Body broadly oval or pyriform, often asymmetrical; flat in lateral view; body reddish to dark brown in older females, with polygonal plates or tessellations on dorsum; median area with raised carina or ridge; without an obvious wax covering; ovisac absent. Young females similar in appearance to species of Coccus. Occurring on leaves and stems. Males apparently absent. Eggs hatch within the body of the female.
Eucalymnatus tessellatus is unique among the commonly intercepted soft scales by having a distinctive polygonal pattern on older adult females; no tubular ducts; no preopercular pores; and 1 pair of preopercular setae.
U.S. quarantine notes
This species was intercepted 77 times at U. S. ports-of-entry between 1995 and 2012, with specimens originating from Antigua and Barbuda, Australia, Brazil, Costa Rica, Dominica, Ecuador, El Salvador, Guatemala, Guyana, Hawaii, India, Italy, Jamaica, Malaysia, Marshall Islands, Micronesia, Mexico, Peru, The Philippines, Puerto Rico, Tonga, and Vietnam. We also have examined specimens taken in quarantine from Australia (Anthurium, Gardenia); Barbados (Laurus, Pimenta); Bermuda (Laurus, Nerium, Pimenta, Roystonea); Brazil (palm); Cook Island (Alyxia); Costa Rica (orchid); Cuba (Musa); Dominica (Anthurium, Cinnamomum, Corpha); England (palm); Haiti (Mangifera); Hawaii (Alyxia, Cocos, Litchi); Hong Kong (unknown host); Italy (Fatsia, Gardenia); Jamaica (Kentia); Japan (Aspidistra; Rhapis); Martinique (Mangifera); Mexico (Caryota, Cocos, Codiaeum, Chamaedorea, Gardenia); Pago Pago (Alpinia); Portugal (palm); Puerto Rico (Caryota, Psidium); Rarotonga (Alyxia); St. Lucia (Caryota); Surinam (Iriartea); Tahiti (Mangifera). ScaleNet includes hosts in over 50 plant families including a wide diversity of palms from all zoogeographic regions. There are no other species of Eucalymnatus that have been taken at U. S. ports-of-entry.