Two species of the Asian genus Greenidea have been introduced into the United States, Greenidea ficicola Takahashi and Greenidea psidii van der Goot. Synonymy confusion between Greenidea formosana (Maki) and G. psidii is resolved in favor of G. psidii. Both species colonize Ficus spp., and G. psidii colonizes a few other plants, mostly in Myrtaceae. The two species can be distinguished by the ornamentation on the siphunculi on the apterous forms, and usually also by the arrangement of rhinaria on antennal segment III of the alate forms.
The Asian genus Greenidea (Rhynchota: Aphididae) belongs to the subfamily Greenideinae (Greenideini). Most species of aphids in this subfamily, including those in the genus Greenidea, have long siphunculi with correspondingly long setae. Until recently, no species in the subfamily were found in the Western Hemisphere except Brasilaphis bondari Mordvilko (Cervaphidini) (Ghosh 1982) native to Brazil, and a fossil species in Dominican amber (Wegierek 2001). Two species, Greenidea psidii van der Goot and Greenidea ficicola Takahashi, now have been found in the USA. Both species have the potential to become pests of certain ornamental plants.
Greenidea(Trichosiphum) psidii van der Goot 1916 (= Greenidea (Trichosiphum) formosana (Maki) 1917), new synonymy (? = Greenidea (Trichosiphum) guangzhouensis Chang 1979 (Remaudière & Remaudière 1997)) (= Greenidea (Trichosiphum) formosana subsp. heeri D. N. Raychaudhuri, M. R. Ghosh, M. Banerjee & A. K. Ghosh 1973 (Remaudière & Remaudière 1997)) (= Trichosiphum formosanum Maki 1918)
Greenidea psidii was reported (under G. formosana) in Hawaii in 1993 (Beardsley 1993). In 1998, G. psidiiappeared in California (Gill 1998). Outside of the United States, G. psidii is reported from Bangladesh, China, India, Japan, Java, Loochoo Islands (Ryukyus), Nepal, Philippines, Sumatra, and Taiwan (Blackman & Eastop 1994; Blackman & Eastop 2000). I have a specimen from Brisbane, Australia that also appears to be this species.
Reported hosts of G. psidii include Psidium guajava L. and other Myrtaceae (Callistemon, Eucalyptus, Eugenia, Melaleuca, Metrosideros, Rhodomyrtus, Syzygium, and Tristania). It also infests Ficus (Moraceae), Engelhardtia (Juglandaceae), Scurrula (Loranthaceae), Lagerstroemia (Lythraceae) and Nesua ferrea (Clusiaceae) (Beardsley 1993; Blackman & Eastop 1994; Blackman & Eastop 2000; Gill 1998; Noordam 1994).
There is some nomenclatural confusion about G. psidii. The most recent catalogue (Remaudière & Remaudière 1997) lists this species as G. formosana; however, the most recent revision of the genus (Noordam 1994), lists it as Greenidea psidii van der Goot 1917. The Maki description (G. formosana) was listed as having been published on October 8, 1917 in honor of the sixtieth birthday of Mr. Yasushi Nawa. In the 1917 journal version of the van der Goot paper (G. psidii), it says he finished his work in 1915 and added corrections in January 1916. It seems likely that the book was published early in 1917, but there is no month listed for the publication date, so according to the International Code of Zoological Nomenclature, the date is assumed to be 31 December 1917 (ICZN 2000, Article 21.3.2). However, both the California Academy of Sciences and the library of the Netherlands Entomological Society have copies of an “Extrait,” or separate, that lacks a title page but appears to have been distributed in 1916. In both cases, “1916" has been written on the book. According to the International Code of Zoological Nomenclature, “Before 2000, an author who distributed separates in advance of the specified date of publication of the work in which the material is published thereby advanced the date of publication” (ICZN 2000, Article 21.8). Thus, the species should be Greenidea psidii van der Goot 1916.
Greenidea ficicola Takahashi 1921 (= Greenidea neoficicola A. K. Ghosh, M. R. Ghosh & D. N. Raychaudhuri (Remaudière & Remaudière 1997))
Greenidea ficicola (Fig. 1 and Fig. 2) was first suspected in the Western Hemisphere when a single damaged alate form was collected in a suction trap sample collected 22-27 XI 2002 from Kendall, Florida, near Miami (Florida State Collection of Arthropods (FSCA) #E2002-5901). No other specimens were found until colonies were located on Ficus aurea Nutt. on 18 II 2003 (FSCA# E2003-569). There have been several subsequent finds in the Miami area, including more trap collections. The newly established aphid also has been found in Naples, in southwest Florida (FSCA# E2004-810, 849). In addition to Florida, G. ficicola is reported from Australia, Bangladesh, Burundi (recent introduction), China, India, Indonesia, Japan, Malaysia, Nepal, Pakistan, Philippines, eastern Russia, and Taiwan (Blackman & Eastop 2000).
Greenidea ficicola seems to be restricted to Ficus spp. throughout most of its range; however, in India, there are reports of infestations on Psidium guajava. Noordam (1994) had a collection from Streblus elongatus (Miq.) Corner (Moraceae). The record of G. ficicola from litchi reported in Blackman & Eastop (2000) is probably spurious (Victor F. Eastop, pers. comm., 12 March 2003). In Florida, we have confirmed field colonization on F. aurea Nutt., Ficus rigo (Bailey) Corner, and Ficus microcarpa L. f. We were able to rear colonies for several weeks on Ficus benjamina L. and Ficus carica L. in the laboratory.
Because both species colonize Ficus spp., it is important to be able to differentiate between them. A short key is provided:
1a.Apterae with reticulations covering most of the length of the siphunculi (Fig. 3); alatae with 17-21 rhinaria on antennal segment III, in a line and not crowded or touching each other (Fig. 4)
1b.Apterae with reticulations only at the base of the siphunculi; siphunculi ornamented with irregularly spaced spinules (Fig. 5); alatae with 20-31 rhinaria, some crowded and not in line with the others, often touching (Fig. 6)
Both of the newly established species of Greenidea have the potential to become pests of certain species of ornamental plants. Both colonize Ficus, a genus that includes popular landscape and interiorscape plants, and G. psidii colonizes several species in the Myrtaceae. In the laboratory, G. ficicola caused significant leaf drop on F. benjamina. Greenidea psidii already has been intercepted in Florida in a shipment of Myrtus communis L. cut flowers from California (FSCA# E2003-1827). The aphids colonize the buds and new shoots of the host plants. No holocycle is known for either species (Blackman & Eastop 2000), suggesting that freezing temperatures may be limiting, but both species should do well in the neotropics and New World subtropics wherever suitable host plants occur. Interiorscapes, where temperatures do not fall below freezing, also may sustain populations.
I thank Rosser Garrison, Raymond Gill and John Sorensen, California Department of Food and Agriculture, for providing specimens of California Greenidea, Julieta Brambila (DPI) for technical assistance, Beverly Pope (DPI), Paul Piron (Plant Research International, Wageningen, the Netherlands), and Larry Currie (California Academy of Sciences) for library assistance, Michael Thomas (DPI) for photography and graphics assistance, and Cal Welbourn, Greg Hodges, Michael Thomas (all DPI), Victor Eastop (The Natural History Museum, London), George Remaudière (Museum National d’Histoire Naturelle, Paris), and David Voegtlin (Illinois Natural History Survey) for reviewing the manuscript.