Ferris, 1938
Diagnosis
In life, scale cover of adult female nearly circular, flat, 1.5-2.5 mm diameter, dark grey to black with orange or reddish brown central exuviae CHRBIL1.jpg . Male scale cover similar to that of the female but oval with subcentral exuviae. Body of living female yellow (Gill, 1997) CHRBIL.jpg .
Body of slide-mounted adult female membranous, pyriform (never reniform); with front of head rounded; metathorax with a short, pointed marginal spur present on either side; two prepygidial segments (abdominal segments I and II) each bearing a cluster of more than five submarginal ducts on each side CHRBIS.jpg . Pygidium broad, subtended by an angle greater than 90°, with three pairs of rounded lobes; perivulvar pores present; paraphyses present only between third lobes, each paraphysis longer than a median lobe; first two plates lateral to third lobe often clavate or only slightly fringed CHRBIP.jpg .
Host range
Chrysomphalus bifasciculatus is a polyphagous species that feeds on leaves; Davidson and Miller, 1990, record it from hosts belonging to 40 genera in 26 plant families, but its host range is probably wider than this. This species has been successfully reared on potato tubers and pumpkin (Li and Liao, 1990) and squash (Tanaka and Kobayashi, 1970). Hosts include species of: Aralia, Aspidistra, Aucuba, Buxus, Camellia, Catha, Celastrus, Cinnamomum, Citrus, Cucurbita, Cycas, Cyperus, Dendropanax, Dianella, Elaeagnus, Euonymus, Fatsia, Ficus, Hakea, Hedera, Ilex, Laurus, Libertia, Ligustrum, Musa, Nerium, Olea, Ophiopogon, Osmanthus, Pandanus, Phoenix, Pittosporum, Poncirus, Prunus, Quercus, Rhaphiolepis, Rhus, Sindora, Solanum, Strelitzia and Viburnum.
Affected plant stages: vegetative growing, flowering and fruiting stages
Affected plant parts: on the leaves CHRBIL3.jpg
Biology and ecology
Chrysomphalus bifasciculatus has two generations per year in Japan (Murakami, 1970). Crawlers are the primary dispersal stage and move to new areas of the plant or are dispersed by wind or animal contact. Mortality due to abiotic factors is high in this stage. Dispersal of sessile adults and eggs occurs through human transport of infested plant material.
Symptoms
The toxic saliva injected during feeding causes chlorosis of adjacent leaf tissues CHRBIL2.jpg , so reducing the effective leaf area for photosynthesis.
Economic impact
Chrysomphalus bifasciculatus is of no economic importance in California (Gill, 1997), although this species has caused severe damage to Euonymus and Hedera there in the past (McKenzie, 1956). Most of the literature mentioning this species originates from Japan, but makes no specific mention of any damage caused. It seems to be a useful species for culturing natural enemies for biological control purposes (Tanaka and Kobayashi, 1970).
Detection and inspection methods
Examine the leaves of the host-plants listed above closely, for circular, flat, dark grey to black scale covers with orange or reddish brown central exuviae.
Natural enemies
Parasitoids:
- Aphytis sp., in Japan
- Comperiella bifasciata, in Japan
Distribution
See Chrysomphalus bifasciculatus distribution.
Microscopic examination of slide-mounted adult females is required for authoritative identification to species. This species is indistinguishable from C. aonidum in the field (Gill, 1997).
Comments
Chrysomphalus bifasciculatus is a tropical species, possibly of Oriental origin. It has not been recorded from the Western Hemisphere, Africa, Australia, or from the Pacific islands, and is little known in Europe.
Europe
Former USSR: under glass (Danzig and Pellizzari, 1998)
Asia
China: present, no further details (Takagi, 1969)
Hainan: present, no further details (Tao, 1999)
Hunan: present, no further details (Tao, 1999)
Inner Mongolia: present, no further details (Tao, 1999)
Jiangsu: present, no further details (Tao, 1999)
Jiangxi: present, no further details (Tao, 1999)
Zhejiang: present, no further details (Tao, 1999)
Japan: present, cannot read any further details (Kawai, 1980; Takagi, 1969)
Korea: present, no further details (Nakahara, 1982)
South-East Asia: present, no further details (Danzig and Pellizzari, 1998)
Taiwan: present, no further details (Tao, 1999)
Western Hemisphere
Mexico: present, no further details (Nakahara, 1982; Miller, 1996)
North America: present, no further details (Danzig and Pellizzari, 1998)
USA
Alabama: present, no further details (Nakahara, 1982)
California: one small, localized infestation only (Gill, 1997)
Delaware: present, no further details (Nakahara, 1982)
Georgia: present, no further details (Nakahara, 1982)
Hawaii: present, no further details (Nakahara, 1981)
Louisiana: present, no further details (Nakahara, 1982)
Maryland: present, no further details (Nakahara, 1982)
North Carolina: present, no further details (Nakahara, 1982)
New Jersey: present, no further details (Nakahara, 1982)
Oklahoma: present, no further details (Nakahara, 1982)
South Carolina: present, no further details (Nakahara, 1982)
Texas: present, no further details (Nakahara, 1982)
Virginia: present, no further details (Nakahara, 1982)