Colder is better: The differential effects of thermal acclimation on life history parameters in a parasitoid fly.

In this article, we assessed the effect of the rearing temperature on life history traits of the poorly known fly Phasmovora phasmophagae (Diptera: Tachinidae), a parasitoid of Agathemera crassa (Phasmatodea: Agathemeridae) in order to: i) test the effect of ambient temperature on life history traits and ii) assess the potential trade-off between reproduction and survival. Parasitoids were obtained from a population of hosts located in the Andes range of central Chile. Upon emergence from the host parasitoids were randomly allocated to three thermal treatments (15°C, 22.5°C and 30°C) and several life history traits were measured. We recorded higher survival at 15°C and 22.5°C and a lower survival at 30°C.We found differences for both body mass and head width among thermal treatments. In females, body mass was higher at 15°C than at 30°C. An effect of breeding temperature and sex was observed only for developmental time. In addition, males reared at different temperatures during the pupal stage and held as adults at 22.5°C, exhibited no differences in longevity between treatments. A significant effect of temperature on the mass of ovaries and lipid was recorded in females. These patterns suggest a trade-off between reproduction and survival. Overall, data seem to support the "colder is better" hypothesis, because Andean parasitoid P. phasmophagae inhabiting and experimentally reared in colder environments have a higher performance in all environments.

Comparative characterization of the hemocyanin-derived phenol oxidase activity from spiders inhabiting different thermal habitats.

Enzymes adapted to cold temperatures are commonly characterized for having higher Michaelis-Menten constants (KM) values and lower optimum and denaturation temperature, when compared to other meso or thermophilic enzymes. Phenoloxidase (PO) enzymes are ubiquitous in nature, however, they have not been reported in spiders. It is the oxygen carrier protein hemocyanin (Hc), found at high concentrations in their hemolymph, which displays an inducible PO activity. Hence, we hypothesize that Hc-derived PO activity could show features of cold adaptation in alpine species. We analyzed the Hc from two species of Theraphosidae from different thermal environments: Euathlus condorito (2400 m a.s.l.) and Grammostola rosea (500 m a.s.l.). Hc was purified from the hemolymph of both spiders and was characterized by identifying subunit composition and measuring the sodium dodecyl sulfate (SDS)-induced PO activity. The high-altitude spider Hc showed higher PO activity under all conditions and higher apparent Michaelis-Menten constant. Moreover, the optimum temperature for PO activity was lower for E. condorito Hc. These findings suggest a potential adaptation at the level of Hc-derived PO activity in Euathlus condorito, giving insights on possible mechanisms used by this mygalomorph spider to occupy extremes and variable thermal environments.

Touching the Sky: Coccinellids (Coleoptera: Coccinellidae) at High Altitudes in South America.

Records of extreme altitudes where several coccinellid species from South America inhabit the Andes of Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru are provided. After an intensive review of several entomological collections and literature, records for 35 species with at least one location over 3500-m elevation were obtained, including the genera Cycloneda (ten species), Eriopis (15 species and one subspecies), Harmonia (one species), Hippodamia (two species), Mimoscymnus (two species), Psyllobora (one species), and Stenadalia (four species). In total, 184 location records are listed, of which 119 were from between 3000 and 4000 m, 57 between 4000 and 4900 m and eight above 4900 m, with the highest altitude record at 5250 m for Eriopis minima Hofmann. All records above 4000 m were obtained in the Puna biogeographic province within the Paramo Puneña biogeographic subregion. These records are the highest altitudes observed for the American continent and by far surpass others known for coccinellids worldwide. Several species of coccinellids living in sympatry at these high altitudes were verified, and in some cases, in situ development was inferred by the presence of immature stages. These findings are important to foresee the future effects of global warming that will affect especially the biological communities of extreme altitudes.

Microartrópodos de la estepa altoandina altiplánica, con detalle de especies de oribátidos (Oribatida: Acarina) / Microarthropods from the altiplanic andean steppe, with focus on oribatid species (Oribatida: Acarina)

En los suelos asociados a plantas de la región altiplánica chilena más septentrional, se encontraron 20 ordenes o subordenes de microartrópodos, incluyendo 21 especies de ácaros Oribatida, bajo siete tipos de vegetación nativa y una de plantación; no se encontraron oribátidos en suelos alejados de la vegetación. En cuanto a los oribátidos, siete especies son la primera mención para Chile. Se entregan datos de abundancia promedio (nº ind./1000 ml) y se detalla la información de distribución geográfica y tipo de vegetación, además del estatus taxonómico actual para cada especie. Diez de estas especies forman un grupo coherente, propio de los ecosistemas altoandinos de Chile, Perú y Bolivia. Otras tres especies se han encontrado también en lugares más australes de Argentina y un grupo de ocho especies son de tendencia cosmopolita.

In soils under seven types of high altitude, native vegetation and one plantation in the northernmost Chilean Altiplanic region, 20 microarthropod orders or suborders were found, including 21 oribatid mite species. Seven of these species are first mentioned for Chile. No oribatid mites were found in soils far from vegetation. Data are given as average densities (nº ind./1000 ml), accounting for plant preference, geographical distribution and updated taxonomic status for each species. Ten oribatid species form a group of Andean altiplanic steppe fauna also found in Peru and Bolivia. Other three species have been also found in different austral ecosystems in Argentina, and a group of eight species seems to be cosmopolitan.