Citrus leafminer

Scientific name

Phyllocnistis citrella (Lepidoptera: Gracillariidae)

Similar species

citrus peelminer, Marmara gulosa

• Damage caused by the citrus leafminer is easily distinguished from the citrus peelminer because a fecal (frass) trail is only left in the tunnels made by the citrus leafminer.
• The citrus leafminer is not known to attack twigs. During heavy pest pressure, citrus leafminer may mine on fruit rinds like the citrus peelminer.

Distribution

United States: Alabama, California, Florida, Louisiana, and Texas.

Worldwide: Australia, China, Hong Kong, India, Indonesia, Israel, Italy, Japan, New Guinea, Saudi Arabia, Southeast Asia, South America, Spain, and Turkey.

Native to Asia.

Diagnostic characteristics

Adults

• 2 mm (0.08 in.) in length when resting with folded wings, 4 mm (0.16 in.) wingspan.
• White with silver scales; black and tan makings.
• A prominent black spot is noticeable at the tip of each front wing. The rear wings, headhead:
  one of the three main body segments in insects; the anterior-most segment containing the many sensory structures including the eyes, antennae, and mouthparts
  , and body are white.
• Four wings present, but the hindwings appear "feathery" because of long wing scales.
• Thread-like (filiform) antennae. Female has 33 segments. Males have 31 segments.

Pupae

• Curl over the edge of a leaf and pupate at the leaf margin.

Larvae

• Four instars.
• 3 mm (0.12 in.).
• Translucent, greenish-yellow.
• Found in tunnels that wind through the epidermis on the both surfaces of host leaves.

Eggs

• 0.2 mm (0.008 in.) in length and 0.3 mm (0.011 in.) in width.

Hosts

Citrus hosts

• common mandarins (including tangerine), Citrus reticulata
• grapefruit, Citrus paradisi
• lemon, Citrus limon
• Mexican (or Key) Lime, Citrus aurantifolia
• sweet orange, Citrus sinensis

Non-citrus hosts

• calamondin, Fortunella spp.
• kumquat, Fortunella margarita

Host damage

Fruits

• Mining on the rind can occur during heavy pest pressure.

Leaves

• The serpentine tunnels of larvae cause leaf deformation, limited chlorosischlorosis:
  yellow or white spotting on leaves and fruit resulting from feeding by certain pests
  , necrosis, and some leaf drop.
• Older leaves that have hardened are not susceptible.
• Mines may provide access for the citrus canker bacterium, Xanthomonas axonopodis.

Biology

Females lay eggs singly on the underside of newly-flushed leaves. The larvae burrow within leaves for 5 - 20 days until ready to pupate. The larvae form a protective webbed cocooncocoon:
the protective covering around the pupa of some insects
over themselves by using a curled leaf edge and pupate from 6 - 22 days. Adults live only one to two weeks, tend to be active early in the morning, dusk, or nighttime, and typically lay eggs at night.

Comments

Adult leafminers are very small and not easily noticed. They are approximately the size of a mosquito.

References

Belasque Jr., J. 2005. Adult citrus leafminers (Phyllocnistis citrella) are not efficient vectors for Xanthomonas axonopodis pv. citri. Plant Dis. 89: 590-594.

Grafton-Cardwell, E.E., D.H. Headrick, K.E. Godfrey, J.N. Kabashima, B.A. Faber, V.F. Lazaneo, and J.G. Morse. 2010. Citrus leafminer: Integrated pest management for home gardeners and landscape professionals. Pest Notes, Pub. 74137. (http://www.ipm.ucdavis.edu/PDF/PESTNOTES/pncitrusleafminer.pdf).

Grafton-Cardwell, E.E., K.E. Godfrey, D.H. Headrick, P.A. Mauk, and J.E. Peña. 2008. Citrus leafminer and citrus peelminer. Div. Agric. Nat. Resources, Univ. of California, Pub. 8321. (http://ucanr.org/freepubs/docs/8321.pdf).

Heppner, J.B. 1995. Citrus leafminer (Lepidoptera: Gracillariidae) on fruit in Florida. Fla. Entomol. 78: 183-186.

Heppner, J.B. 2006. Pest alert: citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae: Phyllocnistinae), (http://www.doacs.state.fl.us/pi/enpp/ento/clm.html).

Heppner, J.B., and T.R. Fasulo. 2008. Featured creatures fact sheet: Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae). Publication EENY-38. University of Florida. (http://entnemdept.ufl.edu/creatures/citrus/citrus_leafminer.htm).

Kernasa, O., W. Suasa-ard, and K. Charernsom. 2008. Citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Phyllocnistidae) and its natural enemies, Kasetsart J. (Nat. Sci.) 42: 238-245.

Taek-Lim, U., and M.A. Hoy. 2006. Overwintering the citrus leafminer, Phyllocnistis citrella (Lepidoptera: Gracillariidae), without diapausediapause:
temporary cessation of development caused by a physiological response to unfavorable conditions
in Florida. Fla. Entmol. 89: 361-366.

Authors

Weeks, J.A., K.W. Martin, A.C. Hodges, and N.C. Leppla