Oviposition of Quesada gigas in weed no hostess: implication in pest management / Oviposição de Quesada gigas em planta daninha não hospedeira: implicação no manejo de pragas

This study recorded the choice of dry plant of Conyza spp as oviposition site by cicada Quesada gigas (Olivier, 1790). We presented issues of natural history of the cicadas that indicate the inability of immatures to complete life cycle in this species of plant. Some implications on cultures where Q. gigas has economic importance are also discussed.

Registra-se a escolha de plantas secas de Conyza spp como local de oviposição pela cigarra Quesada gigas (Olivier, 1790). São apresentadas questões da história natural das cigarras que indicam a impossibilidade dos imaturos completarem seu ciclo de vida nessa espécie vegetal. São discutidas algumas implicações no manejo de culturas onde Q. gigas possui importância econômica.

Oviposition of Quesada gigas in weed no hostess: implication in pest management / Oviposição de Quesada gigas em planta daninha não hospedeira: implicação no manejo de pragas

This study recorded the choice of dry plant of Conyza spp as oviposition site by cicada Quesada gigas (Olivier, 1790). We presented issues of natural history of the cicadas that indicate the inability of immatures to complete life cycle in this species of plant. Some implications on cultures where Q. gigas has economic importance are also discussed.(AU)

Registra-se a escolha de plantas secas de Conyza spp como local de oviposição pela cigarra Quesada gigas (Olivier, 1790). São apresentadas questões da história natural das cigarras que indicam a impossibilidade dos imaturos completarem seu ciclo de vida nessa espécie vegetal. São discutidas algumas implicações no manejo de culturas onde Q. gigas possui importância econômica.(AU)

Scarabaeoidea (Insecta: Coleoptera) no Cerrado brasileiro: estado atual do conhecimento / Scarabaeoidea (Insecta: Coleoptera) in the Brazilian Cerrado: current state of knowledge

Besouros pertencentes à superfamília Scarabaeoidea ocupam habitats variados, possuem hábitos alimentares diversificados, desempenham importante papel ecológico e diversas espécies apresentam importância agrícola. No entanto, estudos com esse grupo na região do Cerrado são escassos. Nesta revisão realizou-se um levantamento dos artigos publicados nos últimos 30 anos a respeito dos Scarabaeoidea no Cerrado. Foram recuperados 64 artigos, realizados em nove unidades da federação, que focavam quatro temas principais: espécies praga, aspectos bioecológicos, biodiversidade e importância ecológica, e técnicas e metodologias de coleta de Scarabaeoidea. Os resultados desta revisão indicam que poucos estudos foram realizados com os Scarabaeoidea no Cerrado brasileiro nas últimas décadas frente à importância e diversidade desse grupo de insetos.(AU)

Beetles belonging to the superfamily Scarabaeoidea occupy different habitats, present feeding habits diversified, play an important ecological role and several species have agricultural importance. However, studies with this group in the Brazilian Cerrado are scarce. In this review we carried out a survey of scientific articles published in the past 30 years concerning Scarabaeoidea in the Cerrado. Were found 64 studies in nine Brazilian states. The studies focused on four main topics: pest species, bioecology, biodiversity and ecological importance, techniques and methodologies for collecting Scarabaeoidea. The results of this review indicate that few studies have been conducted with Scarabaeoidea in the Cerrado in recent decades compared to the importance and diversity of this group of insects.(AU)

Functional response of Phytoseiulus macropilis under different Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) population density in laboratory

We tested the functional response of the phytoseiid predator Phytoseiulus macropilis (Banks, 1904) to different population densities of Tetranychus urticae Koch, 1836 (the two-spotted spider mite - TSSM) in the laboratory. We evaluated the curve that best fits the data obtained, based on the reduced X². The predators were obtained from leaves of Oso Grande strawberries at the municipality of Bom Princípio, state of Rio Grande do Sul, Brazil. Fifteen seemingly healthy females of P. macropilis were randomly chosen and individualized in each of the arenas with different TSSM densities. The following prey densities were tested: 1, 2, 3, 5, 10, 20, 30, 35, 45, 55, 70 and 125 females. The tests were performed in a germination chamber with photoperiod of 12 hours at 28 ± 1ºC per day and 22 ± 1ºC at night and 80 ± 5% relative humidity. In all tests with up to three prey items, P. macropilis showed low functional response, whereas higher rates were observed when more prey items were offered. There was a strong positive correlation between increased prey numbers and daily prey consumption (r = 0.84 and p = 0.0006). A significant correlation was found between prey consumption and total oviposition (r = 0.70, p = 0.01). The daily oviposition rate was lower when few prey items were offered, increasing significantly with increased prey availability. The results showed a positive correlation between the number of prey items offered to the predator and its oviposition rate (r = 0.66, p = 0.01). Nevertheless, a strong correlation was observed between the daily consumption of prey and eggs/female/day (r = 0.92, p 0.0001). A shorter oviposition period was reported when up to three prey items were offered. The oviposition period and the increase in prey numbers were positively correlated (r = 0.30, p = 0.34), but the difference was not statistically significant. Nevertheless, the longer the egg-laying period, the greater the oviposition rate (r = 0.90, p 0.0001). The curve that best fits the data obtained in each case was also calculated, based on the least square method.

