Adrise Medeiros Nunes

Moscas frugívoras e seus parasitoides nos municípios de Pelotas e Capão do Leão, Rio Grande do Sul, Brasil

Frugivorous flies (Tephritoidea) are the main pests in temperate-zone fruit crop in Brazil. The objective of this research is to evaluate the infestation of these flies and the incidence of their parasitoids in fruit trees from 2007/08 and 2008/9 crops in Pelotas and in Capao do Leao, located in the south of Rio Grande do Sul. Fruits were collected from yellow guava and red guava (Psidium cattleianum Sabine, 1821), pindo palm [Butia capitata (Mart.) Becc., 1916], persimmon (Diospyros kaki Linnaeus, 1753), wild cherry (Eugenia involucrata DC., 1828), guava [Psidium guajava (Linnaeus, 1753)], feijoa tree [Acca sellowiana (Berg.) Burret, 1941], medlar [Eriobotrya japonica (Thunb.) Lindley, 1822], peach [Prunus persicae (L.) Batsch, 1801], surinam cherry (Eugenia uniflora Linnaeus,1753) and (Eugenia pyriformis Cambessedes, 1832). The fruit was collected and transported to the laboratory, where the following parameters were individually determined: fly infestation rate, parasitism rate, and its frequency per parasitoid specie. It was found two species of Tephritidae, Anastrepha fraterculus (Wiedemann, 1830) (90.5%) and Ceratitis capitata (Wiedemann, 1824) (9.5%) and two of Lonchaeidae, Neosilba zadolicha McAlpine & Steyskal, 1982 (87.8%) and a species not yet described, called Neosilba n. sp. 3 (12.2%). Anastrepha fraterculus is the most abundant species in the two cities and it was detected in most fruit crops collected. The persimmon and the guava were the hosts that showed the highest index of C. capitata infestation. Regarding to the species of Neosilba, the highest infestation occurred in fruits of feijoa tree. From the emerged parasitoids, it was identified three species two of Braconidae, Doryctobracon areolatus (Szepligeti, 1911) (52.6%) and Opius bellus (Gahan, 1930) (27.5%) and a species of Figitidae, Aganaspis pelleranoi (Brethes, 1924) (20.0%). Doryctobracon areolatus was the most frequent parasitoid in most sampled fruit trees, except for surinam cherry and wild cherry, where O. bellus was predominant and for peach, A. pelleranoi.

Biologia e potencial de parasitismo de Doryctobracon areolatus em larvas de Anastrepha fraterculus

The objective of this work was to study the biology and parasitic potential of Doryctobracon areolatus on larvae of Anastrepha fraterculus. The egg-adult period, the sex ratio, the longevity, the pupal viability, and the parasitism rate of D. areolatus were determined in laboratory, using A. fraterculus as host. The parasitoid development from oviposition to adult emergence required 25.00±1.70 days, the sex ratio was 0.62±0.09, and the mean longevity was 16.36±3.62 days for males and 10.24±1.71 days for females. The mean parasitism rate was 53.50±8.93%, varying from 41.60 to 68.60%, which shows the potential of this parasitoid for biological control of A. fraterculus.

ADEQUAÇÃO DE UMA DIETA ARTIFICIAL PARA OS BIÓTIPOS "MILHO" E "ARROZ" DE SPODOPTERA FRUGIPERDA (LEPIDOPTERA: NOCTUIDAE) ( 1 )

Spodoptera frugiperda is considered one of the main pest in corn and irrigated rice (fall armyworm) crops, causing high leaf losses. The objective of this study was to obtain an appropriate artificial diet to rear the biotypes “corn” and “rice” of S. frugiperda in laboratory. The insects were collected in areas cultivated with corn and irrigated rice in the meadow ecosystem and the identification was accomplished by the analysis of the DNA genomic. The development of the two biotypes was accompanied on Greene’s diet and the same diet modified to 25 ± 1oC, UR of 70 10% and fotofase of 14 hours. The study was accomplished with 150 larvae by diet individualized in glass tubes containing artificial diet. At emergency 20 couples were individualized and fed with aqueous solution of honey to 10%. The Greene diet made possible better development of the two biotypes, providing larger development speed, larger weight of larvae in the maximum development, weight of pupas and total fecundity, besides higher values of the net reproductive rates, intrinsic and finite rates of increase.

Longevidade e oviposição de Ophyra albuquerquei (Diptera, Muscidae) em condições de laboratório

Aspects related to the longevity and oviposition of Ophyra albuquerquei Lopes, 1985 are studied. Males had a mean lifespan longer than females (40.24 vs. 33.15 days, respectively), while still possessing qualitative advantages during this period. Females O. albuquerquei were fed on powdered milk, fish flour, refined sugar and water, and provided fish flour and moistened sawdust for oviposition. The length of the oviposition period for females was 46.75 days, and most of the deposition of the eggs occurred in the first days of the colony. Females completed 50% of their egg deposition by Day 16, seven days before the large last mortality peak and about 12 days after the first oviposition in the colony. Females deposited an average of 184 eggs per individual. Mortality of males, unlike females, was low until the 28th day, and increased thereafter. It was demonstrated that it is possible to maintain colonies of this species under laboratory conditions for at least 28 days with high fertility and low cost.

Strategies for Establishing a Rearing Technique for the Fruit Fly Parasitoid: Doryctobracon brasiliensis (Hymenoptera: Braconidae)

Abstract 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.