Scielo RSS <![CDATA[Revista Brasileira de Entomologia]]> vol. 61 num. 3 lang. es <![CDATA[SciELO Logo]]> <![CDATA[Two new species of <em>Trichomyia</em> Haliday 1839 (Diptera, Psychodidae, Trichomyiinae) from the Pantanal of Mato Grosso, Brazil]]> Abstract Two new species in the Trichomyiinae (Psychodidae), Trichomyia pantanensis sp. nov. and Trichomyia lamasi sp. nov., are described and illustrated. New records are given for the two additional species Trichomyia spinicauda Araújo &amp; Bravo, 2016 and Trichomyia hispida Araújo &amp; Bravo, 2016. These four species comprise the first records of the genus in the Pantanal region. <![CDATA[Three new species of <em>Pelidnota</em> MacLeay (Coleoptera, Scarabaeidae, Rutelinae) and new distributional records from northeast Brazil]]> Abstract Three new species of Pelidnota MacLeay, 1819 are described from Brazil, P. beckeri sp. nov., P. nordestina sp. nov., and P. pernambucana sp. nov. The diagnostic characters of the new species are presented, and they are included in the previously published key to Pelidnota. Illustrations of the male genitalia and photographs of males and females of the new species are also provided. It is reported the first record of the genus for the Brazilian Caatinga (tropical seasonal forest). New records of four species and two subspecies of Pelidnota are presented, all from Bahia state, northeastern Brazil. <![CDATA[Variation of cuticular chemical compounds in three species of <em>Mischocyttarus</em> (Hymenoptera: Vespidae) eusocial wasps]]> Abstract The social wasps have a remarkable system of organization in which chemical communication mediate different behavioral interactions. Among the compounds involved in this process, cuticular hydrocarbons are considered the main signals for nestmate recognition, caste differentiation, and fertility communication. The aims of this study were to describe the cuticular chemical compounds of the species Mischocyttarus consimilis, Mischocyttarus bertonii, and Mischocyttarus latior, and to test whether these chemical compounds could be used to evaluate differences and similarities between Mischocyttarus species, using gas chromatography coupled to mass spectrometry (GC-MS). Workers from these three species presented a variety of hydrocarbons ranging from C17 to C37, and among the compounds identified, the most representative were branched alkanes, linear alkanes and alkenes. The results revealed quantitative and qualitative differences among the hydrocarbon profiles, as confirmed by discriminant analysis. This study supports the hypothesis that cuticular chemical profiles can be used as parameters to identify interspecific and intercolony differences in Mischocyttarus, highlighting the importance of these compounds for differentiation of species and populations. <![CDATA[A new species of Neotropical <em>Drosophila</em> (Diptera, Drosophilidae) belonging to the <em>guarani</em> group]]> Abstract Drosophila butantan sp. nov., a species belonging to the guarani group and closely related to Drosophila nigrifemur from Bolivia, is described based on a female, and some of its offspring, collected at the forest reserve of the Instituto de Biociências da Universidade de São Paulo, Cidade Universitária "Armando de Salles Oliveira", São Paulo City, state of São Paulo, Brazil. Although externally similar, the two apparently forest-dwelling species can be told apart by having distinct oviscapt valves and spermathecal introverts and tips. Accordingly, a proposal is made to also include D. nigrifemur, a previously unassigned species, in the guarani group. The two species seem to be also related to Drosophila alexandrei and Drosophila guaraja as indicated by their external morphology, their elongate spermathecae and the not so sharply pointed oviscapt valves. The karyotypes of the new species differ from those described for D. alexandrei and D. guaraja, while those of D. nigrifemur remain still unknown. Photomicrographs of the male and female imagines, in addition to drawings and photos of their terminalia, are also included. <![CDATA[New species of <em>Lopesia</em> Rübsaamen (Diptera: Cecidomyiidae) associated with <em>Andira humilis</em> Mart. ex Benth. (Fabaceae)]]> Abstract A new species of Lopesia Rübsaamen, 1908 induces leaf galls on Andira humilis (Fabaceae) in the Cerrado biome (Brazilian savanna) of Bahia, Mato Grosso and São Paulo states, Brazil. Larva, pupa, female, and male of this new species of gall midge are described and illustrated in this paper. <![CDATA[Morphological traits, allometric relationship and competition of two seed-feeding species of beetles in infested pods]]> Abstract Pair-wise competition produces asymmetric consequences for the interacting species, resulting in reduction of species fitness at the individual scale; however, little is known of the effects of competition on the allometric patterns of insects. In this study, we explored how competition, by means of pod infestation, affects the development of female and male individuals in the co-occurring bruchine beetles Merobruchus terani and Stator maculatopygus. We found differences between M. terani and S. maculatopygus in all morphometric traits, but no significant differences between males and females in either species. We also found, with an increasing degree of pod infestation, a positive trend in the pronotum, elytron and body weight of M. terani and a negative trend in morphological traits and body weight of S. maculatopygus. A negative allometry was maintained, suggesting that with increasing body weight, the body structures did not increase proportionally. On the other hand, we found that increasing the degree of pod infestation produced a wider variation in the individuals' body size than in low levels of infestation. Finally, we discuss how pod infestation can trigger competition between species, with both positive and negative impacts, even though the species function similarly in resource exploitation. <![CDATA[Diversity of Drosophilidae (Insecta, Diptera) in the Restinga forest of southern Brazil]]> Abstract Although members of Drosophilidae are frequently the topic of ecological studies in Brazil, few have explored Restinga or, until only recently, Pampa biome environments. This study proposes to describe the diversity and temporal variation of the Drosophilidae assemblage from a Restinga forest of Rio Grande do Sul, Brazil. We performed monthly collections from February 2013 to January 2014 using yeasted banana-baited traps. A total of 25,093 individuals of 46 species were sampled. Drosophila simulans and the D. willistoni subgroup were the dominant taxa; D. polymorpha, D. immigrans, D. paraguayensis and Zygothrica orbitalis were of intermediate abundance, and the other 40 species were rare. Based on sampling effort estimators, our collections were sufficient. Jaccard and Morisita indices evaluated using ANOSIM reveal little similarity in the composition of samples across months. Canonical correspondence analysis shows that the variables of maximum and minimum temperature are the main factors responsible for differentiation of the species composition of the assemblage throughout the year, whereby collections in the coldest periods (July, August and September) are those with a more differentiated composition. In these months, the dominance of D. simulans and the D. willistoni subgroup decreases while increased abundance of the D. tripunctata group (as D. paraguayensis) and Z. orbitalis occurs. In comparison to other studies carried out in environments in southernmost Brazil, we observed a similar pattern of fluctuation in abundance over the year, with a higher abundance of dominant species in warmer months and population sizes decreasing in colder months. <![CDATA[Biology of <em>Blepyrus clavicornis</em> (Compere) (Hymenoptera: Encyrtidae), a parasitoid of <em>Pseudococcus viburni</em> (Signoret) (Hemiptera: Pseudococcidae)]]> Abstract Encyrtids (Hymenoptera: Encyrtidae) are the most important and diverse group of natural enemies of mealybugs (Hemiptera: Pseudococcidae). Blepyrus clavicornis (Compere) is the most common parasitoid associated with Pseudococcus viburni (Signoret) in the Serra Gaúcha region, Brazil. We conducted laboratory studies to assess the development time, sex ratio, adult longevity, host stage selection for parasitism, and effect of food on the longevity of adult females of B. clavicornis. The experiments were conducted in a climate chamber at 25 ± 1 °C, 70 ± 10% RH and 12:12 L:D photoperiod. The solitary parasitoid B. clavicornis parasitized third-instar and adult female stages of P. viburni. The development time was more than 30 days (31.75 ± 0.38 for females and 30.02 ± 0.34 for males) when B. clavicornis laid eggs in adult mealybug females, and 35 days (36.50 ± 0.50 for females and 34.24 ± 0.43 for males) on third-instar mealybug nymphs. The wasps did not survive longer than four days when they were fed only water, while females survived for about 30 days when fed with honey. The lifespan of females is about 20 days longer than the lifespan of males. Although B. clavicornis can provide significant natural control, reducing the number of individuals in the next generation by parasitizing advanced mealybug instars, we consider it unpromising for use in applied biological-control programs. Furthermore, the predominance of males in the progeny observed here suggests that P. viburni may not be the most suitable or preferred host for B. clavicornis. <![CDATA[New synonymy in <em>Platyphora</em> Gistel (Coleoptera, Chrysomelidae, Chrysomelinae)]]> Abstract New synonymy in Platyphora Gistel (Coleoptera, Chrysomelidae, Chrysomelinae). Doryphora cliensStål, 1858 is considered a synonym of Doryphora congenerStål, 1858. <![CDATA[Genetic divergence of a newly documented population of the cecidogenous micromoth <em>Eugnosta azapaensis</em> Vargas & Moreira (Lepidoptera: Tortricidae) in the Atacama Desert of northern Chile]]> Abstract Eugnosta azapaensis Vargas and Moreira, 2015 (Lepidoptera: Tortricidae) is a micromoth native to the Atacama Desert whose larvae induce fusiform galls in shoots of Baccharis salicifolia (Ruiz &amp; Pav.) Pers. (Asteraceae). The presence of this cecidogenous tortricid was previously recorded only from the type locality, the Azapa Valley, Arica Province, northern Chile. However, fusiform galls on shoots of B. salicifolia were recently found in Chaca, another coastal valley of the Atacama Desert. The adults obtained from these galls were preliminarily identified as E. azapaensis based on morphology. Subsequently, to assess an additional source of evidence for the taxonomic identification of E. azapaensis in this new locality, sequences of the DNA barcode fragment of the cytochrome oxidase subunit I mitochondrial gene from the two localities were analyzed. Four haplotypes were detected, two restricted to Azapa and two restricted to Chaca. The genetic divergence (K2P) between haplotypes of each locality was 0.2-0.8%, while it was 1.1-1.4% between haplotypes of different localities, and 8.7-13.5% between the Chilean haplotypes and other species of Eugnosta Hübner, 1825. In addition, all the sequences of Azapa and Chaca were clustered in a well-supported group in a Maximum Likelihood (ML) analysis. Accordingly, divergence and ML analyses support the morphological identification of E. azapaensis in the Chaca Valley. Furthermore, although preliminary, the analyses suggest that the genetic variation of the populations of this insect could be geographically structured, a pattern that must be assessed in further studies.