BIOLOGICAL CONTROLÑWEEDS Laboratory Host Range of Parafreutreta regalis (Diptera: Tephritidae), a Candidate Agent for Biological Control of Cape-Ivy

1,2 1 3 3 JOE BALCIUNAS, CHRIS MEHELIS, LIAME´ VAN DER WESTHUIZEN, AND STEFAN NESER

Environ. Entomol. 39(3): 841Ð848 (2010); DOI: 10.1603/EN08220 ABSTRACT Cape-ivy (Delairea odorata Lamaire) is an ornamental that has escaped into natural areas in many countries and become a serious pest. It is native to the eastern part of South Africa, and surveys there located several potential biological control agents for this weed. One of these is Parafreutreta regalis Munro, a tephritid ßy that causes large galls to form on the stems of the vine. In a collaborative effort, we began to evaluate, in both and South Africa, the host range of this ßy. Between the two locations, we tested 93 species and 2 varieties of Cape-ivy to see if, after being exposed to four pairs of ßies for a week, any galls would develop on them. No galls were formed on any of the test species, although an average of six galls developed on each of the Cape-ivy controls. We also tested to see whether P. regalis showed any preference for either of the two varieties of Cape-ivy. There was no signiÞcant difference between the numbers of galls forming on the stipulate or astipulate varieties. Our tests indicate that this ßy is essentially monospeciÞc. Earlier research had shown that P. regalis galls cause a signiÞcant reduction in the height and nongall biomass of Cape-ivy. A petition has been submitted to initiate the process of obtaining permission to release P. regalis in California to control the Cape-ivy infestations there.

KEY WORDS weed biological control, Senecio mikanioides, German ivy, host speciÞcity, nontarget impacts

Cape-ivy (Delairea odorata Lemaire), also known as galling ßy that is one of the few previously German ivy and Senecio mikanioides Otto, is a winter- reared from Cape-ivy (Munro 1940). During 1999, the ßowering perennial, widely used as ornamental, that South African team attempted to determine the Þeld has escaped from cultivation and has become a serious host range of these potential agents by collecting in- pest in natural areas. Its shoots form dense mats on the sects from 10 other species of , closely related to ground and clamber up adjacent vegetation, fre- Cape-ivy, at sites where one or more of these pro- quently smothering it. It is now well established in spective agents were present on Cape-ivy (Grob- coastal regions of California and upland Hawaii, as belaar 2000). After making collections at 43 sites in well as in several other countries, including Australia, four provinces, they found that several of these insects England, Italy, New Zealand, and Spain (Haselwood seemed to be restricted to Cape-ivy (Grobbelaar and Motter 1983, Webb et al. 1988, Jacobi and War- 2000). They found stem galls on Þve other vine species schauer 1992, de la Torre-Ferna´ndez and Alvarez- in the tribe Senecioneae, but the ßies emerging from Arbesu´ 1999, Robison et al. 2000; Balciunas 2004a). In these galls were other species (Grobbelaar 2000). California, this vine is most invasive and widespread in We are currently studying the biology of this ßy, coastal riparian areas and coastal scrub communities. under controlled temperatures, in our quarantine in Originally, it was thought that Cape-ivy did not pro- Albany, CA. A simpliÞed life cycle is as follows. A duce viable seeds in California (Bossard 2000), but the female P. regalis oviposits several to many eggs in a presence of viable seed there has been recently con- node or growing tip of Cape-ivy. After ϳ2 wk, the Þrst Þrmed (Balciunas 2001, Robison 2001). swelling, indicating gall formation, becomes detect- Cape-ivy is native to South Africa (Hilliard 1977), able. A month after oviposition, the gall is fully formed, and we launched a biological control project there and the larvae chew a small, circular “window,” cov- targeting Cape-ivy in 1998. The surveys in South Africa ered by the intact plant cuticle, on the side of the gall. indicated a half dozen potential biological control After another month, adult ßies, usually 5Ð12 in num- agents (Grobbelaar et al. 2003). One of these is ber, break the “window” and begin emerging from the Parafreutreta regalis (Diptera: Tephritidae), a stem- gall. Thus, the life cycle from oviposition to adult emergence is ϳ2 mo but is temperature dependent, 1 USDAÐARS, Exotic and Invasive Weed Research Unit, Western requiring an additional 1 or 2 wk during winter and 1 Regional Research Center, 800 Buchanan St., Albany, CA 94710. or 2 wk less in summer. The female will begin to 2 Corresponding author, e-mail: [email protected]. 3 Weeds Research Division, ARCÐPlant Protection Research Insti- oviposit within a day or two of emergence, and the tute, Private Bag x134, Pretoria 0001, South Africa. adults live for ϳ2 wk. 842 ENVIRONMENTAL ENTOMOLOGY Vol. 39, no. 3

