Stickney spider mite

Systematic position. The Stickney spider mite (Oligonychus stickneyi) belongs to the class Arachnida, order Trombidiformes, and family Tetranychidae. This mite species is known for its ability to thrive in hot and arid environments, making it a significant challenge for agricultural regions where dry spells are common during the crop growing season.

Affected crops. The primary host plant for this pest is corn (maize), although it has been documented feeding on various other species within the Poaceae family. These mites can easily move between corn fields and adjacent wild grasses, which serves as a reservoir for populations when the main crop is absent or after harvest.

Biology and life cycle. The life cycle consists of the egg, larva, protonymph, deutonymph, and adult stages. High temperatures (above 30°C) and low humidity accelerate the developmental rate, allowing the mite to complete several generations in a very short time. Overwintering occurs in the adult stage, often in soil cracks or debris located at field margins.

Damage and economic importance. These mites feed by piercing plant cells, primarily on the underside of leaves, and extracting sap. This leads to the characteristic stippling, yellowing, and eventual browning (necrosis) of the foliage. Excessive web production is a clear indicator of a severe infestation, which ultimately causes significant yield loss and plant stress.

Control measures. Integrated Pest Management (IPM) is essential for effective control:

• Maintaining good soil moisture to reduce plant stress.
• Weed control at field borders to eliminate alternative hosts.
• Scouting for early infestations to apply localized chemical treatments.
• Using effective acaricides according to regional regulations and economic thresholds.
• Promoting biological control agents, such as predatory mites and lady beetles.