Phyllococcus oahuensis (Ehrhorn)

Percy, Diana M., Watson, Gillian W. & Hodgson, Chris J., 2024, The endemic Hawaiian mealybug genus Phyllococcus Ehrhorn, 1916 (Hemiptera: Coccomorpha: Pseudococcidae): redescription of the type species and description of a new species on an endangered host plant, Cryptocarya mannii (Lauraceae), Zootaxa 5447 (3), pp. 355-372 : 357

Phyllococcus oahuensis (Ehrhorn)

( Figs 1A & B , 2 , 3 )

Cissococcus? oahuensis Ehrhorn 1912: 149 .

Phyllococcus oahuensis ( Ehrhorn, 1912) ; Ehrhorn 1916: 236, change of combination.

Phyllococcus oahuensis was considered to be extinct by Moir (2021), but a population was found on Maui in 2007 and the leaf galls were photographed by Dr Karl Magnacca [on Urera glabra , -. viii.2007, Kahanaiki Gulch below Puu Kukui cabins, Maui, Hawaii] ( Fig. 1 ). Subsequently, the species was collected in 2012 by Keahi Bustamente on U. glabra in the East Maui Mountains, and this material is described below. These Maui collections represent a new island record for Ph. oahuensis . Note that the recorded host, either as Urera sandwicensis or U. glabra , is now considered to be a synonym of Touchardia sandwicensis (Wedd.) ( POWO 2023; Wells et al. 2021).

Material studied. Lectotype and paralectotypes: 1 slide containing 7 adult females with a single label: “ Cissococcus ? / oahuensis / n.sp. / on Urera sandwichensis [sic] / Tantalus / Oahu / EME 1.30.1911 ”; specimens in fairly good condition (but most slightly distorted by pressure of coverslip); the lectotype, here designated, is the specimen located nearest the edge of the circular coverslip, and is marked with an adjacent black ink spot ( BPBM). The remaining 6 adult females on the same slide become paralectotypes .

Other material studied: 2 slides, each containing 1 adult female and 1 adult male: Hawaii, Mountains nr Koele, Lanai Island , June 1913, ex herbarium specimens of Urera glabra , coll. C.N. Forbes; det. J.W. Beardsley (good, but large air bubbles under the coverslips have displaced and tilted some of the specimens). Description below made from 2 slides, each containing 3 adult females labelled: Hawaii, West Maui Mountains , Maui, ex Urera glabra leaf galls, coll. Keahi Bustamente, 22.viii.2012, det. J. Garcia (good).

Note. Although the type series and the material identified by Beardsley were seen by GW, the description and illustrations were made from non-type specimens due to restrictions on the loan of the type slide to CH. We are, however, convinced that the specimens examined from West Maui Mountains are conspecific with those from Oahu.

Figures

FIGURE 1. A. Galls of Phyllococcus oahuensis (Ehrhorn) on a leaf of Touchardia sandwicensis, found on Maui in 2007; B. Closer view of galls of Ph. oahuensis. Photographs by Karl Magnacca.

FIGURE 2. Adult female of Phyllococcus oahuensis (Ehrhorn). A. Trilocular pore; B. Dorsal and ventral views of anal plates; E. Spinules on anal plates and margins of dorsal shield; F. Margin of dorsal shield; L. Dorsal seta; K. Simple pores; M. Anterior view of hind leg; S. Spiracle; Z. Illustration of gall by Ferris (in Zimmerman 1948: 160, fig. 93).

FIGURE 3. Adult male Phyllococcus oahuensis (Ehrhorn). A. Dorsal ocular sclerite, showing dorsal simple eye (d) and ocellus (o); D. Fleshy seta on leg; E. Hair-like seta on leg; F. Dorsal view of posterior half of penial sheath; G. Ventral view of penial sheath; H. Metatibia + tarsus; J. Loculate pores.