First inventory of ants (Hymenoptera: Formicidae) on Baltra Island, Galapagos

Baltra Island is vulnerable to ant invasions because it is one of the principal ports of entry to the Galapagos archipelago. In spite of this, little was known about its ant fauna. We present 13 new records of ants for Baltra collected during 2005 and 2006: Tapinoma melanocephalum, Camponotus planus, Paratrechina longicornis, Paratrechina sp., Monomorium destructor, M. floricola, Pheidole sp., Solenopsis geminata, S. globularia pacifica, Tetramorium bicarinatum, T. lanuginosum and T. simillimum. In addition to this, we report a new species for Galapagos: Monomorium sp. nr. pharaonis. S. geminata and M. destructor are considered threats to native faun

Distribution and habitat preferences of Galápagos ants (Hymenoptera: Formicidae).

Presentamos la primera revisión exhaustiva de los taxones de hormigas del archipiélago de Galápagos. La revisión se basa en datos recopilados durante búsquedas bibliográficas, encuestas de campo y la revisión de especímenes de museos, e incluye información sobre la distribución, hábitat y ecología de 47 especies. Se supone que al menos nueve de estas especies son nativas o endémicas de las islas y al menos 32 especies se han introducido a través de vías asociadas a los humanos. Se desconoce el estado de las seis especies restantes. La información compilada en este estudio nos permitirá comprender mejor el papel ecológico de las especies indígenas y su potencial como indicadores de la salud del ecosistema. La información de referencia sobre la distribución de hormigas introducidas será indispensable para evaluar el impacto y la propagación dentro del archipiélago.We present the first comprehensive review of the ant taxa of the Galápagos archipelago. The review is based on data gathered during literature searches, field surveys, and the revision ofmuseum specimens, and includes information on the distribution, habitat, and ecology of 47 species. At least nine of these species are assumed to be native or endemic to the islands and at least 32 species have been introduced through human-associated pathways. The status of the remaining six species is unknown. The information compiled in this study will allow us to better understand the ecological role of indigenous species and their potential as indicators of ecosystem health. Baseline information on the distribution of introduced ants will be indispensable for assessing impact and spread within the archipelago

Philornis downsi (Diptera: Muscidae), an avian nest parasite invasive to the Galápagos Islands, in Mainland Ecuador

Philornis downsi (Dodge and Aitken) is a bird-parasitic muscid fly native to mainland South America that recently invaded the Galápagos Islands where it is parasitizing Darwin's finches and other land birds. This parasite was previously known only from Argentina, Brazil, and Trinidad and Tobago. The first report of P. downsi from mainland Ecuador is provided, supporting the hypothesis that the invasion route of P. downsi from its native range to the Galápagos Islands includes mainland Ecuador. Four different morphologies of pupal exuviae, which belong to different fly species, were uncovered. Dipteran puparia were found in 20% of naturally occurring nests collected in 2013 and in 27% of nests in 2014 at the two sites in western Ecuador. P. downsi accounted for 74% and 40% of the puparia in 2013 and 2014, respectively. Two new bird host species for the genus Philornis were recorded: the streak-headed woodcreeper (Lepidocolaptes souleyetii) and the fasciated wren (Campylorhynchus fasciatus). The levels of nest parasitism found were much lower than levels reported for the Galápagos Islands. Finally, parasitism of P. downsi by a parasitoid in the genus Brachymeria (Hymenoptera, Chalcididae) is documented. Overall, 9% of fly puparia collected in 2013, and 19% of those collected in 2014, had parasitoid emergence holes.Fil: Bulgarella, Mariana. University of Minnesota; Estados UnidosFil: Quiroga, Martin Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Brito Vera, Gabriel A.. Universidad de Guayaquil; EcuadorFil: Dregni, Jonathan S.. University of Minnesota; Estados UnidosFil: Cunninghame, Francesca. Charles Darwin Foundation for the Galápagos Islands; EcuadorFil: Mosquera Muñoz, Denis A.. Universidad de Guayaquil; EcuadorFil: Monje, Lucas Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Causton, Charlotte E.. Charles Darwin Foundation for the Galápagos Islands; EcuadorFil: Heimpel, George E.. University of Minnesota; Estados Unido

Distribution of the sand wasp Bicyrtes variegatus (Oliver, 1789) (Hymenoptera, Crabronidae) in the Galápagos Islands, with notes on its ecology

Very little is known about the sand wasp, Bicyrtes variegatus, in the Galápagos archipelago. In this study, we compiled information from surveys, museum collections and the literature to better understand its distribution and ecology. We found records of B. variegatus on seven islands with the earliest known record from 1964, from San Cristóbal Island. Wasps have been collected in the littoral, arid, transition and humid vegetation zones and have been reported visiting endemic, native, cryptogenic, and introduced plants. Sun dances and a tight cluster of wasps, similar in form to what others have called “mating balls”, were observed in the hot season

Trypanosomatids Detected in the Invasive Avian Parasite Philornis downsi (Diptera: Muscidae) in the Galapagos Islands

Alien insect species may present a multifaceted threat to ecosystems into which they are introduced. In addition to the direct damage they may cause, they may also bring novel diseases and parasites and/or have the capacity to vector microorganisms that are already established in the ecosystem and are causing harm. Damage caused by ectoparasitic larvae of the invasive fly, Philornis downsi (Dodge and Aitken) to nestlings of endemic birds in the Galapagos Islands is well documented, but nothing is known about whether this fly is itself associated with parasites or pathogens. In this study, diagnostic molecular methods indicated the presence of insect trypanosomatids in P. downsi; to our knowledge, this is the first record of insect trypanosomatids associated with Philornis species. Phylogenetic estimates and evolutionary distances indicate these species are most closely related to the Crithidia and Blastocrithidia genera, which are not currently reported in the Galapagos Islands. The prevalence of trypanosomatids indicates either P. downsi arrived with its own parasites or that it is a highly suitable host for trypanosomatids already found in the Galapagos Islands, or both. We recommend further studies to determine the origin of the trypanosomatid infections to better evaluate threats to endemic fauna of the Galapagos Islands

Population dynamics of an invasive bird parasite, Philornis downsi (Diptera: Muscidae), in the Galapagos Islands.

The invasive parasitic fly, Philornis downsi (Muscidae), is one of the greatest threats to the avifauna of the Galapagos Islands. The larvae of this fly feed on the blood and tissues of developing nestlings of at least 18 endemic and native birds. The aim of the current study was to investigate biotic and abiotic factors that may influence the population dynamics of this invasive parasite. To study the influence of vegetation zone and related climatic factors on fly numbers, a bi-weekly monitoring program using papaya-baited traps was carried out at a dry, lowland site and at a humid, highland site on Santa Cruz Island between 2012-2014. Female flies, a large proportion of which were inseminated and gravid, were collected throughout the year at both sites, indicating females were active during and between the bird breeding seasons. This is the first evidence that female flies are able to persist even when hosts are scarce. On the other hand, catch rates of male flies declined between bird breeding seasons. Overall, catch rates of P. downsi were higher in the drier, lowland habitat, which may be a consequence of host or resource availability. Time was a stronger predictor of adult fly numbers than climate, further suggesting that P. downsi does not appear to be limited by its environment, but rather by host availability. Seasonal catch rates suggested that populations in both habitats were continuous and multivoltine. Numbers of adult female flies appeared to be regulated chiefly by simple direct density dependence, and may be governed by availability of bird nests with nestlings. Nevertheless, confounding factors such as the existence of reservoir hosts that perpetuate fly populations and changes in behavior of P. downsi may increase the vulnerability of bird hosts that are already IUCN red-listed or in decline