The Butterflies of Barro Colorado Island, Panama: Local Extinction since the 1930s

Abstract

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 used published lists and recent monitoring programs to evaluate changes in butterfly composition on 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 the 1923–2013 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 could not be collected during the recent period, despite a much higher sampling effort in recent times. We consider these species locally extinct from BCI and they conservatively represent 6% of the estimated local pool of resident species. Extinct species represent distant phylogenetic branches and several families. The butterfly traits most likely to influence the probability of extinction were host growth form, wing size and host specificity, independently of the phylogenetic relationships among butterfly species. On BCI, most likely candidates for extinction were small hesperiids feeding on herbs (35% of extinct species). However, contrary to our working hypothesis, extinction of these species on BCI cannot be attributed to loss of host plants. In most cases these host plants remain extant, but they probably subsist at lower or more fragmented densities. Coupled with low dispersal power, this reduced availability 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 that small preserves may be far more effective at conserving invertebrates than vertebrates and, therefore, should not necessarily be neglected from a conservation viewpoint.

The Saturniidae of Barro Colorado Island, Panama: A model taxon for studying the long‐term effects of climate change?

“…In 2009, the ForestGEO (Forest Global Earth Observatory) Arthropod Initiative started long‐term monitoring among multiple contrasting taxa, including saturniid moths, within and near the permanent botanical plot of the Center for Tropical Forest Science (CTFS) on BCI. The program aims to detect long‐term changes in the abundance and composition of focal arthropod assemblages, driven primarily by climatic fluctuations and anomalies, as opposed to short‐term stochastic changes (Anderson‐Teixeira et al., ; Basset et al., , ). Our present contribution reviews the minimum information necessary to discuss local saturniid assemblages in the tropics and relatively long‐term changes in their population dynamics, hence developing a framework onto which other recent time‐series of tropical arthropods may be similarly characterized and studied.…”

Diversity and recent population trends of assassin bugs (Hemiptera: Reduviidae) on Barro Colorado Island, Panama

“…In Panama, the CTFS‐ForestGEO Arthropod Initiative has been monitoring arthropods within and near the permanent ForestGEO vegetation plot of Barro Colorado Island (BCI) since 2009 (Basset et al ., , ; Anderson‐Teixeira et al ., ). The aims of this arthropod monitoring programme are to detect long‐term changes in the abundance and composition of focal assemblages of arthropods, driven primarily by climatic cycles and changes, as opposed to short‐term stochastic changes.…”

Species delimitation and evolutionary relationships among Phoebis New World sulphur butterflies (Lepidoptera, Pieridae, Coliadinae)

“…At first, the favoured 24-species hypothesis might be considered as taxonomic oversplitting. However, it is in fact a combination of old species concepts based on phenotypic and genitalic differences (Illiger, 1801;Butler, 1869;Brown, 1929), along with the cryptic species discovered in the last decade by barcode studies (Janzen et al, 2009;Basset et al, 2015;Lavinia et al, 2017).…”

“…With no obvious differences between the other two entities, the assignment of one of them to P. argante is impossible until DNA from holotypes becomes available. The other two taxa have been referred to provisionally as P. arganteDHJ01 and P. arganteDHJ03 (Janzen et al, 2009;Basset et al, 2015;Lavinia et al, 2017). Rearing records show that P. hersilia larvae feed on legumes of the genus Inga, which is used also by P. arganteDHJ01 and P. arganteDHJ03, but so far there are no hosts in common between the last two (P. arganteDHJ03 adults have only been collected by net, and hundreds of P. arganteDHJ01 have been reared from larvae in the same forest).…”

“…The taxonomy of Phoebis has been assessed mainly by classical morphological approaches, through the study of external features and genitalia (Brown, 1929(Brown, , 1933Klots, 1929;d'Almeida, 1940). Recent large-scale screenings of Central and South American butterfly faunas using cytochrome oxidase subunit I (COI) barcodes have suggested the existence of cryptic diversity in the genus (Janzen et al, 2009;Basset et al, 2015;Lavinia et al, 2017). More recently, the genus has been revised by Murillo-Ramos et al (2018) using 20 morphological characters and four genes.…”