The occurrence and effect of a protozoan parasite, Ophryocystis elektroscirrha (Neogregarinida: Ophryocystidae) on overwintering monarch butterflies, Danaus plexippus (Lepidoptera: Danaidae) from two California winter sites

Abstract

Abstract. 1. Monarch butterflies, Danaus plexippus, from two overwintering populations, were found to have Ophryocystis elektroscirrha spores on their scales at rates between 53% and 68%. The frequency of butterflies with 0,elektroscirrhaspores remained about the same between sites and throughout the winter.2. The spores, recovered from all parts of the body of the butterfly, were most numerous on the abdomen, particularly near the posterior third.3. Butterflies with spores survived as long as those without detectable spores at 10.1"C +0.4SE and 78.3% r.h. +0.6SE. Insects with spores held at 19.4"C +0.4SE and 44.9%r.h. +1.5SE showed a significantly higher rate of moisture loss and survived a shorter period than monarch buttedies without detectable spores.

Interactions between frequency–dependent and vertical transmission in host–parasite systems

“…Examples of this transmission combination in larger vertebrates come from hosts such as humans and koalas where vertical transmission appears to occur primarily as a side effect of infected genital tissues, while a much larger number of examples involve host species with high reproductive rates (e.g. Rosen et al 1989;Leong et al 1992;Mink 1993). While the important transmission routes of many parasites remain undocumented, these analyses suggest that vertical transmission will occur in combination with horizontal frequency-dependent transmission for a wide range host-parasite systems involving hosts with high reproductive rates.…”

“…These conditions are consistent with current data regarding virulence and transmission rates of O. elektroscirrha. Although severely infected monarch butterflies die shortly after emergence, mean lifespans for infected and healthy adults differ by only a few days (Leong et al 1992;S. Altizer, unpublished data).…”

“…In monarch butterflies, Ophryocystis elektroscirrha, spores are usually passed maternally, but spores transferred by males during mating can infect the offspring of healthy females (Leong et al 1992;S. Altizer, unpublished data).…”

On the Dangers of Interpopulational Transfers of Monarch Butterflies

“…Leong et al (1992) determined that O. elektroscirrha is present to a high degree in coastal California overwintering populations. In the winter of 1990-1991, Leong and colleagues found 53% and 68% of individuals sampled at two sites to be infected.…”

Host Diet Affects the Morphology of Monarch Butterfly Parasites

“…Neogregarines are members of the phylum Apicomplexa, a group of obligate unicellular parasites which include the widely-studied parasites Cryptosporidium spp., Toxoplasma spp., and Plasmodium spp. Ophryocystis elektroscirrha undergoes 2 main life stages: an actively reproducing cycle within the monarch's tissues and a dormant, transmissible spore stage on the exterior of the monarch adult (McLaughlin and Myers, 1970;Leong et al, 1992). These external spores are dormant and are typically observed as elliptical shapes on the butterfly scales (McLaughlin and Myers, 1970;Vickerman et al, 1999;Sternberg et al, 2012).…”