Open Access. Powered by Scholars. Published by Universities.®

Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Biology

Competitive Abilities In Experimental Microcosms Are Accurately Predicted By A Demographic Index For R*, Ebony G. Murrell, Steven A. Juliano Sep 2012

Competitive Abilities In Experimental Microcosms Are Accurately Predicted By A Demographic Index For R*, Ebony G. Murrell, Steven A. Juliano

Faculty Publications – Biological Sciences

Resource competition theory predicts that R*, the equilibrium resource amount yielding zero growth of a consumer population, should predict species' competitive abilities for that resource. This concept has been supported for unicellular organisms, but has not been well-tested for metazoans, probably due to the difficulty of raising experimental populations to equilibrium and measuring population growth rates for species with long or complex life cycles. We developed an index (R-index) of R* based on demography of one insect cohort, growing from egg to adult in a non-equilibrium setting, and tested whether R-index yielded accurate predictions of competitive abilities using mosquitoes as …


Seasonal Photoperiods Alter Developmental Time And Mass Of An Invasive Mosquito, Aedes Albopictus (Diptera: Culicidae), Across Its North-South Range In The United States, Steven A. Juliano, Donald A. Yee, Steven M. Vamosi Jul 2012

Seasonal Photoperiods Alter Developmental Time And Mass Of An Invasive Mosquito, Aedes Albopictus (Diptera: Culicidae), Across Its North-South Range In The United States, Steven A. Juliano, Donald A. Yee, Steven M. Vamosi

Faculty Publications – Biological Sciences

The Asian tiger mosquito, Aedes albopictus (Skuse), is perhaps the most successful invasive mosquito species in contemporary history. In the United States, Ae. albopictus has spread from its introduction point in southern Texas to as far north as New Jersey (i.e., a span of approximate to 14 degrees latitude). This species experiences seasonal constraints in activity because of cold temperatures in winter in the northern United States, but is active year-round in the south. We performed a laboratory experiment to examine how life-history traits of Ae. albopictus from four populations (New Jersey [39.4 degrees N], Virginia [38.6 degrees N], North …


Wing Shape As An Indicator Of Larval Rearing Conditions For Aedes Albopictus And Aedes Aegypti (Diptera: Culicidae), C R. Stephens, Steven A. Juliano Jul 2012

Wing Shape As An Indicator Of Larval Rearing Conditions For Aedes Albopictus And Aedes Aegypti (Diptera: Culicidae), C R. Stephens, Steven A. Juliano

Faculty Publications – Biological Sciences

Estimating a mosquito's vector competence, or likelihood of transmitting disease, if it takes an infectious bloodmeal, is an important aspect of predicting when and where outbreaks of infectious diseases will occur. Vector competence can be affected by rearing temperature and inter- and intraspecific competition experienced by the individual mosquito during its larval development. This research investigates whether a new morphological indicator of larval rearing conditions, wing shape, can be used to distinguish reliably temperature and competitive conditions experienced during larval stages. Aedes albopictus (Skuse) and Aedes aegypti (L.) (Diptera: Culicidae) larvae were reared in low intraspecific, high intraspecific, or high …


A Comparison Of Human Chorionic Gonadotropin And Luteinizing Hormone Releasing Hormone On The Induction Of Spermiation And Amplexus In The American Toad (Anaxyrus Americanus), Andrew J. Kouba, Javier Delbarco-Trillo, Carrie K. Vance, Callie Milam, Meghan Carr Jan 2012

A Comparison Of Human Chorionic Gonadotropin And Luteinizing Hormone Releasing Hormone On The Induction Of Spermiation And Amplexus In The American Toad (Anaxyrus Americanus), Andrew J. Kouba, Javier Delbarco-Trillo, Carrie K. Vance, Callie Milam, Meghan Carr

Faculty Publications – Biological Sciences

Background: Captive breeding programs for endangered amphibian species often utilize exogenous hormones for species that are difficult to breed. The purpose of our study was to compare the efficacy of two different hormones at various concentrations on sperm production, quantity and quality over time in order to optimize assisted breeding. Methods: Male American toads (Anaxyrus americanus) were divided into three separate treatment groups, with animals in each group rotated through different concentrations of luteinizing hormone releasing hormone analog (LHRH; 0.1, 1.0, 4.0 and 32 micrograms/toad), human chorionic gonadotropin (hCG; 50, 100, 200, and 300 IU), or the control over 24 …