Thursday, August 6, 2009
Exhibit Hall NE & SE, Albuquerque Convention Center
Background/Question/Methods
Cicadas are plant-sucking bugs that are used as model organisms for speciation and phylogeography studies. The periodical cicadas (Magicicada) is one genus with seven species that is only found in eastern North America; 13-year life cycles can be found generally in the south and midwest and 17-year life cycles have a northern distribution. As adults, they come out in precisely-timed mass-emergences and live above ground for only 6 weeks. They mate using active choruses; males produce species-specific calling songs that females wing-flick to. Females oviposit in small twigs (about a pencil thick) creating v-shaped eggnest. Newly hatched nymphs fall to the ground after 6-10 weeks, burrowing into the soil, where they spend 13 or 17 years. Within the same population, nymphs vary surprisingly in size and instar stage, even when they are from the same age, species and life cycle. Several field trips for cicada nymphs collection were made to Mississippi, Arkansas, Illinois, Oklahoma and Pennsylvania; these sites taken from previous records of mass adult emergences. Methods for data analysis included measurements of nymphs and microscopic identification of instar stage.
Cicadas are plant-sucking bugs that are used as model organisms for speciation and phylogeography studies. The periodical cicadas (Magicicada) is one genus with seven species that is only found in eastern North America; 13-year life cycles can be found generally in the south and midwest and 17-year life cycles have a northern distribution. As adults, they come out in precisely-timed mass-emergences and live above ground for only 6 weeks. They mate using active choruses; males produce species-specific calling songs that females wing-flick to. Females oviposit in small twigs (about a pencil thick) creating v-shaped eggnest. Newly hatched nymphs fall to the ground after 6-10 weeks, burrowing into the soil, where they spend 13 or 17 years. Within the same population, nymphs vary surprisingly in size and instar stage, even when they are from the same age, species and life cycle. Several field trips for cicada nymphs collection were made to Mississippi, Arkansas, Illinois, Oklahoma and Pennsylvania; these sites taken from previous records of mass adult emergences. Methods for data analysis included measurements of nymphs and microscopic identification of instar stage.
Results/Conclusions
Preliminary results shows 13- and 17- years broods of the same age are developing at aproximately the same rates. This supports the hypothesis, that 17-year periodical cicadas stop developing at the 13th year and then wait 4 year fully developed until their emergence.
