Henri Herrera

The Galapagos Islands are located in the Pacific Ocean approximately 1000 kilometers off the coast of Ecuador. The archipelago is comprised of 121 volcanic islands spread out over 8,000 km² . The equator crosses the Galapagos chain at Wolf and Ecuador volcanoes on the northern side of Isabela Island. Most of the islands are located to the south of the equator, with Marchena, Genovesa, Pinta, Darwin and Wolf the only islands to the north of the equator. Approximately 97 percent of the archipelago are protected; Baltra, Floreana, Isabela, San Cristóbal and Santa Cruz are the only islands with human settlements. The Galapagos has two defined seasons?the ?cold dry? season (May to December) and the humid ?hot? season (December to May). Up to seven vegetation zones can be found on the larger islands. The isolation of the Galapagos from continental South America has resulted in a collection of flora and fauna found nowhere else in the world.

There are five subfamilies, 21 genera and 44 species of ants on the Galapagos Islands. Of the 44 taxa, Camponotus macilentus, Camponotus planus, Cyphomyrmex nesiotus, and Pheidole williamsi are endemic to the archipelago. To date, 30 are introduced, with an additional 10 species of undetermined origin. The genera of Dorymyrmex, Hypoponera, Paratrechina and Leptogenys await revision. Introduced species such as the little fire ant, Wasmannia auropunctata, and the tropical fire ant, Solenopsis geminata, are considered serious threats to the terrestrial fauna of Galapagos (Herrera & Causton 2007 in press).

An inventory of Formicidae initiated in 2005 has resulted in new records (Herrera & Longino 2007 in press; Pacheco, Herrera & MacKay 2007 in press), demonstrating that there are still many localities left to inventory, and that much remains to be learned about the ants of the Galapagos.  http://www.antweb.org/galapagos.jsp

Tropical fire ant (TFA), Solenopsis geminata (Fabricius, 1804), is considered as one of the most serious threats to the terrestrial fauna of Galápagos, yet little is known about its distribution and impact in the archipelago. We reviewed literature, studied museum specimens and sampled over 62 sites on ten islands and islets in order to update the distribution of TFA. Since the 1980's, species occurrences for TFA have increased from three to 115 localities, and the species is now recorded on seven islands and 11 islets. Sixty-six new records were registered since the last review in 2008, including the islets Bayas, Champion, Cuevas, and Eden. TFA seems to be present in a wide range of habitats with a clear predominance in human-disturbed zones. Our data, compiled with previous studies, suggest that TFA can behaviorally dominate other ants. TFA was collected on 28 nesting sites of endangered and/or endemic vertebrate species, where it constitutes a potential or proven threat. This study identifies potential invasion sites as well as endemic species that may further be impacted by this highly invasive ant. It also recommends regular monitoring to prevent further invasion.

Collections of the Charles Darwin Research Station, Royal Belgian Institute of Natural Sciences, as well as new field samples obtained from several islands on Galapagos yielded new records of nine ant species for the archipelago: Tapinoma sp. HH07, Nylanderia steinheili (Forel, 1893), Crematogaster sp. JTL-022, Pheidole sp. HH01, Tetramorium lucayanum Wheeler, 1905, Strumigenys eggersi (Emery, 1890), Solenopsis sp. HH06, Hypoponera opacior (Forel, 1893), Odontomachus ruginodis Smith, 1937. Currently, the known number of ant species in the Galapagos is 51, 36 of which are thought to be introduced. Reasons for this recent increase of records of introduced ant species are discussed.
Key Words. Formicidae, new records, Galapagos Islands, introductions

