Letters and Sermons of T.B. Larimore

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The butterflies of Barro Colorado Island, Panama: local extinction since the 1930s

Few data are available about the regional or local extinction of tropical butterfly species.When confirmed, local extinction was often due to the loss of host-plant species. We usedpublished lists and recent monitoring programs to evaluate changes in butterfly compositionon Barro Colorado Island (BCI, Panama) between an old (1923–1943) and a recent (1993–2013) period. Although 601 butterfly species have been recorded from BCI during the1923–2013 period, we estimate that 390 species are currently breeding on the island,including 34 cryptic species, currently only known by their DNA Barcode Index Number.Twenty-three butterfly species that were considered abundant during the old period couldnot be collected during the recent period, despite a much higher sampling effort in recenttimes. We consider these species locally extinct from BCI and they conservatively represent6% of the estimated local pool of resident species. Extinct species represent distant phylo-genetic branches and several families. The butterfly traits most likely to influence the proba-bility of extinction were host growth form, wing size and host specificity, independently ofthe phylogenetic relationships among butterfly species. On BCI, most likely candidates forextinction were small hesperiids feeding on herbs (35% of extinct species). However, con-trary to our working hypothesis, extinction of these species on BCI cannot be attributed toloss of host plants. In most cases these host plants remain extant, but they probably subsistat lower or more fragmented densities. Coupled with low dispersal power, this reducedavailability of host plants has probably caused the local extinction of some butterfly species.Many more bird than butterfly species have been lost from BCI recently, confirming thatsmall preserves may be far more effective at conserving invertebrates than vertebrates and,therefore, should not necessarily be neglected from a conservation viewpoin

Hybrid speciation in Heliconius butterflies? A review and critique of the evidence

The evidence supporting the recent hypothesis of a homoploid hybrid origin for the butterfly species Heliconius heurippa is evaluated. Data from selective breeding experiments, mate-choice studies, and a wide variety of DNA markers are reviewed, and an alternative hypothesis for the origin of the species and its close relatives is proposed. A scenario of occasional red wing-pattern mutations in peripheral populations of Heliconius cydno with subsequent adaptive convergence towards sympatric mimicry rings involving H. melpomene and H. erato is offered as an alternative to the HHS hypothesis. Recent twists of this tale are addressed in a postscript

Climate Change and Agriculture in the United States: Effects and Adaptation

This is a report by the USDA as climate change relates to its affect on livestock and agriculture