Suitability of apples as Anastrepha fraterculus hosts
Anastrepha fraterculus (EPPO A1 quarantine pest) occurs in Brazil (it originates from the tropical Americas) where its primary host plants belong to the family Myrtaceae, but several introduced crops (peaches and loquats) have been successfully colonized by it. Apples were commercially introduced into Brazil in the early 1970s, and the cultivated area expanded from 170 ha in 1970 to over 28,000 ha in 1996. A. fraterculus has become a major pest of apple, leading to losses of up to 2 %. Behavioural studies have shown that females readily oviposit in apples, but it is felt that populations have not yet become established in apple orchards. Further studies were carried out in Brazil to compare the life cycle (with emphasis on demography) in apples (cvs. Gala, Fuji, Golden Delicious) and guavas. It was observed that host type had a strong effect on immature stages, mainly on larval development and survival. The following host susceptibility rank was shown: guava;Golden Delicious;Gala;Fuji. High mortality was observed for larval stages, with only 8% survival (from egg to adult) in apple and 24% in guava. Guava produced adults with higher survivorship and reproductive rates. Despite the high mortality observed in immature stages, females showed a high reproductive output, yielding positive values of intrinsic rates of increase on both guavas and apples (0.056 in guavas and 0.031 in Gala apples). Authors concluded that mature apples may be considered as suitable hosts for A. fraterculus.
Sources
Sugayama, R.L.; Kovaleski, A.; Liedo, P.; Malavasi, A. (1998) Colonization of a new fruit crop by Anastrepha fraterculus (Diptera: Tephritidae) in Brazil: a demographic analysis.
Environmental Entomology, 27(3), 642-648.