401 research outputs found
Taxonomic notes on the genus Euaspis Gerstäcker (Hymenoptera: Apoidea: Megachilidae) from Vietnam
Taxonomic notes on species of the genus Euaspis Gerstäcker, 1858 (Hymenoptera: Megachilidae) from Vietnam are presented. Three species of the genus are reported: E. aequicarinata Pasteels is recorded in the central highlands Vietnam (Kon Tum Province) beside the previous record of this species in the northwest (Hoa Binh Province); E. polynesia Vachal is widely recorded throughout Vietnam; the taxonomy of Vietnamese Euaspis basalis (Ritsema, 1874) is a misidentification, and it is indeed Euaspis diversicarinata Pasteels, 1980 and is a new record from Vietnam. A key to the females of Vietnamese species of Euaspis Gerstäcker and a redescription of the female of E. diversicarinata are given with illustrations
Two new genera and species of the termite symbiont lineage Termitohospitini (Coleoptera, Staphylinidae, Aleocharinae) from Bolivia and peninsular Malaysia
Coptotermocola clavicornis gen. & sp. n. and Neotermitosocius bolivianus gen. & sp. n. of the termite inquilinous tribe Termitohospitini are described from peninsular Malaysia and Bolivia, respectively. The Termitohospitini are most readily diagnosable by the distally migrated anterior tentorial pits that are no longer associated with the antennal fossae, and by the enlarged vertex which obscures the antennal fossae dorsally. Additionally, the Termitohospitini are hypothesized to share a recent common ancestor with the Masuriini and Myllaenini due to shared derived morphologies of the lacinia distal teeth with lateral cuticular processes, presence of a unique maxillary palpomere III sensilla, and anterolateral angles of mentum produced. Habitus photographs and illustrations of diagnostic features are provided for the two new genera in order to facilitate future work
Determinants of Bilateral Trade between Ethiopia and Its Major Trading Partners’: A Gravity Model Approach
International trade has increasingly become a keystone of economic prosperity in many countries of the world. Ethiopia is the one which benefit from foreign trade. Therefore, the main focus of this paper is to identify factors influencing bilateral trade between Ethiopia and its major trading partners’. The gravity model of trade was employ for the purpose. A gravity model based on a panel data for the period of 10 years (2000-2009) of sample countries was estimated by fixed effect estimators. The coefficients obtained are then used to predict the basic total trade and export trade potentials for Ethiopia. As a result, we found that the total trade flow was determine by mass (economic size) of the importing and exporting countries, real bilateral exchange rate, FDI of Ethiopia, weighted distance and bordering between Ethiopia and the major trading parents. Ethiopia's export performance to those major trading countries’ are also determine by GDP of the importing countries, GDP of the exporting country, the weighted distance. The results of this study indicate that a depreciation of the real exchange rate would affect the international competitiveness of Ethiopian exports, therefore, we recommends Depreciation of a country's real exchange rate because it will cause a gain in competitiveness of that country and government needs also to pay adequate attention to destination markets with cheaper transport costs. Keywords: Trade Flows, Gravity Model, Ethiopia
Opportunistic Occupation of Nests of Microcerotermes spp. Silvestri (Termitidae, Termitinae) by Partamona seridoensis Camargo & Pedro (Apidae, Meliponini) in the Brazilian Tropical Dry Forest
Social bees make use of natural or animal-built structures to protect their colonies from environmental stressors. Here, particularly attractive shelters are active termite nests because they provide a stable climatic environment for inquilines. Several social bee species form obligatory associations with termites, among these the stingless bee Partamona seridoensis (Apidae, Meliponini), whose distribution is limited to the Tropical Dry Forest in the Brazilian Northeast. So far, colonies of this meliponine species have been found mainly in arboreal nests of the termite Constrictotermes cyphergaster, which suggests a tight relationship between these two social insect species. The present study was conducted in an area of the Tropical Dry Forest in the Brazilian State of Rio Grande do Norte, where P. seridoensis naturally occurs albeit the absence of C. cyphergaster. We registered 14 colonies of P. seridoensis, all occupying active arboreal nests of termites of the genus Microcerotermes. The only other termites with arboreal nests present in the study area, Nasutitermes corniger, never housed P. seridoensis. This selective preference of the bees for Microcerotermes nests might be due to differences between termites concerning defense mechanisms or concerning thermal stability within the nests
How informative are in-sample information criteria to forecasting? the case of Chilean GDP
There is no standard economic forecasting procedure that systematically outperforms the others at all horizons and with any dataset. A common way to proceed, in many contexts, is to choose the best model within a family based on a fitting criteria, and then forecast. I compare the out-of-sample performance of a large number of autoregressive integrated moving average (ARIMA) models with some variations, chosen by three commonly used information criteria for model building: Akaike, Schwarz, and Hannan-Quinn. I perform this exercise to identify how to achieve the smallest root mean squared forecast error with models based on information criteria. I use the Chilean GDP dataset, estimating with a rolling window sample to generate one- to four-step ahead forecasts. Also, I examine the role of seasonal adjustment and the Easter effect on out-of-sample performance. After the estimation of more than 20 million models, the results show that Akaike and Schwarz are better criteria for forecasting purposes where the traditional ARMA specification is preferred. Accounting for the Easter effect improves the forecast accuracy only with seasonally adjusted data, and second-order stationarity is best.data mining; forecasting; ARIMA; seasonal adjustment; Easter-effect
Analysis of Trade in Goods between Indonesia and South Korea on Cooperation Forum IKCEPA
