Aonidomytilus crookiae

Aonidomytilus crookiae is a species of scale insect in the family Diaspididae which are often referred to as "armored scale insects."[1] It is commonly known as "St. John's Wort Scale."[2] Originally named Nelaspis crookiae by Gordon Floyd Ferris in 1954,[3] the taxon was moved to the genus Aonidomytilus in 1984[4] as the result of a 1979 taxonomic revision of the genus.[5] Aonidomytilus multiglandulatus is a junior synonym.[1]

The scale of the female is approximately 1/10th of an inch (2.3mm) in length, oyster shell shaped, light brown in color turning yellowish white toward the apex, with orange yellow exuviae attached apically.[1] The body of the female insect under the scale is slender and spindle-shaped, with lobed ventral margins.[1] Their eggs are light purple in color.[1]

A. crookiae parasitizes plants in the genus Cistus in the rockrose family Cistaceae and the genus Hypericum in the family Hypericaceae including Hypericum microsepalum and H. prolificum.[6]

The species' geographic distribution includes the U.S. states Maryland, Virginia, Georgia, Florida, Alabama, Missouri, Illinois, Indiana, and Ohio, and probably adjacent states.[6]