Ceroplastes japonicus

Japanese wax scale

Description

The Japanese wax scale, also known as Ceroplastes japonicus or tortoise wax scale, originates from Eastern Asia and has become a significant pest affecting citrus and various fruit crops in both Asia and Europe. Its recent presence has been noted in multiple European countries. This scale insect exhibits a broad host range, with reports of infestation on over 100 plant species. All life stages of the insect feed on leaves, stems, and fruits, causing direct damage to the host plant. Moreover, the honeydew produced during feeding fosters the growth of sooty mold, compounding the detrimental effects.

Adult females measure approximately 4mm in length and 3.5mm in width. In regions such as China and Italy, Japanese wax scale typically completes one generation per year. The development of Japanese wax scale depends on the availability of suitable hosts for feeding and oviposition. Eggs are laid in a chamber under the body of the adult female, with each female capable of laying up to 2500 eggs, though typically around 400. The crawler stage, the only mobile stage, facilitates dispersal via wind until they find a suitable feeding site, where they settle and commence wax production to cover themselves. In Italy, mated females overwinter, with oviposition occurring in May and June, followed by egg hatching in June. Nymphal stages progress through the summer, with adult females becoming evident in September as they prepare for the overwintering stage..

Symptom

Characteristic symptoms of Japanese wax scale infestation include reduced vigor, chlorosis of leaves, fruit discoloration, wilting, foliage and/or stem dieback, and premature foliage, flower, and fruit drop. In severe cases, high population densities of the pest can even lead to the death of the host plant. The body of the insect is oval or rectangular in shape, with older females appearing convex and younger ones appearing flat when viewed from the side. Covered in a thick oily wax, the body color ranges from reddish-brown to pinkish-white or pinkish-grey. Nymphs are star-like.

Tree Species: Spindle, Ivy, Citrus, Pear, Apple Tree, Magnolia

Part of a plant- attacked: Leaf / Needle, Branch

Pest significance: Harmful

Pest Category: Insects

Invasive Species: Yes

Present in EU: Yes