News Article | May 18, 2017
By deploying green clay caterpillars across six continents, researchers unmasked an important global pattern. Their study will be published in Science on May 19. Their discovery that predation is most intense near sea level in the tropics--in places like their study sites at the Smithsonian Tropical Research Institute (STRI) in Panama--provides a foundation for understanding biological processes from crop protection and carbon storage to the effects of climate change on biodiversity. Insects drove the trend, not mammals or birds. "As someone who has studied insect biodiversity in the tropics for most of my life, I wasn't surprised that insects were responsible for most of the predation observed," said Yves Basset, leader of the ForestGEO Arthropod Initiative at STRI. The team put out almost 3,000 model caterpillars for four to 18 days at 31 different sites from Australia to Greenland at different altitudes, from zero to 2,100 meters above sea level. Based on characteristic marks left by predators in the clay, they could tell whether the models were attacked by birds, mammals or insects. Tropical sites were the most dangerous. In Greenland, the daily chances of a caterpillar model being attacked by a predator were only 13 percent of the odds at the equator. And for every 100 meters of increase in altitude, the chance of being attacked fell by almost 6.6 percent. At the highest forested site, the daily odds of a predator attack was only 24 percent of the odds of attack at sea level. "Most previous studies that didn't support the conclusion that predation is more intense in the tropics were pieced together from evidence gathered in different ways by different groups of people," Basset said. "My colleagues and I were part of a team of people from around the world who all used the same method at different sites, including a few of the ForestGEO sites. We deployed many replicates of fake caterpillars, modeled after a geometrid moth, and analyzed our results together." "This seems like a very simple experiment but the results are relevant to the way we understand some of the important processes in nature, like the innovation of defenses and how temperature changes may affect biodiversity," Basset said. "The results further emphasize the power of citizen science for simple, yet significant experiments." "Caterpillars eat plants, therefore causing crop damage and forcing plants to create new chemicals in their leaves to defend themselves," Basset said. "Caterpillars also defend themselves from predators. Our finding that predation pressure is stronger in the tropics also suggests that insects in the tropics have to be more innovative in order to defend themselves." The authors of this study represented 35 research centers and universities, including STRI; the Swedish University of Agricultural Sciences; the University of Helsinki, Finland; the Institute of Entomology, Czech Academy of Sciences; the University of South Bohemia, Czech Republic; the New Guinea Binatang Research Center; the University of California-Irvine; Eidgenossische Technische Hochshule, Zurich; the University of Texas-Arlington; the University of New England, Australia; the University of Alberta, Edmonton; the University of Iceland; the University of Sao Paolo; the University of Hong Kong; the Natural History Museum of Denmark, Copenhagen; Instituto de Ecología, Xalapa, Mexico; Escuela Politécnica Nacional, Ecuador; the University of Ostrava, Czech Republic; Zoological Society of London, the University of Oxford; the University of Turku, Finland; Chinese Academy of Sciences; the University of Aberdeen; Makerere University, Uganda; Swarthmore College, U.S.; the State Institution of Education, Zditovo, Belarus; Aarhus University, Demark; the University of Tartu, Estonia; the University of Bergen, Norway; the University of Beyruth, Germany; and the University of Lancaster, UK. The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is a part of the Smithsonian Institution. The Institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems. STRI website: http://www. . Roslin. T., Hardwick, B., Novotny, et al. 2017. Higher predation risk for insect prey at low latitudes and elevations. Science.
Novotny V.,University of South Bohemia |
Miller S.E.,Smithsonian Institution |
Hrcek J.,University of South Bohemia |
Baje L.,New Guinea Binatang Research Center |
And 4 more authors.
