Candidatus Liberibacter spp.
Also known as: Huanglongbing
Abbreviation: HLB
Vectors:
​Citrus greening disease is present in: southern Asia, southern Africa, Central and South America, and was recently found in the Mexican states of Jalisco, Nayarit, Quintana Roo, and Yucatán.
Psyllids (vector) have been detected in Alabama, American Samoa, Arizona, California, Florida, Georgia, Guam, Hawaii, Louisiana, Mississippi, Northern Mariana Islands, Puerto Rico, South Carolina, Texas, and the U.S. Virgin Islands.
Citrus greening is a disease of these Citrus spp. plants and is vectored by the Asian citrus psyllid or via mechanical inoculation:
Fresh Murraya spp. leaves (curry and orange jasmine) are a preferred host of the citrus psyllid. Nursery stock and cut flowers are a potential pathway. In addition, the leaves of Citrus spp. are considered high risk.
Evidence of citrus greening damage includes:
Fruit - fruit may be small and lopsided. Cut fruit may have a curved axis, and the vascular columella can be stained orange-brown. Seed abortion is also common. Fruit may ripen backwards with the stylar end remaining green as the fruit colors.
Leaf - although symptoms differ according to citrus variety, common symptoms may be described. The most characteristic symptom is a blotchy mottle. This mottling usually crosses the veins and is asymmetrically displayed on the leaf blade. Mottling is most frequently found on newly mature hardened-off leaves but fades with leaf age. The blotchy mottle will be visible on both sides of the leaf and have multiple hues of yellow and green. Dark green areas can sometimes be reduced to small circular dark green dots that contrast with the light yellow/green background. In addition to blotchy mottle, infected leaves may be thicker and leathery and have raised corky veins.
Psyllid - adults are gray to brownish in color and 3–4 mm long. When disturbed, adults may jump and fly a short distance. Eggs and nymphs are a yellow-orange color and may be difficult to see without magnification. Nymphs flatten themselves around the shoot; eggs are tucked inside cervices and leaf folds. Nymphs are generally found on new growth.
CBP Agriculture Specialists, please refer to manuals for general inspection guidelines.
When performing inspections, look for:
For additional information (external):
