Transmission of microsporidia, especially Orthosoma operophterae (Canning, 1960) between generations of winter moth Operophtera brumata (L) (Lepidoptera: Geometridae)

Abstract

The transmission mechanisms of microsporidia between generations of Operophtera brumata, a geometrid moth with an univoltine life-cycle, have been investigated. The parasites, Orthosoma operophterae, Pleistophora operophterae and Nosema wistmansi were present in moths collected from Wistman's Wood on Dartmoor. An infection rate of 100% was found in eggs laid by moderately or heavily infected female moths. Thus, 100% infection was found in eggs laid by 78 out of 90 infected females. Lower prevalences were found in eggs laid by the remaining 12 and these moths were subsequently shown to have very light infections. Male moths do not pass on this infection to progeny. The development of O. operophterae was followed during embryonation. The microsporidia do not invade the cells of the developing larva but are restricted to the yolk, where spores accumulate in abundance after earlier merogonies. When the larva is mature and ready to hatch, spores are ingested with the remains of the yolk, as the larva eats its way through the egg-shell. Spores are then found in the meconium in the lumen of the gut. These spores are infective and, once the gut of the larva has become functional, are responsible for infecting the tissues of the larvae which harbour them, as well as healthy larvae reared with them. Spores of O. operophterae held in the natural environment for 7 months from winter until mid-summer still retained infectivity and those contaminating the environment from the bodies of one generation must contribute to transmission between generations.

Genetic diversity and phylogenetic relationships among microsporidia infecting the silkworm, Bombyx mori, using random amplification of polymorphic DNA: Morphological and ultrastructural characterization

“…1). Transovarial transmission or vertical transmission via the gametes among microsporidian parasites has been reported by a number of workers (Ishihara and Fujiwara, 1965;Andreadis, 1983;Canning et al, 1985;Becnel et al, 1989;Dunn et al, 1998). Dunn et al (1993) and Terry et al (1997) felt that vertical transmission from generation to generation might maintain the parasite within the host population.…”

Natural distribution and co-infection patterns of microsporidia parasites in theDaphnia longispinacomplex

“…in winter; Wolinska et al 2004). This could be facilitated by forming resistant spores deposited in lake sediments (Ebert, 1995), by surviving unfavourable periods in alternate hosts (Becnel and Andreadis, 1999) or within the host's diapausing stages themselves (Canning et al 1985). In contrast, parasite composition changed within years, from summer to autumn.…”

Cytological, molecular and life cycle characterization of Anostracospora rigaudi n. g., n. sp. and Enterocytospora artemiae n. g., n. sp., two new microsporidian parasites infecting gut tissues of the brine shrimp Artemia

“…Msp1 is included in the first group, along with various gut-infecting species and two species that do not infect gut epithelia (Mrazekia macrocyclopis and Vittaforma corneae; Silveira and Canning, 1995;Issi et al 2010). Hence, we will only compare Msp1 to other gut microsporidia from Group 1: Endoreticulatus schubergi (Cali and Garhy, 1991), Cystosporogenes operophterae (Canning et al 1985;Canning and Curry, 2004), Crispospora chironomi (Tokarev et al 2010) and G. intestinalis (Larsson et al 1996). Msp1 differs from these species as its parasitophorous vacuole develops only during sporogony.…”