Male ant reproductive investment in a seasonal wet tropical forest: Consequences of future climate change.

Tropical forests sustain many ant species whose mating events often involve conspicuous flying swarms of winged gynes and males. The success of these reproductive flights depends on environmental variables and determines the maintenance of local ant diversity. However, we lack a strong understanding of the role of environmental variables in shaping the phenology of these flights. Using a combination of community-level analyses and a time-series model on male abundance, we studied male ant phenology in a seasonally wet lowland rainforest in the Panama Canal. The male flights of 161 ant species, sampled with 10 Malaise traps during 58 consecutive weeks (from August 2014 to September 2015), varied widely in number (mean = 9.8 weeks, median = 4, range = 1 to 58). Those species abundant enough for analysis (n = 97) flew mainly towards the end of the dry season and at the start of the rainy season. While litterfall, rain, temperature, and air humidity explained community composition, the time-series model estimators elucidated more complex patterns of reproductive investment across the entire year. For example, male abundance increased in weeks when maximum daily temperature increased and in wet weeks during the dry season. On the contrary, male abundance decreased in periods when rain receded (e.g., at the start of the dry season), in periods when rain fell daily (e.g., right after the beginning of the wet season), or when there was an increase in the short-term rate of litterfall (e.g., at the end of the dry season). Together, these results suggest that the BCI ant community is adapted to the dry/wet transition as the best timing of reproductive investment. We hypothesize that current climate change scenarios for tropical regions with higher average temperature, but lower rainfall, may generate phenological mismatches between reproductive flights and the adequate conditions needed for a successful start of the colony.

Revision of the Neotropical spider genus Acanthoctenus (Araneae: Ctenidae: Acanthocteninae).

We revise the genus Acanthoctenus Keyserling, 1877 recognizing thirteen valid species, of which five are new species and two are re-validated. Further, we find one new synonymy and transfer one species. We describe Acanthoctenus alux sp. nov. from Guatemala, A. chickeringi sp. nov. and A. lamarrei sp. nov. from Panama, A. manauara sp. nov. from Brazil and A. torotoro sp. nov. from Bolivia. We revalidate Acanthoctenus dumicola Simon, 1906 stat. res. from Venezuela, and A. virginea (Kraus, 1955) stat. res., comb. nov. from El Salvador. We transfer Acanthoctenus mammifer to Viracucha mammifer (Mello-Leitão, 1939) comb. nov., from Brazil. Acanthoctenus maculatus Petrunkevitch, 1925 and Gephyroctenus kolosvaryi Caporiacco, 1947 are considered species inquirendae in Acanthocteninae and Ctenidae, respectively, and A. obauratus Simon, 1906 and A. rubrotaeniatus Mello-Leitão, 1947 are considered incertae sedis in Acanthocteninae and Acantheinae, respectively. We also describe for the first time the female of Acanthoctenus spiniger Keyserling, 1877, the type species of the genus. We provide illustrations of male and female diagnostic characters, genitalia, habitus, and measurements to support the genus re-description and further identification of its species. We yield a distributional map of the specimens recorded and the description of the natural history of Acanthoctenus manauara sp. nov.

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 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.