In 2001, we began a cooperative effort at our lab- stipulate variety, the most common variety in both oratories in Albany, CA and Pretoria, South Africa, to South Africa and California, in our host range tests. simultaneously evaluate the host range of this ßy to Typically, the Cape-ivy used as controls were in conÞrm that it was safe for release in the United States. 20-cm (8 in) pots and had several stems, and the Cape-ivy is a member of the daisy family, , longest shoot was around 0.4 m long. and currently is the only species in the genus Delairea, The form and size of the test plant species varied although for a century and a half, it was considered to greatly, but they were in similar size pots, and all had be Senecio mikanioides Otto (Jeffrey 1986). The genus at least one stem Ͼ20 cm. Most of the test plants were Senecio at one time was considered the largest genus grown from seeds, seedlings, and cuttings collected of ßowering plants with some 2,000 species (Hilliard from the Þeld by the authors and their colleagues. The 1977), but this genus is clearly not monophyletic and scientiÞc names for the North American species con- the trend for the past few decades, using more modern form to those used by PLANTS Database (USDAÐ techniques, is for botanists to reassign many of these NRCS 2009), whereas the names of South African species to other genera (Bremer 1994). One of the plants conform to National Botanical Institute (1993). more important reassignments has been that more The identities of representative specimens of the plant than one half of the North American Senecio species species used in our tests in Albany were conÞrmed by have now been placed in the genus Packera (Barkley Fred Hrusa and Dean Kelch (California Food and 1999). Delairea, Packera, and Senecio are all members Agriculture, Sacramento, CA), whereas those tested of the subtribe Senecioninae in the tribe Senecioneae in Pretoria were identiÞed by the staff of the Herbar- (Bremer 1994). In choosing plants to test, we followed ium, South African National Biodiversity Institute, the recommendations of the Technical Advisory Group Pretoria, South Africa. Vouchers of the plants tested for Biological Control of Weeds (TAG 2003), which in are retained at our laboratories. We have deposited turn is an elaboration of the “centrifugal” testing ap- voucher specimens of these ßies in the U.S. National proach (Wapshere 1974). Thus, our tests concentrated Museum (USNM) at the Smithsonian in Washington, on the closest relatives of Cape-ivy instead of the more DC, in the California State Collection of Arthropods distant relatives and vines in other families. in Sacramento, CA, and in the National Collection of Insects in Pretoria, South Africa. The strategy for our host range evaluations was to Materials and Methods concentrate on members of this subtribe and tribe but All host range tests reported here were performed to also test at least one member of each of the Aster- from January 2001 through December 2006, plus Þve aceae tribes that have native or naturalized species in additional species in 2009, under containment condi- North America. In Albany, we concentrated on mem- tions in the greenhouse of the USDAÐARS weed bio- bers of the same subtribe, primarily Packera and Se- control quarantine facility located at Albany, CA, or necio spp., which occur in coastal portions of Califor- the laboratories of the Weeds Research Division, Plant nia. These are plant species that are most likely to be Protection Institute, in Pretoria, South Africa. During encountered by an agent released to control Cape-ivy. the tests conducted in the Albany quarantine, al- In South Africa, we tested the single species of Mika- though supplemental heating and cooling were used, niopsis, the genus that is considered to be one of ambient temperatures ranged widely, from 11 to 36ЊC. Cape-ivyÕs closest relatives (Jeffrey 1986, 1992), and Natural lighting was supplemented by four 200-W nearly a dozen other vines in the same subtribe. incandescent bulbs, Ϸ1.5 m above the plants, which Because of the brief longevity of the adults of P. were turned on from 0600 to 2000 hours daily. From regalis (usually Ϸ2 wk), we designed a testing protocol March through mid-May, the lights were turned off at that would provide the maximum amount of informa- midday (1000Ð1600 hours) to assist in keeping the tion during an adultÕs lifespan. These tests (that we call greenhouse cool. The conditions for the tests con- “no-choice/ host added”) are a multiplant species, ducted in Pretoria were less controlled, and supple- no-choice trial, to which, at the beginning of the mental lighting was used only during a portion of some fourth day, a Cape-ivy plant is added. Although mul- winters. tiple plant species were initially present, the known The ßies used in the trials were from our laboratory host was not, so we consider that portion of the test to culture that was colonized from galls originally col- be no-choice (Heard and van Klinken 1998, Hill 1998). lected at the town of Wilderness, in Eastern Cape The procedures used in Albany were as follows: a Province, South Africa. metal screen cage (122 by 91.5 by 91.5 cm) was set up The Cape-ivy plants used in Albany were grown from in our quarantine laboratory greenhouse with four cuttings in our greenhouse, from material originally col- different plant species, one in each corner. A source lected at Rocky Creek, 20 km south of Carmel, CA. of sugar water (50% Mountain Dew) was placed in the The Cape-ivy plants used in Pretoria were grown center of the cage. We released into the cage four from cuttings collected from several locations in Kwa- female-male pairs of ßies, no older than a week past zulu-Natal Province. In both South Africa and Cali- emergence from galls. To verify that the females in the fornia, two varieties of Cape-ivy are found. One has cage were reproductive, after 72 h, we placed a Cape- ear-like, ßattened stipules (sometimes referred to as ivy plant into the center of the cage. Seven to 10 d after auricles) at the base of leaf petioles, whereas the other the start, the test was ended, and the remaining ßies variety lacks these stipules. We used primarily the were recovered. Our initial oviposition studies June 2010 BALCIUNAS ET AL.: LABORATORY HOST RANGE OF P. regalis 843 showed that 70% of female Parafreutreta have begun same species that were screened in Albany. Between to oviposit by this time. Because galls frequently failed the two locations, we tested 32 plant species from the to form on the control Cape-ivy, we used four pairs of same subtribe as Cape-ivy, Senecioninae, and four ßies to increase the likelihood that galls would be species from the other two subtribes in the tribe Se- observed. Plants were watered as necessary and ob- necioneae. We also tested 29 species from nine other served daily for signs of gall formation. If no galls had tribes in the same subfamily, , and a fur- formed after 60 d, or if the plant died earlier, we ther nine species from Þve tribes in the subfamily dissected the stems looking for signs of P. regalis dam- Cichorioideae. We were able to test members from 15 age and disposed of the plants. Tests where no galls of the 16 recognized tribes within the family Aster- formed on the “control” Cape-ivy plants were consid- aceae (Bremer 1994). We also tested 19 plant species ered invalid and were repeated. from 10 other plant families. These were mostly other The host range tests of P. regalis conducted in Pretoria vine species that occur in California, along with a few were also “no-choice, host added” trials, with protocols common crops and weeds. nearly identical to those used in Albany. Three or four Despite differences in the mixtures of plants tested, test plants of roughly similar size were placed in a cage differences in seasons, latitudes, cage sizes, and other (0.56m ϫ 0.56m ϫ 0.6m) with four pairs of newly factors, galls were only formed on Cape-ivy. An av- emerged ßies for three days. Flies were provided with a erage of 6.1 (SE Ϯ 0.43; N ϭ 68) galls per Cape-ivy honey and yeast solution. On day four, the control Ð a plant were formed in the tests in Albany (galls were Cape-ivy plant of similar size Ð was added. After another not counted in Pretoria), whereas no galls were three days of exposure, the ßies were removed, while