Simone M. Mendes

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.

Biologia de Orius insidiosus (Say) (Hemiptera: Anthocoridae) Alimentado com Caliothrips phaseoli (Hood) (Thysanoptera: Thripidae)

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.

Custo da produção de Orius insidiosus como agente de controle biológico

Abstract – The objective of this work was to estimate the individual production cost of the predator Oriusinsidiosus (Say) in laboratory. A rearing model of O. insidiosus in laboratory was used to reach production of33,000 individuals month -1 , using 14.5% to maintain the predator rearing in the laboratory and 28,272 individualsfor commercialization. The prices of different materials and equipments used on predator rearing were fixed atUS

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

1.00 = R

Adequabilidade de diferentes substratos à oviposição do predador Orius insidiosus (Say) (Hemiptera: Anthocoridae)

2.84. The estimated cost for production of each adult predator was US

Desenvolvimento e exigências térmicas de Orius insidiosus (Say) (Hemiptera, Anthocoridae)

0.069, taking all the fixedand variable costs. This parameter is crucial to support O. insidiosus mass rearing, and to use this predator asbiocontrol agent in biological control program of thrips.Index terms: biological control, mass production, predator. Introducao A comercializacao de inimigos naturais e o aumentode seu uso no Manejo Integrado de Pragas (MIP) saodesafios para os entomologistas envolvidos com o con-trole biologico. Uma das respostas a este desafio e areducao do custo de criacao destes agentes, por meiodo aperfeicoamento nas tecnicas de criacao e do au-mento da eficacia dos agentes de controle biologico nocampo (Tauber et al., 2000).A utilizacao de inimigos naturais como agentes decontrole biologico esta intimamente ligada a sua produ-cao em laboratorio. Segundo Chambers (1977), a cria-cao massal e a producao de insetos com aceitavel rela-cao custo/beneficio. O estudo dos aspectos tecnicos eeconomicos da criacao do inimigo natural e fundamen-tal para o seu emprego efetivo como agente de controlebiologico no campo ou em cultivos protegidos. De acordocom Lenteren (2000a), o desenvolvimento de tecnicasde producao massal, controle de qualidade,armazenamento, envio e liberacao de inimigos naturaispode levar a reducao do custo de producao e a melhoriada qualidade do produto, viabilizando sua utilizacao.A criacao comercial economicamente viavel de inse-tos entomofagos tem sido a meta de diversos progra-mas de controle de pragas (Cohen et al., 1999).O predador

Efeito da densidade de ninfas de Aphis gossypii Glover, 1877 (Hemiptera, Aphididae) no consumo alimentar e aspectos biológicos de Orius insidiosus (Say, 1832) (Hemiptera, Anthocoridae)

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.

Influência da temperatura na reprodução e longevidade do predador Orius thyestes Herring (Hemiptera, Anthocoridae)

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 beans stem and pod (Phaseolus vulgaris L.), green beans pod (Phaseolus vulgaris L.) and farmers 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 farmers 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 farmers 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 farmers friend inflorescence (163.3 eggs). The results indicated the preference and suitability of farmers friend inflorescence as an ovipositional substrate for O. insidiosus, in which the females showed better reproductive performance.

Desenvolvimento, consumo ninfal e exigências térmicas de Orius thyestes Herring (Hemiptera: Anthocoridae)

The temperature strongly influences the development time of insects and the understanding of this aspect for natural enemies is essential for its use as biocontrol agents and for mass rearing purpose. The objective of this work was evaluating the effect of different temperatures on the development time of Orius insidiosus (Say, 1832) as well as its thermal requirements. The trials were conducted in climatic chamber at 16, 19, 22, 25, 28 and 31 ±1°C; RH 70±10% and photophase 12h. Eggs of Anagasta kuehniella (Zeller, 1879) were provided as food. The embryonic period was 14.0, 8.9, 6.6, 4.8, 3.9 and 3.3 days at 16, 19, 22, 25, 28 and 31°C, respectively. Nymphs of all instars (independent of originated sex) were affected by the temperature on their development time; there was a reduction of this period with the increase of the temperature. Males and females presented a development time about 12 days at 25°C. The developmental thresholds (To) for egg stage was estimated at 11.78°C, and for the nymphal phase were 12.27°C and 13.03°C for males and females, respectively. The thermal constants (K) for egg stage (63.75 day-degrees) and for nymphal stage were 161.97 and 157.24 day-degrees, for males and females, respectively. The temperature of 25°C was the most suitable for development time of O. insidiosus.

Transfer of Cry1F from Bt maize to eggs of resistant Spodoptera frugiperda

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.