Advisor Information
John McCarty
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
2-3-2018 10:45 AM
End Date
2-3-2018 12:00 PM
Abstract
Monarch butterflies (Danaus plexippus) are suffering from declining populations due to habitat loss. To help offset this habitat loss, conservationists have encouraged planting milkweed gardens to increase the availability of host plants for larvae. A tachinid fly (Lespesia archippivora) and a protozoan parasite (Ophryocystis elektroscirrha) parasitize monarchs and cause lethal/sub-lethal effects in their hosts. Rates of parasitism are variable and can be influenced by habitat. Understanding the influence these gardens have on parasitism rates and monarch recruitment is vital to evaluating the effectiveness of gardens as a conservation strategy. I compared egg/larval abundance and demography at conservation areas to those at residential gardens. Additionally, I collected and reared 392 monarch larvae to compare parasitism rates in both areas. No significant difference existed between conservation areas and garden areas in larval survival in 2016 and 2017 survival (Log-rank, X 2 = 0, df = 1, p = 0.867). There was no significant difference in tachinid parasitism between habitats (X 2 (1, N = 392) = 0.244, p > 0.10). The highest stage of mortality for larvae was from egg to instar 1 in both habitat types. O. elektroscirrha parasitism was 2%. Five monarch adults out of 249 tested were parasitized with spores over the two years. A. syriaca was the most commonly used host plant for monarch larvae (85.17%). Overall monarch survival and parasitism in residential gardens compared to conservation areas is similar, suggesting that gardens are not harming monarch populations and could potentially serve as an effective conservation strategy.
Recruitment, survival, and parasitism of monarch butterflies (Danaus plexippus) in residential gardens and conservation areas.
Dr. C.C. and Mabel L. Criss Library
Monarch butterflies (Danaus plexippus) are suffering from declining populations due to habitat loss. To help offset this habitat loss, conservationists have encouraged planting milkweed gardens to increase the availability of host plants for larvae. A tachinid fly (Lespesia archippivora) and a protozoan parasite (Ophryocystis elektroscirrha) parasitize monarchs and cause lethal/sub-lethal effects in their hosts. Rates of parasitism are variable and can be influenced by habitat. Understanding the influence these gardens have on parasitism rates and monarch recruitment is vital to evaluating the effectiveness of gardens as a conservation strategy. I compared egg/larval abundance and demography at conservation areas to those at residential gardens. Additionally, I collected and reared 392 monarch larvae to compare parasitism rates in both areas. No significant difference existed between conservation areas and garden areas in larval survival in 2016 and 2017 survival (Log-rank, X 2 = 0, df = 1, p = 0.867). There was no significant difference in tachinid parasitism between habitats (X 2 (1, N = 392) = 0.244, p > 0.10). The highest stage of mortality for larvae was from egg to instar 1 in both habitat types. O. elektroscirrha parasitism was 2%. Five monarch adults out of 249 tested were parasitized with spores over the two years. A. syriaca was the most commonly used host plant for monarch larvae (85.17%). Overall monarch survival and parasitism in residential gardens compared to conservation areas is similar, suggesting that gardens are not harming monarch populations and could potentially serve as an effective conservation strategy.