Fruit Flies (Diptera: Tephritidae) Associated with Umbu (Spondias tuberosa) in the Semiarid Region of Bahia, Brazil

Abstract

Arr. Cam. (Anacar-diaceae), is a xerophytic tree species endemic tothe northeastern Brazilian semiarid region in thestates of Piaui, Paraiba, Pernambuco, Bahia, andin the northern part of Minas Gerais (Silva et al.2004). It occurs in the Caatinga biome, which ischaracterized by a semiarid climate and a mosaicof vegetation types varying from dry thorn forestto open shrubby vegetation (Costa et al. 2007).Deforestation has recently increased in Caatingaas a result of an expanding human populationand the demand for timber and land for cattleranching (Coimbra-Filho & Câmara 1996). Fewstudies have focused on the contribution of Caat-inga´s biota to biodiversity in Brazil (Leal et al.2005), and it is considered one of the least knownbiomes in Brazil regarding terrestrial host-depen-dent invertebrates (Lewinsohn et al. 2005).The umbu tree is important from an economicand social standpoint to many populations in Bra-zil’s northeast due to its edible fruit and high tol-erance to drought. Rural communities in thesemiarid region can increase their incomethrough selective extraction of umbu fruit, espe-cially during the prolonged drought periods (Cav-alcanti et al. 2006; Santos 1999). The fruit is around, ovoid, or oblong drupe, 2-3.5 cm long andweighs 10-20 g. The fruit has a thin skin, a largeseed, and high content of moisture, ascorbic acid,and iron. The pulp has a very distinct flavor andaroma and its consumption has been increasingin recent years in several regions in northeasternBrazil, not only for the fresh market but also forthe processing industry (Narain et al. 1992; San-tos 1999).Inventories carried out at a regional level inthe states of Maranhao (Oliveira et al. 2000) andRio Grande do Norte (Araujo et al. 2005) indi-cated that there were fruit flies associated withumbu fruit. A paucity of studies on possible fruitflies in Bahia prompted the current considerationof which fruit fly species and parasitoids might beassociated with umbu fruit in the semiarid regionof Bahia.Umbu fruit were collected in southwestern Ba-hia. Our study site was a 3-ha area on a 10-hafarm located in Manoel Vitorino, Bahia, at 290 mabove sea level (14°21´S, 40°11´W). Climate issemiarid, which corresponds to the BSh climatictype of Koppen, with an annual average tempera-ture of approximately 28°C with little variation.Annual average rainfall usually totals less than800 mm and is concentrated from Jan throughMar (Rodrigues 2005). The farm hosts nativeumbu trees at an average density of about 30trees per hectare. The phenology of 30 umbu treeswas verified through monthly observations in2005 in 3 study parcels of 1 ha each at 200 m spac-ing. Three distinct periods were identified: vege-tative rest from Apr through Aug, flowering fromSep through Nov, and fruiting from Dec throughMar. We collected 770 ripe or ripening umbu fruit,410 from the canopies and 360 that had fallen onthe ground, totaling 10.68 kg in Jan 2006, Jan,Nov and Dec 2007, and Jan 2008. The collectedfruits were counted, weighed, placed in individualplastic containers with a layer of vermiculite, andcovered with voile cloth until larvae emerged andpupated. Puparia were removed weekly. All pu-paria obtained were placed in 30-mL plastic con-tainers with a layer of vermiculite at the bottomand covered with voile cloth until adults emerged.Voucher specimens were deposited at the Labo-ratorio de Entomologia, UESC, Ilheus, Bahia,Brazil.Altogether, 328 fruits (42.6%) were infested bytephritid larvae, corresponding to an infestationrate of 0.65 ± 0.93 (SD) puparia/fruit and 47 pu-paria/kg. The number of puparia per fruit rangedfrom 1 to 4. We obtained 502 puparia from the in-fested fruit, from which 361 adults emerged, rep-resenting a pupal viability of 71.2%. All adultsreared were