Resumo em Inglês:

Abstract Calotropis procera is a xerophytic perennial milkweed shrub native to Asia and Africa, which currently is also widely distributed throughout the Brazilian Caatinga. C. procera is well defended against herbivores, especially with latex and toxic steroidal cardenolides. The goal of this study was to evaluate how patch size of this exotic host plant affect insect herbivory. Eight patches were selected containing a varied number of C. procera individuals (5, 8, 29, 31, 55, 79, 116, and 172 individuals/patch) in the Caatinga. Patches were divided into four categories according to the number of C. procera individuals: very small (5 and 8), small (29 and 31), intermediate (55 and 79), and large (116 and 172). The percentage of herbivory was greater in patch categories with more individuals. Among the herbivorous insects associated with C. procera, larvae of Danaus spp. (Lepidoptera: Nymphalidae) were commonly observed feeding on all patches. These herbivores present specialized behaviors to circumvent the presence of latex on the host leaves. Adult Danaus spp. females probably had higher probability to find large patches of C. procera, leaving a greater abundance of eggs and, consequently, increasing the herbivory by their larvae in these patches. In contrast to immigration tendency, emigration from large patches may be lower, because there is a higher probability of finding resources (e. g. suitable C. procera leaves) inside large patches compared with small patches. We conclude that patch size of the host plant C. procera is a major factor affecting herbivory.

Resumo em Inglês:

ABSTRACT Biotic factors such as predation, although important drivers of the black fly community, are rarely investigated in the literature. This study aimed to test the hypothesis that the patterns of co-occurrence of black fly larvae and its potential predators is not random and that there is a correlation between its frequencies and Simuliidae larvae abundances. Larvae were sampled from two localities in the Pedra Branca State Park, Rio de Janeiro, Brazil, during the dry season in june 2018. We collected Simulium pertinax Kollar, 1832, Simulium subpallidum Lutz, 1910, Simulium (Inaequalium) sp., Simulium (Psaroniocompsa) sp. and Simulium (Trichodagmia) sp. The predators families present were Perlidae, Hydropsychidae, Leptoceridae, Libellulidae and Chironomidae. The null models showed that species co-occurred significantly more than expected by chance. The canonical correlation analyses for the Vargem Grande and Pau da Fome areas area showed a significant relationship between black fly abundances and predator abundances. In Vargem Grande the abundance of Chironomidae showed a highly significant positive correlation to S. (Psaroniocompsa) sp., while Hydropsychidae was significantly correlated to Simulium sp. On the other hand, in Pau da Fome Libellulidae was significantly correlated to S. (Psaroniocompsa) sp. and Simulium sp. and Chironomidae correlated significantly to Simulium sp. The result is consistent with what would be expected of organisms that exercise mutual population regulation, although other factors than biotic interactions may be causing these patterns. However the lack of mechanistic evidences on the effect of biotic interactions on black fly populations pose a challenge on the understanding of these patterns.

Resumo em Inglês:

Abstract Two conspicuous Steganinae species, Stegana (Steganina) magnifica Hendel, 1913 from Amazonian Peru and Stegana (Ceratostylus) fumipennis (Enderlein, 1922) from southern Brazil, are redescribed based on holotypes, and their identities are clarified. Both species are exclusive to the Neotropical Region and the first, with a body length of about 5.5 mm, is the largest species of Stegana described so far in this region, while the latter displays a peculiar antenna bearing an unusual, forward-projected, comma-shaped flagellomere 1. The photomicrographs of the habitus and terminalia of each specimen are also provided.

Resumo em Inglês:

Abstract In the Neotropical region, especially South America, Leptophlebiidae achieves its higher diversity, with 45 genera and almost 250 species. In Colombia, the diversity about this family is underestimated, with only 22 species reported so far. In order to contribute to the current knowledge of the Leptophlebiidae in Colombia we examined the adults of this family deposited at the Colección Entomológica del Programa de Biología, Universidad de Caldas. In addition to the historical records herein presented, nine species are registered for the first time from the country (Farrodes savagei, F. tepui, F. xingu, Hagenulopsis minuta, Terpides contamanensis, T. echinovaris, T. ornatodermis, Tikuna atramentum, and Ulmeritoides flavopedes). Besides that, additional records are presented for 12 species of the following genera: Askola, Farrodes, Simothraulopsis, Tikuna, Ulmeritoides, Hydrosmilodon, Terpides, Choroterpes, Paramaka, and Hagenulopsis. With these additional and new records, we update the list of Leptophlebiidae from Colombia to 33 species and 14 genera.

