Shade cloth over citrus

The effect of permanent protective netting on insect pest prevalence in citrus orchards in South Africa

The use of protective netting is becoming an increasingly popular practice in the citrus industry in South Africa. However, data on its effects on biotic factors, particularly insect pests, are limited. This study focused on the effect nets have on key citrus pests in the Eastern Cape province. Orchards under nets and open orchards, of similar cultivars, ages and management practices, were monitored at several sites over two seasons for pest infestation and damage. Weekly monitoring was conducted for Thaumatotibia leucotreta infestation. Other pests were monitored either monthly or once a season. During the first season, T. leucotreta infestation was higher in orchards under nets, probably because, unlike the open orchards, the nets provided protection for the existing high levels of T. leucotreta. No T. leucotreta infestation was recorded in both orchard types in 2019. This was due to generally lower than usual pest abundance and dramatically improved area-wide management of T. leucotreta. Pheromone traps were used to monitor T. leucotreta males, including sterile moths used in a sterile insect technique programme.