Avocado round scale

The avocado round scale (scientific name Acutaspis perseae) is a destructive insect pest belonging to the Diaspididae family within the order Hemiptera. This pest is a significant threat to tropical and subtropical orchards, particularly impacting avocado production worldwide due to its ability to colonize foliage and fruit surfaces.

The host range of this insect includes avocado, citrus, mango, and various ornamental plants. By attaching firmly to the plant tissue, the scales create a protective barrier that shields them from adverse environmental conditions, making them challenging to manage effectively once an infestation is established.

The biological cycle of Acutaspis perseae involves distinct stages, including the egg, crawler (nymph), and adult stages. The crawler stage is the most mobile phase, allowing the pest to spread across the orchard. Adult females remain stationary, feeding underneath their hardened, circular protective covers for their entire lifespan.

Feeding damage is caused by the extraction of sap, which leads to plant stress, reduced photosynthesis, leaf yellowing, and eventual defoliation. Furthermore, the presence of these scales on the fruit skin causes aesthetic defects, which often result in the rejection of produce during post-harvest sorting and quality control processes.

Effective management requires a multi-faceted approach. Monitoring programs are essential to detect the emergence of crawlers, which are the most susceptible stage to chemical applications. Integrated pest management (IPM) practices, including the release of natural enemies and the targeted use of systemic insecticides or oils, are recommended for maintaining orchard health.

• Regular pruning to improve spray penetration and light exposure.
• Implementation of biological control using parasitic wasps.
• Strategic timing of insecticide applications targeting the crawler stage.
• Strict quarantine inspections for incoming plant material to prevent spread.