scholarly journals Do Tunnel Patterns of Coptotermes formosanus and Coptotermes gestroi (Blattodea: Rhinotermitidae) Reflect Different Foraging Strategies?

Sociobiology ◽  
2014 ◽  
Vol 59 (1) ◽  
pp. 189 ◽  
Author(s):  
Nirmala K. Hapukotuwa ◽  
J. Kenneth Grace
Keyword(s):  
Coptotermes Formosanus ◽  
Foraging Strategies ◽  
Tropical Species ◽  
Tunnel Length ◽  
Network Construction ◽  
The Pacific ◽  
Homogenous Distribution ◽  
Coptotermes Gestroi ◽  
The Tropics ◽  
Tunneling Behavior

Tunnel network construction and time to food (wood) discovery by Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae) (formerly known as Coptotermes vastator Light in the Pacific region) was examined when wood was present in a clumped distribution that mimics field conditions in the subtropical and temperate regions where C. formosanus naturally occurs. Previous research has noted that the tropical species C. gestroi constructs a highly branched tunnel network, while the subtropical C. formosanus constructs longer tunnels with few branches. Grace et al. (2004) hypothesized that this difference in tunneling behavior may relate to a more homogenous distribution of woody resources in the tropics vs. a disjunct and clumped distribution of fallen wood in the cooler subtropics. Thus, C. gestroi may exhibit a thorough search of the immediate area where wood is initially located, while it may be more energetically efficient for C. formosanus to tunnel greater distances in search of scattered resources. To test this hypothesis, we placed two wood resources at the opposite ends of laboratory foraging arenas, and released 1500 termites (1350 workers: 150 soldiers) into each arena. Arenas were observed every 24 hours for 14 days. We measured the total daily tunnel length, number of tunnels created in each quadrant of the arenas, and average time to discover food at both ends. Total daily tunnel length was relatively longer with C. formosanus and average time to discover food at either end was longer for C. gestroi. Although replication was limited in this study, these observations lend support to the hypothesis that C. formosanus is able to locate distant resources more efficiently than C. gestroi.

scholarly journals Coptotermes formosanusandCoptotermes gestroi(Blattodea: Rhinotermitidae) Exhibit Quantitatively Different Tunneling Patterns

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Nirmala K. Hapukotuwa ◽  
J. Kenneth Grace
Keyword(s):  
Spatial Dispersion ◽  
Coptotermes Formosanus ◽  
Subterranean Termite ◽  
Foraging Strategies ◽  
Subterranean Termites ◽  
Termite Species ◽  
Coptotermes Gestroi ◽  
Distribution And Ecology ◽  
Tunneling Behavior ◽  
Made In

Tunneling behavior and the spatial dispersion of tunnels constructed by the subterranean termitesCoptotermes formosanusShiraki andCoptotermes gestroi(Wasmann) (formerly known asC. vastatorLight) (Blattodea: Rhinotermitidae) were examined in foraging arenas. The results indicated that these two termite species construct quantitatively different tunnel systems, supporting visual observations made in earlier studies.Coptotermes gestroiconstructed thin, highly branched tunnels, whileC. formosanustended to construct wider and less branched tunnels. Tunnels ofC. gestroishowed more spatial dispersion than those ofC. formosanus, and this species constructed a larger number of tunnels compared toC. formosanus. The presence or absence of food (wood) within the arena did not influence the tunneling pattern of either species. Although previous observations have suggested that these two termite species exhibit different tunneling behaviors; this is the first quantification of the differences. Comparative studies of the foraging behavior of subterranean termite species contribute to our understanding of their distribution and ecology and may help to improve pest management programs, particularly those based on placement of toxic baits. Moreover, differences in tunneling patterns may reflect different foraging strategies optimized for either tropical (C. gestroi) or subtropical/temperate (C. formosanus) environments.

scholarly journals Interspecific and intraspecific foraging differentiation of neighbouring tropical seabirds

