The Asian citrus psyllid, (Diaphorina citri), is an important pest of citrus in several countries as it is a vector of a serious citrus disease called greening disease or Huanglongbing. It is widely distributed in southern Asia and the disease is responsible for the destruction of several citrus industries in Asia and Africa. In North America, it has spread through most of the southern states and Mexico however the state of Florida is the most affected area by the vectored disease.
Life cycle of Asian citrus psyllid
Adult Asian citrus psyllids are mottled brown wings insects of about 25 to 35 mm long. The adults are active, jumping/flying insects and can readily fly short distances when disturbed. The psyllid’s life cycle includes an egg stage and five nymphal instars. The elongated-oval eggs are light yellow when freshly deposited and bright orange with two distinct red eye spots at maturity. Eggs are anchored to plant tissue in an upright position, and large numbers of eggs may be found on a single spot. Nymphs are green or dull orange. First instar nymphs are docile and move only when disturbed or over-crowded. Development from egg to adult varied from 14 days at 28°C/82.4°F to 49 days at 15°C/59°F. New adults reach reproductive maturity within 2 or 3 days, oviposition begins about 1 or 2 days after mating and adults live for several months. Females psyllids lay more than 800 eggs during their life cycle.
The psyllid is a sucking insect that inserts its mouthparts into plant tissue to feed. Adults feed on young stems and on leaves of all developmental stages. Nymphs feed on young leaves and stems, continuously secreting copious amounts of honeydew and a thread-like waxy substance so black sooty mold develops on the honeydew. Their feeding damages citrus by burning back new shoots or causing leaves to twist or notch as they mature. Worst damage is done when the insect is vector of the bacterium Candidatus Liberibacter asiaticus that cause the fatal citrus disease called citrus greening or huanglongbing (HLB). Nymphs and adults of the psyllid take the bacteria into their bodies by feeding on bacteria-infected plants and then disease is spread when adults fly to a healthy plant and injects bacteria into it as they feed. The disease can kill a citrus tree in as little as five years, and there is no known cure.