New records of ants (Hymenoptera: Formicidae) for Colombia / Nuevos registros de hormigas (Hymenoptera: Formicidae) para Colombia

Abstract Even though Colombia has high levels of ant species richness in the Neotropical region, this richness continues to increase. New records of the ant subfamilies Amblyoponinae, Dolichoderinae, Dorylinae, Myrmicinae, and Ponerinae are presented. Two species of Fulakora, two species of Azteca, one species of Cylindromyrmex, 25 species of Myrmicinae belonging to 12 genera (Acanthognathus, Basiceros, Daceton, Eurhopalothrix, Hylomyrma, Mycetomoellerius, Mycetophylax, Mycocepurus, Octostruma, Pheidole, Rogeria, and Talaridris), and one species of Leptogenys are registered for the first time for Colombia. Five species are new records for South America. For each species, the geographical distance of the record closest to the Colombian locality is offered. Several factors, such as access to previously unexplored conserved areas, sampling techniques that cover heterogeneous microhabitats such as leaf litter, and many more taxonomic researches have allowed the knowledge of ant fauna in Colombia to continue growing.

Resumen Aunque Colombia tiene altos niveles de riqueza de especies de hormigas en la región neotropical, esta riqueza continúa aumentando. Se presentan nuevos registros de las subfamilias de hormigas Amblyoponinae, Dolichoderinae, Dorylinae, Myrmicinae y Ponerinae. Se registran por primera vez para Colombia, dos especies de Fulakora, dos especies de Azteca, una especie de Cylindromyrmex, 25 especies de Myrmicinae pertenecientes a 12 géneros (Acanthognathus, Basiceros, Daceton, Eurhopalothrix, Hylomyrma, Mycetomoellerius, Mycetophylax, Mycocepurus, Octostruma, Pheidole, Rogeria, y Talaridris), y una especie de Leptogenys. Cinco especies son nuevos registros para América del Sur. Para cada especie, se ofrece la distancia geográfica del registro más cercano a la localidad colombiana. Varios factores, como el acceso a áreas conservadas previamente inexploradas, las técnicas de muestreo que cubren microhábitats heterogéneos, como la hojarasca, y muchas más investigaciones taxonómicas han permitido que el conocimiento de la fauna de hormigas en Colombia continúe creciendo.

New records of natural enemies of Plutella xylostella (L.) (Lepidoptera: Plutellidae) in Pernambuco, Brazil

We report the occurrence of natural enemies of Plutella xylostela (L.) in organically farmed kale in Pernambuco, Brazil. Seven natural enemies were observed parasitizing or preying on larvae and pupae of P. xylostella - three parasitoids: Cotesia plutellae Kurdjumov (Hym.: Braconidae), Conura pseudofulvovariegata (Becker) (Hym.: Chalcididae) and Tetrastichus howardi (Olliff) (Hym.: Eulophidae), and four predators: Cheiracanthium inclusum (Hentz) (Araneae: Miturgidae), Pheidole sp.Westwood (Hym.: Formicidae), nymphs and adults of Podisus nigrispinus (Dallas) (Hem.: Pentatomidae), and one unidentified species of solitary wasp. Beyond recording these natural enemies, data on predation of P. xylostella larvae in the field and laboratory by C. inclusum are presented.

Formigas em ambiente hospitalar e seu potencial como transmissoras de bactérias / Ants in a hospital environment and its importance as vector of bacteria

A comunidade de formigas da área externa ao hospital do Hospital Municipal de Morrinhos, GO, caracterizou-se pelos baixos índices de riqueza, diversidade, dominância e eqüidade de abundância das espécies. Pheidole sp.1, uma espécie poligínica, dominou esse ambiente apesar da coexistência com espécies potencialmente competitivas. A mesma espécie de formiga predominou no interior de praticamente todas as repartições do hospital e sua distribuição espaço-temporal aproximou-se da agregada (variância/média = 1.102, χ2 = 29.38, P < 0.01). Escherichia, Salmonella, Aeromonas, Enterococcus, Staphylococcus e Klebsiella foram os gêneros de bactérias associados a essa espécie de formiga em praticamente todas as repartições do hospital. O unicolonialismo de Pheidole sp.1 tende a potencializar o processo de contaminação e disseminação de agentes infecto-contagiosos. O manejo e controle da espécie devem ser acompanhados de técnicas que reduzam o processo de colonização por novas rainhas e a quantidade de locais de nidificação no interior do hospital.

The external ant community of Hospital Municipal de Morrinhos, in Morrinhos, Goiás State, was characterized by the low rates of richness, diversity, dominance and equity of species abundance. Pheidole sp.1, a polygynic species was numerically dominant in this environment, although it coexists with potentially competitive species. This ant species prevailed within all hospital departments and its space-time distribution was a little aggregated (variance/mean ratio = 1.102, χ2 = 29.38, P < 0.01). Escherichia, Salmonella, Aeromonas, Enterococcus, Staphylococcus and Klebsiella were the bacteria associated to this ant species in nearly all hospital annexes. The unicolonialism of Pheidole sp.1 tends to increase the contamination and dissemination process of infecto-contagious agents. The control and management of this ant species must be followed by practices that reduce the colonization process by other queens and the quantity of site nidification within the hospital.