the formed on any of the test plants. Frequently (e.g., 35 plants were left in the cage and gall development mon- times in Albany), the ßies did not oviposit on the itored. At both locations, we attempted to test each plant Cape-ivy controls, and galls failed to form. This re- species at least Þve times. sulted in Ͼ100 replicates, all without galls, being ex- In Albany, during 2003 and 2004, we also conducted cluded from the data presented in Table 1. We do not tests to determine whether this ßy had a preference know why the ßies failed to oviposit on their host, for one of the varieties of Cape-ivy. These tests were Cape-ivy, but we observed a similar high rate of invalid very similar to the host range tests described above tests when testing another tephritid, Chaetorellia suc- and used the same cages. Four Cape-ivy plants (two cinea (Costa) (Balciunas and Villegas 2007). Obvi- stipulate and two astipulate) were placed the corners ously, P. regalis females are very fastidious in choosing of the cage, and four pairs of P. regalis adults were their oviposition hosts, and these ßies appear to be released into the cage. To ensure many galls, another absolutely monospeciÞc to Cape-ivy. four pairs were added to the cage a week later. After The results of our tests to determine whether one of 15Ð21 d, we removed the dead and living ßies and the two varieties of Cape-ivy was preferred by P. monitored the Cape-ivy vines for gall development regalis are presented in Table 2. The number of dif- and adult emergence. After 85 d, we removed all of the ferent types of galls, as well as the number of puparia galls from the Cape-ivy vines and dissected them to produced in these galls, are nearly identical for both count any larvae, pupae, or dead adults. Each gall was varieties, and statistical analyses conÞrmed that there classiÞed into one of three classes. Underdeveloped were no signiÞcant differences. Thus, all of the Cape- galls were swellings at nodes that were induced by P. ivy in California should be susceptible to attack by P. regalis oviposition (conÞrmed by dissection), but the regalis if it is released here. larvae had died early, and these galls never reached their typical size. Fully developed without windows Discussion were galls that reached a normal size, but windows had never formed, and they contained only dead larvae, Host Þdelity seems to be a common feature to mem- but not pupae. Fully developed with windows were bers of the genus Parafreutreta. There are 16 described galls from which adults sometimes emerged, and species in this genus (ITIS 2009), and 9 of these have which, on dissection, contained mixtures of dead and known host plants. Seven Parafreutreta species are live larvae and/or dead adults. We also tested whether restricted to a single species of Senecio, including P. the two varieties of Cape-ivy differed in the numbers regalis, which was originally described from Senecio of each type of gall or in the number of adults and mikanioides, now known as Delairea odorata (Munro pupae produced in the galls, using StudentÕs t-test 1929, 1935, 1939, 1940, and 1953). An eighth species, P (Statistix 2005). Before analyses, we “normalized” the conferta (Bezzi), has two Senecio vines as a host (Mu- data by transforming these counts by square root (x ϩ nro 1929, 1940). Only P. mavoana Munro has a non- 0.01) (Snedecor and Cochran 1967). Senecio host, having been reported from Dodonaea viscosa L. Jacquin in the family Sapindaceae (Munro 1952). Recent taxonomic realignments have trans- Results ferred all members of the maple family, Aceraceae, Table 1 lists all 93 plant species, in addition to Cape- into the Sapindaceae (Judd et al. 2002). We therefore ivy, that were included in our host range tests from tested Þve species of Sapindaceae, including D. viscosa, 2001 through 2009. In Albany, 56 plant species/vari- and no galls were formed on any of them (Table 1). eties (including both varieties of Cape-ivy) were We feel that our results reported here, and the tested, and in Pretoria, another 41 species, plus 2 of the earlier Þeld host range studies in South Africa (Grob- 844 ENVIRONMENTAL ENTOMOLOGY Vol. 39, no. 3

