Tropical forests are among the most biodiverse biomes on the planet. Nevertheless, quantifying the abundance and species richness within megadiverse groups is a significant challenge. We designed a study to address this challenge by documenting the variability of the insect fauna across a vertical canopy gradient in a Central Amazonian tropical forest. Insects were sampled over two weeks using 6-m Gressitt-style Malaise traps set at five heights (0 m–32 m–8 m intervals) on a metal tower in a tropical forest north of Manaus, Brazil. The traps contained 37,778 specimens of 18 orders of insects. Using simulation approaches and nonparametric analyses, we interpreted the abundance and richness of insects along this gradient. Diptera, Hymenoptera, and Coleoptera had their greatest abundance at the ground level, whereas Lepidoptera and Hemiptera were more abundant in the upper levels of the canopy. We identified species of 38 of the 56 families of Diptera, finding that 527 out of 856 species (61.6%) were not sampled at the ground level. Mycetophilidae, Tipulidae, and Phoridae were significantly more diverse and/or abundant at the ground level, while Tachinidae, Dolichopodidae, and Lauxaniidae were more diverse or abundant at upper levels. Our study suggests the need for a careful discussion of strategies of tropical forest conservation based on a much more complete understanding of the three-dimensional distribution of its insect diversity.

Drosophilidae comprises more than 4,000 described species worldwide. Despite the huge number of papers published on the genus Drosophila Fallén, 1823, large parts of the family are still poorly known. The drosophiline genus Cladochaeta Coquillet, 1900 has more than 100 Neotropical and several southern Nearctic described species, but there is quite a large number of undescribed species. The Brazilian fauna of the genus was studied and 12 new species are herein described-Cladochaeta armatopsis nov. sp., C. balbiae nov. sp., C. paraitinga nov. sp., C. asapha nov. sp., C.chauliodactyla nov. sp., C. conicophallus nov. sp., C. dicrophallus nov. sp., C.grimaldii nov. sp., C. atlantica nov. sp., C. periotoi nov. sp., C. phallotrixa nov. sp. and C. stigmata nov. sp. We set the first record of C. arthrostyla Grimaldi & Nguyen, 1999 for northeastern Brazil a species otherwise known from Costa Rica, and the first record of C. bomplandi (Malloch, 1934) for the state of Minas Gerais, a species known for northeastern Argentina and southern Brazil. The descriptions include photographs for each species and detailed illustrations of the male terminalia in different views. A synopsis on the taxonomy and natural history of the genus is provided, as well as comments about the relationships of species in the genus, a discussion on problems of male terminalia sclerite homology and the problem of association between males and females.

A new species of Cladochaeta Coquillett (Diptera: Drosophilidae) is described, C. caxiuana sp. nov. from the Brazilian Amazon, based on 10 male and 10 female specimens obtained from nymphs of Sphodroscarta trivirgata (Amyot Serville, 1843) (Hemiptera: Auchenorrhyncha: Aphrophoridae). The female of Cladochaeta atlantica Pirani Amorim, 2016 is described based on specimens reared from spider egg sacs of the spider Cryptachaea migrans (Keyserling, 1884) (Araneae: Theridiidae) obtained in the state of Espírito Santo, Brazil. This is the first record of this fly genus attacking a spider egg sac. The species Cladochaeta sororia (Williston, 1896) is recorded for the first time from Brazil, based on specimens collected in an urban garden in the Amazon. In addition, an unidentified female specimen of Cladochaeta Coquillett, 1900 was obtained from the cocoon of a spider wasp of the genus Notocyphus Smith (Hymenoptera: Pompilidae).

For slightly more than a century only the type specimen has been known for Pyrgometopa penicillata, a monotypic genus of Drosophilidae whose sole species has an ocellar triangle distended into a bizarre tubercle bearing a tuft of large, spine-like bristles in both sexes. Here we report additional specimens of both sexes of the species, recently rediscovered from Brazil, Peru and French Guyana, allowing us to state that Pyrgometopa is a junior synonym for Stegana, a large cosmopolitan genus. A detailed redescription of Stegana penicillata (Kertész) new combination is provided, including new morphological information, like the male and female terminalia, the egg and a short discussion is provided about its hallmark feature.

Roraima is a Brazilian state located in the northern portion of the Amazon basin, with few studies regarding its biodiversity. The Ecological Station of Maracá (Brazil, state of Roraima) harbors the third largest Brazilian pluvial island and is composed of a transitional landscape of savanna and Amazon rainforest components. Despite its ecological importance and strategic localization, few studies covered the dipterofauna of this locality. An updated checklist addressing 41 families of true flies (Diptera) occurring in Roraima is presented based on the literature and the specimens collected during a field expedition that occurred in 2015. This checklist brings several improvements such as new records of 165 taxa to the state of Roraima, 29 taxa to Brazil, and 259 morphotypes, mostly likely representing undescribed species.