American Naturalist | Year: 2012
Classical niche theory explains the coexistence of species through their exploitation of different resources. Assemblages of herbivores coexisting on a particular plant species are thus expected to be dominated by species from host-specific guilds with narrow, coexistence- facilitating niches rather than by species from generalist guilds. Exactly the opposite pattern is observed for folivores feeding on trees in New Guinea. The least specialized mobile chewers were the most species rich, followed by the moderately specialized semiconcealed and exposed chewers. The highly specialized miners and mesophyll suckers were the least species-rich guilds. The Poisson distribution of herbivore species richness among plant species in specialized guilds and the absence of a negative correlation between species richness in different guilds on the same plant species suggest that these guilds are not saturated with species. We show that herbivore assemblages are enriched with generalists because these are more completely sampled from regional species pools. Herbivore diversity increases as a power function of plant diversity, and the rate of increase is inversely related to host specificity. The relative species diversity among guilds is thus scale dependent, as the importance of specialized guilds increases with plant diversity. Specialized insect guilds may therefore comprise a larger component of overall diversity in the tropics (where they are also poorly known taxonomically) than in the temperate zone, which has lower plant diversity. © 2012 by The University of Chicago.
Dem F.F.,New Guinea Binatang Research Center |
Dem F.F.,Griffith University |
Stewart A.J.A.,University of Sussex |
Gibson A.,New Guinea Binatang Research Center |
And 3 more authors.
Journal of Tropical Ecology | Year: 2015
We documented one of the most species-rich assemblages of tropical rain-forest Auchenorrhyncha, comprising 402 phloem- and xylem-feeding species, by sampling adults from forest vegetation. Further, we reared 106 species from larvae sampled on 14 plant species. Both xylem- and phloem-feeding guilds exhibited wide host-plant ranges, as 74% of species fed onmore than one plant family. In comparison, using data extracted from the temperatezone literature, phloem-feeders exhibited lower host specificity in Papua New Guinea than in Germany, because in Papua New Guinea theywere dominated by generalist Fulgoroideawhile in Germany by specialistMembracoidea. The similarity of Auchenorrhyncha assemblages from different plant species was unrelated to the phylogenetic distance between their hosts. Host specificity, abundance and species composition of Auchenorrhyncha assemblages were unrelated to the optimum of their host plant species on succession gradient from secondary to primary forest. Higher host specificity did not lead to greater species richness in Auchenorrhyncha assemblages feeding on different plant species, but the number of species feeding on a particular plant species was a strong predictor of the Auchenorrhyncha abundance on that plant. These patterns suggest that Auchenorrhyncha assemblages on these plant species are not saturated with species and determined by division of limited resources among competitors, but instead are dependent on the number of colonizers from the regional species pool. © Cambridge University Press 2013.
Klimes P.,University of South Bohemia |
Klimes P.,Academy of Sciences of the Czech Republic |
Idigel C.,New Guinea Binatang Research Center |
Rimandai M.,New Guinea Binatang Research Center |
And 7 more authors.
Journal of Animal Ecology | Year: 2012
Species diversity of arboreal arthropods tends to increase during rainforest succession so that primary forest communities comprise more species than those from secondary vegetation, but it is not well understood why. Primary forests differ from secondary forests in a wide array of factors whose relative impacts on arthropod diversity have not yet been quantified. We assessed the effects of succession-related determinants on a keystone ecological group, arboreal ants, by conducting a complete census of 1332 ant nests from all trees with diameter at breast height≥5cm occurring within two (unreplicated) 0·32-ha plots, one in primary and one in secondary lowland forest in New Guinea. Specifically, we used a novel rarefaction-based approach to match number, size distribution and taxonomic structure of trees in primary forest communities to those in secondary forest and compared the resulting numbers of ant species. In total, we recorded 80 nesting ant species from 389 trees in primary forest but only 42 species from 295 trees in secondary forest. The two habitats did not differ in the mean number of ant species per tree or in the relationship between ant diversity and tree size. However, the between-tree similarity of ant communities was higher in secondary forest than in primary forest, as was the between-tree nest site similarity, suggesting that secondary trees were more uniform in providing nesting microhabitats. Using our rarefaction method, the difference in ant species richness between two forest types was partitioned according to the effects of higher tree density (22·6%), larger tree size (15·5%) and higher taxonomic diversity of trees (14·3%) in primary than in secondary forest. The remaining difference (47·6%) was because of higher beta diversity of ant communities between primary forest trees. In contrast, difference in nest density was explained solely by difference in tree density. Our study shows that reduction in plant taxonomic diversity in secondary forests is not the main driver of the reduction in canopy ant species richness. We suggest that the majority of arboreal species losses in secondary tropical forests are attributable to simpler vegetation structure, combined with lower turnover of nesting microhabitats between trees. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.
