The abundance and diversity of fruit flies and their parasitoids change with elevation in guava orchards in a tropical Andean forest of Peru, independent of seasonality

Abstract

Lower elevations are generally thought to contain a greater abundance and diversity of insect communities and their natural enemies than higher elevations. It is less clear, however, how changes in seasons influence this pattern. We conducted a 2-year study (2013‒2014) in guava orchards located in a tropical Andean forest of Peru to investigate differences in fruit flies (Diptera: Tephritidae) and their parasitoid communities at two elevations and over two seasons. Fruit fly traps were installed, monitored, and guava fruits were sampled from eight orchards at low (800–950 m above sea level) and high (1,700–1,900 m above sea level) elevations and during the dry and rainy seasons. At each orchard, adult fruit fly trap captures and emergence of fruit flies and their parasitoids from guava fruit were quantified to determine their abundance and species composition. There was a greater abundance and species richness of fruit flies captured in traps at lower elevations, as well as higher abundance and species evenness of fruit flies that emerged from fruit, indicating that lower elevations are associated with larger fruit fly populations. The abundance, species richness and diversity of parasitoids were also greater at lower elevations. Consequently, guava fruit infestation and fruit fly parasitism rates were also greater at lower elevations. Seasonality also influenced fruit fly populations with a greater number of flies emerging from guava fruit and more fruit infested in the rainy season. However, seasonality had no effect on parasitoid population parameters or rate of parasitism, nor did it interact with elevation as an influence of populations of fruit flies or their parasitoids in guava orchards. This study highlights the importance of examining both elevation and seasonality for a better understanding of the population dynamics of fruit flies and their parasitoids in tropical agroecosystems.

Island and Mountain Ecosystems as Testbeds for Biological Control in the Anthropocene

“…For a complex of Tephritid hosts (dominated by Anastrepha striata Schiner) and a broad altitudinal range (300-2,264 m), parasitism increased with altitude. This contrasts with studies in other agricultural settings (Sivinski et al, 2000), over narrow elevational bands or with lower sample sizes (Salazar-Mendoza et al, 2021), where marked declines were recorded. While Sivinski et al (2000) logged the highest parasitism levels (16%) at 600-800 m in central Veracruz (Mexico), values of 26.5% (max.…”

“…A second exercise draws on published datasets of Tephritid fruit fly parasitoids from the tropical Andes i.e., multiple sites in Colombia and Peru (e.g., Ruiz-Hurtado et al, 2013;Saavedra-Díaz et al, 2017;Salazar-Mendoza et al, 2021;Figure 2B). For a complex of Tephritid hosts (dominated by Anastrepha striata Schiner) and a broad altitudinal range (300-2,264 m), parasitism increased with altitude.…”

Changes in the potential distribution of the guava fruit fly Anastrepha striata (Diptera, Tephritidae) under current and possible future climate scenarios in Colombia

“…Among 16 species collected from traps, Salazar-Mendoza et al . (2021) found the same three fruit fly species from guava in the altitudinal transect in Peru, with A. fraterculus predominant in lowlands and A. striata in highlands. Among species in the A. fraterculus complex, those from lowlands in Peru were different from those from highlands in Peru, Ecuador, and Colombia (Hernández-Ortiz et al ., 2015).…”

“…Our results indicated that A. striata currently inhabits a significant portion of Colombian territory, probably because of its thermal physiological plasticity (Baker et al, 1944) and all abovementioned faunistic interactions acting together. Data on Colombian GFF hosts are widely lacking; however, species of Myrtaceae, its main hosts, could be found through a wide altitudinal range (Parra, 2014); due to the effect of the host on insect distribution (Castañeda et al, 2010;Salazar-Mendoza et al, 2021), A. striata may use the available host species according to altitude. In Colombia, guava is parasitized by A. striata, A. obliqua, Anastrepha fraterculus s.l., and Anastrepha ornata (Núñez et al, 2004;Castañeda et al, 2010;Saavedra-Díaz et al, 2017).…”

“…Data on Colombian GFF hosts are widely lacking; however, species of Myrtaceae, its main hosts, could be found through a wide altitudinal range (Parra, 2014); due to the effect of the host on insect distribution (Castañeda et al ., 2010; Salazar-Mendoza et al ., 2021), A. striata may use the available host species according to altitude. In Colombia, guava is parasitized by A. striata , A. obliqua , A nastrepha fraterculus s.l., and Anastrepha ornata (Núñez et al ., 2004; Castañeda et al ., 2010; Saavedra-Díaz et al ., 2017).…”