INSECT HOT TOPICS: New scale insect in Hawaii

by James A. Bethke

Invasive insects commonly expand their host range following establishment in new habitats. Here’s another example. Fiorinia phantasma Cockerell & Robinson (Hemiptera: Diaspididae), an armored scale insect, was originally described from collections from the undersides of Neolitsea sp. (Lauraceae) leaves in the Philippines. It invaded Oahu, Hawaii in December 2004, infesting the undersides of wax leaf privet, Ligustrum japonicum (Oleaceae). It was collected again in Hawaii on November 2008 on Pittosporum tobira, and in September 2011, it was reported as a serious pest on areca palms in the landscape in Maui. Since 2008, this insect has been observed on numerous hosts including those listed in Table 1.

Table 1. Documented host plants of Fiorinia phantasma Cockerell & Robinson.

Fiorinia phantasma are mussel shaped, similar to the oyster scale. Mature female scales shrink in size, becoming encased within their second instar shed skin. They commonly have distinct red horizontal stripes running across their width (fig.1). However, some vary and have indistinct or pale red dashes, a full red covering, or a full pale yellow to clear covering. When the hard scale is turned over, female insects are yellow with relatively large eggs (1/5 of their body size). Male and female scale can be found intermingled on the undersides of leaves (fig.1), but when populations reach high densities, crawlers begin to colonize the topsides of foliage.

Fig. 1. Female (striped) and male (white) Fiorinia phantasma on the undersides of areca palm. 
Photo by Dr. Arnold Hara.

Damage caused by F. phantasma is recognizable by the yellow blotches on the upper leaf surfaces of host plants (fig.2). As the scale population increases, intense feeding damage to the leaf causes leaf drop on some plants.

Fig. 2. Damage on the upper surface of areca palms.  Photo by Dr. Arnold Hara.

A variety of predators and a parasite have been observed feeding and parasitizing F. phantasma in Hawaii. Predators include Telsimia nitida (Coccinellidae), Cybocephalus nipponicus (Cybocephalidae), Chrysoperla comanche (Chrysopidae), and Aleurodothrips fasciapennis (Phlaeothripidae). A single species of Aphytis sp. (Aphelinidae) emerged from parasitized scales at a rate of about 10%.

Hawaii markets ornamental plant products to California brokers, ornamental plant producers and retail outlets, and a common palm that moves to California is the areca palm, Chrysalidocarpus lutescens. If you are importing these palms from Hawaii, you should be careful to isolate incoming shipments until they are assured to be free of this pest.

For more information about Fiorinia phantasma, see the following web sites:

http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/21682/43_59-61.pdf?sequence=1

http://www.sel.barc.usda.gov/catalogs/diaspidi/Fioriniaphantasma.htm#Fioriniaph%20antasma_distrib

http://scholarspace.manoa.hawaii.edu/handle/10125/21682

http://hawaii.gov/hdoaladmin-rules/pi/ppc/npa-1/Fiorinia%20phantasma%20NPA.pdf

http://www.wpdn.org/webfm_send/233

Photos are provided by Dr. Arnold Hara, Department of Plant and Environmental Protection Sciences, Beaumont Research Center, University of Hawaii.

James A Bethke is Farm Advisor for Nurseries and Floriculture, UC Cooperative Extension, San Diego and Riverside Counties.