red nail gall mite

Eriophyid mites (Eriophyes spp.) are so small that they are almost impossible to see with the naked eye. Unless a scanning electron microscope is available, a morphological description of an adult individual is useless. However, many mites can be easily identified by the shape of the galls they produce and the plant species on which they are found.

Red nail gall mite is a specialized plant feeder. In Minnesota it can be found on American basswood and littleleaf linden, mostly on the lower leaves.

The nail galls appear randomly scattered across the upper side of a leaf. There are usually many galls on a single leaf. The are generally absent along the veins.

The galls are tube-shaped and 3 ⁄16″ to ½″ long. They taper at the top to a rounded or pointed tip. They may be straight or curved, erect or oblique. They are mostly solitary though sometimes two galls join at the base but remain separate at the top. They are greenish-yellow to pinkish at first, eventually turning red to brown.

Tiny, almost microscopic

Linden wart gall midge (Contarinia verrucicola) creates round, wart-like or beebee-like galls, each one raised on both the upper and lower leaf surfaces.

In Minnesota, American basswood and littleleaf linden.

One generation per year: June to August

The adult overwinters in a bark crevice or near a bud. It emerges in the spring and seeks a newly developing leaf. As it feeds on the leaf, a chemical in its saliva causes the leaf cell to expand, creating a finger-like gall. In late summer the adult leaves the gall and seeks a location to overwinter.

Sources

7, 24, 29, 30, 82.

Common

The superfamily Eriophyoidea was formerly placed in the order Trombidiformes. A recent mitochondrial DNA study and phylogenetic analysis (Arribas et al., 2020) showed that the superfamily evolved earlier than Trombidiformes. It is sometimes now included in the order Endeostigmata. In modern taxonomic treatments Eriophyoidea is sister to the clade containing Trombidiformes.

Sarah Boeka
5/13/2020

Location: Washington County, Nebraska

Luciearl
5/28/2018

Location: Cass County

Location: 10th Ave S between 54th and 55th St E

I'm sure it is a much larger area as nearly every tree on the block seems overrun.