Aceria litchii

The lychee erinose mite (LEM), Aceria litchii (Keifer) (Acari: Eriophyidae), is one of the most important pests of lychee (Litchi chinensis Sonn., Sapindaceae). This eriophyid mite pest is native to Asia and has been reported in India, Pakistan, Bangladesh, Thailand, China and Taiwan, Hawaii, and Australia ... in Brazil [it] has caused an estimated 70–80% yield reduction ... In February 2018, LEM was found in Lee County, Florida, and since then it has spread to several counties in central and south Florida ... 

Erinea develop initially on the lower side of the leaves, presenting a white/transparent coloration, and causing leaves to become distorted or curled. However, at this stage of the infestation, a color change of the leaf can also be visible on the upper side. As LEM populations grow, the erinea change color, thickness, and density. Dense white erinea have fewer mites present in comparison to amber colored erinea. Erinea of dark brown or black color have little to no mites present. At this stage, the mites have overexploited the leaf and have dispersed in search of a new flush within the same plant. Erinea may also develop on petioles, stems, panicles, flower buds, and fruit. They may vary in size, shape, and color. Heavy infestations have typically multiple, much larger erinea that may vary in maturation due to the time it takes for the mites to disperse within the plant ... 

[click below for photos]

The Lychee Erinose Mite Aceria Litchii (Keifer) (Acari: Eriophyidae)