Functional response of Phytoseiulus macropilis under different Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) population density in laboratory

We tested the functional response of the phytoseiid predator Phytoseiulus macropilis (Banks, 1904) to different population densities of Tetranychus urticae Koch, 1836 (the two-spotted spider mite - TSSM) in the laboratory. We evaluated the curve that best fits the data obtained, based on the reduced X². The predators were obtained from leaves of Oso Grande strawberries at the municipality of Bom Princípio, state of Rio Grande do Sul, Brazil. Fifteen seemingly healthy females of P. macropilis were randomly chosen and individualized in each of the arenas with different TSSM densities. The following prey densities were tested: 1, 2, 3, 5, 10, 20, 30, 35, 45, 55, 70 and 125 females. The tests were performed in a germination chamber with photoperiod of 12 hours at 28 ± 1ºC per day and 22 ± 1ºC at night and 80 ± 5% relative humidity. In all tests with up to three prey items, P. macropilis showed low functional response, whereas higher rates were observed when more prey items were offered. There was a strong positive correlation between increased prey numbers and daily prey consumption (r = 0.84 and p = 0.0006). A significant correlation was found between prey consumption and total oviposition (r = 0.70, p = 0.01). The daily oviposition rate was lower when few prey items were offered, increasing significantly with increased prey availability. The results showed a positive correlation between the number of prey items offered to the predator and its oviposition rate (r = 0.66, p = 0.01). Nevertheless, a strong correlation was observed between the daily consumption of prey and eggs/female/day (r = 0.92, p 0.0001). A shorter oviposition period was reported when up to three prey items were offered. The oviposition period and the increase in prey numbers were positively correlated (r = 0.30, p = 0.34), but the difference was not statistically significant. Nevertheless, the longer the egg-laying period, the greater the oviposition rate (r = 0.90, p 0.0001). The curve that best fits the data obtained in each case was also calculated, based on the least square method.

Functional response of Phytoseiulus macropilis under different Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) population density in laboratory

We tested the functional response of the phytoseiid predator Phytoseiulus macropilis (Banks, 1904) to different population densities of Tetranychus urticae Koch, 1836 (the two-spotted spider mite - TSSM) in the laboratory. We evaluated the curve that best fits the data obtained, based on the reduced X². The predators were obtained from leaves of Oso Grande strawberries at the municipality of Bom Princípio, state of Rio Grande do Sul, Brazil. Fifteen seemingly healthy females of P. macropilis were randomly chosen and individualized in each of the arenas with different TSSM densities. The following prey densities were tested: 1, 2, 3, 5, 10, 20, 30, 35, 45, 55, 70 and 125 females. The tests were performed in a germination chamber with photoperiod of 12 hours at 28 ± 1ºC per day and 22 ± 1ºC at night and 80 ± 5% relative humidity. In all tests with up to three prey items, P. macropilis showed low functional response, whereas higher rates were observed when more prey items were offered. There was a strong positive correlation between increased prey numbers and daily prey consumption (r = 0.84 and p = 0.0006). A significant correlation was found between prey consumption and total oviposition (r = 0.70, p = 0.01). The daily oviposition rate was lower when few prey items were offered, increasing significantly with increased prey availability. The results showed a positive correlation between the number of prey items offered to the predator and its oviposition rate (r = 0.66, p = 0.01). Nevertheless, a strong correlation was observed between the daily consumption of prey and eggs/female/day (r = 0.92, p 0.0001). A shorter oviposition period was reported when up to three prey items were offered. The oviposition period and the increase in prey numbers were positively correlated (r = 0.30, p = 0.34), but the difference was not statistically significant. Nevertheless, the longer the egg-laying period, the greater the oviposition rate (r = 0.90, p 0.0001). The curve that best fits the data obtained in each case was also calculated, based on the least square method.

