ABSTRACT
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.
Subject(s)
Animals , Male , Female , Wasps , Tephritidae , Hymenoptera , Triticum , Diet/veterinary , Flour , LarvaABSTRACT
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.
Subject(s)
Hymenoptera , Tephritidae , Wasps , Animals , Diet/veterinary , Female , Flour , Larva , Male , TriticumABSTRACT
Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is the most important pest in South American orchards. When control measures are not adopted, this pest can cause losses of up to 100%. Doryctobracon brasiliensis (Szépligeti) (Hymenoptera: Braconidae) is a larval-pupal endoparasitoid that can be used as a native biological control agent against A. fraterculus. This study aimed to develop a rearing technique for D. brasiliensis in larvae of A. fraterculus. Trials were carried out to: 1) determine the optimal instar for parasitism, 2) define the exposure time of larvae to parasitoids, 3) determine the density requirements of A. fraterculus larvae offered to each parasitoid, and 4) evaluate the effect of diet on adults of D. brasiliensis. In all trials, we evaluated the number of offspring, parasitism rate, and sex ratio. Moreover, in the experiment to investigate the effects of diet, we determined the longevity of males and females. In both choice and nonchoice parasitism tests, the parasitoids preferred third-instar larvae of A. fraterculus over second- and first-instar larvae. An exposure time of 12 h of A. fraterculus larvae produced larger numbers of parasitoids and higher parasitism rates. The density of 15 larvae of A. fraterculus to each female of D. brasiliensis produced a larger number of offspring. A supply of honey solution (20 and 50%) to the parasitoids yielded the highest number offspring and resulted in greater longevity. Our findings can be used to support the development of a mass rearing protocol for D. brasiliensis.
Subject(s)
Host-Parasite Interactions , Life History Traits , Pest Control, Biological/methods , Tephritidae/parasitology , Wasps/physiology , Animals , Female , Fertility , Larva/growth & development , Larva/parasitology , Larva/physiology , Longevity , Male , Pupa/growth & development , Pupa/parasitology , Pupa/physiology , Sex Ratio , Tephritidae/growth & development , Wasps/growth & developmentABSTRACT
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.
ABSTRACT
Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is among the most important pests of fruit trees in South America, where it can cause losses of up to 100% in fruit orchards. The endoparasitoid Aganaspis pelleranoi (Brèthes) (Hymenoptera: Figitidae) is one of the main natural enemies of A. fraterculus in Neotropical countries and can be used as a biological control agent against this pest. This study aimed to provide background biological information for the development of a method for mass rearing of A. pelleranoi in larvae of A. fraterculus . We determined the effects of diet on the longevity and parasitism capacity of A. pelleranoi adults, the optimal instar of A. fraterculus for parasitism, the ideal exposure time of the larvae to the parasitoid, and the parasitism capacity of females of A. pelleranoi . The results showed that a 30% honey:water solution maximized parasitoid longevity. Third-instar larvae of A. fraterculus should be used in parasitoid multiplication. An exposure time of 4 h of A. fraterculus larvae produced a larger number of parasitoid offspring, with the highest proportion of females. In addition, the estimated mean parasitism capacity of females of A. pelleranoi was 10 larvae per day. This information can help to develop a mass-rearing method for A. pelleranoi in larvae of A. fraterculus .