Resumo em Inglês:

Abstract Within the subgenus Dichotomius (Selenocopris) Burmeister 1846, D. nisus (Olivier, 1789) and D. superbus (Felsche, 1901) had been historically arranged in the “Nisus” section by Luederwaldt, however, according to the revised classification of the subgenus, the two species now belong to different species groups. In this paper, the taxonomic history concerning the species once included by Luederwaldt in the “Nisus” section is revised and discussed. The following new synonyms are proposed: Pinotus taunayi (Luederwaldt, 1931) as a subjective synonym of D. geminatus (Arrow, 1913), and Pinotus taunayi pilosus (Luederwaldt, 1931) as a subjective synonym of D. nisus. Lectotypes are designated for D. nisus and Pinotus garbei. Redescriptions, diagnoses and updated distribution data are provided for D. nisus and D. superbus. The diagnostic characters of the male genitalia of these species are described and illustrated for the first time.

Resumo em Inglês:

ABSTRACT Atta capiguara grass-cutting ants are commonly found in the Cerrado biome, in open fields. Although grass-cutting ants build giant nests, little has been elucidated about this building pattern and when chambers and tunnels emerge. The present study describes the nest architecture development of A. capiguara grass-cutting ants from data on 31 cement-molded nests. A. capiguara nests grow with increases in the number of fungus chambers and emergence and increase of waste chambers and foraging tunnels. The structural growth of A. capiguara nests in the first year and a half of age (18 months) is vertical, with the building of the first chambers in the soil profile. After 18 months, the nests grow sideways with the addition of chambers and tunnels, and the first waste chambers appear. Between 18 and 54 months, the number of fungus chambers increases from 1-3 to 21-32, and the chambers are concentrated at the soil surface, although they can be found more than 3 m deep. In addition, the total volume of the waste chambers increases with the increment in the fungus chambers volume. Thus, this study contributes to understanding the nest architecture development of A. capiguara grass-cutting ants and demonstrates that the total volume of waste chambers is proportional to the total volume of fungus chambers suitable for the colony.

Resumo em Inglês:

Abstract Ants are known to feed on a variety of plant resources. Nevertheless, there are very few reports in the literature on ants using flower parts. Here, we describe how two Odontomachus chelifer (Latreille) ants teared and removed a part of an inner tepal of a Neomarica candida (Hassl.) (Iridaceae) flower at the restinga sandy forest in the Cardoso Island State Park, Brazil. To determine which part of the perianth attracted these ants, we performed two independent two-choice field assays: tepals (inner and outer tepals) were cut in two parts (basal and apical), with contrasting colors, which were offered to ants leaving a colony. Our results show that ants significantly preferred to remove or lick the basal part of the inner tepal. Based on the knowledge of N. candida’s floral anatomy, we hypothesize that ants were attracted by the nectar produced by trichomatic nectaries at the basal part of the inner tepals. These tepal parts containing nectar are likely to be used as an alternative food resource amid the scarcity of arthropods usually preyed or scavenged by O. chelifer, since the restinga forest is known as an arthropod-poor habitat.

