Phyllocnistis citrella

Phyllocnistis citrella Stainton, 1856
Citrus Leafminer
PHYLLOCNISTINAE, GRACILLARIIDAE, GRACILLARIOIDEA

Don Herbison-Evans,
(donherbisonevans@yahoo.com)
and
Stella Crossley

caterpillar, highly magnified
(Photo: courtesy of Ted Cadwallader, Swan Hill, Victoria)

This Caterpillar is green and yellow, with bulgy segments that taper at head and tail.

leaf mine with caterpillar at right-hand end
(Photo: courtesy of Wendy Moore, Melbourne, Victoria)

The caterpillar is an agricultural pest, mining the leaves and even young fruit of various members of the Citrus plant family (RUTACEAE), including :

Bael ( Aegle marmelos ),

Calamondin ( Citrofortunella microcarpa ),

Lemon ( Citrus limon ),

Grapefruit ( Citrus paradisi ),

Pomelo ( Citrus maxima ),

Cumquat ( Fortunella margarita ),

Orange Jasmine ( Murraya paniculata ), and

Hardy Orange ( Poncirus trifoliata ),

as well as :

Mangosteen ( Garcinia mangostana, CLUSIACEAE ),

Pongam ( Pongamia pinnata, FABACEAE ),

Kannada ( Alseodaphne semecarpifolia, LAURACEAE ),

Mistletoes on Citrus ( Loranthus sp., LORANTHACEAE ), and

Maid of Orleans ( Jasminum sambac, OLEACEAE ).

The eggs are white and globular, and are laid singly usually on the undersides of the leaves. On hatching, the caterpillar bores into and eats the flesh of the leaf. It leaves an empty wiggly path in the leaf between the top and bottom leaf surfaces. The caterpillar grows to a length of about 0.3 cm.

(Photo: courtesy of Ingeniero Técnico Agricola, Seville, Spain)

It pupates in a cocoon in its leafy mine, and the leaf typically curls over protecting the pupa.

(Photo: courtesy of Wendy Moore, Melbourne, Victoria)

The adult moths are satin-cream, with a black dot on the tip and a gold bar across the middle of each fore wing. The hind wings are fringed by long hairs. The adults have a wingspan of about 0.5 cm. They fly nocturnally, and only live for a few days.

(Photo: courtesy of the RMNH and the Centre for Biodiversity Genomics, University of Guelph)

The pheromones of this species have been identified. Various studies are being made of ways to control the pest, including:

infrequent pruning,

natural insecticides like Spinosad,

Neem or its extract Azadirachtin,

the bacterium Bacillus thuringiensis,

a wasp Cirrospilus ingenuus ( EULOPHIDAE ),

a wasp Quadrastichus citrella ( EULOPHIDAE ),

the wasp Pnigalio pectinicornis ( EULOPHIDAE ),

the wasp Zagrammosoma multilineatum ( EULOPHIDAE ),

a wasp Galeopsomyia species ( ICHNEUMONIDAE ),

the wasp Ageniaspis citricola ( ENCYRTIDAE ),

lacewings Semielacher petiolatus ( EULOPHIDAE ), and

lacewings Chrysopa species ( CHRYSOPIDAE ).

(Photo: courtesy of Wendy Moore, Melbourne, Victoria)

The species was introduced into Australia by accident sometime before 1940. It is now found in every state of Australia. The details of infestationare being studied. It has now been reported to be an agricultural pest in: