José R. Valério

Sobre a ocorrência de uma nova praga, Haematobia irritans (L.) (Diptera, Muscidae), no Brasil

The horn fly, Haematobia irritans (L.) (Diptera, Muscidae), is reported as introduced into Boa Vista, Roraima, Brasil, possibly from Northern South America (Venezuela).

Seleção de introduções do gênero Brachiaria (Griseb) resistentes à cigarrinha Zulia entreriana (Berg) (Homoptera: Cercopidae)

Spittlebugs are the most damaging pasture pests in tropical America where extensive monocultures of Brachiaria decumbens cv. Basilisk have favoured the buildup of spittlebug populations. Under severe spittlebug attack, the entire above-ground portion of the plant appears dry and dead, reducing the stocking rates of damaged pastures. Host plant resistance is a low-cost method of controlling spittlebugs, which farmers can easily adopt. High level of spittlebug resistance is found in the cultivar B. brizantha cv. Marandu, but it requires more fertile soils. A Brachiaria germplasm provided by the International Center for Tropical Agriculture and available at the National Center for Beef Cattle Research (CNPGC) has been screened for spittlebug resistance. In the present study 30 introductions of Brachiaria were evaluated for resistance to the spittlebug Zulia entreriana (Berg), based on nynphal survival and period. Three introductions (BRA 1945, BRA 3115 and BRA 3425), all B. brizantha, were selected as resistant. Given the great number of available introductions and even hibrids resulting from the breeding program, this test has been done routinely at the CNPGC in the search for sources of resistance. Complementary evaluations aiming the releasing of new spittlebug resistant Brachiaria cultivars are in progress.

Meiotic chromosomes and nucleolar behavior in testicular cells of the grassland spittlebugs Deois flavopicta, Mahanarva fimbriolata and Notozulia entreriana (Hemiptera, Auchenorrhyncha)

Spittlebugs annually infest pastures and cause severe damage, representing a serious problem for the tropical American beef cattle industry. Spittlebugs are an important biotic constraint to forage production and there is a lack of cytogenetic data for this group of insects. For these reasons, we conducted this work, in which the spermatogenesis and nucleolar behavior of Deois flavopicta, Mahanarva fimbriolata and Notozulia entreriana were studied. The males possessed testes in the shape of a “bunch of grapes”; a variable number of testicular lobes per individual and polyploid nuclei composed of several heteropycnotic bodies. A heteropycnotic area was located in the periphery of the nucleus (prophase I); the chiasmata were terminal or interstitial; metaphases I were circular or linear and anaphase showed late migration of the sex chromosome. The chromosome complement had 2n = 19, except for N. entreriana (2n = 15); the spermatids were round with heteropycnotic material in the center and elongated with conspicuos chromatin. The analysis of testes after silver nitrate staining showed polyploid nuclei with three large and three smaller nucleolar bodies. Early prophase cells had an intensely stained nucleolar body located close to the chromatin and another less evident body located away from the chromatin. The nucleolar bodies disintegrated during diplotene. Silver staining occurred in two autosomes, in terminal and subterminal locations, the latter probably corresponding to the nucleolus organizer regions (NORs). The spermatids were round with a round nucleolar body and silver staining was observed in the medial and posterior region of the elongated part of the spermatid head.

Parasitismo de ovos de cigarrinhas-das-pastagens (Homoptera: Cercopidae) pelo microhimenóptero Anagrus urichi pickles (Hymenoptera: Mymaridae) na região de Campo Grande, MS

Egg parasitism by the microhymenopteran Anagrus urichi Pickles was found on samples of spittlebug eggs collected in Brachiaria decumbens pasture. It is the first record of spittlebug egg parasitism for the State of Mato Grosso do Sul, Brazil. The rate of 10.4% of parasitism was observed in 1688 spittlebug eggs, comprising seven samples. On average, 4.7 wasps emerged from each parasitized egg. Thirteen percent of parasitism were observed when 100 eggs of the spittlebug Notozulia entreriana (Berg), obtained in the laboratory, were exposed to eight of these parasitoids. It is anticipated the possibility of mass rearing A. urichi.

Ultrastructure and redescription of Notozulia entreriana (Berg) (Hemiptera: Cercopidae)

The ultrastructure of the spittlebug Notozulia entreriana (Berg) is presented. The study resulted in 32 scanning electron microscope photos, with detailed species description.

Ocorrência de Blissus antillus Leonard (Hemiptera: Lygaeidae: Blissinae) em pastagem no estado de Mato Grosso do Sul

Embrapa, Centro Nacional de Pesquisa de Gado de Corte,Caixa postal 154, 79002-970, Campo Grande, MS.An. Soc. Entomol. Brasil 28(3): 527-529 (1999)The Occurrence of Blissus antillus Leonard (Hemipera: Lygaeidae: Blissinae)in Tangola Pasture in Mato Grosso do Sul State, BrazilABSTRACT – The occurrence of Blissus antillus Leonard was registered inTangola pasture (hybrid between Tanner grass Brachiaria arrecta (syn. B.radicans) and Angola grass, B. mutica ) in Mato Grosso do Sul State, Brazil, inMarch 1996. Population, averaging 582 chinch bugs per m

Genetic mapping with allele dosage information in tetraploid Urochloa decumbens (Stapf) R.D. Webster reveals insights into spittlebug (Notozulia entreriana Berg) resistance

Urochloa decumbens (Stapf) R.D. Webster is one of the most important forage grasses in Brazilian beef production; therefore, genomic studies such as constructing molecular maps and defining the genetic architecture of relevant agronomic traits, are essential to understanding U. decumbens genetic structure and advancing breeding programs. The study objectives were to (i) obtain an integrated U. decumbens genetic map using molecular markers with allele dosage information, (ii) detect QTLs for spittlebug (Notozulia entreriana) resistance, and (iii) seek putative candidate genes involved in resistance/defense against pathogens. We used five pseudo-genome references to align GBS reads and selected 4,240 high-quality SNP markers identified in the Setaria viridis genome. Of these markers, 1,000 were distributed throughout nine homologous groups with a cumulative map length of 1,335.09 cM and an average marker density of 1.33 cM. The map contains SNP markers with different configurations for a tetraploid species. For the first time, this study detected QTLs for resistance to spittlebug, an important pasture insect pest, explaining between 4.66% and 6.24% of the variation. These QTLs had markers linked to putative candidate genes related to resistance/defense against pathogens. Because this is the first U. decumbens map to include SNP dosage data and QTL detection, it will be useful for future evolutionary studies, genome assembly, and other quantitative trait locus analyses in Urochloa spp. Moreover, the results might facilitate the isolation of spittlebug-related genes and help clarify the mechanism of spittlebug resistance. These approaches will improve selection efficiency and accuracy in U. decumbens molecular breeding. The GBS sequence data files supporting the conclusions of this article are in the process of submission to the NCBI Sequence Read Archive (SRA), with accession number SRP092493