Epiblema strenuana (Walker, 1863)
Ragweed Borer
(one synonym : Steganoptycha flavocellana Clemens, 1865)
Don Herbison-Evans
Raman Anantanarayanan
Stella Crossley

Epiblema strenuana
live neonate larva
tunnelling downward into Parthenium hysterophorus shoot.

This Caterpillar originated in America, where its foodplants are from various genera of the family ASTERACEAE including:

  • Ragweeds ( Ambrosia species),
  • Cockleburs ( Xanthium species),

    as well as

  • Goosefoots ( Chenopodium species) CHENOPODIACEAE ).

    Epiblema strenuana
    mature larva within its gall
    also tunnelling downward into Parthenium hysterophorus shoot
    (preserved and slightly wrinkled specimen)

    In 1982, it was introduced into Australia from Mexico to control the weeds

  • Feverfew ( Parthenium hysterophorus, ASTERACEAE ).

    It has been considered for the same purpose in Canada.

    The eggs are very small, and pale in colour. They are laid singly on the leaves of a foodplant. The first instar larva burrows into the leaf to feed. Later, the caterpillar burrows into the centre of a growing shoot, feeding on the terminal meristem, and growing to length of about 1 cm. This induces the plant to thicken the stem, creating an elongated gall, about 1 cm across and with a length of about 2 cms. In this gall, the caterpillar subsequently lives, feeds, and pupates. In due course, the adult moth emerges from the gall from approximately the same position as that at which the caterpillar originally entered the shoot, thus having executed a nifty about-turn inside the gall.

    Epiblema strenuana
    (Photo: courtesy of Allen Barlow, Tennessee, USA)

    The adult moths are dark brown with pale markings. The moths have a wingspan of about 1.5 cms.

    Epiblema strenuana
    (Photo: courtesy of the Photography Group, Centre for Biodiversity Genomics, University of Guelph)

    The species still occurs in

  • Mexico,
  • U.S.A.,

    and in 1990-1993 was proposed for introduction into

  • China.

    Epiblema strenuana
    (Picture: courtesy of CSIRO)

    Although the caterpillar and pupa are attacked by a number of Australian native Lepidoptera parasitoids, the species now occurs in

  • Queensland,
  • New South Wales, and
  • South Australia.

    Further reading :

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press, 1990, p. 73.

    K. Dhileepan, Catherine J. Lockett, and Rachel E. McFadyen,
    Larval parasitism by native insects on the introduced stem-galling moth Epiblema strenuana Walker (Lepidoptera: Tortricidae) and its implications for biological control of Parthenium hysterophorus (Asteraceae) ,
    Australian Journal of Entomology,
    February 2005, vol. 44, no. 1, pp. 83-88.

    Francis Walker,
    Tortricites & Tineites,
    List of the Specimens of Lepidopterous Insects in the Collection of the British Museum,
    Part 28 (1863), p. 383, No. 139.

    Australian Butterflies
    Australian Moths

    (updated 11 October 2009, 2 February 2023)