Trachymela sloanei (Blackburn)

Matsunaga, Janis N., Howarth, Francis G. & Kumashiro, Bernarr R., 2019, New State Records and Additions to the Alien Terrestrial Arthropod Fauna in the Hawaiian Islands, Proceedings of the Hawaiian Entomological Society 51 (1), pp. 1-71 : 4

Trachymela sloanei (Blackburn)

NEW STATE RECORD

Trachymela sloanei was first discovered in 2011 on Eucalyptus camaldulensis trees exhibiting peculiar notches along leaf edges, characteristic of caterpillar feeding. A closer inspection of the red gum trees revealed numerous larvae and two adult chrysomelids under the tree bark. Species identification was confirmed by Alexander Konstantinov at USDA-ARS-SEL in December, 2011.

This native to Australia ferociously invaded New Zealand in 1976 ( Brockerhoff and Bain 2000), defoliating eucalyptus trees throughout the country. In 1998, it was detected in California, the first record of this species in the U.S. This species is known to be intercepted at Honolulu ports of entry on shipments of cut myrtle. This discovery of T. sloanei in Waimanalo represented the first records of the Australian tortoise beetle in Hawaii. In May 2013, T. sloanei was collected from red gum trees at Kapalua, Maui, a new island record.

Trachymela sloanei adults and larvae are nocturnal, feeding at night on the leaves, and hiding under the tree bark during the day. They sometimes hide high up in the trees and it is common to see the feeding damage but not find the culprits. The adult is 6-7 mm long, entirely brown with darker mottled spots and can be mistaken for a ladybug. Eggs are laid under the bark or on the leaves. T. sloanei is reported to feed on a variety of Eucalyptus species, but in Hawaii it has only been confirmed feeding on E. camaldulensis thus far.

Collection records: OAHU, Waimanalo, University of Hawaii Research Station, 24.II.2011 (Correction to Conant 2013 - printed as first collection in 2009), ex. Eucalyptus camaldulensis foliage, coll. W. Nagamine, det. A. S. Konstantinov, 20.XII.2011. MAUI, Kapalua , 10.V.2013, ex. E. camaldulensis foliage, coll. C. Baker, det. B. Kumashiro, 16.V.2013. Vouchers at HDOA.