Olive whitefly

The olive whitefly (Aleurolobus olivinus) is a specialized insect pest belonging to the order Hemiptera and the family Aleyrodidae. It is a major concern for commercial olive cultivation, particularly in Mediterranean climates. This pest thrives in warm, humid conditions and can cause significant economic losses if left unmanaged.

Regarding its biology, the life cycle consists of the egg stage, the crawler (nymphal) stage, the puparium, and the adult insect. Eggs are typically laid on the underside of olive leaves. Upon hatching, the mobile nymphs migrate to a suitable feeding site, settle down, and remain fixed, extracting nutrients directly from the leaf tissues.

The damage caused by Aleurolobus olivinus is twofold. Primarily, the feeding activity leads to chlorosis, leaf deformation, and premature defoliation. Secondly, the insects secrete large amounts of honeydew, which serves as a substrate for sooty mold growth. This fungal layer blocks sunlight, significantly inhibiting the tree's photosynthetic capacity.

The economic threshold of this pest is quite low, as even moderate infestations can lead to decreased oil yield and overall tree decline. Persistent infestations weaken the tree's vigor, making it more susceptible to other environmental stressors and secondary infections, ultimately leading to lower quality fruit production.

Management and protection measures should focus on integrated pest management (IPM) strategies:

• Regular monitoring of olive groves, particularly inspecting the lower leaf surfaces.
• Application of horticultural mineral oils during the crawler emergence phase.
• Pruning techniques to improve crown aeration, which creates an unfavorable environment for whitefly colonies.
• Encouraging biological control agents, including parasitic wasps that naturally predate on whitefly populations.