The thelastomatoid pinworm fauna (Nematoda: Oxyurida: Thelastomatoidea) was surveyed in 3 endemic species and 6 introduced species of cockroach hosts (Insecta: Blattaria) in the Galápagos Islands, Ecuador. A total of 658 host specimens were examined from preserved collections that had been collected between 1966 and 2003 from 7 islands in the archipelago. Eight species of pinworms were identified from these cockroach hosts, including the dominant species Cephalobellus ovumglutinosus and a Severianoia sp., as well as Leidynema appendiculata, Hammerschmidtiella diesingi, an unidentified Cephalobellus species resembling C. magalhaesi, an unidentified Protrellus species closely resembling P. shamimi, and an undescribed Blattophila species. Five new host records are identified for C. ovumglutinosus, including the endemic Galápagos cockroaches Chorisoneura carpenteri, Ischnoptera snodgrassii, and Ischnoptera santacruzensis. These endemics were also infected with an undescribed Blatticola sp. Other species recorded resemble known pinworms from other hosts around the world. Prevalence between islands and between host species was variable, but total prevalence for individual pinworm species was consistently low (<10%). A single host specimen examined was infected with more than 1 pinworm species; otherwise only a single species was observed in each infected host. At least 1 introduced pinworm species carried to the islands via invasive cockroach hosts was present in endemic host species, but several globally widespread introduced pinworm species were absent from endemic cockroaches. Santa Cruz was inhabited by the greatest number of pinworm species, likely due to a higher rate of invasive host introduction. This survey, the first from this region, showed that the distribution and transmission of pinworms in the Galápagos Islands is complex and may provide future models of invertebrate dispersal and speciation in an ecosystem already rich with examples of evolution.

Excluding the families Bulimulidae and Succineidae, 27 species of land shells were identified in the Galápagos Archipelago (Ecuador), recorded in 14 islands. Many of the species are endemic, belonging to Helicinidae (two species), Achatinellidae (two), Pupillidae (four), Vallonidae (two), Strobilopsidae (one), Pristilomatidae (two), and Euconulidae (three). The most abundant records are found in the human inhabited islands: Santa Cruz, San Cristóbal, Isabela and Floreana. None of the families or genera is exclusive to the archipelago; the only endemic subgenus is Strobilops (Nesostrobilops). The most widespread species is Gastrocopta munita, recorded from 12 islands. Only a few species are recorded as unique to a single island (e.g., Nesopupa (Infranesopupa) galapagensis). A new species of Ambrosiella (Achatinellidae) from Floreana is described: characterized by a parietal lamella in the aperture, this species is related to the Chilean insular fauna. Human inhabited islands host several exotic species of inadvertently introduced micromolluscs and slugs, and one intentional introduction (Lissachatina fulica). Although the introduced species are dominant in anthropogenic altered sectors of the islands, they have also invaded natural areas.
New records extend the distribution of almost all terrestrial gastropod species in the Archipelago.
Key words: Molluscs, Neritimorpha, Pulmonata, South America, Ecuador, Galápagos.

Biodiversity inventories are an essential part of conservation science. Ecologist cannot afford to ignore poorly known species groups, assuming that understanding the ecology of few emblematic species is sufficient to preserve biodiversity of complex ecosystems. The Galapagos Islands as one of the best studied tropical archipelagos is a prime example of an ecosystem where iconic species historically received much attention but other important groups were neglected.
At least in part, this negligence is a result of an increasing alienation of taxonomists and ecologists. Taxonomy, the science of describing species, must again become an integral part of biodiversity research in any ecosystem. As such it cannot be reduced to the elaboration of phylogenies; it has a mandate not only to classify, but also to describe organisms.
Even relatively species-poor island ecosystems like the Galapagos are still characterized by an enormous biodiversity. It is not unusual that ecological studies therefore frequently focus on few, better known species. An estimate based on the first attempt to assemble a centralized register of all known Galapagos species suggests that between 17,000 and 42,000 species may inhabit this archipelago, a huge range fraught with methodological challenges. As in most parts of the world vascular plants and vertebrates are best known and continue to receive most attention. Terrestrial and marine invertebrates are much less studied, and fungi continue to be almost entirely neglected.
In Galapagos saving many individual, emblematic species has been extremely successful, but an objective approach to conservation of all biodiversity must also account for lesser known species groups. Currently an unrealistic goal to restore pristine ecosystems largely ignores the effects of control and eradication of invasive species on native, often poorly known species. While complete biodiversity inventories may not be realistic, a pragmatic approach to assess restoration must no longer ignore the fact that ecosystems are more complex than their most iconic species. To minimize biodiversity loss and design efficient conservation strategies for entire ecosystems, not only individual species, ecologists and taxonomists have to look beyond the scope of their own disciplines and better integrate their research.