Helicoverpa armigera Harm 1 Haplotype Predominates in the Heliothinae (Lepidoptera: Noctuidae) Complex Infesting Tomato Crops in Brazil.

Tomato (Solanum lycopersicum L.) is a natural host for the Helicoverpa-Chloridea (Lepidoptera: Noctuidae: Heliothinae) pest complex. The species Helicoverpa armigera (Hübner) was responsible for significant yield losses in several crops after its detection in Brazil. The morphology of its larval stage resembles common Heliothinae species, making pest control decisions difficult. The overall lack of studies on the Heliothinae associated with tomatoes in Brazil and the establishment of H. armigera in the country plus their recent outbreaks supported our investigation about the relative importance of the insects from the Helicoverpa-Chloridea complex in this vegetable crop. A nationwide survey was carried out across fresh-market and processing tomato fields. Molecular analyses targeting a segment of the mitochondrial cytochrome oxidase subunit I (mtCOI) gene and their sequence analyses indicated the presence of a pest complex, comprising the introduced species H. armigera and the indigenous species, Helicoverpa zea (Boddie), and Chloridea virescens (Fabricius). The Harm 1 haplotype of H. armigera was identified as the predominant Heliothinae pest infesting fresh-market tomatoes. The New World species Chloridea subflexa (Guenée) as well as the exotic Solanaceae-specific species Helicoverpa assulta (Guenée) were not found in our survey. Additional larvae surveys in processing tomato fields during 2013/2014 in Central Brazil also indicated H. armigera as the most abundant Heliothinae species (95%) together with H. zea (4.75%) and C. virescens (0.25%). The occurrence of distinct Helicoverpa species (which are potentially capable of interbreeding) indicates that novel crop management strategies will be necessary in order to minimize damages caused by this pest complex in tomatoes.

New features on the genomic organization of a novel dicistrovirus identified from the sweet potato whitefly Bemisia tabaci.

The whitefly Bemisia tabaci is an agricultural pest causing large economic losses worldwide. We analysed the genomic sequence of a new viral member of the family Dicistroviridae identified by high-throughput sequencing of total RNA extracted from whiteflies. The virus, tentatively named Bemisia-associated dicistrovirus 2 (BaDV-2), has a genome of 8012 nucleotides with a polyadenylated 3' end. In contrast to typical dicistroviruses, BaDV-2 has a genome containing three open reading frames (ORFs) encoding predicted proteins of 1078 (ORF1a), 481 (ORF1b) and 834 (ORF2) amino acids, which correspond to replicase A (containing helicase and cysteine protease domains), replicase B (a domain of an RNA-dependent RNA polymerase - RdRP) and capsid proteins, respectively. The 3' end of ORF1a contains a potential frameshift signal, suggesting that ORF1a and ORF1b may be expressed as a single polyprotein (replicaseFS), corresponding to other dicistroviruses. The BaDV-2 genomic sequence shares the highest nucleotide identity (61.1 %) with Bemisia-associated dicistrovirus 1 (BaDV-1), another dicistrovirus identified from whiteflies. The full BaDV-2 replicaseFS polyprotein clustered with aparaviruses, whereas the capsid polyprotein clustered with cripaviruses in phylogenetic analyses, as with BaDV-1. The intergenic region (IGR) between ORF1b and ORF2 is predicted to adopt a secondary structure with atypical features that resembles the dicistrovirus IGR IRES structure. Our analyses indicate that BaDV-2 is a novel dicistrovirus and that BaDV-2 together with BaDV-1 may not be appropriately grouped in any of the three currently accepted dicistrovirus genera.

Determination of an Economic Injury Level for Old World Bollworm (Lepidoptera: Noctuidae) in Processing Tomato in Brazil.

