A temperatura e o alimento têm um importante papel no desenvolvimento e nas atividades de adultos de espécies de Orius, e esses parâmetros biológicos são fundamentais para propósitos de criação massal de inimigos naturais e seu uso em programas de controle biológico. O objetivo deste trabalho foi avaliar a influência de diferentes temperaturas no desenvolvimento ninfal do predador Orius thyestes Herring alimentado com ovos de Anagasta kuehniella (Zeller). Também foram determinadas as exigências térmicas e o consumo ninfal. O experimento foi conduzido em câmaras climáticas a 16, 19, 22, 25, 28 e 31 ± 1ºC, UR de 70 ± 10% e fotofase de 12h. O. thyestes apresentou cinco ínstares. O período ninfal foi cerca de seis vezes maior a 31ºC (9,8 dias) do que a 16ºC (58,2 dias). A menor sobrevivência ninfal do predador foi a 16ºC, com somente 40% das ninfas atingindo a fase adulta. Maiores percentagens de sobrevivência das ninfas foram observadas a 22ºC (96,4%), 25ºC (94,5%) e 28ºC (100%). Cada ninfa de O. thyestes consumiu 39,4 ovos de A. kuehniella. O predador apresentou temperatura base e constante térmica para a fase ninfal de 12,8ºC e 173,82 graus-dia, respectivamente. O intervalo mais adequado para o desenvolvimento de O. thyestes situa-se entre 22ºC e 28ºC. O. thyestes provavelmente encontra melhores chances de colonização e estabelecimento em regiões tropicais e subtropicais.

Temperature and food play an important part in the development time and adult activities of Orius species, and these biological parameters are important for purpose of mass rearing of natural enemies for use on biological control programs. The objective of this research was to evaluate the influence of different temperatures on nymphal development of Orius thyestes Herring when fed with Anagasta kuehniella (Zeller) eggs in climatic chambers at 16, 19, 22, 25, 28 and 31 ± 1°C, 70 ± 10% RH and 12h photophase. The thermal requirements and nymphal consumption were also determined. O. thyestes presented five instars. The nymphal period was about six times shorter at 31°C (9.8 days) than at 16°C (58.2 days). Nymph survival was lowest at 16°C, with only 40% of the nymphs reaching adult stage. The higher nymph survival were found at 22°C (96.4%), 25°C (94.5%) and 28ºC (100%). Each nymph of O. thyestes consumed 39.4 eggs of A. kuehniella. The lower temperature threshold and thermal constant for the nymphal development of O. thyestes were 12.8°C and 173.82 day-degrees, respectively. The interval from 22°C to 28°C is more suitable for nymphal development of O. thyestes. O. thyestes finds probably better chance for colonization and establishment in tropical and subtropical regions.

Fêmeas de Orius insidiosus (Say) colocam seus ovos endofíticamente, em diversas plantas, e um obstáculo para a criação massal desse predador é a seleção de um substrato de oviposição que seja de fácil obtenção e aceito pelo inseto. O objetivo deste estudo foi avaliar a preferência e a adeqüabilidade de diferentes substratos de oviposição para O. insidiosus. Os testes foram conduzidos em câmaras climatizadas reguladas a 25 ± 1°C, UR de 70 ±10% e fotofase de 12h. Os substratos avaliados quanto à preferência e adequabilidade foram caule de caruru (Amaranthus viridis L.), caule e vagem de feijão (Phaseolus vulgaris L.), vagem de feijão-de-vagem (Phaseolus vulgaris L.) e inflorescências de picão-preto (Bidens pilosa L.). Na adequabilidade também foi avaliado o caule de poaia-do-campo (Spermacoce latifola Aubl.). Fêmeas submetidas aos testes com e sem chance de escolha preferiram ovipositar em inflorescências de picão-preto. O período de pré-oviposição foi influenciado pelo tipo de substrato, sendo menor na presença da inflorescência de picão-preto (3,0 dias) e no feijão, tanto no caule (3,1dias) como na vagem (3,7 dias) comparado aos demais substratos. O período de oviposição, bem como a longevidade foram cerca de três a quatro vezes menores na presença do caule de poaia-do-campo (8,9 dias). O número total de ovos/fêmea de O. insidiosus foi maior em inflorescências de picão-preto (163,3 ovos). Os resultados indicam a adeqüabilidade das inflorescências de picão-preto como substrato de oviposição para O. insidiosus, sendo o preferido nos testes, com e sem chance de escolha, e onde as fêmeas apresentaram melhor performance reprodutiva.

