Sedgwick Reserve

27 Jun, 02 PM - 30 Jun, 02 AM

Life history trade-offs play a fundamental role in the evolution of various traits. In wing-polymorphic field crickets, for example, the flight-capable long-winged morph (LW) retains the ability to fly, and disperse from unfavourable environments. Because of the high energetic costs of maintaining flight capability, LW individuals have lower reproductive success than flight-incapable short-winged (SW) individuals. Long-winged, flight-capable individuals (LW-F), however, can histolyze their flight muscles and become flightless (LW-H). As wing-polymorphism is partly a polyphenetic trait, these crickets are an ideal subject for testing possible costs of phenotypic plasticity. For my doctoral dissertation, I plan on examining several possible costs of phenotypic plasticity using the variable field cricket, Gryllus lineaticeps, including reproductive, life-history and ecological costs. I plan on studying differences in several behavioural traits between full-sibling families of crickets varying in levels of plasticity. Last fall I collected crickets at the Sedgwick reserve for setting up my lab colonies, and recorded male songs in the field. This year, in the second field stage of this project, I would like to (1) further observe these crickets in a natural setting, (2) collect approximately 40 field-matured females to introduce new genetic variability in my lab stocks (for paternity analyses to be conducted later in the year), at the University of Nebraska ? Lincoln, (3) make further field recordings of males and score them for wing morph, (4) assess how many females males of different morphs attract, by placing recorded males (from goal 3) in small net containers and making observations, and finally, (5) assess immune function of field crickets by drawing hemolymph from field captured crickets to transport back to the lab for analysis of lysozyme, prophenoxidase, and hemocyte concentrations, as well as rates of melanization. Finally, I would also like to catch a few natural predators (tarantulas, black widow spiders, wolf spiders and assassin bugs) to bring back to UNL for a predator-prey experiment to be carried out in the fall of 2007. If you would like to see the detailed methodology of any of the above protocols, please let me know and I will send them to you promptly. Except for the collections, my experiments will be very non-invasive, and I do not plan on causing any disturbances to the reserve's ecosystem or cultural resources, or on introducing any species or genotypes. These experiments will help attain my goal of assessing morph-specific differences between individuals in life-history, reproductive and immune traits, as well as ability to escape predators. Once I have these experiments complete, I will move on to assessing variation in costs of plasticity via a large-scale quantitative genetics study. I hope to spend approximately one month at the Sedgwick reserve this summer, late June through to beginning August. If possible, I would like to keep my arrival and departure dates somewhat fluid. My advisor, Dr. William E. Wagner Jr., will be in California from late May, and has agreed to scout out cricket activity for me ? if activity is very low in late June, I may delay my trip into July, and leave later in August. Please let me know if it is possible for me to keep my dates somewhat flexible.

Visit #12762 @Sedgwick Reserve

Approved

Under Project # 7182 | Research

Costs of phenotypic plasticity in the wing-polymorphic field cricket, Gryllus lineaticeps

graduate_student - University of Nebraska

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Chandreyee Mitra Jun 27 - 30, 2007 (4 days)

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Studio Apartment 1 Jun 27 - 30, 2007