Broad mite

The broad mite (genus Hemitarsonemus) is a destructive plant pest belonging to the Tarsonemidae family. These mites are microscopic in size and typically inhabit the undersides of young, developing leaves or deep within the growing tips of host plants, making them difficult to detect in the early stages of infestation.

This pest affects a wide range of horticultural and agricultural crops, including ornamentals like begonias, cyclamens, and impatiens, as well as vegetables such as peppers, cucumbers, and tomatoes. They thrive in warm, humid greenhouse environments where conditions remain stable for their rapid development.

The life cycle of Hemitarsonemus is characterized by short development times, often requiring only a few days to complete an entire generation. Eggs are laid in clusters, and the resulting larvae quickly begin feeding on plant tissues, often causing damage that is mistaken for viral diseases or herbicide injury.

Damage to plants is caused by the mite injecting toxic saliva while feeding. Typical symptoms include curling and distortion of young leaves, stunted terminal growth, and the development of a bronze or purplish discoloration on the undersides of leaves. If left untreated, the entire plant can become severely deformed and stunted.

Managing broad mite populations requires an integrated approach. Chemical control is often necessary, but it must be precise due to the mites' small size and protected locations. Key control strategies include:

• Systemic and contact acaricides application;
• Maintaining optimal humidity to discourage explosive reproduction;
• Removing and destroying heavily infested plant material immediately;
• Regular monitoring with magnifying lenses to catch outbreaks early.