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Asian Citrus Psyllid Distribution and Management
University of California
Asian Citrus Psyllid Distribution and Management

What Am I Looking For?

What does the insect look like?

The Asian citrus psyllid adult is tiny - the size of an aphid.  The wings are  brown along the edge, with a clear area. The psyllid feeds with its rear end tilted up at a 45o angle, making the insect appear almost thorn-like on leaves and stems. The tilted body and wing pattern is unique to this pest.

Asian citrus psyllid adult
Asian citrus psyllid adult

Juveniles (nymphs) produce white, waxy tubules and are always found on new leaf growth or young stems.  The waxy tubules are unique to this pest.

ACP nymph producing curly waxy tubules
ACP nymph producing curly waxy tubules

The eggs of the Asian citrus psyllid are yellow and are found on the newest leaf growth, nestled among unfolded leaves. They are very tiny and hard to see without a hand lens.

ACP eggs tucked in tiny leaves
ACP eggs tucked in tiny leaves

 

What does the disease look like?

The first symptom in a Huanglongbing-infected tree, and the most important one to watch for is yellowed leaves. However, citrus trees often have yellow leaves because of nutritional deficiencies so its important to know the difference. Nutrient deficiency causes a similar pattern of yellowing on both sides of the leaf.  HLB causes blotchy yellow mottling and is not the same on both sides of the leaf (see this link for more photos of yellow citrus leaves).

Blotchy yellow HLB-infected leaves
Blotchy yellow HLB-infected leaves

 Later symptoms of HLB-infected trees include lopsided, small fruit, bitter juice and excessive fruit drop. Eventually the tree will stop producing fruit and die.

A citrus tree dying from huanglongbing
A citrus tree dying from huanglongbing

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