Moscas-das-frutas associadas a fruteiras de importância socioeconômica no estado do Amapá

Abstract

The objective of this work was to evaluate the importance of Psidium guajava L., Myrtaceae, as food resource for fruit flies and potential fruits of Spondias mombin L., Anacardiaceae, as parasitoid multiplier plant in the state of Amapá, Brazil. To assess the importance of P. guajava as food source for fruit flies in guava fruit were collect performed in 12 municipalities of the state of Amapá (144 samples, each one consisting of 10 fruits, totaling 1,440 fruits assessed individually), in April, July and December 2013 and February and March 2014. We calculated the infestation index (pupae/fruit) and the parasitism index. The influence of the fruit weight with the tephritids’s infestation was assessed by Pearson linear correlation analysis. Of the total collected fruits, 997 showed infestation by fruit flies. We obtained 8,356 pupae, from which emerged 4,776 specimens of Anastrepha, 846 Bactrocera carambolae and 127 Hymenoptera. The infestation rates were quite variable, with the highest average amount recorded in Serra do Navio (12.2 pupae/fruit). We obtained three species of the genus Anastrepha: Anastrepha striata Schiner, Anastrepha fraterculus (Wiedemann) and Anastrepha zenildae zucchi. Anastrepha striata was the most abundant species, occurring in all sampled municipalities. Only in Pracuúba there was no parasitism of fruit flies. The highest mean percentage of parasitism was registered in Laranjal do Jari (6.3%). We obtained two species of parasitoids: Doryctobracon areolatus (Szépligeti) (120 specimens) and Doryctobracon sp. 2 (7). Anastrepha striata (native from American continent) and B. carambolae (exotic) coexisted in guava fruits, thus sharing the same food source. The result of the Pearson correlation coefficients indicated that fruit weight does not determine the number of pupae in fruit, or fruit size does not influence the condition of being infested or not. The results showed the importance of plant species in maintaining the populations of fruit flies, acting as a food resource for these insects. To evaluate the potential fruits of Spondias mombin as parasitoid multiplier plant we collected fruits of S. mombin in the municipalities of Oiapoque, Porto Grande and Mazagão (10 samples per municipality, each one consisting of about 1 kg of fruit) in February and March 2014. Only one sample showed no infestation of fruit flies. We obtained 2,715 puparia, from which emerged 891 specimens of Anastrepha and 261 Hymenoptera. The infestation rates were quite variable, with the highest average amount recorded in Porto Grande (99.8 pupae/kg of fruit). We obtained four species of the genus Anastrepha: Anastrepha obliqua (Macquart), Anastrepha antunesi Lima, Anastrepha fraterculus (Wiedemann) and Anastrepha striata Schiner. Anastrepha obliqua was the most abundant species in the three municipalities. Of the 29 samples infested by fruit flies, only seven (24.1%) did not present parasitism. The highest mean percentage of parasitism was registered in Mazagão (18.9%). We obtained five species of parasitoids: Opius bellus Gahan (50.6% of total), Doryctobracon areolatus (Szépligeti) (26.8%), Asobara anastrephae (Muesebeck) (16.5%), Utetes anastrephae (Viereck) (5.7%) and Aganaspis pelleranoi (Brèthes) (0.4%). We discussed our results in relation to other work already carried out in Amapá and in the Brazilian Amazon, showing the importance of this plant species in maintaining the populations of parasitoids of the fruit flies