Abstract Global biodiversity loss by anthropogenic impacts is an under-recognized form of global environmental change. Global defaunation is still poorly documented in the case of insects, showing a significant decrease in populations and diversity. The blowfly Neta chilensis (Walker 1837) is poorly known and presumed to be confined to southern-South America, with an unclear distributional pattern. It was last collected in 1984. We aimed, through Ecological Niche Models, to identify regions highly suitable for N. chilensis; to test the suitability of regions with doubtful records; to understand the impact that climatic change and human activities have had; and to identify regions with high chances to find it. We compiled 130 presence records from Argentina and Chile and 117 localities where it was sought but not found between 1987 and 2018. Results indicate that suitable conditions are restricted to southern and central Chile and to southwestern Argentina, that doubtful records are predicted in unsuitable areas, that N. chilensis occupies a narrow niche and that its decline is not mainly caused by climate changes but more probably to habitat loss and to the biological invasion. We identified two regions where the chances of finding the species are higher in the case that it is not extinct already.

ABSTRACT Although the majority of threatened species are likely to be tropical insects, knowledge of the diversity, ecological role and impact of insect biodiversity loss on ecosystem processes is very limited. Specimens belonging to four families of Heteroptera: Pentatomidae, Coreidae, Alydidae and Rhopalidae, were collected from a protected area in the Paraná Forest, the largest ecoregion of the Atlantic Forest, in Argentina. The assemblages were characterized and the biodiversity estimated, and they were compared with the assemblages found in five other protected areas in the Brazilian Atlantic Forest. In our study area, Pentatomidae had the greatest richness and diversity; Coreidae was the second most diverse family, with highest sampling deficit, highest percentage of singletons, and lowest inventory completeness; and Rhopalidae was the best sampled family with asymptotic rarefaction curves. We explored the application of the Species Conservation Importance index, following four criteria, to evaluate the relative importance of the pentatomid species studied and its usefulness for assigning conservation values to areas. We found similar Site Conservation Values among the six areas and noted that the use of criteria was limited by the lack of information, being crucial to increase the knowledge of most of the species.

A new Neotropical species of Sphaerocysta Stål, (Hemiptera, Heteroptera, Tingidae) is described. Sphaerocysta costai n. sp. was collected in the Argentinian Yungas, in the provinces of Jujuy (Calilegua) and Salta (Urundel). The most important diagnostic characters are illustrated for adults and fifthinstar nymphs. This new species provides relevant evidence for the understanding of evolutionary trends within the family as its nymphal morphology exhibits unique features among Tingidae. Comments on the systematics of Sphaerocysta, and an identification key to its species are provided.

Se describe una nueva especie neotropical de Sphaerocysta (Hemiptera, Heteroptera, Tingidae). Sphaerocysta costai n. sp. fue colectada en las Yungas Argentinas, en las provincias de Jujuy (Calilegua) y Salta (Urundel). Se ilustran los principales caracteres diagnósticos de los adultos y del quinto estadío ninfal. Esta nueva especie brinda información relevante para comprender las tendencias evolutivas de la familia ya que la morfología de sus ninfas presenta caracteres únicos entre los Tingidae. Se brindan comentarios sobre la sistemática de Sphaerocysta y una clave para la identificación de sus especies.

Stenocoris (Stenocoris) schaeferi, a new species of Alydidae (Micrelytrinae: Leptocorisini) from Argentina, is described and illustrated. Lyrnessus geniculatus (Guérin-Méneville) and Stenocoris (Oryzocoris) furcifera (Westwood) are registered from Argentina for the first time. A key and a distributional map to the Argentinean Leptocorisini are also provided.

Stenocoris (Stenocoris) schaeferi, una nueva especie de Alydidae (Micrelytrinae: Leptocorisini) de Argentina, es descripta e ilustrada. Lyrnessus geniculatus (Guérin-Méneville) y Stenocoris (Oryzocoris) furcifera (Westwood) son citadas por primera vez para la Argentina. Además, se brinda una clave y un mapa de distribución de las especies argentinas de Leptocorisini.

A new Pleseobyrsa, P. persea n. sp. is described for Costa Rica. The host plant of this new species is Persea americana P. Mill. This corresponds to the second species of the genus known for the country and the third whose host plant is P. americana (avocado). A description of the adult as well as of instar V are provided, together with a key to species, photographs taken in the field, and illustrations of the fifth nymph stage, adult, and the main characters.

Se describe una especie nueva de Pleseobyrsa, P. persea n. sp. de Costa Rica, cuya planta huésped es Persea americana P. Mill., siendo ésta la segunda especie del género conocida del país y la tercera cuya planta huésped es P. americana (aguacate). Se describen tanto el adulto como el estadio ninfal V; se agrega una clave modificada de Froeschner para las especies, y se ilustran ejemplares en el campo, el quinto estadio ninfal, adulto y los principales caracteres.

A new species, Ischnodemus brusai, from Ucayali, Peru is described and illustrated, including characters of the male genitalia. Adult males and females, and immature specimens of I. subflavus Slater and Wilcox 1969 were collected on Sporobolus rigens (Trinius) Desvaux (Poaceae) in the province of Chubut, Argentina. This is the first record of the male for this species. Descriptions and illustrations of a male individual, as well as male and female genitalia and immature stages II to V are provided. Affinities with other Neotropical species of Ischnodemus are discussed.

Se describe e ilustra una especie nueva, Ischnodemus brusai de Uyacali, Perú, incluyendo caracteres de los genitales masculinos. Se recolectaron adultos machos, hembras y estadios inmaduros de I. subflavus Slater and Wilcox 1969 sobre Sporobolus rigens (Trinius) Desvaux (Poaceae) en la provincia de Chubut, Argentina. Éste es el primer registro de un macho para esta especie. Se proveen descripciones e ilustraciones del macho, genitales masculinos y femeninos, y los estadios II a IV. Se discuten las afinidades con otras especies neotropicales del género.