Table 1. Plant species tested in Albany, California and Pretoria, South Africa and the no. of valid tests for each species after exposure to four pairs of P. regalis flies for 1 wk

Valid tests/ Species tested Region of endemism, notes Test site tests w/galls Family Asteraceae (Order ) Subfamily Asteroideae Tribe: SenecioneaeÑ120 genera worldwide, 21 in the United States Subtribe SenecioninaeÑ68 genera worldwide, 7 in the United States Delairea sp. (2/2) D. odorata Lemaire with stipulesa Target weed, S. Africa, both stipulate Pretoria and 141/141 D. odorata Lemaire without stipulesa and astipulate varieties tested Albany 6/6 Mikaniopsis sp. (0/0) M. cissampelina C. Jeffery S. Africa, closest relative of Cape ivy Pretoria 5/0 (Jeffery 1986) Senecio sp. (86/34) S. angulatus L. f. S. Africa, ornamental Pretoria 7/0 S. articulatus (L.) C.H. “Bipontinus” Schultz S. Africa Pretoria 5/0 S. blochmaniae E. Greene N. America, U.S. west coast dune Albany 8/0 shrub S. brachypodus de Candolle S. Africa Pretoria 6/0 S. deltoideus Lessing S. Africa Pretoria 5/0 S. flaccidus Lessing N. America, widespread in Both 10/0 southwest United States S. gerrardii Harvey S. Africa, widespread shrub Pretoria 5/0 S. glastifolius L. f. S. Africa Pretoria 6/0 S. helminthiodes (C.H. “Bipontinus” Schultz) Hilliard S. Africa, widespread shrub Pretoria 6/0 S. jacobaea L.a Africa, noxious weed in several Albany 7/0 United States states S. macroglossus de Candolle S. Africa, ornamental Pretoria 5/0 S. oxydontus de Candolle (form A) S. Africa Pretoria 9/0 S. oxydontus de Candolle (form B) S. Africa Pretoria 5/0 S. oxyriifolius de Candolle S. Africa Pretoria 6/0 S. pleistocephalus S. Moore S. Africa Pretoria 5/0 S. tamoides de Candolle S. Africa, widespread, ornamental Pretoria 5/0 S. triangularis W. Hooker N. America, common in riparian Albany 5/0 areas S. vulgaris L.a Europe and N. Africa, widespread Albany 7/0 United States weed Packera sp. (67/22) P. bolanderi(Gray) W.A. Weber and A. Lo¨ve N. America, west coast herb Albany 10/0 P. breweri (Burtt-Davy) W.A. Weber and A. Lo¨ve N. America, woodland herb Albany 5/0 P. ganderi (Barkley and Beauchamp) W.A. Weber and A. Lo¨ve N. America, woodland herb, Albany 6/0 California listedÐRare P. macounii (Greene) W.A. Weber and A. Lo¨ve N. America, widespread in United Albany 5/0 States Pericallus sp. (1/1) P. hybrida (Regal) B. Nordenstam Africa, ornamental in the United Albany 5/0 States, formerly Senecio hybridus Pseudogynoxys sp. (1/1) P. chenopodioides Kuntha S America, ornamental, formerly Albany 5/0 Senecio confusus Cineraria sp. (0/0) C. “butterßy” ornamental cultivar hybrid S. Africa, ornamental cultivar hybrid Pretoria 8/0 C. deltoidea Sonder S. Africa, coastal herb in S. Africa Pretoria 5/0 C. saxifraga de Candolle S. Africa, ornamental in United Pretoria 9/0 States Erechtites sp. (8/4) E. glomerata (Desfontaines ex Poiret) de Candollea Europe, West coast in United States Albany 5/0 Euryops sp. (2/0) E. chrysanthemoides (de Candolle) B. Nordenstama S. Africa, ornamental in United Pretoria 9/0 States E. pectinatus L. Cassinia S. Africa, ornamental in United Both 10/0 States E. subcarnosus de Candollea S. Africa, weed in Arizona Albany 6/0 Subtribe Tus silagininaeÑ48 genera worldwide, 12 in the United States Lepidospartum sp. (3/2) L. latisquamum S. Watson N. America, desert shrub Albany 5/0 Luina sp. (2/1) L. hypoleuca Benthelot N. America, Northwest shrub Albany 5/0 June 2010 BALCIUNAS ET AL.: LABORATORY HOST RANGE OF P. regalis 845

