No abstract

Strains of the genera Saccharopolyspora and Streptomyces were isolated from Protopolybia sp. and Metapolybia sp. social wasps in Costa Rica. Draft genome sequences were obtained for six isolates, ranging from 6.4 Mb to 9.1 Mb long and having GC contents of 71 to 73%.

Los insectos son un grupo de organismos indispensables en los ecosistemas naturales y en aquellos modificados por el hombre como los cultivos y las ciudades. Estos organismos han sido estudiados desde hace mucho tiempo; sin embargo, con el surgimiento de áreas como la biotecnología, el enfoque que se le ha dado a los estudios con insectos está cambiando. Un caso es el de los insectos sociales, organismos que están siendo investigados debido a las relaciones simbióticas que mantienen con microorganismos productores de sustancias antimicrobianas. Es por este motivo que en el Centro de Investigación en Biotecnología (CIB) del Instituto Tecnológico de Costa Rica (ITCR) se están realizando dos estudios para determinar la presencia de actinobacterias en colonias de avispas sociales, y probar su actividad antibiótica. Se aislaron 49 cepas de microorganismos con morfología de actinomicetos de las celdas de cría, y la actividad antibiótica se midió en 45 cepas de las cuales 36 (80%) mostraron actividad positiva contra patógenos. Otro proyecto pretende aislar microorganismos de las glándulas y cutícula de los adultos de avispas, al ser éstos posiblemente los que dispersan las sustancias antibióticas por la colonia. Los resultados obtenidos demuestran que las avispas Epiponini sí mantienen relaciones simbióticas con actinomicetos, y que algunas cepas presentan actividad antibiótica. Esto demuestra que estos organismos tienen un gran potencial para el desarrollo de investigaciones biotecnológicas.

In the Epiponini, queen number declines through colony cycle, becausesome queens are expelled from colonies. Here we demonstratethat Epiponini wasps may accept expelled queens in situations ofqueenlessness. One colony of Protopolybia exigua was observed at theUniversity of São Paulo in Brazil; and another of Metapolybia docilis wasobserved at La Selva Biological Station in Costa Rica. Queen removaltests were performed to study workers’ acceptance of expelled queensand queens from other colonies. In P. exigua, the experimental queenelimination caused a change in the workers’ behavior, ranging fromaggressive expulsion of non-selected queens to re-acceptance. In M.docilis workers were willing to accept queens from other colonies afterqueen elimination. Our results indicate that because of a decrease inworkers aggressiveness during the colony cycle, workers may acceptexpelled queens (even foreign ones, in experimental situations) in orderto ensure colony survival.

The coNSEquences of climate change have challenged researchers to generate models and projections to understand climate behavior under different scenarios. In Costa Rica, as in other countries, climate-change (CC) models and projections are essential to make decisions about the management of natural resources, mainly water. To understand climate change’s impact on hydraulic parameters such as velocity, depth, and river surface area, we studied the Pejibaye river basin, located in Jiménez in Cartago, Costa Rica. This watershed is characterized by having more than 90% of its surface area covered by forest. We used the precipitation and temperature data from meteorological stations (2000 to 2009) and climate-change scenarios (2000–2099) to predict the response of the basin in different periods. First, we calibrated (NSE = 0.77) and validated (NSE = 0.81) the HBV hydrological model using ten years of daily data from 2000 to 2009. The climate-change data (2000–2099) were incorporated into the calibrated HBV model. This allowed us to determine the impact of CC on the basin water regime for the periods 2040–2059 (CCS1) and 2080–2099 (CCS2). The IBER mathematical model was used to determine the changes in the hydraulic variables of the river flow. For the CCS1, we determined a 10.9% decrease in mean velocity and a 0.1-meter decrease in depth, while for CCS2, the effect will be an 11.3% reduction in mean velocity and a 0.14-meter decrease in depth. The largest decreases in river surface area per kilometer will occur in May (1710 m2) for CCS1 and April (2250 m2) for CCS2.