Biologia comparada de Spodoptera cosmioides (Walk.) (Lepidoptera: Noctuidae) em cebola, mamona, soja e feijão

The biology of Spodoptera cosmioides (Walk.) was studied on four natural hosts (onion leaves, castor oil plant, soy cv. Embrapa 48 and bean cv. Carioca). The duration and viability of immature phases and total cycle, instar number, pupals weight, sexual ratio, percentage of deformed adults and adults not released of pupal beg, adults' longevity, fecundity and eggs viability were evaluated. It was observed in castor oil plant and onion shorter duration and larger viability of total cycle (39.7 days and 21.7%; 40.5 days and 21.8%, respectively), in contrast of soy (46.0 days and 3.9%). The pupal weight was 444.6 mg on onion, 420.0mg on bean, 396.6mg on castor oil plant and 298.7 mg on soy. Onion and castor oil plant leaves had a predominance of six larval instars, also happening seven for some of them, while in soy the occurrence of seven prevailed, also happening eight instars, indicating less nutritional adaptation of this host. The females had pupal phase significantly smaller than the males in all the hosts, making adults emergency happen before the males. In onion, the longevity of the adults was significantly superior comparing with the other hosts. The fecundity was better on onion and castor oil plant (3224 and 3206 eggs/female, respectively), therefore on soy was observed 1353 eggs/female. In bean leaves, the development of the insect was harmed by morphologic characters, which promoted high mortality in the larval phase.

Estudou-se a biologia de Spodoptera cosmioides (Walk.) sobre quatro hospedeiros naturais (folhas de cebola, mamona, soja cv. Embrapa 48 e feijão cv. Carioca). Foram avaliados a duração e viabilidade das fases imaturas e do ciclo total, número de ínstares, peso de pupas, razão sexual, porcentagem de deformação de adultos e de adultos não liberados dos invólucros pupais, longevidade de adultos, fecundidade e viabilidade de ovos. Observou-se menor duração e maior viabilidade do período ovo-adulto para mamona e cebola (39,7 dias e 21,7% e 40,5 dias e 21,8%, respectivamente), do que para soja (46,0 dias e 3,9%). O peso pupal foi de 444,6 mg em cebola, 420,0 em feijão, 396,6 em mamona e 298,7 em soja. Constatou-se um predomínio de seis ínstares larvais em folhas de cebola e mamona, ocorrendo também sete para alguns indivíduos, enquanto que em soja predominou a ocorrência de sete, também verificando oito ínstares, indicando uma menor adequação nutricional deste hospedeiro. As fêmeas apresentaram duração da fase pupal significativamente menor do que os machos em todos hospedeiros, fazendo com que a emergência do adulto ocorresse antes dos machos. Em cebola, a longevidade de adultos foi significativamente superior aos demais hospedeiros. A fecundidade foi maior em cebola e mamona (3224 e 3206 ovos/fêmea, respectivamente), enquanto que para soja observou-se 1353 ovos/fêmea. Em folhas de feijão, o desenvolvimento do inseto foi prejudicado por caracteres morfológicos - pilosidade, que promoveram elevada mortalidade na fase larval.

Fator chave para Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae) em cultura de soja, para o estado de São Paulo

The biology and fluctuation of Anticarsia gemmatalis was studied in soybean fields to determine the key stage and factor. Experiments were conducted from 1992 through 1997. Two biological studies were performed each year. In each season, the natural occurrence of eggs and larvae were determined, which allowed the construction of ecological life tables. The net reproduction rate of the species was observed to increase 2.9-to 7.5-fold in relation to the initial population, but the increse was estimated as 15.5-fold for the life table constructed from the averages of annual values. Mean duration time for progenies varied from 33.5 to 40.2 days (mean of 37.9), leading to an average survival per generation between 1.2 and 3.2% (mean of 6.6). The key stage of the population was not determined due the observed low R2. The key factor accounting for population mortality was the fertility of females.

Estudou-se a biologia e a flutuação de Anticarsia gemmatalis em campos de soja com o objetivo de construir tabelas de vida ecológica visando determinar o estágio e o fator chave. Os experimentos foram conduzidos durante os períodos agrícolas de 1992 a 1997. Em cada ano foram realizados dois estudos biológicos. Simultaneamente durante o ciclo da soja, nos seis anos estudados, foram realizadas amostragens para determinar a flutuação natural de ovos e de lagartas de A. gemmatalis. De posse desses dados foram construídas tabelas de vida ecológica, tendo-se observado que a taxa líquida de reprodução da espécie aumentou de 2,9 a 7,5 vezes em relação a população inicial, sendo que, para a tabela construída com a média dos dados, esse valor subiu para 15,5 vezes. O tempo médio de duração nas gerações variou de 33,5 a 40,2 dias, com média de 37,9 dias, acarretando uma sobrevivência, por geração entre 1,2 a 3,2%, porém, na média, esta subiu para 6,6%. O estágio chave da população não pôde ser determinado com precisão devido aos baixos valores de R2 obtidos mas, o fator chave, responsável pela mortalidade da população, foi a fertilidade real de fêmeas.

