Influence of the host diet on the performance of Doryctobracon areolatus (Hymenoptera: Braconidae) / Influência da dieta do hospedeiro na performance de Doryctobracon areolatus (Hymenoptera: Braconidae)

Abstract Fitness in parasitoids is generally influenced by host quality. We evaluated the development parameters of Doryctobracon areolatus (Hymenoptera: Braconidae) parasitoid on Anastrepha fraterculus (Diptera: Tephritidae) larvae, reared in artificial diets with different protein sources. Larvae of A. fraterculus were reared in the diets based on 1) raw wheat germ (control); 2) whole rice flour; 3) corn flour; and, 4) whole wheat flour + soybean meal. The larvae were used for the development of D. areolatus, to evaluate the number of offspring/female, emergence rate, sex ratio, egg-adult period, adult weight posterior tibia length and longevity. Larvae of A. fraterculus reared in the diets based on wheat germ and corn flour obtained a greater number of offspring, with shorter duration of egg-adult period for males and females. In diets with rice flour and corn flour, A. fraterculus larvae generated adults of D. areolatus with greater weight, longer tibia length and higher sex ratio, whereas larvae reared in wheat flour + soybean meal diet had a lower sex ratio. The diets based on rice flour and corn are the most appropriate for multiplication of the parasitoid.

Resumo O custo adaptativo de parasitoides é geralmente influenciado pela qualidade do hospedeiro. Nós avaliamos parâmetros de desenvolvimento do parasitoide Doryctobracon areolatus (Hymenoptera: Braconidae) em larvas de Anastrepha fraterculus (Diptera: Tephritidae) criadas em dieta artificial com diferentes fontes proteicas. Larvas de A. fraterculus foram criadas em dietas a base de: 1) germe de trigo cru (testemunha); 2) farinha de arroz integral; 3) farinha de milho; e, 4) farinha de trigo integral + farelo de soja. As larvas foram usadas para o desenvolvimento de D. areolatus para avaliar o número de descendentes/fêmea, taxa de emergência, razão sexual, duração do período ovo-adulto, peso de adultos, comprimento da tíbia posterior e longevidade. Larvas de A. fraterculus criadas nas dietas a base de germe de trigo e farinha de milho, permitiram obter um maior número de descendentes do parasitoide, com menor duração do período de desenvolvimento ovo-adulto, para ambos os sexos. Nas dietas com farinha de arroz e farinha de milho, larvas de A. fraterculus geraram adultos de D. areolatus com maior peso e tamanho de tíbia de machos e fêmeas e uma maior quantidade de fêmeas. A dieta contendo farinha de trigo + farelo de soja afetou a geração de descendentes, causando uma menor razão sexual. As dietas a base de farinha de arroz e milho são as mais adequadas para a multiplicação do parasitoide.

Influence of the host diet on the performance of Doryctobracon areolatus (Hymenoptera: Braconidae)

Abstract Fitness in parasitoids is generally influenced by host quality. We evaluated the development parameters of Doryctobracon areolatus (Hymenoptera: Braconidae) parasitoid on Anastrepha fraterculus (Diptera: Tephritidae) larvae, reared in artificial diets with different protein sources. Larvae of A. fraterculus were reared in the diets based on 1) raw wheat germ (control); 2) whole rice flour; 3) corn flour; and, 4) whole wheat flour + soybean meal. The larvae were used for the development of D. areolatus, to evaluate the number of offspring/female, emergence rate, sex ratio, egg-adult period, adult weight posterior tibia length and longevity. Larvae of A. fraterculus reared in the diets based on wheat germ and corn flour obtained a greater number of offspring, with shorter duration of egg-adult period for males and females. In diets with rice flour and corn flour, A. fraterculus larvae generated adults of D. areolatus with greater weight, longer tibia length and higher sex ratio, whereas larvae reared in wheat flour + soybean meal diet had a lower sex ratio. The diets based on rice flour and corn are the most appropriate for multiplication of the parasitoid.

Resumo O custo adaptativo de parasitoides é geralmente influenciado pela qualidade do hospedeiro. Nós avaliamos parâmetros de desenvolvimento do parasitoide Doryctobracon areolatus (Hymenoptera: Braconidae) em larvas de Anastrepha fraterculus (Diptera: Tephritidae) criadas em dieta artificial com diferentes fontes proteicas. Larvas de A. fraterculus foram criadas em dietas a base de: 1) germe de trigo cru (testemunha); 2) farinha de arroz integral; 3) farinha de milho; e, 4) farinha de trigo integral + farelo de soja. As larvas foram usadas para o desenvolvimento de D. areolatus para avaliar o número de descendentes/fêmea, taxa de emergência, razão sexual, duração do período ovo-adulto, peso de adultos, comprimento da tíbia posterior e longevidade. Larvas de A. fraterculus criadas nas dietas a base de germe de trigo e farinha de milho, permitiram obter um maior número de descendentes do parasitoide, com menor duração do período de desenvolvimento ovo-adulto, para ambos os sexos. Nas dietas com farinha de arroz e farinha de milho, larvas de A. fraterculus geraram adultos de D. areolatus com maior peso e tamanho de tíbia de machos e fêmeas e uma maior quantidade de fêmeas. A dieta contendo farinha de trigo + farelo de soja afetou a geração de descendentes, causando uma menor razão sexual. As dietas a base de farinha de arroz e milho são as mais adequadas para a multiplicação do parasitoide.

