Anastrepha species trapped in tropical orchards in Mexico
Studies on Anastrepha species were carried out in five orchards of different fruit species in the Soconusco region in Chiapas, Mexico. The main host plants were orange (Citrus sinensis), guava (Psidium guajava; lowland and highland guavas), sapodilla (Achras zapota), chalum (Inga micheliana). Adult population fluctuations were studied by using McPhail traps. Ten Anastrepha species were trapped in the five orchards during approximately a four year period: Anastrepha bezzi, A. chiclayae, A. distincta, A. fraterculus (EPPO A1 quarantine pest), A. leptozona, A. ludens (EPPO A1 quarantine pest), A. obliqua (EPPO A1 quarantine pest), A. serpentina, A. striata and an Anastrepha sp. Species predominance varied markedly in each orchard, with 1 or 2 predominant species representing 43 to 86 % of the Anastrepha individuals. In the sapodilla orchard, 86.61 % of all individuals captured were A. serpentina, whereas in the orange and the Inga orchards, 76.23 and 66.23 % of all individuals captured were A. ludens and A. distincta, respectively. In the case of the guava orchards, the pattern was more balanced. In the lowland orchard, 2 species were mainly found: A. fraterculus* (44.31 %) and A. obliqua (43.59 %). In the highland orchard, there were 3 species: A. fraterculus (48.50 %), A. distincta (20.32 %), and A. ludens (19.36 %). Adult populations varied strongly between and within orchards. In all cases, peak population numbers were recorded shortly after the period of maximum host fruit availability. The authors felt that fruit fly populations in tropical orchards are more influenced by the fruiting phenology and availability of host fruit than weather conditions. The authors also noted that without large availability of the preferred host fruit, populations can remain at very low or undetectable numbers for long periods (in some cases up to 7 months). They stressed that this may have significant implications for pest management or eradication. In particular, they pointed out that to declare eradication of a given species, one should wait for the next fruiting season during which the species concerned should not be detected.
* These trapping results confirm earlier reports of A. fraterculus in Mexico. However, it must be recalled that in 1992, the Mexican Plant Protection Service had declared that A. fraterculus records were erroneous arising from confusion with A. obliqua.
Celedonio-Hurtado, H.; Aluja, M.; Liedo, P. (1995) Adult population fluctuations of Anastrepha species (Diptera: Tephritidae) in tropical orchard habitats of Chiapas, Mexico.
Environmental Entomology, 24(4), 861-869.