Vlasanek P.,Academy of Sciences of the Czech Republic |
Sam L.,Griffith University |
Sam L.,New Guinea Binatang Research Center |
Novotny V.,Academy of Sciences of the Czech Republic |
Novotny V.,New Guinea Binatang Research Center
Ecological Entomology | Year: 2013
In an intensive mark-release-recapture study of all butterfly species in a tropical rainforest understory, 5903 individuals from 90 butterfly species (from the estimated total of 104 ± 9 species present in understory habitat) were marked, and 1308 recaptured at least once. The study proved that mark-recapture methods are feasible in tropical rainforests, but also showed its limitations, as after 232 person-days of sampling we could only characterise dispersal for one-third of the species present. The mean dispersal distance was 184 ± 46.1 m per species, while for six of the 14 species studied >1% of individuals were estimated to disperse 1 km or more. These parameters are, however, strongly dependent on the size and spatial configuration of the study plots, particularly in large homogeneous habitats. A new method proposed here to correct this bias revised the mean distance between two captures from 135 ± 33.6 to 325 ± 87.0 m per species. These results, in combination with data from large permanent rainforest plots, suggest that most woody plant species in tropical forests are sufficiently abundant to serve as host plant species even to monophagous Lepidoptera species. © 2013 The Royal Entomological Society.
Sam K.,University of South Bohemia |
Koane B.,New Guinea Binatang Research Center
Bulletin of the British Ornithologists' Club | Year: 2014
The north slopes of Mt. Wilhelm, the highest peak in Papua New Guinea, support a complete elevational gradient of relatively undisturbed rainforest, from 200 m to the tree line at 3,700 m. Based on field work in 2010 and 2012 over the Mt. Wilhelm elevational gradient, we report novel distribution data for 43 species, including geographic and elevational range extensions, demographic data, and new records of species poorly known in New Guinea. © 2014 British Ornithologists' Club.
Nieves-Aldrey J.L.,CSIC - National Museum of Natural Sciences |
Butterill P.T.,Academy of Sciences of the Czech Republic |
Butterill P.T.,New Guinea Binatang Research Center
Zootaxa | Year: 2014
Lithonecrus papuanus Nieves-Aldrey & Butterill, a new genus and species of inquiline oak gall wasps (Hymenoptera: Cynipidae: Synergini), is described from material reared from galls on Lithocarpus celebicus (Miq.) Rehd., collected in Papua New Guinea. The new genus and species is the first record of a cynipid from Papua New Guinea and the whole Oceanian biogeographic region, and represents the easternmost oriental record of a cynipid wasp (Hymenoptera: Cynip-idae). The new genus is similar to Saphonecrus Dalla Torre & Kieffer, and to the recently described Lithosaphonecrus Tang, Melika & Bozsó, but differs from these genera in several important diagnostic characters. Taxonomic affinities and differences with related genera and species and biogeographical implications are discussed. Copyright © 2014 Magnolia Press.
