Chilades pandava

University of Guam Cooperative Extension Service Agriculture and Natural Resources Section

Pest Fact Sheet Series

Prepared by Aubrey Moore, Entomologist, University of Guam

Images

• Ovipositing Chilades pandava.jpg ''Chilades pandava'' ovipositing on emerging ''Cycas micronesica'' foliage. Photo by Aubrey Moore; Ritidian Point, Guam: 24 May 2006.
• 

  Chilades pandava eggs on emerging Cycas micronesica foliage. Photo by Aubrey Moore; Ritidian Point, Guam: 24 May 2006

• Chilades pandava egg.jpg Close-up of ''Chilades pandava'' egg. Photo by Aubrey Moore; 23 May 2006.
• Chilades pandava early instar larva.jpg Early instar ''Chilades pandava'' larva. Photo by Thomas Marler; Ritidian Point, Guam; 14 SEP 2005.
• Chilades pandava later instar with ant attendant.jpg Late instar ''Chilades pandava'' larva with attendant ant, ''Anoplolepis gracilipes'', on ''Cycas micronesica''. Photo by Thomas Marler; Ritidian, Guam; 14 Sep 2005.
• Chilades pandava adult.jpg ''Chilades pandava'' feeding on ''Bidens pilosa''or ''B. alba''(Ask McConnell for verification). Photo by Aubrey Moore, Ritidian Point, Guam, 13 Sep 2005. (Note damage to right forewing.)
• Chilades pandava with open wings.jpg ''Chilades pandava'' with open wings. Photo by Thomas Marler; Ritidian Point, Guam; 14 Sep 2005.

Common Name(s)

• cycad blue butterfly
• plains cupid

Scientific Name

• Order: Lepidoptera (moths and butterflies)
  • Family: Lycaenidae (coppers, hairstreaks, blues)
    • Species: Chilades pandava

Host(s)

• Cycas revoluta (sago palm)
• Cycas micronesica (fadang)

Biology

Caterpillars of the cycad blue butterfly, Chilades pandava, were first detected on Guam in 2005 feeding on two species of cycad: fadang, Cycas micronesica and sago palm, C. revoluta (A. Moore 2005). Previously, they were found on Saipan in 1996 feeding on C. revoluta (Schreiner & Nafus 1997). They were found on Rota in 2006 (Badilles 2006). The native range of this species is Sri Lanka to Thailand and eastern Indonesia. It was first recorded on the island of Mauritius in 2000 and caused the death of many cycad plants there (MacDonald et. al 2003).

Eggs, which are pale green in color, are laid singly on newly emerging fronds before the leaves open. They are very small, but can be easily seen with the aid of a hand lens. Early instar larvae are purple and later instar larvae are green. The caterpillars feed only on new foliage before it hardens.

High populations of cycad blue butterfly caterpillars result in complete defoliation of new foliage. Repeated defoliation may lead to plant mortality. Cycads on Guam are currently very susceptible to mortality because many have lost most or all of their leaves due to a severe infestation of the cycad Aulacaspis scale, Aulacaspis yasumatsui. Loss of cycads from scale infestation has resulted in Guam's endemic, Cycas micronesica, being added to the Red List of Threatened Species maintained by the International Union for the Conservation of Nature and Natural Resources (IUCN) (Marler et al. 2006).

Late instar larvae of Chilades pandava are often attended by ants belonging to several species. Ant associations are common within the family Lycaenidae (Australian Museum Online 2006). Ants protect larvae from parasites and predators in return for a sugary liquid exuded from special glands on the caterpillars' backs. Several species of ants have been observed to attend Chilades pandava on Guam and Saipan.

Control

Defoliation caused by cycad blue butterfly larvae may be prevented by weekly applications of microbial insecticides containing Bacillus thuringiensis kurstaki such as Dipel®*. These insecticides only kill feeding caterpillars and do not harm other organisms.

University of Guam scientists are planning tests of injectable insecticides such as Abacide2®* for longterm protection of cycads.

Effective natural control of Chilades pandava by predators or parasites has not been observed on Guam. An egg parasite has been found, but the proportion of eggs parasitized is very low (Moore 2006). Protection of larvae by attendant ants may hinder establishment of effective biological control for this invasive species

References

Australian Museum Online 2006.
http://www.amonline.net.au/factsheets/lycaenid.htm

Badilles, A. 2006. Personal communication.

Macdonald, I.A.W., J.K. Reaser, C. Bright, L.E. Neville, G.W. Howard, S.J. Murphy & G. Preston (eds.) 2003. Invasive alien species in southern Africa: national reports & directory of resources. Global Invasive Species Programme, Cape Town, South Africa.
http://www.gisp.org/downloadpubs/SOUTHERN.PDF

Marler, T., Haynes, J. & Lindstrom, A. 2006. Cycas micronesica. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. http://www.iucnredlist.org Downloaded on 26 May 2006.

Moore, A. 2005. Unpublished observations.

Moore, A. 2006. Unpublished observations.

Schreiner, I.H. & D.M. Nafus 1997. Butterflies of Micronesia. University of Guam Press.
http://www.micronesianinsects.com/PUB/ButterfliesOfMicronesia.pdf

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