Luís Cláudio Paterno Silveira

Type of prey influences biology and consumption rate of Orius insidiosus (Say) (Hemiptera, Anthocoridae)

Generalist predators are capable of consuming different types of prey, and as each prey may have distinct nutritional values, each may have a distinct impact on the biology of the predator. Therefore, the aim of this study was to determine how the consumption of different prey influences certain biological characteristics and the predatory capacity of Orius insidiosus (Say). The investigation was performed in climatic chamber at 25 ±1 oC, RH 70 ± 10% and fotophase 12. Eggs of Anagasta kuehniella (Zeller), adults of Caliothrips phaseoli (Hood) and nymphs of Aphis gossypii Glover were used as prey and were provided daily ad libitum for all the mobile stages of the predator. The results showed that biological parameters of O. insidiosus are affected differently depending on the type of prey ingested. The development time of the nymphal stage was 13.1, 11.23 and 10.25 days for O. insidiosus feeding on eggs of A. kuehniella, nymphs of A. gossypii and adults of C. phaseoli, respectively. Longevity was five times larger for adults fed on eggs of A. kuehniella (56.25 days) compared to that of adults that preyed on nymphs of A. gossypii (11.44 days), and four times larger when the prey were adults of C. phaseoli (13.58 days). The consumption of eggs of A. kuehniella by predator females resulted in a shorter pre-oviposition period (3.2 days) and a longer oviposition period (44.4 days) when compared to the consumption of other types of prey. In addition, fecundity was increased with the consumption of eggs of A. kuehniella (195.25 eggs laid / female) when compared to feeding on the other prey, C. phaseoli (70.00 eggs laid / female) or A. gossypii (22.50 eggs laid / female). However, the consumption of aphids was larger (148.28 nymphs/ nymphal stage) than that of thrips (74.10 thrips / nymphal stage) or eggs of A. kuehniella (37.03 eggs /nymphal stage) for all of the nymphal stages of the predator. The results indicate that the eggs of A. kuehniella are the type of prey best suited for rearing this predator insect under laboratory conditions. Also fecundity was better with this prey even though the predator consumed during its nymphal stage a lesser quantity of eggs compared to the other prey.

Plantas cultivadas e invasoras como habitat para predadores do gênero Orius(Wolff) (Heteroptera: anthocoridae)

The aim of this research was to record the Orius species present on some crops and weeds in areas located in the southeast region in Brazil, during 1999 and 2000. The insect collections were made through the tapping method to dislodge the insects from the plant into a plastic bag. The identifications of the specimens was done in the laboratory. Orius insidiosus (Say) was collected on the following crops: corn (Zea mays L.), pearl millet (Pennisetum glaucum (L.) R.Br.), sorghum (Sorghum spp.), bean (Phaseolus vulgaris L.), sunflower (Helianthus annuus L.), alfalfa (Medicago sativa L.), soybean (Glycine max (L.) Merr.), chrysanthemum (Chrysanthemum spp.), tango (Solidago canadensis L.) and carthamus (Carthamus tinctorius L.). On weeds, O. insidiosus was found on farmers friend (Bidens pilosa L.), amaranth (Amaranthus sp.), parthenium weed (Parthenium hysterophorus L.) and Josephs coat (Alternanthera ficoidea L.). Orius thyestes Herring was found on weed plants farmers friend, amaranth and Josephs coat. Orius perpunctatus (Reuter) and Orius sp. were collected mainly on weed plants (farmers friend, amaranth and Josephs coat) and corn. Many of these plants are natural hosts for these predators, providing refuge, prey and pollen.