Table 1. Continued

Valid tests/ Species tested Region of endemism, notes Test site tests w/galls Petasites sp. (7/2) P. frigidus var. palmatus L. Fries N. America, common in riparian Albany 5/0 Subtribe BlennospermatinaeÑ4 genera worldwide, 2 in the areas United States Blennosperma sp. (4/4) B. nanum var. nanum (W. Hooker) Blake N. America, uncommon west coast Albany 5/0 Tribe: AnthemideaeÑ109 genera worldwide, 13 in the United plant States Achillea sp. (20/9) A. millefolium L. N. America, common herbaceous Albany 6/0 plant Artemisia sp. (102/21) A. californica Lessing N. America, common west coast Albany 6/0 Tribe: AstereaeÑ170 genera worldwide, 57 in the United States shrub Baccharis sp. (25/12) B. pilularis de Candolle N. America, common west coast Albany 6/0 shrub Erigeron sp. (255/53) E. glaucus Ker-Gawler N. America, common west coast Albany 5/0 shrub Grindelia sp. (55/24) G. stricta de Candolle N. America, common west coast Albany 5/0 shrub Symphyotrichum sp. (139/23) S. chilense (Nees) G.L. Nesom N. America, formerly Aster chilensis Albany 6/0 Tribe: Calenduleae (Calendula officinalis and C. arvensis are the only representatives from this tribe in the United States) Calendula sp. (2/2) C. officinalis L.a N. Africa, ornamental Albany 5/0 Tribe: EupatorieaeÑ170 genera worldwide, 26 in the United States Ageratina sp. (20/4) A. adenophora (Spreng.) R.M. King and H.E. Robinsa S. America, weed in S. Africa and Pretoria 6/0 United States A. riparia (Regel) R.M. King and H.E. Robins S. America, noxious weed in HI Pretoria 5/0 Ageratum sp. (4/1) A. houstonianum P. Millera S. America, minor S. African weed Pretoria 5/0 Campuloclinium sp. (0/0) C. macrocephalum (Lessing) de Candolle S. America, invasive in S. Africa Pretoria 5/0 Chromolaena sp. (9/0) C. odorata (L.) R.M. King and H.E. Robins S. America, weed in HI and S. Africa Pretoria 5/0 Mikania sp. (10/0) M. capensis de Candolle S. America, S. African vine Pretoria 9/0 Tribe: GnaphalieaeÑ180 genera worldwide, 8 in the United States Anaphalis sp. (1/1) A. margaritacea L. Bentham ex. C.B. Clarke N. America, widespread in the Albany 5/0 United States Gamochaeta sp. (6/5) G. purpurea (L.) Cabrera N. America, widespread weed Albany 7/0 Tribe: HelenieaeÑ110 genera worldwide, 71 in the United States Eriophyllum sp. (28/28) E. staechadifolium Lagasca y Segura N. America, common west coast Albany 6/0 shrub Madia sp. (24/24) M. elegans D. Don ex Lindley N. America, common west coast Albany 5/0 plant Tagetes sp. (8/2) T. erecta L. N. America, ornamental - marigold Albany 5/0 T. minuta L.a N. America, noxious weed in CA Pretoria 5/0 Tribe: HeliantheaeÑ189 genera worldwide, 52 in the United States Bidens sp. (67/4) B. formosa (Bonato) C.H. “Bipontinus” Schultz N. and S. America, global weed Pretoria 5/0 Coreopsis (33/12) C. cf. lanceolata L. (garden cultivar) N. and S. America, ornamental in Pretoria 5/0 S. Africa Dahlia sp. (1/0) D. pinnata Cavanilles cv.a S. America, ornamental in S. Africa Pretoria 6/0 Galinsoga sp. (2/2) G. parviflora Cavanillesa S. America, weed in S. Africa and Pretoria 5/0 United States 846 ENVIRONMENTAL ENTOMOLOGY Vol. 39, no. 3

