Introduction

The hosts of more than 50% of all Anastrepha species are unknown, many of them are probably native species (Norrbom et al. 1988). Of the 213 Anastrepha species known, 47% occur in Brazil, although there are host-records for less than half of these species (Zucchi 2007). Anastrepha fumipennisLima, 1934 (Diptera: Tephritidae) and A. nascimentoiZucchi, 1979 are known exclusively from Brazil. A. fumipennis was only known from two type-specimens collected in Rio de Janeiro state, before being rediscovered in a fruit fly survey undertaken in commercial papaya orchards in the state of Espírito Santo (Martins et al. 2000). A. nascimentoi was recorded in the states of Bahia (Zucchi 1979; Nascimentoi et al. 1981) and Espírito Santo (Martins et al. 2005). However, the host plant was unknown for both fruit fly species.

To survey native fruit fly hosts an assay was undertaken in the “Reserva Natural da Companhia Vale do Rio Doce”, an Atlantic Rain Forest remnant area in Linhares county, Espírito Santo state, Brazil.

Materials and Methods

Fruits, which had recently fallen or were picked from the tree, were sampled at the “Reserva Natural da Companhia Vale do Rio Doce” (19°06′ and 19°18′S; 39°45′ and 40°19′W). Vegetation in the Reserva corresponds to a secondary dense ombrophilous forest (Souza et al. 2002), situated on the surface of Tertiary mesas in the Barreira formation (lowland forest “mata de tabuleiro”), which is characterized by a sequence of low-elevation hills (28–65 m) and flat-bottom valleys (Vicens et al. 1998). Fruits of Geissospermum laeve (Vell.) Baill and Cathedra bahiensis Sleumer were collected, according to the fruiting season of each species, from February/2003 to July/2007. Fruits of both species were counted, weighed and placed in vials with vermiculite to obtain puparia, which were transferred to adult emergence cages. As A. fumipennis shows remarkable external morphological characters, females and males could be identified (Figures 1a, 1b, 1c).

Figure 1.

Anastrepha fumipennis: female (a), wing (b), aculeus tip (c).

Normally, A. nascimentoi cannot be identified based on the male, however, as only females of this species were reared from the sample, the males of this sample were considered as also belonging to A. nascimentoi (Figures 2a, 2b, 2c). Voucher specimens were deposited in the collection of the Escola Superior de Agricultura Luiz de Queiroz, section of Entomology, Piracicaba, São Paulo. Plants were deposited in the Reserva herbarium.

Results and Discussion

248 fruit tree species belonging to 51 families were sampled totalizing 330 fruit samples (Uramoto 2007). Among these, three samples of Geissospermum laeve (Vell.) Baill. (Apocynaceae), known as “pau-pereira”, were collected in March 2003, February 2004 and 2006, in addition to one of Cathedra bahiensis Sleumer (Olacaceae), known as “baleira”, collected in January 2004. G. laeve is of common occurrence in the reserve, fruiting from December to March. The peel of the ripe fruit is brownish and the pulp very soft (Figure 3a). C. bahiensis fruits are small, with a yellow peel (Figure 3b). The fruiting period is from December to January.

Of three samples of G. laeve, adults of A. fumipennis (26 ♀ and 27 ♂) emerged from only one. The thin peel and soft pulp of G. laeve fruits are appropriate for A. fumipennis egg-laying, since the aculeus of this species has a rounded truncate tip, without serrations (Figure 1c). Specimens of A. nascimentoi (2 ♀ and 3 ♂) were reared from a single sample of C. bahiensis fruits. According to the host plant database (Norrbom 2004), no host was known for these two Anastrepha species so far. Therefore, this is the first host-plant record for both species. A. fumipennis is placed in the grandis species group as it shares apomorphies with A. atrigona Hendel, one of the species of this group (Norrbom et al. 1999). Recently, A. atrigona was also obtained from another species, G. argenteum Woodson (Apocynaceae), collected in the state of Amapá (Xavier et al. 2006). Although A. nascimentoi is not sorted in any species group, it may belong to the spatulata group, which is mainly associated with Euphorbiaceae and Olacaceae (Norrbom et al. 1999). Thus, these findings reinforce the hypothesis that host-plant associations of Anastrepha appear to be correlated with phylogenetic relationships within the genus (Norrbom et al. 1999). The mean fruit weight and infestation index values were 41.34 g and 0.32 puparia.g-1 for G. laeve and 13.40 g and 0.06 puparia.g-1 for C. bahiensis.

Figure 2.

Anastrepha nascimentoi: female (a), wing (b), aculeus tip (c).

It is most likely that the host for these Anastrepha species was unknown because they maintain a specific association with their native hosts. This would also explain why their hosts were discovered only when native fruits were surveyed in a natural reserve. Considering G. laeve distribution, it is likely that A. fumipennis also occurs in the states of Amazonas, Bahia and the Federal District (state of Goiás), in addition to Rio de Janeiro (Lima 1934) and Espírito Santo (Martins et al. 2000). Likewise, A. nascimentoi may also occur in the state of Pernambuco, besides Bahia (Zucchi 1979; Nascimento et al. 1981) and Espírito Santo (Martins et al. 2005), as mentioned above coincides with the distribution of its host plant (New York Botanical Garden 2007). Recently A. nascimentoi was also recorded in the state of Rio de Janeiro, in Araruama (Aguiar-Menezes et al. 2006). This municipality is close to the border of the state of Espírito Santo, where C. bahiensis occurs.

Figure 3.

Geissospermum laeve ripe fruits (a), Cathedra bahiensis fruits (b).