Marigold (Tagetes erecta L.) as an attractive crop to natural enemies in onion fields

4 UFLA - Depto. de Biologia. *Corresponding author ABSTRACT: Onion is the third most grown vegetable crop in Sao Paulo state, Brazil. Organic onion farming is expected to increase in the state due to the increasing demand. Pest management in organic onion farming is based on plant extracts with insecticide effects. However, the efficacy of such plant extracts has not been proved yet, and it was observed that they do negatively affect natural enemies. Plants surrounding onion fields, and that are attractive to natural enemies, may be a good option to farmers, since they may lead to increased diversity of arthropod species and, consequently, the natural control of pest populations. This study deals with the effect of marigold plants as a resource plant to natural enemies in onion fields. The experiment was set in a certified organic farm using marigold rows at a center of an onion field. Samples were taken from marigold and the onion plants 5 m (near) and 30 m (far) from the flowering strips. Higher numbers of arthropod pests were observed in onion plants 30 m from the marigold strip, while higher numbers of predators and parasitoids were found at 5 m distance. Species richness and Shannons diversity index were higher at 5 m from marigold. Therefore, marigold rows next to onion fields resulted in higher number of entomophagous species, potentially enhancing the natural control of onion pests. In the study field, marigold strips may be an alternative to crop sprays for organic control of onion pests.

Efeito de genótipos de milho no desenvolvimento de Spodoptera frugiperda (J.E. Smith)

The effect of corn (Zea mays) genotypes on the biology of Spodoptera frugiperda (J.E.Smith) was evaluated to identify possible sources of resistance. The development of the insect was compared on 5 inbred lines from Mississippi (EUA), 5 genotypes from Instituto Agronomico de Campinas and one genotype from Central America (Zapalote Chico). Results showed that the duration of larval stage and larval weight 10 days after emergence were affected by genotypes Mp707, Zapalote Chico, Mp701, Mp706 and Mp705. Viability of larval stage was affected by genotypes Mp705 and Mp706, while the pupal weight was smaller on genotype IAC103 BPl. The duration and viability of pupal stage, sexual ratio, and % of malformed adults were less important to discriminate these cultivars. It was concluded that the least suitable genotypes for development of the insect were Mp707 and Zapalote Chico, followed by Mp706, Mp705 and Mp701, while the most adequates were IAC103 N, IAC701 N and Mp496.

Influência do fotoperíodo na reprodução e longevidade de Orius insidiosus (Say) (Heteroptera: Anthocoridae)

Orius insidiosus (Say) is an important predator of thrips and photoperiod can affect the reproduction of this insect. The objective of this work was to verify the occurrence of reproductive diapause in O. insidiosus in laboratory conditions. The experiments were carried out in environmental chambers, at photoperiods of 9L:15D, 10L:14D, 11L:13D, 12L:12D, 13L:11D and 14L:10D, temperature of 25±1oC and RH of 70±10%. Fecundity and sex ratio were not affected by the different photoperiods; an average number of 162.0, 189.8, 175.8, 195.2, 132.2 and 125.1 eggs/female, respectively, were found on these photoperiods. However, the photoperiods affected longevity of the predator. Longevity varied from 77.1 days, at photoperiod 10L:14D, to 40.1 days at photoperiod 9L:15D. O. insidiosus did not enter reproductive diapause in the conditions carried out in this experiment. This information is important to understand the factors that are involved on performance and use of O. insidiosus on biological control of thrips on protected cultivation.

Record of two species of Orius Wolff (Hemiptera, Anthocoridae) in Brazil

The genus Orius Wolff, 1811 comprises predatory species, with approximately 70 known species. Informations about the genus in Brazil are scarce. Therefore, the aim of this investigation was to identify Orius species present in four localities in the southeastern Brazil. Samples were taken from several plants, and the material screened in laboratory. The genitalia of both sexes were studied and illustrated. Two species were identified, Orius insidiosus (Say, 1832) and Orius thyestes Herring, 1966. O. insidiosus, the most common species, was collected in all of the localities sampled [Lavras (MG), Holambra, Pindorama and Campinas (SP)]. O. thyestes, registered for the first time in Brazil, occurred only in Lavras (MG) and Pindorama (SP). Some morphologic aspects of these two species are also presented.

Orius insidiosus (Say, 1832) (Heteroptera, Anthocoridae): sensibilidade ao fotoperíodo e diapausa reprodutiva?

