Scientific nameAulacaspis yasumatsui
English: snow scale, Thai scale
All adult female Aulacaspis yasumatsui (cycad aulacaspis scale (CAS)) have a waxy outer covering for the protection of themselves and their eggs (the scale) (Weissling et al. 1999). The scale of mature females of A. yasumatsui are: white, 1.2-1.6mm long and highly variable in form. They tend to have a pyriform shape with the exuviae at one end, but are often irregularly circular, conforming with leaf veins, adjacent scales and other objects. The ventral scale is extremely thin to incomplete. The scale of the juvenile male is similar to those of other species of Diaspididae, being 0.5-0.6mm long, white and tricarinate, with exuviae at the cephalic end. Scales of males are nearly always more numerous than those of females (Howard et al. 1999). Adult males are orange-brown, and are similar in appearance to tiny flying midges, with one pair of wings and well-developed legs and antennae (Heu et al. 2003). Adult females are also orange in colour (Weissling et al. 1999).
ASEAN: Thailand
WORLD: China
ASEAN: Singapore
WORLD: Cayman Islands; Cote D'ivoire; France; Guam; Hong Kong; New Zealand; Northern Mariana Islands; Palau; Puerto Rico; Taiwan; United States; Virgin Islands, U.S.
Transport - Parasites on plants
Aulacaspis yasumatsui (cycad aulacaspis scale (CAS)) can be transported to new locations by the import of infested cycad plants. There is high potential for CAS to spread in this manner as one or more fecund females hidden in the cycad can easily escape detection (EPPO, 2005).
Both the citrus and Asian longhorn beetles originate from Eastern Asia where they seriously damage forest and agricultural plant hosts; both pose a potential economic and ecological threat to urban and natural environments where they are introduced in North America and Europe.
Source: Global Invasive Species Database (2020) Species profile: Aulacaspis yasumatsui. Downloaded from on 07-04-2020.
FilenameAulacaspis yasumatsui.pdf
Filesize238.02 kB
Filetypepdf (Mime Type: application/pdf)
Last updated on 04/07/2020 02:04