Tomato plants host various herbivores, including the Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), recently introduced into South and Central America. It is a harmful pest for tomato crops, damaging mainly the flowers and fruits. The assessment of losses and the establishment of economic injury level (EIL) and economic threshold (ET) are core steps toward establishing a control program. We determined losses caused by H. armigera on processing tomato and estimated EIL/ET values. Trials were run during two growing seasons using tomato plants caged in the field. The field cage experiment consisted of six densities of H. armigera second instar larvae (0, 1, 3, 6, 12, and 24 larvae per row meter) at two infestations periods spaced 15 d apart with the first infestation done 90 d after transplanting. The larvae were placed individually on the third upper fully developed leaf. The number of healthy and damaged fruits, size, and weight of the fruits were measured. Yield losses as a function of infestation of 1-24 larvae per row meter ranged from 4 to 34% and resulted in a yield reduction of 1.22-12.77 kg per row meter. The EIL ranged from 1.41 to 1.72 and from 2.11 to 2.58 larvae per row meter of plants in 2017 and 2018 cropping seasons, respectively. Helicoverpa armigera causes significant reduction of tomato yield. These EIL values will enable better control decision-making in processing tomato.

Complete genome sequence and phylogenetic analysis of a novel dicistrovirus associated with the whitefly Bemisia tabaci.

A novel single-stranded RNA virus was detected in a whitefly (Bemisia tabaci) sample subjected to high-throughput sequencing. The 8293 nt-long genome presents a polyadenylated 3' end, and contains two ORFs encoding putative 1596 and 849 aa-long proteins. These putative proteins display significant similarity to replicase and capsid polyproteins, respectively, of discitroviruses. Its complete genome sequence shared the highest nucleotide identity (59.8%) with cricket paralysis virus (family Dicistroviridae, genus Cripavirus). Phylogenetic analyses showed that this new virus putative protein sequences clustered with those from members of Dicistroviridae. However, the replicase and capsid polyprotein sequences clustered with those of members of different genera, respectively to Aparavirus and Cripavirus. RT-PCR using newly collected adult and nymph whitefly samples confirmed the presence of this virus in field populations of B. tabaci. Genome sequence and organization, and polyproteins comparison indicate that this virus is a new species of the family Dicistroviridae. The name Bemisia-associated dicistrovirus 1 is proposed for this virus.

Erratum to: Discovery of two small circular ssDNA viruses associated with the whitefly Bemisia tabaci.

The complete genome sequences of two novel small circular DNA viruses isolated from sweet-potato whiteflies collected in Central-West (AdDF) and Southeast (AdO) regions of Brazil were determined by Next Generation Sequencing (NGS), and confirmed by cloning and Sanger sequencing. The genomes are 2,199 and 2,211 nt-long, respectively, encoding a putative coat protein (CP) and a replication-associated protein (Rep) and showing a genomic organization typical of viruses from the family Genomoviridae. Phylogenetic analysis with deduced amino acid sequences of Rep indicates that the virus from AdO is closely related to other members of the genus Gemycircularvirus, while the virus from AdDF is related to those of the genus Gemyduguivirus. These new genomoviruses are tentatively named bemisia-associated genomovirus AdO and bemisia-associated genomovirus AdDF.

Discovery of two small circular ssDNA viruses associated with the whitefly Bemisia tabaci.

The complete genome sequences of two novel small circular DNA viruses isolated from sweet-potato whiteflies collected in central-West (AdDF) and Southeast (AdO) regions of Brazil were determined by Next Generation Sequencing (NGS), and confirmed by cloning and Sanger sequencing. The genomes are 2,199 and 2,211 nt-long, respectively, encoding a putative coat protein (CP) and a replication-associated protein (Rep) and showing a genomic organization typical of viruses from the family Genomoviridae. Phylogenetic analysis with deduced amino acid sequences of Rep indicates that the virus from AdO is closely related to other members of the genus Gemycircularvirus, while the virus from AdDF is distantly related to other genomovirus. It was thus classified in a putative new genus, for which the name "Gemybolavirus" is proposed. These new genomoviruses are tentatively named "Bemisia associated gemybolavirus AdDF", and "Bemisia associated gemycircularvirus AdO".

Volatiles mediating a plant-herbivore-natural enemy interaction in resistant and susceptible soybean cultivars.