Fator chave para Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae) em cultura de soja, para o estado de São Paulo

The biology and fluctuation of Anticarsia gemmatalis was studied in soybean fields to determine the key stage and factor. Experiments were conducted from 1992 through 1997. Two biological studies were performed each year. In each season, the natural occurrence of eggs and larvae were determined, which allowed the construction of ecological life tables. The net reproduction rate of the species was observed to increase 2.9-to 7.5-fold in relation to the initial population, but the increse was estimated as 15.5-fold for the life table constructed from the averages of annual values. Mean duration time for progenies varied from 33.5 to 40.2 days (mean of 37.9), leading to an average survival per generation between 1.2 and 3.2% (mean of 6.6). The key stage of the population was not determined due the observed low R2. The key factor accounting for population mortality was the fertility of females.

Estudou-se a biologia e a flutuação de Anticarsia gemmatalis em campos de soja com o objetivo de construir tabelas de vida ecológica visando determinar o estágio e o fator chave. Os experimentos foram conduzidos durante os períodos agrícolas de 1992 a 1997. Em cada ano foram realizados dois estudos biológicos. Simultaneamente durante o ciclo da soja, nos seis anos estudados, foram realizadas amostragens para determinar a flutuação natural de ovos e de lagartas de A. gemmatalis. De posse desses dados foram construídas tabelas de vida ecológica, tendo-se observado que a taxa líquida de reprodução da espécie aumentou de 2,9 a 7,5 vezes em relação a população inicial, sendo que, para a tabela construída com a média dos dados, esse valor subiu para 15,5 vezes. O tempo médio de duração nas gerações variou de 33,5 a 40,2 dias, com média de 37,9 dias, acarretando uma sobrevivência, por geração entre 1,2 a 3,2%, porém, na média, esta subiu para 6,6%. O estágio chave da população não pôde ser determinado com precisão devido aos baixos valores de R2 obtidos mas, o fator chave, responsável pela mortalidade da população, foi a fertilidade real de fêmeas.

Biologia comparada de Spodoptera cosmioides (Walk.) (Lepidoptera: Noctuidae) em cebola, mamona, soja e feijão

The biology of Spodoptera cosmioides (Walk.) was studied on four natural hosts (onion leaves, castor oil plant, soy cv. Embrapa 48 and bean cv. Carioca). The duration and viability of immature phases and total cycle, instar number, pupals weight, sexual ratio, percentage of deformed adults and adults not released of pupal beg, adults' longevity, fecundity and eggs viability were evaluated. It was observed in castor oil plant and onion shorter duration and larger viability of total cycle (39.7 days and 21.7%; 40.5 days and 21.8%, respectively), in contrast of soy (46.0 days and 3.9%). The pupal weight was 444.6 mg on onion, 420.0mg on bean, 396.6mg on castor oil plant and 298.7 mg on soy. Onion and castor oil plant leaves had a predominance of six larval instars, also happening seven for some of them, while in soy the occurrence of seven prevailed, also happening eight instars, indicating less nutritional adaptation of this host. The females had pupal phase significantly smaller than the males in all the hosts, making adults emergency happen before the males. In onion, the longevity of the adults was significantly superior comparing with the other hosts. The fecundity was better on onion and castor oil plant (3224 and 3206 eggs/female, respectively), therefore on soy was observed 1353 eggs/female. In bean leaves, the development of the insect was harmed by morphologic characters, which promoted high mortality in the larval phase.

Estudou-se a biologia de Spodoptera cosmioides (Walk.) sobre quatro hospedeiros naturais (folhas de cebola, mamona, soja cv. Embrapa 48 e feijão cv. Carioca). Foram avaliados a duração e viabilidade das fases imaturas e do ciclo total, número de ínstares, peso de pupas, razão sexual, porcentagem de deformação de adultos e de adultos não liberados dos invólucros pupais, longevidade de adultos, fecundidade e viabilidade de ovos. Observou-se menor duração e maior viabilidade do período ovo-adulto para mamona e cebola (39,7 dias e 21,7% e 40,5 dias e 21,8%, respectivamente), do que para soja (46,0 dias e 3,9%). O peso pupal foi de 444,6 mg em cebola, 420,0 em feijão, 396,6 em mamona e 298,7 em soja. Constatou-se um predomínio de seis ínstares larvais em folhas de cebola e mamona, ocorrendo também sete para alguns indivíduos, enquanto que em soja predominou a ocorrência de sete, também verificando oito ínstares, indicando uma menor adequação nutricional deste hospedeiro. As fêmeas apresentaram duração da fase pupal significativamente menor do que os machos em todos hospedeiros, fazendo com que a emergência do adulto ocorresse antes dos machos. Em cebola, a longevidade de adultos foi significativamente superior aos demais hospedeiros. A fecundidade foi maior em cebola e mamona (3224 e 3206 ovos/fêmea, respectivamente), enquanto que para soja observou-se 1353 ovos/fêmea. Em folhas de feijão, o desenvolvimento do inseto foi prejudicado por caracteres morfológicos - pilosidade, que promoveram elevada mortalidade na fase larval.