The minute pirate bugs, Orius spp., are known as predators on several pests as thrips, aphids, spider mites and whiteflies. Orius insidiosus is an important thrips predator, commercially used around the world. However, one of the main problems on biological control of thrips in temperate regions is the occurrence of reproductive diapause in Orius species. This characteristic promotes the interruption of biological control strategies when predators are exposed to short photoperiods. This research had as objective to evaluate the influence of different photoperiod conditions on eggs/nymphs and adults of O. insidiosus in laboratory. The trials were carried out through the combination of eggs/nymphs and adults reared under the photoperiods 10L:14D; 11L:13D; 12L:12D and 13L:11D, at 25±2oC and 70±10% RH. The predators were maintained during their pre-imaginal development time under one of the photoperiods and, after being emerged as adults transferred to another photoperiod regime. The predator had a tendency to present longer development time under photoperiod 13L:11D. There was no influence of the different photoperiods conditions on the reproduction of O. insidiosus. The females laid eggs normally during all their lifetime. O. insidiosus is not sensitive to photoperiod evaluated and do not enter in reproductive diapause.

Qualidade de mangas cultivadas no Estado de São Paulo

The mango (Mangifera indica L.) is one of the most consumed fruits in the world. The choice of variety for cultivation should be related with preferences of the consuming market, that include fruits with larger pulp percentage and larger tenor of total soluble solids, properties of great importance for industrial processing and for internal and external markets. The overall quality of fruits from 39 mango varieties (Adams, Alda, Brasil, Cacipura, Carabao, Carrie, Castro, Edward, Eldon, Familia, Foice, Haden, Haden 2H, Haden TR, IAC 10 Bourbon, Itamarati, Joe Welch, Julima, Lima Peru, M20-222 Winter, Mabrooca, Neves, Palmer, Pele de Moca, Petacon, Pope, Regina, Rocha, Rosa, Rubi, Sensation, Smith, Surpresa, Torbet, Torrinha, Uba, Wesley, White Langra and Zill) from the collection of Polo Apta Centro-Norte, located at Pindorama, Sao Paulo State, was appraised, with the objective of gathering information regarding fruits produced in this area. Twenty fruits of each variety were picked ripe traits such as fresh weight, weight of the peel, weight of the pit, pulp, peel and pit percentages, tenor of total soluble solids (SST) and infestation for fruit-flyes were evaluated. A design in randomized blocks was used for the analysis of the data of pulp percentage and SST. Averages were compared by the Tukey test of 5% of probability. Based on results, it can be concluded that the variety Smith stands out for exhibiting fruits with larger total weight (694 g), larger pulp percentage (85,7%), smaller pit percentage (6,3%) and larger tenor of SST (24,9o Brix), adequate for industrial processing and for internal and external markets.

Occurrence of Lysiphlebus testaceipes parasitizing Aphis gossypii in watermelon in the State of Rio Grande do Norte, Brazil

This is the first report of the parasitoid Lysiphlebus testaceipes (Cresson) as a biological control agent of the aphid Aphis gossypii Glover in watermelon crop in Vale do Acu, RN. It was observed that near the harvest, almost all collected aphids were mummified, and after analyzing the emerged parasitoids, the parasitoid L. testaceipes was identified. Therefore, in the future, this species may be included in A. gossypii integrated management programs.

Cravo-de-defunto como planta atrativa para tripes em cultivo protegido de melão orgânico

ABSTRACT MARIGOLD AS ATTRACTIVE PLANT FOR THRIPS IN PROTECTEDORGANIC MELON CULTIVATION The attractiveness of Tagetes patula L. (marigold) to thrips (Thysanoptera) in greenhoused melonwas evaluated. Abundance, dominance, frequency, and constancy of thrips species were studied by usingfaunistic analysis, cluster analysis (CA) and principal component analysis (PCA). Marigold was plantedonly at the edge of the greenhouses. Insect sampling on melon plants was taken by shaking three vinegrowing ends on a white tray whereas similar procedure was used for sampling marigold but shakingall plants of 1 m 2 . Samplings points where on T. patula edge, on melon planted along with marigold,and on melon planted at 6m, 12m, 18m, and 24m from marigold edge. Eleven thrips species were foundon both melon and marigold plants: Neohydatothrips sp., Frankliniella sp. 1, Frankliniella sp. 2, Frankliniella ( 1 ) Parte da Dissertacao de Mestrado da primeira autora. Recebido para publicacao em 26 de junho de 2007 e aceito em 24de abril de 2009.(