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
R. E. Austin ◽  
F. De Pascalis ◽  
S. C. Votier ◽  
J. Haakonsson ◽  
J. P. Y. Arnould ◽  
...  
Keyword(s):  
Large Population ◽  
Foraging Strategies ◽  
Tropical Species ◽  
Cayman Islands ◽  
Seabird Species ◽  
Data Loggers ◽  
Foraging Decisions ◽  
The Caribbean ◽  
Coexisting Species ◽  
The Tropics

Abstract Background Social interactions, reproductive demands and intrinsic constraints all influence foraging decisions in animals. Understanding the relative importance of these factors in shaping the way that coexisting species within communities use and partition resources is central to knowledge of ecological and evolutionary processes. However, in marine environments, our understanding of the mechanisms that lead to and allow coexistence is limited, particularly in the tropics. Methods Using simultaneous data from a suite of animal-borne data loggers (GPS, depth recorders, immersion and video), dietary samples and stable isotopes, we investigated interspecific and intraspecific differences in foraging of two closely-related seabird species (the red-footed booby and brown booby) from neighbouring colonies on the Cayman Islands in the Caribbean. Results The two species employed notably different foraging strategies, with marked spatial segregation, but limited evidence of interspecific dietary partitioning. The larger-bodied brown booby foraged within neritic waters, with the smaller-bodied red-footed booby travelling further offshore. Almost no sex differences were detected in foraging behaviour of red-footed boobies, while male and female brown boobies differed in their habitat use, foraging characteristics and dietary contributions. We suggest that these behavioural differences may relate to size dimorphism and competition: In the small brown booby population (n < 200 individuals), larger females showed a higher propensity to remain in coastal waters where they experienced kleptoparasitic attacks from magnificent frigatebirds, while smaller males that were never kleptoparasitised travelled further offshore, presumably into habitats with lower kleptoparasitic pressure. In weakly dimorphic red-footed boobies, these differences are less pronounced. Instead, density-dependent pressures on their large population (n > 2000 individuals) and avoidance of kleptoparasitism may be more prevalent in driving movements for both sexes. Conclusions Our results reveal how, in an environment where opportunities for prey diversification are limited, neighbouring seabird species segregate at-sea, while exhibiting differing degrees of sexual differentiation. While the mechanisms underlying observed patterns remain unclear, our data are consistent with the idea that multiple factors involving both conspecifics and heterospecifics, as well as reproductive pressures, may combine to influence foraging differences in these neighbouring tropical species.

Systematics, Biogeography, and Morphological Character Evolution of the Hemiepiphytic Subfamily Monsteroideae (Araceae)

2019 ◽  
Vol 104 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Alejandro Zuluaga ◽  
Martin Llano ◽  
Ken Cameron
Keyword(s):  
Dna Sequences ◽  
Pacific Islands ◽  
R Package ◽  
Morphological Characters ◽  
Ancestral State ◽  
Seed Shape ◽  
Long Distance ◽  
The Pacific ◽  
And Migration ◽  
The Tropics

The subfamily Monsteroideae (Araceae) is the third richest clade in the family, with ca. 369 described species and ca. 700 estimated. It comprises mostly hemiepiphytic or epiphytic plants restricted to the tropics, with three intercontinental disjunctions. Using a dataset representing all 12 genera in Monsteroideae (126 taxa), and five plastid and two nuclear markers, we studied the systematics and historical biogeography of the group. We found high support for the monophyly of the three major clades (Spathiphylleae sister to Heteropsis Kunth and Rhaphidophora Hassk. clades), and for six of the genera within Monsteroideae. However, we found low rates of variation in the DNA sequences used and a lack of molecular markers suitable for species-level phylogenies in the group. We also performed ancestral state reconstruction of some morphological characters traditionally used for genera delimitation. Only seed shape and size, number of seeds, number of locules, and presence of endosperm showed utility in the classification of genera in Monsteroideae. We estimated ancestral ranges using a dispersal-extinction-cladogenesis model as implemented in the R package BioGeoBEARS and found evidence for a Gondwanan origin of the clade. One tropical disjunction (Monstera Adans. sister to Amydrium Schott–Epipremnum Schott) was found to be the product of a previous Boreotropical distribution. Two other disjunctions are more recent and likely due to long-distance dispersal: Spathiphyllum Schott (with Holochlamys Engl. nested within) represents a dispersal from South America to the Pacific Islands in Southeast Asia, and Rhaphidophora represents a dispersal from Asia to Africa. Future studies based on stronger phylogenetic reconstructions and complete morphological datasets are needed to explore the details of speciation and migration within and among areas in Asia.