Orius insidiosus (Say) females lay eggs inside plant tissue. An obstacle for its mass rearing is the selection of a plant that is suitable and well-accept by the female for oviposition. The objectives of this work were to evaluate the preference and the suitability of different plant structures as ovipositional substrates for O. insidiosus. The trials were conducted in climatic chamber at 25 ± 1°C, RH 70 ± 10% and photophase 12h. The plant sites as amaranth stem (Amaranthus virides L.), common bean's stem and pod (Phaseolus vulgaris L.), green bean's pod (Phaseolus vulgaris L.) and farmer's friend inflorescence (Bidens pilosa L.) were evaluated in no-choice and choice tests. The broadleaf button weed stem (Spermacoce latifola Aubl.) was also used to evaluate the suitability on the reproductive parameters. The females of O. insidiosus preferred to oviposit in farmer's friend inflorescence in no-choice and choice tests. The pre-oviposition period was affected by the plant site used as an ovipositional substrate, being shorter in farmer's friend inflorescence (3.0 days) and in common bean (both on stem (3.1 days) and pod (3.7 days) compared to all substrates evaluated. The oviposition period and the longevity were about three or four times shorter on broadleaf button weed stem (8.9 days). The total number of eggs/ female was higher in farmer's friend inflorescence (163.3 eggs). The results indicated the preference and suitability of farmer's friend inflorescence as an ovipositional substrate for O. insidiosus, in which the females showed better reproductive performance.

Effect of ninfal density of Aphis gossypii Glover, 1877 (Hemiptera, Aphididae) on feed consumption and biological aspects of Orius insidiosus (Say, 1832) (Hemiptera, Anthocoridae). The influence of different densities of A. gossypii (10, 20, 30, 40, 50, 60 nymphs/day) on consumption rate, development time, survival, and reproduction of Orius insidiosus (Say, 1832) was investigated. The trials were carried out in climatic chamber at 25 ± 1 °C, 70±10% RH, and photoperiod 12:12h (L:D). Consumption rates of nymphs and adults increased under a linear form as the densities of aphids increased. Development time was longest when reared in 10 nymphs density (15.4 days). Nymphal survival was different under the densities of A. gossypii and no significant difference for the periods of preoviposition (4.8 days) and oviposition (8.9 days) were found. The oviposition increased with the prey densities (2.00, 11.33, 10.67, 21.30, 17.89 and 53.38 eggs), as well as the viability: 0.00, 52.49, 57.86, 58.14, 50.11 and 72.89%, respectively. Nymphs of A. gossypii as prey were suitable for the complete development of O. insidiosus.

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.

A biologia do percevejo predador Orius insidiosus (Say), utilizando como alimento, adultos de Caliothrips phaseoli (Hood), foi estudada em câmara climática com temperatura de 25±1°C, 70±10 % de UR e 12h de fotofase. O período de desenvolvimento ninfal foi de 10,2 dias, não apresentando diferença significativa para machos e fêmeas. A duração do estágio ninfal foi 1,9, 1,7, 1,4, 1,8 e 3,1 dias para o 1º, 2º, 3º, 4º e 5º ínstares, respectivamente. A viabilidade ninfal foi de 69,0%, sendo que a maior mortalidade ocorreu no 2º ínstar (16,0%). O. insidiosus predou 73,7 tripes durante todo o estágio ninfal. O consumo de presas pelas ninfas de O. insidiosus aumentou com os sucessivos instares: 6,1, 9,0, 11,4, 16,7 e 29,3 tripes do 1º ao 5º ínstares, respectivamente. Não houve diferença no tempo de busca para os diferentes ínstares do predador, sendo que durou em média 52 min., a captura da presa foi dificultada pela intensa reação de defesa apresentada pela mesma, que consistiu na sua maioria, em saltos e pequenas corridas. As fêmeas ovipositaram 77,8 ovos com viabilidade de 71,6% e com um período embrionário de 5,3 dias. A longevidade das fêmeas (21 dias) foi significativamente maior que a dos machos (12,4 dias). O consumo das fêmeas foi de 159,1 tripes e o dos machos de 60,7 tripes. Não foi observada diferença no tempo de busca para os diferentes instares de O. insidiosus. Os resultados indicam que adultos de C. phaseoli são presas adequadas ao desenvolvimento e reprodução do predador O. insidiosus.

The biology of Orius insidiosus (Say) fed on thrips Caliothrips phaseoli (Hood) was studied in a climatic chamber at 25±1°C, 70±10% RH and 12h photophase. Nymphal developmental time (10.2 days) was the same for males and females. The durations of the nymphal instars were 1.9, 1.7, 1.4, 1.8 and 3.1 days for the 1st, 2nd, 3rd, 4th and 5th instars respectively. Nymphal survival was 69%, and the highest mortality occurred at the 2nd instar. O. insidiosus consumed 73.7 C. phaseoli throughout its nymphal stage. The amount of prey fed upon by O. insidiosus nymphs increased during the successive instars: 6.1, 9.0, 11.4, 16.7 and 29.3 thrips from the 1st to the 5th instar respectively. Females laid 77.8 eggs. Egg development in O. insidiosus took 5.3 days and only 71.6% of the eggs hatched. Female longevity was significantly higher (21 days) than that of males (12.4 days); consequently, females ate more thrips (159.1) than the males (60.7). The search time of O. insidiosus was the same for all instars. Thus, adults of C. phaseoli were proved suitable to the development and reproduction of the predator O. insidiosus.