Klimes P.,University of South Bohemia |
Klimes P.,New Guinea Binatang Research Center |
McArthur A.,South Australian Museum
Myrmecological News | Year: 2014
New Guinea is one of the last remaining regions of extensive tropical forest and is an important biodiversity hotspot, yet most of its canopy ant species are poorly known. Here, we provide the first study of arboricolous ant communities of the genus Camponotus MAYR, 1861 from a lowland rainforest in New Guinea. We censused Camponotus nests in trees from two 0.32 ha forest plots in primary forest (389 trees) and secondary forest (296 trees) and explored their species diversity and nesting preferences. In total, 293 nests of 19 species were found. In 16 of the 19 species, major workers exhibited a set of morphological traits (i.e., flattened anterior part of head, swollen fore femora and maximal distance between frontal carinae greater than a third of head width) associated with phragmosis, an adaptation for arboricolous nesting. In primary forest, we detected 15 species in 124 nests versus only eight species in 169 nests in secondary forest. Only four species were shared between the two forest plots. Camponotus species differed significantly in their prefer-ences for nesting microhabitats in both forest plots, ranging from species that were opportunistic and relatively abundant to those that specialized and nested only in living tree branches high in the canopy where they tended myrmecophilous scale insects. Of the 19 species collected, 13 are newly reported for New Guinea, including four that are described here as new species: Camponotus anezkae sp.n., Camponotus rotundus sp.n., Camponotus triangulatus sp.n. and Campo-notus wanangus sp.n. In addition, Camponotus aruensis KARAVAIEV, 1933 is redescribed. Diagnostic features for species identification, digital photos of all available castes and morphological measurements are provided. The study demons-trates the high diversity of arboricolous Camponotus ants and their nesting habits within a single tropical forest site.
Konecna M.,University of South Bohemia |
Urlacher S.S.,New Guinea Binatang Research Center |
Urlacher S.S.,Harvard University
American Journal of Physical Anthropology | Year: 2015
Objectives Cultural practices may compromise the accuracy of salivary hormone measurements and must be considered when designing human biology research protocols. This study aims to evaluate the acute effect of one common human practice-chewing betel nut-on the measurement of salivary cortisol levels under field conditions. Materials and Methods Data were collected from 17 adult habitual betel nut users (males = 11; females = 6; mean age = 32.8 years) from a small rural community in Papua New Guinea. Saliva was collected in time series from each participant before and at 0, 15, 30, 45, 60, and 75 min after chewing betel nut. Samples were analyzed by radioimmunoassay and cortisol levels were compared across time using linear mixed effects modeling. Results Measured mean cortisol concentration fell nearly 40% immediately following betel nut use and remained significantly below baseline levels for the following 45 min (all P < 0.05). Cortisol concentrations measured at 60 min and 75 min were indistinguishable from baseline levels (all P > 0.16). Discussion Chewing betel nut is associated with a transient but significant reduction in measured levels of salivary cortisol. Future research must take this into account in populations where betel nut use is prevalent. Am J Phys Anthropol 158:151-154, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
PubMed | University of South Bohemia, Griffith University, New Guinea Binatang Research Center and Academy of Sciences of the Czech Republic
Type: | Journal: Journal of evolutionary biology | Year: 2016
Much of the worlds insect and plant biodiversity is found in tropical and subtropical hotspots, which often include long elevational gradients. These gradients may function as diversity pumps and contribute to both regional and local species richness. Climactic conditions on such gradients often change rapidly along short vertical distances, and may result in local adaptation and high levels of population genetic structure in plants and insects. We investigated the population genetic structure of two species of Ficus (Moraceae) along a continuously forested elevational gradient in Papua New Guinea. This speciose plant genus is pollinated by tiny, species specific and highly co-evolved chalcid wasps (Agaonidae) and represented by at least 73 species at our study gradient. We present results from two species of Ficus sampled from six elevations between 200 m-2,700 m a.s.l. (almost the entire elevational range of the genus) and 10 polymorphic microsatellite loci. These results show that strong barriers to gene flow exist between 1,200 m and 1,700 m a.s.l. Whereas lowland populations are panmictic across distances over 70 km, montane populations can be disjunct over 4 km, despite continuous forest cover. We suggest that the limited gene flow between populations of these two species of montane Ficus maybe driven by environmental limitations on pollinator or seed dispersal in combination with local adaptation of Ficus populations. Such a mechanism may have wider implications for plant and pollinator speciation across long and continuously forested elevational gradientsif generalist insect pollinators and vertebrate seed dispersers also form populations based on elevation. This article is protected by copyright. All rights reserved.