Abstract: Indonesia Korea Comprehensive Economic Cooperation Partnership (IKCEPA) arises from the desire of both countries to boost trade performance and make the free trade agreement more comprehensive. CEPA agreement with South Korea has targeted the reduction and elimination of tariffs that cover more products and services. This study analyzed the relationship between Indonesia merchandise trade cooperation with South Korea. Besides, look at the potential of the Korean market for goods exports from Indonesia featured. To deepen the study simple equilibrium analysis is used to analyze the potential of the South Korean market for goods exports Indonesia. The analysis showed that after the implementation of AKFTA in 2007, Indonesia merchandise trade performance by sector turned out to have an average growth of imports by 21.36 percent, higher than the average export growth of 8.19 percent. There are some items which have the potential to become a mainstay of exports to Korea that includes textiles, wood processing, manufacturing goods such as spare parts of household appliances, bicycles and others. Likewise, there are some agricultural products such as pineapple, guava, and animals such as freshwater fish, crabs, cuttlefish and others. However, the export of these items to South Korea is still hampered by their tariff barriers. Forum IKCEPA cooperation can be a bridge to fill the gap between the two countries for tariff reduction, market acces and an increase in exports of both countries.Keywords: IKCEPA, negotiation, expor
How Informative are In–Sample Information Criteria to Forecasting? The Case of Chilean GDP
There is no standard economic forecasting procedure that systematically outperforms the others at all horizons and with any dataset. A common way to proceed, in many contexts, is to choose the best model within a family based on a fitting criteria, and then forecast. I compare the out-of-sample performance of a large number of autoregressive integrated moving average (ARIMA) models with some variations, chosen by three commonly used information criteria for model building: Akaike, Schwarz, and Hannan-Quinn. I perform this exercise to identify how to achieve the smallest root mean squared forecast error with models based on information criteria. I use the Chilean GDP dataset, estimating with a rolling window sample to generate one- to four-step ahead forecasts. Also, I examine the role of seasonal adjustment and the Easter effect on out-of-sample performance. After the estimation of more than 20 million models, the results show that Akaike and Schwarz are better criteria for forecasting purposes where the traditional ARMA specification is preferred. Accounting for the Easter effect improves the forecast accuracy only with seasonally adjusted data, and second-order stationarity is best.
Alocanthedon, a new subgenus of Chalicodoma from Southeast Asia (Hymenoptera, Megachilidae)
This is the publisher's version, also available electronically from http://www.pensoft.net.A new subgenus, Alocanthedon Engel and Gonzalez subg. n., is described for five species of unusual Southeast Asian bees in the genus Chalicodoma Lepeletier de Saint Fargeau (Megachilinae: Megachilini). The subgenus is most noteworthy for the deep postgenal depression or furrow in males (bordered outwardly near the base of the mandible by a protuberant, thick lamella) and the presence of a dense patch of black setae posteriorly in the forewing medial cell (except in one species) [resembling the dense patch of setae among the submarginal cells of Thrinchostoma Saussure (Halictidae: Halictinae: Halictini)]. The subgenus is characterized and distinguished from the related Callomegachile Michener. A key to the following five species presently included in the subgenus is provided: Chalicodoma aterrimum (Smith), C. atratiforme (Meade-Waldo) comb. n., C. memecylonae Engel sp. n., C. odontophorum Engel sp. n., and C. apoicola Engel sp. n. Chalicodoma (Callomegachile) atratiforme sininsulae (Cockerell) is newly placed in synonymy with C. (C.) fulvipenne (Smith). Species have been collected from Memecylaceae (Myrtales) and Fabaceae (Fabales). The phylogenetic relationships of Alocanthedon among other Megachilini are briefly elaborated upon
Unlike rolling stones: not every Myrmecina species actively rolls away from danger (Hymenoptera, Formicidae)
Actively rolling away is a very rare escape strategy in the animal kingdom, which to date has only been documented in a few arthropod and one vertebrate species. One of these arthropods is a West-Palearctic ant, Myrmecina graminicola, which has very recently been demonstrated to actively curb into a ball-like shape rolling away upon disturbance, and to selectively display this behavior only under particular circumstances. We tested whether one of the other three W-Palearctic Myrmecina species, the rare insular endemism M. sicula, exhibited the same behavioral response, using the same experimental approach used for M. graminicola. Our results showed that M. sicula reacted to moderate disturbance by either freezing its body or walking away. Only when the individual lost contact with the substratum, it could curl into a ball-like shape, yet this was significantly less refined than the one displayed by M. graminicola, as the appendages of M. sicula are not tightly kept close to its body. However, M. sicula never performed the active rolling behavior that is readily exhibited by M. graminicola. Ecological, morphological, and phylogenetic constraints may have determined the lack of a developed active rolling escape-strategy in M. sicula. Further investigations are required to assess the presence or absence of this unique behavior across Myrmecina lineages
A scientific note on the natural merger of two honeybee colonies (Apis mellifera capensis)
Natural mergers of honeybee colonies are commonplace in tropical Africa (Hepburn and Radloff, 1998), but their consequences on organizational structure are unknown. Here we determine the spatial distribution and division of labor of workers (Apis mellifera capensis Esch.) following a merger of two colonies. Two unrelated colonies (each ~3000 bees) were placed in threeframe observation hives. When workers emerged from the sealed brood of each colony, they were individually labeled and reintroduced into their respective mother hives. They are referred to as cohorts Aand B, each comprising 300 workers of the same age. The behaviors and positions of all labeled workers and queens were recorded twice daily for 24 days (Kolmes, 1989; Pirk et al., 2000). On day 14 colony B was dequeened, left its nest and merged with colony A on day 15
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