Photo by Fernando Alferez, UF/IFAS
By Jawwad Qureshi
Young citrus trees produce shoots with feather-stage leaves more frequently, making them highly attractive to the Asian citrus psyllid (ACP). This pest requires young shoots with feather-stage leaves to develop and reproduce. ACP is the pathogen’s primary vector responsible for causing huanglongbing (HLB) disease. Plant infection with HLB at an early age makes it challenging to bring trees to production. Therefore, protection from the vector psyllid is critical.
Individual protective covers (IPCs) are being investigated and used as a tool to protect young trees from ACP and HLB. These covers serve as mini cages made from fine mesh. They do an excellent job of protecting young trees from ACP. There are no reports of ACP or HLB finds inside IPCs from the researchers evaluating them. However, it is important to remember that ACP and several other pests such as scales, mites, leafminers, aphids, thrips, whiteflies and mealybugs are likely in the IPCs.
There are several ways in which pests can get introduced into IPCs. Pests may already be present on the plant at planting or colonize the plants during the time lag between planting and covering with IPCs. Once IPCs are installed, pests could still enter these structures through the holes made in the mesh that can result from from animal activity, weather events or space along the tree’s trunk if not appropriately fastened. Insects such as moths can lay eggs on the mesh, and the neonates can find their way in the IPCs through holes in the mesh or space along the trunk.
It is critical to scout the IPCs regularly. It may be useful to check them monthly for any damage to the mesh and possible entry holes. Examine inside the IPCs for the presence of pests every two months. At the time of examination, tree canopies need to be checked thoroughly for pest problems. Scales or mealybugs present on the leaf surfaces or stems or feeding damage to the foliage from larvae are visible from the outside.
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers have observed scales, mealybugs, mites and the larvae and pupae of an armyworm inside the IPCs. The armyworm moths laid egg batches on the surface of the IPCs, and upon hatching, larvae were able to find their way into the structure.
Females of several pests have the potential to lay hundreds of eggs. Once inside the IPCs, the populations can quickly increase to high numbers and damage plants because they are protected from the natural enemies that keep them at low levels in open production systems.
Learn about managing pests in IPCs here.
Jawwad Qureshi is an assistant professor at the UF/IFAS Southwest Florida Research and Education Center in Immokalee.