Several studies have documented the positive effects of controlling the Asian citrus psyllid (ACP, Figure 1) for citrus tree health and sustainability in Florida. The mature blocks established before and after the discovery of huanglongbing (HLB) in 2005 continue to benefit from psyllid control.
One psyllid is enough to infect a tree with HLB for life, and repeated infestations negatively affect tree health and contribute to the spread of the disease. Therefore, psyllid control continues to be a necessity for successful citrus production. An efficient pest management program should consider psyllid biology, tree phenology, application timing and method, and chemical effectiveness.
ACP LIFE CYCLE
ACPs go through three distinct life stages: egg, nymph and adult.
Females lay eggs in buds and unopened leaves of young shoots. Eggs are small and almond shaped with a pale yellow to orange color.
Upon emergence, nymphs feed on the soft tissues of new leaves and shoots and develop through five instars. They are generally light yellow with orange or blue-green coloration on the abdomen and have dark red eyes. They produce white secretions of wax called honeydew. The secretions are easy to observe when hanging from the rear ends of the nymphs or on the leaf surface. The secretions later cause sooty mold.
The mature nymph transforms into an adult with mottled wings held “roof-like” over the body. The adult abdomen stays at an angle of 30 to 45 degrees with the plant surface. It takes about two to three weeks from egg to the development of the adult, depending on the temperature.
SEARCHING FOR PSYLLIDS
The best place to look for the adults and their progeny is the newly developing buds and young shoots (known as flush). Adults are found aggregated on the young shoots where they feed, mate and reproduce. They also feed and survive on mature growth, generally feeding on the underside of the leaves.
The mature nymphs and adults are …..
Written by Jawwad Qureshi, assistant professor at the UF/IFAS Southwest Florida Research and Education Center in Immokalee.
Read more about Dormant Sprays for Asian Citrus Psyllid Management on the Citrus Industry website.