Resumo em Inglês:

ABSTRACT Vatiga manihotae (Drake 1922) (Hemiptera: Tingidae) is an important cassava pest due to the great potential damage and the increasing population in recent years. However, few studies about bioecology and control of the cassava lace bug have been conducted and their results don't provide adequate control strategies. An alternative to maintain the population below economic injury levels is through the adoption of host plant resistance. To improve the understanding about the bioecology and find new sources of resistance in cassava, the biological parameters and demographics of V. manihotae on five cassava genotypes (Santa Helena, MEcu 72, Col 22, Clone 02 and Clone 03) under controlled conditions (25±2°C, 14L/10D) were evaluated. Duration and viability of the stages, the period egg-adult, sex ratio, the pre-oviposition period, fecundity and longevity of male and female was determined, and a fertility life table was prepared. Insects fed on MEcu 72 showed increased nymphal, egg-adult, and pre-oviposition periods and reduced female fecundity and longevity in comparison to the other genotypes. Demographic parameters (Ro, rm, T, DT) showed a significant impact on the growth potential of V. manihotae fed on MEcu 72 indicating that the populations would diminish over time. The combined effect of these parameters indicated that MEcu 72 has resistance on V. manihotae specimens hindering their development.

Resumo em Inglês:

ABSTRACT Hexapods, commonly known as insects, are a neglected taxonomic group in the Fernando de Noronha archipelago, with unanswered questions about their species richness and the ecological processes in which they are involved (e.g., colonization, introduction, establishment, and extinction). Herein, we provide an updated Hexapod checklist with current nomenclatural combinations. The entomofauna of the Fernando de Noronha archipelago is currently composed of 453 species in 21 orders. The orders, and their respective number of species, are: Blattaria (9), Coleoptera (118), Collembola (29), Dermaptera (3), Diplura (1), Diptera (134), Embioptera (1), Hemiptera (29), Hymenoptera (59), Isoptera (2), Lepidoptera (25), Mantodea (1), Neuroptera (3), Odonata (5), Orthoptera (11), Phasmatodea (1), Phthiraptera (6), Psocoptera (3), Siphonaptera (1), Thysanoptera (10), and Zygentoma (2). The archipelago has 263 new taxon records (family + genera + species). Thirty-eight species (3.39%) were described from local specimens and most of them are likely endemic species. This study more than doubles our knowledge (from the previous 190 records) of the entomofauna in this large Brazilian archipelago. This study also provides a baseline for studies on its conservation status and for implementing future environmental management programs.

Resumo em Inglês:

ABSTRACT The structural morphology of mouthparts, the distribution of sensilla on the mouthparts, histology, and the morphology of the alimentary canal in adult Eusomus ovulum Germar, 1824 were examined under both light and scanning electron microscopy (SEM). The mouthparts are located at the tip of the short rostrum. The mandibles, the maxillae and the labial palpi comprise the moveable mouthparts. Also there are sensillae which act as chemoreceptors on the terminal segment of the snout. Alimentary canal of adult E. ovulum is divided into three main regions, foregut, midgut and hindgut. The first part of the gut is foregut, which is made up of a pharynx, esophagus, crop and proventriculus. The pharynx extends from the mouth, having muscle attachments radiating out from its surface and connecting with the head region. The esophagus is a narrow epithelial tube contiguous and posterior to the pharynx. The proventriculus consists of 8 sclerotized plates. The midgut, which is anteriorly bulbous with a tubular posterior half. Gastric caeca were found on the posterior region of the midgut. The midgut is surrounded by outer muscles and inner columnar epithelium. The hindgut has pylorus, ileum, colon, and rectum. There are three histological layers of the hindgut from lumen to hemocoel: intima, epithelium, muscles. The hindgut has a cryptonephridial attachment for the six Malpighian tubes anterior to the rectum. The aim of the present study is to contribute information on the morphology of mouthparts, and the morphology and histology of the alimentary tract of the insect.

Resumo em Inglês:

Abstract The genus Dolichocodia Townsend, 1908 has a New World distribution with four described species: D. bivittata (Coquillett, 1902), D. erratilis Reinhard, 1958, D. furacis Reinhard, 1958 and D. rava (van der Wulp, 1891). Two new combinations are suggested for this genus: D. errans (Curran, 1927) comb. nov., and D. praeusta (van der Wulp, 1891) comb. nov. Redescriptions and lectotype designations for D. rava and D. praeusta are given. An identification key to Dolichocodia species is presented. Dolichocodia rava, described from Mexico, is newly recorded from United States.