Asian Citrus Psyllid

This tiny invader and its even tinier bacterial hitchhikers threaten to take our favorite citrus fruits off our tables.  These bacterial hitchhikers cause a disease called “Huanglongbing,” which means “Yellow Dragon Disease” in Chinese.  Cool name, very bad bacteria!  Check out the image slider below and scroll down to learn more and help Laura Wilkins battle these two troublemakers.

Printable Field Guide: PDF

  • Asian Citrus Psyllid usually feeds head down, tail up as it sucks sap from a leaf.  Photo Credit: David Hall, USDA Agricultural Research Service, Bugwood.org

  • Close-up  showing the coloration of an adult Asian Citrus Psyllid.  Photo Credit: David Hall, USDA Agricultural Research Service, Bugwood.org

  • Side view of the Asian Citrus Psyllid (Diaphorina citri) showing how its wings are almost clear in the middle and darker around the edges.  Photo Credit: Pest and Diseases Image Library, Bugwood.org

  • Top view of the Asian Citrus Psyllid showing its light brown head and slightly darker colored body.  Photo Credit: Pest and Diseases Image Library, Bugwood.org

  • The adult Asian Citrus Psyllid (Diaphorina citri) is usually about 1/8 inch (four millimeters) long.  Photo Credit: Pest and Diseases Image Library, Bugwood.org

  • Close-up of leaf showing both adult and nymph Asian Citrus Psyllids. One female can lay almost 1000 eggs during her lifetime! Photo Credit: J.M. Bové, INRA Centre de Recherches de Bordeaux, Bugwood.org

  • After the eggs hatch the Asian Citrus Psyllid nymph goes five stages (called instars) before becoming an adult. The nymphs start out pale yellow, but darken and develop prominent wing pads as they mature.  Photo Credit: David Hall, USDA Agricultural Research Service, Bugwood.org

  • Asian citrus psyllid eggs are tiny (less then 1/2 millimeter long) and oblong. They begin very pale but darken as they mature.  Photo Credit: David Hall, USDA Agricultural Research Service, Bugwood.org

  • Close-up showing the typical placement of eggs, between or on the tips of growing shoots, and near unfolding leaves.  Photo Credit: Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org

  • At 1/8 inch (four millimeters) long, even the adults are small!  Photo Credit: Natalie Hummel, Louisiana State University AgCenter, Bugwood.org

  • Close-up showing how tiny (about one millimeter) Asian Citrus Psyllid is during the nymph stage!  Photo Credit: Natalie Hummel, Louisiana State University AgCenter, Bugwood.org

  • Branch of an orange tree (Citrus × sinensis) showing both flower and fruit.  Photo Credit: Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org

  • Commercial grove of orange trees that are under threat from Asian Citrus Psyllid! Photo Credit: William M. Brown Jr., Bugwood.org

  • Typical orchard orange - heavy with fruit that's vulnerable to citrus greening!  Photo Credit: Lesley Ingram, Bugwood.org

  • Tangerine (Citrus reticulata) is another tasty treat threatened by Asian Citrus Psyllid and citrus greening.  Photo Credit: Forest and Kim Starr, Starr Environmental, Bugwood.org

  • Grapefruit (Citrus x paradisi) is also vulnerable to Asian Citrus Psyllid and citrus greening.  Photo Credit: Rebekah D. Wallace, University of Georgia, Bugwood.org

  • Even though its fruits are small and very bitter, hardy orange (Poncirus trifoliata) is a nice ornamental - just watch out for the thorns!  Photo Credit: James H. Miller, USDA Forest Service, Bugwood.org

  • Pumelo (Citrus maxima) is another tasty fruit in danger! Photo Credit: Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org

  • Lemons (Citrus x limon) and limes (Citrus x aurantiifolia) are both vulnerable to Asian Citrus Psyllid and citrus greening.  Photo Credit: Forest and Kim Starr, Starr Environmental, Bugwood.org

  • Flower and fruit of the lime tree (Citrus x aurantiifolia).  Photo Credit: Forest and Kim Starr, Starr Environmental, Bugwood.org

  • Close-up showing the beautiful white flowers of a lime tree.  Photo Credit: Forest and Kim Starr, Starr Environmental, Bugwood.org

  • Infected fruits taste very bitter and their seeds often don't mature or are rotten.  Yuck!  Photo Credit: J.M. Bové, INRA Centre de Recherches de Bordeaux, Bugwood.org

  • Because Asian Citrus Psyllid sucks out the plant's sap, it can cause leaves and young branches to become thick and deformed.  Photo Credit: INRA-Bordeaux Archive, Institut National de la Recherche Agronomique, Bugwood.org

  • Close-up of Asian Citrus Psyllids feeding on a twig.  The end of the twig at the left is black, meaning that their feeding has killed the new growth on this shoot.  Photo Credit: Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org

  • Attack by the Asian Citrus Psyllid can cause new leaves to be shrunken and deformed.  Photo Credit: Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org

  • As citrus greening progresses, more and more leaves turn yellow, and may curl up and fall off the plant.  Photo Credit: Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org

  • Asian Citrus Psyllid has been here!  The front tree is showing the typical splotchy yellow and green patches of citrus greening on its leaves and fruit.  Photo Credit: H.D. Catling, Bugwood.org

  • An entire side of the citrus tree can turn yellow while the other part looks healthy.  Photo Credit: J.M. Bové, INRA Centre de Recherches de Bordeaux, Bugwood.org

  • Grapefruit leaves showing irregular yellow splotches, an almost sure sign they are infected with citrus greening!  Photo Credit: J.M. Bové, INRA Centre de Recherches de Bordeaux, Bugwood.org

  • Leaves with yellow splotches, called "mottling," are very common in plants with citrus greening.  Photo Credit: Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org

  • Branch of a citrus tree showing citrus greening symptoms: yellowed, splotchy leaves and fruit that doesn’t ripen properly.  Photo Credit: Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org

  • White waxy droppings on the leaves of citrus are a clue that Asian Citrus Psyllid might be present!  Photo Credit: R. Anson Eaglin, USDA-APHIS

  • Oranges can only be sold if they are bright orange and sweet like these healthy fruits! No one wants to eat the hard, deformed, bitter fruits affected by Asian Citrus Psyllid and citrus greening.  Photo Credit: USDA ARS Photo Unit, USDA Agricultural Research Service, Bugwood.org

  • Because there is no cure for citrus greening, infected trees must be destroyed.  That hurts many farmers and makes our orange juice more expensive!  Photo Credit: Gerald Holmes, Valent USA Corporation, Bugwood.org

Scientific Name: Diaphorina citri

Description:  Asian citrus psyllid adults are gnat-sized insects that suck the sap out of the shoots and leaves of citrus trees.  They have mottled brown bodies that have a dusty appearance because of a layer of whitish wax.  Adults look like they are doing a head-stand when they feed and will jump when approached. 

 

Native Range: Southern Asia

 

Introduced Range: In the U.S., the Asian Citrus Psyllid has been found in Alabama, American Samoa, Arizona, California, Florida, Georgia, Guam, Hawaii, Louisiana, Mississippi, Puerto Rico, South Carolina, Texas and the Virgin Islands.  It has also been introduced to parts of the Middle East, South and Central America and the Caribbean. 

 

Habitat: In the U.S., ACP is found in citrus orchards and on planted citrus trees in yards and gardens.

 

Host Trees: The Asian Citrus Psyllid likes all kinds of citrus trees, including orange, lemon, lime, grapefruit, tangerine, mandarin and others.  It also feeds on citrus relatives such as curry leaf and orange jasmine.

 

The Facts:  Asian Citrus Psyllids are tiny insects that suck sap from citrus shoots and leaves.  Their young are called nymphs and also feed on the sap of new plant parts.  Because the psyllid injects toxins into the plant while it feeds, it often causes shoots and leaves to become stunted and deformed.  But, that isn’t the worst this bad bug has to offer.  ACP also vectors, or carries from tree to tree, one of the most devastating citrus diseases in the world!  It is a nasty bacterial disease, called citrus greening, which produces mottled and yellowed leaves and bitter, green misshapen fruits on sick citrus trees.  Infected fruit cannot be sold, and there is no way to cure sick trees, which must be cut down immediately to help prevent the spread of the disease.  Citrus greening has already destroyed millions of citrus trees in the U.S., and the best way to stop its spread is to stop the ACP!  In states where ACP has been found, strict quarantines have been put in place to prevent movement of citrus fruit, plants, and tree parts because ACP is easily moved along with them.  If you have a citrus tree in your yard, you can help our Plant Heroes stop the deadly ACP by enjoying your fruit at home!