The effect of ground cover on the mortality of ground-dwelling immature stages of Ceratitis capitata in Eastern Spain

Abstract Three developmental stages of Mediterranean fruit fly, Ceratitis capitata, can be found in the soil (late third instar larvae, pupae, and teneral adults). These stages are susceptible to predation by generalist ground-dwelling predators. Our objectives have been to investigate the association between ground cover management (bare soil/BS, a seeded cover of Festuca arundinacea/FA and a mulch of straw/M), the emergence success of C. capitata, and the activity density of the most important groups of ground-dwelling predators (spiders, beetles, ants and earwigs). As expected, C. capitata emergence was lower in a seeded cover of Festuca arundinacea (FA) and a mulch of straw (M) (10.2%) relative to bare soil (BS) (13.2%). This was related to higher diversity and activity density of ground-dwelling predators in FA and M compared to BS. The contribution of the ground-dwelling predators considered in this study to this reduction highlights the key role of beetles, earwigs and, to a lesser extent, ants, while the contribution of the most abundant group of ground-dwelling predators, spiders, remains unclear. Ground covers appear as a strong and sustainable conservation biological control method that should be taken into consideration for the management of C. capitata populations in fruit orchards.