Diversity and infestation indices of fruit flies (Diptera: Tephritidae) in guava (Psidium guajava L.)

The fruit flies are considered major pests in the world fruit production due to the direct damage they cause to fruits and the ability to adapt to areas where they are introduced. The objective of this research was to study the fruit fly diversity, the infestation indices in fruits and to characterize the tephritids community in a guava (Psidium guajava L.) cultivar "Paluma", in a commercial orchard located in Sao Luis, state of Maranhao, northeastern Brazil. In the survey, fly hunting bottles containing hydrolyzed protein in a ratio of 500 ml/10 L of water were used. To assess the infestation indices, fruits were collected, individualized in plastic containers with sterile sand, and kept in a climate-controlled chamber. 2,901 specimens of fruit flies were collected. From these, 2,328 were collected in traps and 573 in fruit samples. The species found belong to the genus Anastrepha, including Anastrepha striata, Anastrepha obliqua, Anastrepha fraterculus, Anastrepha sororcula, Anastrepha distincta, Anastrepha zenildae and Anastrepha pickeli. Considering the total tephritids collected in fruits and traps, a low diversity (H’ = 0.2689 and 0.4147, respectively) was found. A. striata predominated among the collected species. The largest number of insect pests captured occurred in May 2008, a period of increased guava fruit availability in the orchard. The infestation indices were 231.02 pupae/kg and 26.42 pupae/fruit.   Key words: Tephritids, Myrtaceae, population dynamics, ecology.