Ground cover increases activity of generalist ground-dwelling predators to control subterranean life stages of Ceratitis capitata
Ceratitis capitata (Diptera: Tephritidae – EPPO A2 List) is a highly polyphagous pest which has been recorded from more than 350 different confirmed hosts worldwide. Economic costs include direct crop losses, control and prevention of infestations, both pre- and post-harvest, and limited or loss of access to export markets. Treatment and control methods against C. capitata have included chemical control, pheromone trapping (e.g. lure-and-kill), biological control (classical, augmentative and conservation), and sterile insect techniques. For conservation biological control, the development stages of C. capitata which occur in the soil can be targeted. In total, three stages of the fly’s life cycle can be found in the soil: the late 3rd instar stage, the pupae stage and teneral adults, all of which can be predated by generalist ground-dwelling predators. To investigate the association with ground cover management (bare soil, seeded cover of Festuca arundinacea and straw mulch), the emergence of C. capitata, and the activity of the most important groups of ground-dwelling predators (spiders, beetles, ants and earwigs) experiments were set up in a citrus orchard in Spain in 2019/2021. Twenty-four, two-year-old clementine trees were individually enclosed in a cage and the cages received one of the three ground management treatments. A controlled number of C. capitata third instar larvae were added to the three ground management treatments. C. capitata emergence was significantly lower in a seeded cover of Festuca arundinacea and a mulch of straw compared to bare soil. Ground cover was related to higher diversity and activity of ground-dwelling predators in the two former treatments compared to bare soil. Ground covers appear to be a strong and sustainable conservation biological control method that should be taken into consideration for the management of C. capitata populations.
Sources
Cruz-Miralles J, Guzzo M, Ibáñez-Gual MV, Dembilio Ó, Jaques JA (2022) Ground‑covers affect the activity density of ground‑dwelling predators and their impact on the Mediterranean fruit fly, Ceratitis capitata. BioControl https://doi.org/10.1007/s10526-022-10168-0