scholarly journals Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution

2017 ◽  
Vol 4 (4) ◽  
pp. 170105 ◽  
Author(s):  
Karen L. Bell ◽  
Haripriya Rangan ◽  
Manuel M. Fernandes ◽  
Christian A. Kull ◽  
Daniel J. Murphy
Keyword(s):  
The Philippines ◽  
Historical Sources ◽  
Long Distance ◽  
Old World ◽  
South Central ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Spanish Explorers ◽  
The Tropics ◽  
Old World Tropics

Acacia s.l. farnesiana , which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human-mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human-mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal for disjunct plant distributions.

scholarly journals Impact of dams and irrigation schemes in Anopheline (Diptera: Culicidae) bionomics and malaria epidemiology

2012 ◽  
Vol 54 (4) ◽  
pp. 179-191 ◽  
Author(s):  
Jordi Sanchez-Ribas ◽  
Gabriel Parra-Henao ◽  
Anthony Érico Guimarães
Keyword(s):  
Control Measures ◽  
Successful Implementation ◽  
Negative Effects ◽  
Irrigation Scheme ◽  
Tropical Regions ◽  
Malaria Epidemiology ◽  
The Pacific ◽  
The Tropics ◽  
And Control ◽  
Anopheline Mosquitoes

Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas). Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.

scholarly journals Coastal Wave Extremes around the Pacific and Their Remote Seasonal Connection to Climate Modes

Climate ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 168
Author(s):  
Julien Boucharel ◽  
Loane Santiago ◽  
Rafael Almar ◽  
Elodie Kestenare
Keyword(s):  
Large Scale ◽  
Wind Wave ◽  
Boreal Summer ◽  
Opposite Hemisphere ◽  
Ocean Surface Waves ◽  
First Order ◽  
Coastal Waves ◽  
The Pacific ◽  
Wide Range ◽  
The Tropics

At first order, wind-generated ocean surface waves represent the dominant forcing of open-coast morpho-dynamics and associated vulnerability over a wide range of time scales. It is therefore paramount to improve our understanding of the regional coastal wave variability, particularly the occurrence of extremes, and to evaluate how they are connected to large-scale atmospheric regimes. Here, we propose a new “2-ways wave tracking algorithm” to evaluate and quantify the open-ocean origins and associated atmospheric forcing patterns of coastal wave extremes all around the Pacific basin for the 1979–2020 period. Interestingly, the results showed that while extreme coastal events tend to originate mostly from their closest wind-forcing regime, the combined influence from all other remote atmospheric drivers is similar (55% local vs. 45% remote) with, in particular, ~22% coming from waves generated remotely in the opposite hemisphere. We found a strong interconnection between the tropical and extratropical regions with around 30% of coastal extremes in the tropics originating at higher latitudes and vice-versa. This occurs mostly in the boreal summer through the increased seasonal activity of the southern jet-stream and the northern tropical cyclone basins. At interannual timescales, we evidenced alternatingly increased coastal wave extremes between the western and eastern Pacific that emerge from the distinct seasonal influence of ENSO in the Northern and SAM in the Southern Hemisphere on their respective paired wind-wave regimes. Together these results pave the way for a better understanding of the climate connection to wave extremes, which represents the preliminary step toward better regional projections and forecasts of coastal waves.

scholarly journals Dispersion to the Tropics of the Spiraea Aphid, Aphis spiraecola Patch

