically transmitted, and cause feminization of the host offspring, leading to distorted sex ratios (8,9). In contrast, Vairimorpha disparis (also from the Nosema clade) causes high-density infection of the fat body, leading to death of the gypsy moth host and subsequent horizontal transmission (10).…”