Several studies have shown that herbivore-induced plant volatiles act directly on herbivores and indirectly on their natural enemies. However, little is known about the effect of herbivore damage on resistant and susceptible plant cultivars and its effect on their natural enemies. Thus, the aim of this study was to evaluate the attraction of the herbivorous pentatomid bug Euschistus heros and its egg parasitoid Telenomus podisi to two resistant and one susceptible soybean cultivars with different types of damage (herbivory, herbivory+oviposition, and oviposition). In a Y-tube olfactometer, the parasitoids were attracted to herbivory and herbivory+oviposition damaged soybean plants when compared to undamaged soybean plants for the resistant cultivars, but did not show preference for the susceptible cultivar Silvânia in any of the damage treatments. The plant volatiles emitted by oviposition-damaged plants in the three cultivars did not attract the egg parasitoid. In four-arm-olfactometer bioassays, E. heros females did not show preference for odors of damaged or undamaged soybean plants of the three cultivars studied. The Principal Response Curves (PRC) analysis showed consistent variability over time in the chemical profile of volatiles between treatments for the resistant cultivar Dowling. The compounds that most contributed to the divergence between damaged soybean plants compared to undamaged plants were (E,E)-α-farnesene, methyl salicylate, (Z)-3-hexenyl acetate, and (E)-2-octen-1-ol.

Use of serological techniques for determination of Spodoptera frugiperda(J E Smith) predators (Lepidoptera: Noctuidae).

Spodoptera frugiperda (J E Smith) is an important pest of several crops, but especially on maize in Brazil. The implementation of biological control measures hinges on the identification of its predators and other natural enemies. As a means of identifying predators, antibodies against S. frugiperda eggs were generated by inoculating rabbits with macerated S. frugiperda eggs, and the production of antibodies against S. frugiperda egg proteins was verifi ed by double immunodiffusion (DID). These antibodies were then utilized in another serological technique, counterimmunoeletrophoresis (CIE), to identify insects that could have ingested S. frugiperda eggs. Macerates of entire insects collected in maize plantations and of individual parts of their digestive tract, including the crop, were the source of antigens in the CIE, while predators fed S. frugiperda eggs in the laboratory served as the control. Antibodies produced by the inoculated rabbits were effective in detecting S. frugiperda egg proteins, especially if crop macerates were used as antigens. Among the species of insects collected from maize plantations, Lagria villosa Fabricius (Coleoptera: Lagriidae) and a species of Lygaeidae (Hemiptera) were identified as possible S. frugiperda predators.

Use of serological techniques for determination of Spodoptera frugiperda (J E Smith) predators (Lepidoptera: Noctuidae)

Spodoptera frugiperda (J E Smith) is an important pest of several crops, but especially on maize in Brazil. The implementation of biological control measures hinges on the identification of its predators and other natural enemies. As a means of identifying predators, antibodies against S. frugiperda eggs were generated by inoculating rabbits with macerated S. frugiperda eggs, and the production of antibodies against S. frugiperda egg proteins was verifi ed by double immunodiffusion (DID). These antibodies were then utilized in another serological technique, counterimmunoeletrophoresis (CIE), to identify insects that could have ingested S. frugiperda eggs. Macerates of entire insects collected in maize plantations and of individual parts of their digestive tract, including the crop, were the source of antigens in the CIE, while predators fed S. frugiperda eggs in the laboratory served as the control. Antibodies produced by the inoculated rabbits were effective in detecting S. frugiperda egg proteins, especially if crop macerates were used as antigens. Among the species of insects collected from maize plantations, Lagria villosa Fabricius (Coleoptera: Lagriidae) and a species of Lygaeidae (Hemiptera) were identified as possible S. frugiperda predators.

Effect of some biorational insecticides on Spodoptera eridania in organic cabbage.

BACKGROUND: To reduce pest attack, several biorational products are allowed for use on organic vegetables in Brazil. This study investigated eight biorational products applied singly or in combination against Spodoptera eridania Cramer in field plots of cabbage intercropped with coriander. The treatments were applied once a week over a 5 week period, beginning 34 days after transplanting. The evaluations consisted of counting the larvae of S. eridania on the day before and 7 and 21 days after spraying. The damage to leaves and cabbage head, the commercial weight of head and the percentage of head losses were evaluated. RESULTS: Leaf injury in plots treated with Beauveria bassiana and neem oil (Dalneem) yielded scores of 1.3 and 2.5 (scale ranging from 0 to 4) respectively, in comparison with a score of 3.6 from untreated plots. Head weight losses were 6.1, 5.3 and 4.9% with an aqueous extract of neem leaves, neem oil and B. bassiana respectively, compared with 24.6% lost from untreated plots. CONCLUSION: Dalneem, B. bassiana and the extract of neem leaves at 20% exhibited the best performance for control of S. eridania.