1969 ◽  
Vol 39 (1) ◽  
pp. 32-40
Author(s):  
George N. Wolcott
Keyword(s):  
United States ◽  
Puerto Rico ◽  
Central America ◽  
Pacific Coast ◽  
Virus Disease ◽  
Aphis Spiraecola ◽  
The Pacific ◽  
Northern United States ◽  
The Tropics ◽  
Young Growth

The spiraea aphid, Aphis spiraecola Patch, which previous to 1924 was known only on species of Spiraea in the northern United States, in that year appeared in mass infestations on citrus trees in Florida and Cuba, causing enormous damage by distorting and resetting the young growth. By 1926 it had spread to Puerto Rico, attacking not only various endemic trees and plants, but being implicated in the transmission of a new virus disease of papaya. By 1928, it was reported on citrus from Honduras in Central America, and it has since dispersed to Costa Rica, and on a great variety of hosts to California, Oregon, and Washington on the Pacific Coast.

Statistical Characterization of Zonal and Meridional Ocean Wind Stress

2005 ◽  
Vol 22 (9) ◽  
pp. 1353-1372 ◽  
Author(s):  
Sarah T. Gille
Keyword(s):  
Wind Stress ◽  
Frequency Spectra ◽  
Low Frequencies ◽  
Statistical Characterization ◽  
Weather Forecasts ◽  
The Pacific ◽  
Meridional Winds ◽  
Wind Events ◽  
Environmental Prediction ◽  
The Tropics

Abstract Four years of ocean vector wind data are used to evaluate statistics of wind stress over the ocean. Raw swath wind stresses derived from the Quick Scatterometer (QuikSCAT) are compared with five different global gridded wind products, including products based on scatterometer observations, meteorological analysis winds from the European Centre for Medium-Range Weather Forecasts, and reanalysis winds from the National Centers for Environmental Prediction. Buoy winds from a limited number of sites in the Pacific Ocean are also considered. Probability density functions (PDFs) computed for latitudinal bands show that mean wind stresses for the six global products are largely in agreement, while variances differ substantially, by a factor of 2 or more, with swath wind stresses indicating highest variances for meridional winds and for zonal winds outside the Tropics. Higher moments of the PDFs also differ. Kurtoses are large for all wind products, implying that PDFs are not Gaussian. None of the available gridded products fully captures the range of extreme wind events seen in the raw swath data. Frequency spectra for the five gridded products agree with frequency spectra from swath data at low frequencies, but spectral slopes differ at higher frequencies, particularly for frequencies greater than 100 cycles per year (cpy), which are poorly resolved by a single scatterometer. In the frequency range between 10 and 90 cpy that is resolved by the scatterometer, spectra derived from swath data are flatter than spectra from gridded products and are judged to be flatter than ω−2/3 at all latitudes.

Phylogenetic relationships among species of Ganoderma (Ganodermataceae, Basidiomycota) from Cameroon

2012 ◽  
Vol 60 (6) ◽  
pp. 526 ◽  
Author(s):  
T. R. Kinge ◽  
A. M. Mih ◽  
M. P. A. Coetzee
Keyword(s):  
Plant Species ◽  
Phylogenetic Relationships ◽  
Internal Transcribed Spacer ◽  
New Records ◽  
Small Subunit ◽  
Species Level ◽  
Molecular Techniques ◽  
Tropical Species ◽  
The Tropics

Ganoderma is an important genus of the Polyporales in the tropics. Identification of tropical species has mainly been based on morphology, which has led to misidentification. This study aimed to elucidate the diversity and phylogenetic relationships of Ganoderma isolates from different hosts in Cameroon using morphological and molecular techniques. Analyses of basidiocarp morphology and the internal transcribed spacer and mitochondria small subunit were undertaken for 28 isolates from five plant species. The results show that the isolates belong to eight species. Three of the species were identified to species level; of these only G. ryvardense has been previously described from Cameroon while G. cupreum and G. weberianum are new records. The five remaining species did not match with any previously described species and have been designated as Ganoderma with different species affinities.

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