Distribución espacio-temporal de hormigas en un gradiente de luz, dentro de un sistema agroforestal de café, en Turrialba, Costa Rica

Temporal and spatial distribution of ants in a light gradient, in a coffee agroforestry system, Turrialba, Costa Rica. Shade trees are frequently present in coffee (Coffea arabica L.) agroforestry systems of Mesoamerica. These systems can harbor a rich entomofauna, including ants, which could be predators of key pests in these systems. However, the role of shade on the distribution and abundance of these ants is unknown, yet such knowledge could suggest guidelines for manipulating certain environmental conditions of their habitat, thereby achieving their conservation and increase. Therefore, we studied the effect of shade on the spatial and temporal distribution of three ant species (Solenopsis geminata, Pheidole radoszkowskii and Crematogaster curvispinosa) that may prey on the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae), and the mahogany shootborer, Hypsipyla grandella (Lepidoptera: Pyralidae). To do this, abundance was evaluated across a sun-shade gradient in a coffee plantation with four alternate plots (from pure sun to total shade) in Turrialba, Costa Rica. In the community that was studied 28 species of ants were collected, of which S. geminata was the dominant species (79 % of the total individuals), followed by P. radoszkowskii (16 %). S. geminata and C. curvispinosa preferred sunny areas, while P. radoszkowskii showed no defined preference. Likewise, with respect to location, S. geminata predominated in the soil, while P. radoszkowskii and C. curvispinosa predominated in coffee bushes. Rev. Biol. Trop. 55 (3-4): 943-956. Epub 2007 December, 28.

En los sistemas agroforestales de café (Coffea arabica L.) de Mesoamérica es frecuente la presencia de árboles de sombra. Estos sistemas pueden albergar una rica entomofauna, incluyendo hormigas, la cuales podrían depredar a plagas claves en dichos sistemas. Sin embargo, se desconoce el papel de la sombra sobre la distribución y abundancia de dichas hormigas, lo cual podría sugerir pautas para manipular ciertas condiciones de su hábitat y lograr su conservación e incremento. Por tanto, se estudió el efecto de la sombra sobre la distribución espacial y temporal de tres especies de hormigas (Solenopsis geminata, Pheidole radoszkowskii y Crematogaster curvispinosa) que pueden depredar a la broca del café, Hypothenemus hampei (Coleoptera: Scolytidae) y al barrenador de las meliáceas, Hypsipyla grandella. Para ello se evaluó su abundancia a través de un gradiente de sol-sombra en un cafetal con cuatro parcelas alternas (desde pleno sol hasta sombra total), en Turrialba, Costa Rica. En la comunidad estudiada se recolectaron 28 especies de hormigas, de las cuales S. geminata fue la dominante (79 % del total de individuos), seguida por P. radoszkowskii (16 %). S. geminata y C. curvispinosa prefirieron las áreas soleadas, mientras que P. radoszkowskii no mostró una preferencia definida. Asimismo, en cuanto a su ubicación, S. geminata predominó en el suelo, mientras que P. radoszkowskii y C. curvispinosa lo hicieron en los arbustos de café.

Natural enemies of the gall-maker Eugeniamyia dispar (Diptera, Cecidomyiidae): predatory ants and parasitoids

Natural enemies of the gall maker Eugeniamyia dispar (Diptera: Cecidomyiidae) were studied on the urban area of Porto Alegre, RS, Brazil from October 1993 to March 1996. Galls and associated arthropods were followed weekly in the field on individual host plants (Eugenia uniflora, Myrtaceae) and also in the laboratory. Three species of ants attacked the galls, the most common being Pseudomyrmex sp. A proportion of galls was parasitised by Rileya sp. (Eurytomidae). The adults of this solitary ectoparasitoid were also attacked by the ants and fell prey to spider webs.

Inimigos naturais do galhador Eugeniamyia dispar (Diptera: Cecidomyiidae) foram estudados na área urbana de Porto Alegre, RS, Brasil, entre outubro de 1993 e março de 1996. Galhas e artrópodos associados a estas foram acompanhados no campo sobre as plantas hospedeiras (Eugenia uniflora, Myrtaceae) e também em laboratório. Três espécies de formiga foram encontradas atacando as galhas, sendo a mais comum Pseudomyrmex sp. Uma proporção considerável das galhas foi parasitada por Rileya sp. (Eurytomidae). Os adultos desse ectoparasitóide solitário também foram atacados pela espécie mais comum de formiga e caíram presas de teias de aranha próximas.