SUMMARY Polyphenism is a key strategy used by solitary insects to adapt to changing environmental conditions and by eusocial insects for existing collaboratively in a social environment. In social insects, the morphogenetic juvenile hormone(JH) is often involved in directing the differentiation of polyphenic behavioral castes. The present study examines the effects of JH, environment and feeding on caste polyphenism in a eusocial insect, the termite Reticulitermes flavipes (Kollar). Our approach included a combination of model JH bioassays, SDS-PAGE and western blotting. Our findings revealed significant temperature-dependent effects on (1) JH-induced soldier caste differentiation, (2) abundance of soldier-inhibitory hexamerin proteins and(3) JH-sequestration by hexamerin proteins. Additionally, although it appears to be dependent on a complex interaction of factors, feeding apparently plays a significant upstream role in enhancing hexamerin accumulation under normal colony conditions. These findings offer important new information on termite eusocial polyphenism by providing the first mechanistic evidence linking an intrinsic caste regulatory factor (hexamerin proteins) to an upstream extrinsic factor (environment) and a downstream response (caste differentiation). These observations are consistent with the hypothesis that the hexamerins serve as an environmentally and nutritionally responsive switching mechanism that regulates termite caste polyphenism.

In lower termites, the worker caste is a totipotent immature stage that is capable of differentiating into other adult caste phenotypes. We investigated the diversity of family 4 cytochrome P450 (CYP4) genes in Reticulitermes flavipes workers, with the specific goal of identifying P450s potentially involved in regulating caste differentiation. Seven novel CYP4 genes were identified. Quantitative real-time PCR revealed the tissue distribution of expression for the seven CYP4s, as well as temporal expression changes in workers in association with a release from colony influences and during juvenile hormone (JH)-induced soldier caste differentiation. Several fat-body-related CYP4 genes were differentially expressed after JH treatment. Still other genes changed expression in association with removal from colony influences, suggesting that primer pheromones and/or other colony influences impact their expression. These findings add to a growing database of candidate termite caste-regulatory genes, and provide explicit evidence that colony factors influence termite gene expression.

Nine extinct species and one genus of aderid beetles (Coleoptera: Tenebrionoidea: Aderidae) are described from Baltic and Bitterfeld amber from Germany, Russia (Kaliningrad), Poland, and Denmark. These new species include: Escalerosia igori sp. nov., Picemelinus irinae sp. nov., Vanonus ulmerigicus sp. nov., Vanonus aestiorum sp. nov., Cnopus kraxtepellenensis sp. nov., and four species from the extinct genus Palaeocnopus gen. nov.: P. densipunctatus sp. nov., P. saeticornis sp. nov., P. glabricornis sp. nov., and P. mara sp. nov. A key to the species of Palaeocnopus in amber is provided. The newly described taxa of these ant-like leaf beetles are photographed, illustrated, and compared with extinct and related extant representatives of the genera.

for their assistance and review of this manuscript. Appreciation is also extended to the funding sources at the University of New Mexico that supported my studies (GRAC, SRAC, and the Grove Scholarship). I also wish to thank Gino Nearns and Nathan Lord, whose critique, helpfulness, and friendship resulted in the marked improvement of this project. Their own graduate experiences were lent to my benefit and for that I am extremely grateful. Thanks also to Dave Lightfoot, Sandy Brantley, and Sharyn Davidson for their continued assistance and friendship throughout my time here. They helped me to feel at home in my new surroundings of the museum. My appreciation is also extended to the entire Miller Lab (especially Lauren Cleavall, Alicia Hodson, Billy Edelman, April Tafoya, and Emily Hodson) for their support and encouragement throughout graduate school. Last, but not least, I thank my family and friends both here and afar who listened to my frustration, rejoiced in my excitement, and gave me a shoulder to lean on when needed. Though they often didn't know the details of my experiences, they were the ones I turned to in my trying times. They are my emotional backbone and I thank them endlessly. v

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