[Mating behavior of the coffee leaf-miner Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae)]. / Comportamento de acasalamento do bicho-mineiro-do-cafeeiro, Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae).

Despite the importance of Leucoptera coffeella (Guérin-Mèneville) in coffee production worldwide, there is a lack of information on its reproductive biology. This knowledge will help in mass rearing, as well as support the development of behavioral control techniques for this insect. The purpose of the study was to determine the periodicity of mating and male capture and describe the mating behavior L. coffeella. In laboratory, we observed the periodicity of mating with virgin couples of different ages, zero to five days after emergence. Male activity was studied in a 0.7 ha coffee plantation, cv. Catuaí, where Delta traps were installed at 0.5 m above ground, using either virgin females or rubber septa lured with the synthetic sex pheromone. The sequence of mating behavior was studied by making visual observations and recorded of pairs placed on individual plastic tubes. Mating occurred between 4h and 6h of photophase, when the highest frequencies involved pairs with ages of one and three days after emergence, with peak of mating occurring in 5th hour of photophase. The young or old pairs showed significantly copulation frequency and the peak of matings advance in 1h. The highest male capture occurred at 12p.m. and 13 p.m. by traps with virgin females or traps with synthetic sex pheromone lures, respectively. L. coffeella is one insect with diurnal mating and the mating behavior was not different from what is know for other Lepidoptera species.

Comportamento de acasalamento do bicho-mineiro-do-cafeeiro, Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae) / Mating behavior of the coffee leaf-miner Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae)

Leucoptera coffeella (Guérin-Mèneville) é praga-chave na cafeicultura; contudo, faltam informações sobre sua reprodução para o desenvolvimento de táticas de controle por comportamento. Este trabalho teve como objetivos determinar a periodicidade de cópulas; a periodicidade de captura dos machos e caracterizar o comportamento de acasalamento de L. coffeella. A periodicidade de acasalamento foi avaliada em laboratório com casais virgens de diferentes idades, zero a cinco dias após a emergência, individualizados em tubos transparentes. A periodicidade de captura foi avaliada em café cv. Catuaí, onde foram instaladas armadilhas Delta com dois atraentes: fêmeas virgens e septos de borracha impregnados com o feromônio sexual sintético. As etapas do comportamento de acasalamento foram descritas a partir de observação direta e de filmagens de casais virgens individualizados em tubos transparentes. Os acasalamentos ocorreram entre 4h e 6h da fotofase, onde as maiores freqüências envolveram casais com idades entre um e três dias da emergência, com pico de acasalamentos na quinta hora da fotofase. Os casais recém-emergidos ou velhos mostraram significativamente menor freqüência de cópulas e o pico dos acasalamentos antecipado em 1h. A maior captura ocorreu às 12:00h e 13:00h, nas armadilhas com fêmeas virgens e feromônio sexual sintético, respectivamente. Pelos resultados, L. coffeella é um inseto com acasalamento diurno e os comportamentos de chamamento e corte seguem o padrão encontrado em outros Lepidoptera.

Despite the importance of Leucoptera coffeella (Guérin-Mèneville) in coffee production worldwide, there is a lack of information on its reproductive biology. This knowledge will help in mass rearing, as well as support the development of behavioral control techniques for this insect. The purpose of the study was to determine the periodicity of mating and male capture and describe the mating behavior L. coffeella. In laboratory, we observed the periodicity of mating with virgin couples of different ages, zero to five days after emergence. Male activity was studied in a 0.7 ha coffee plantation, cv. Catuaí, where Delta traps were installed at 0.5 m above ground, using either virgin females or rubber septa lured with the synthetic sex pheromone. The sequence of mating behavior was studied by making visual observations and recorded of pairs placed on individual plastic tubes. Mating occurred between 4h and 6h of photophase, when the highest frequencies involved pairs with ages of one and three days after emergence, with peak of mating occurring in 5th hour of photophase. The young or old pairs showed significantly copulation frequency and the peak of matings advance in 1h. The highest male capture occurred at 12p.m. and 13 p.m. by traps with virgin females or traps with synthetic sex pheromone lures, respectively. L. coffeella is one insect with diurnal mating and the mating behavior was not different from what is know for other Lepidoptera species.