Optimization of formula of artificial diets for Poecilobdella manillensis by orthogonal test / 中草药

Objective: To optimize the formula of artificial diets for Poecilobdella manillensis. Methods: Survival rate and individual body weight growth rate of P. manillensis were chosen as indexes. The three factors [NP-90 spray-dried hemoglobin powder, NP-2002 spray-dried plasma powder, and vitamin C (VC)] of the formula of artificial diets were investigated by L9(34) orthogonal test. AHP was applied to statistical analysis on non-interacting orthogonal test, the effect weight of each factor for test result was obtained, and principal-secondary sequence of factors and optimal project was given. Results: The effects of the three components in artificial diets on the survival rate were in the following decreasing order: VC>NP-90>NP-2002. And the optimization of components of artificial diets was 0 NP-90 spray-dried hemoglobin powder, 1% NP-2002 spray-dried plasma powder, and 0.05% VC. When the individual body weight growth rate was chosen as the index, the effects of the three components in artificial diets on the individual body weight growth rate were in the following decreasing order: NP-2002>NP-90>VC. The optimization of components of artificial diets was 0.5% NP-90 spray-dried hemoglobin powder, 3% NP-2002 spray-dried plasma powder, and 0.05% VC. The weight of principal-secondary sequence of factors and levels influences on the tests' results was NP-90>NP-2002>VC. The weight of 0.5% NP-90 spray-dried hemoglobin powder, 3% NP-2002 spray-dried plasma powder and 0.05% VC was maximum. And the optimization of components in artificial diets was 0.5% NP-90 spray-dried hemoglobin powder, 3% NP-2002 spray-dried plasma powder, and 0.05% VC. According to the results, P. manillensis bred with the artificial diets (0.5% NP-90 spray-dried hemoglobin powder, 3% NP-2002 spray-dried plasma powder, 3% NP-2002 spray-dried plasma powder, 0.05% VC, and other components) had the survival rate of 100% and the individual body weight growth rate was 19.91%. Conclusion: The optimal artificial diets could be used to feed P. manillensis.

Produção de juvenis do linguado Paralichthys orbignyanus: efeito da duração do período de co-alimentação durante o desmame / Production of Brazilian flounder Paralichthys orbignyanus juveniles: the effect of co-feeding period during the weaning

O desmame, ou seja, a substituição do alimento vivo por alimento inerte é uma etapa crítica para a produção de alevinos de peixes marinhos. Este trabalho teve por objetivo avaliar o efeito do período de co-alimentação (alimento vivo e inerte) sobre a sobrevivência, o crescimento e os custos de produção de juvenis do linguado Paralichthys orbignyanus. Durante o período de co-alimentação, os juvenis (idade inicial 32 dias) receberam Artemia enriquecida juntamente com ração. Foram testados três períodos de co-alimentação: 15, 20 e 25 dias, mais um grupo controle alimentado com Artemia enriquecida. Ao final do experimento (76 dias), os juvenis alimentados exclusivamente com Artemia enriquecida apresentaram sobrevivência (82 por cento), peso (480±157mg) e comprimento (35,5±5,0mm) significativamente maiores (P<0,05) que os juvenis alimentados com ração. Não houve diferença significativa (P>0,05) no crescimento entre os juvenis alimentados com ração nos diferentes períodos, entretanto, um período maior de co-alimentação favoreceu a sobrevivência. Os resultados obtidos demonstram que os linguados alimentados exclusivamente com Artemia apresentam melhor performance do que aqueles alimentados com ração. Entretanto, o custo de produção quando a Artemia é substituída por ração aos 58 dias de vida é menor do que quando o desmame é realizado mais cedo ou quando os alevinos são alimentados apenas com Artemia.

Weaning is a critical period for production of marine fish juveniles. The objective of this research was to evaluate the effect of co-feeding on survival, growth, and cost of production after the weaning of juveniles of Brazilian flounder Paralichthys orbignyanus. Juvenile flounder (32 days after hatching) were fed on HUFA enriched Artemia and subsequently three periods of co-feeding with dry diets (15, 20, and 25 days) were tested, a control group, where flounder were fed exclusively on Artemia was also followed until the end of the experiment. Juveniles fed on Artemia showed significantly higher (P<0.05) survival (82 percent), weight (480±157mg) and total length (35.5±5.0mm) than flounder weaned into dry diets, independent of the co-feeding period. Growth was similar (P>0.05) for juveniles fed on dry diets, but a higher survival rate was registered when the co-feeding period was longer. The results obtained demonstrate that flounder fed exclusively on Artemia have a better performance than those weaned into dry diets. However, unitary cost of production is reduced when juveniles are weaned 58 days after hatching.