Table 1. Continued

Valid tests/ Species tested Region of endemism, notes Test site tests w/galls Helianthus sp. (68/15) H. annuus L. N. America, sunßowerÐcommercial Pretoria 6/0 crop H. tuberosus L. N. America, Jerusalem artichoke Pretoria 9/0 Rudbeckia sp. (44/5) R. hirta (garden cultivar) N. America, ornamentalÐconeßower Pretoria 5/0 Zinnia sp. (8/0) Z. violacea Cavanilles cv.a S. America, ornamental Pretoria 5/0 Tribe: InuleaeÑ38 genera worldwide, 1 in the United States Dittrichia sp. D. graveolens L. W. Greutera N. Africa, minor weed in the United Albany 5/0 Tribe: PlucheeaeÑ28 genera worldwide, 3 in the United States States Pluchea sp. (14/3) P. odorata Cassini N. America, widespread in United Albany 7/0 States wetlands Subfamily Cichorioideae Tribe: ArctoteaeÑ16 genera worldwide, 6 in the United States (All N. American species are introduced) Arctotheca sp. (1/1) A. calendula L. Levynsa S. Africa, noxious weed in CA Pretoria 5/0 Tribe: Cardueae - 83 genera worldwide, 11 in the United States Carthamus sp. (6/5) C. tinctorius L.a Eurasia, safßowerÐcommercial crop Albany 6/0 Centaurea sp. (35/18) C. melitensis L.a Eurasia, weed in many states Albany 5/0 Cynara sp. (2/2) C. scolymus L.a Europe, artichokeÐcommercial crop Albany 5/0 Tribe: LactuceaeÑ98 genera worldwide, 32 in the United States Cichorium sp. (2/2) C. intybus L.a Europe, chicoryÐminor crop and Albany 8/0 weed Lactuca sp. (20/9) L. sativa L.a Europe, lettuceÐcommercial crop Pretoria 6/0 Picris sp. (6/1) P. echioides L.a Europe, widespread weed in the Albany 5/0 Tribe: MutisieaeÑ76 genera worldwide, 8 in the United States United States Adenocaulon sp. (1/1) A. bicolor Hooker N. America, common woodland Albany 5/0 Tribe: VernonieaeÑ 98 genera worldwide, 4 in the United States herb Vernonia sp. (32/0) V. missurica RaÞnesque N. America, endangered in Ohio Albany 6/0 Family Campanulaceae (Order Asterales) Campanula muralis L. Europe, ornamental in the United Albany 6/0 States Lobelia erinus L.a Europe, ornamental in the United Albany 6/0 States Family Amaranthaceae (Order Caryophyllales) Beta vulgaris ssp. cicla L. Koch Europe, chardÐcommercial crop Pretoria 5/0 Family Apiaceae (Order Apiales) Hedera canariensis Willdenowa Europe, ornamental vine Albany 5/0 Hedera helix L.a Europe, ornamental vine, weedy Albany 7/0 Family (Order ) californica Torrey N. America, including California Albany 5/0 Family Brassiceae (Order Brassicales) Brassica oleracea L.a Europe, cabbageÐcommercial crop Pretoria 5/0 Lepidium latifolium L.a Europe, noxious weed in several Albany 5/0 states Raphanus sativus L.a Europe, radishÐcommercial crop Pretoria 5/0 Family (Order ) Marah fabaceus (Naudin) Naudin ex Greene N. America, common vine in Albany 6/0 California scabra subsp. scarab (L. f.) Sonder S. Africa Pretoria 5/0 Family Ranunculaceae (Order Ranunculales) Clematis lingusticifolia Nuttall N. America, common vine in Albany 6/0 western United States Family Rosaceae (Order Rosales) Fragaria chiloensis (L.) P. Miller N. America, common United States Albany 8/0 west coast plant June 2010 BALCIUNAS ET AL.: LABORATORY HOST RANGE OF P. regalis 847

Table 1. Continued

Valid tests/ Species tested Region of endemism, notes Test site tests w/galls Family Sapindaceae (Order Sapindales) Acer macrophyllum Pursh N. America, common United States Albany 5/0 west coast tree Acer negundo var. californicum (Torrey and A. Gray) Sargent N. America, common California tree Albany 5/0 Aesculus californica (Spach) Nuttall N. America, common California tree Albany 5/0 Cardiospermum halicacabum L. N. America, ornamental vine Albany 5/0 Dodonaea viscosa L. Jacquin N. America, ornamental, host of Pa. Albany 5/0 mavoana Family Vitaceae (Order Vitales) Vitis californica Bentham N. America, widespread western Albany 5/0 United States vine

Valid tests were those where the control Cape-ivy plant produced galls (see Materials and Methods). Families from Judd et al. (2002). Number genera/species from Bremer (1994) and USDAÐNRCS (2009). a Naturalized or crop species not native to the United States. belaar 2000), conÞrm that P. regalis is highly host known under its acronym TAG. This is the Þrst step in speciÞc. However, host speciÞcity is not enough, be- gaining regulatory approval to release P. regalis in cause there is concern that even highly speciÞc agents California. can cause unpredictable indirect effects (Simberloff and Stiling 1996; Holt and Hochberg 2001; Balciunas Acknowledgments 2004b; Pearson and Callaway 2005, 2006). The weed biocontrol community is now sensitized to the need We thank M. W. Mansell for determining the identity of P. for greater concern for the effectiveness of biological regalis, E. Lednicky for growing the plants used in these trials, control agents, and 1 of the 12 Guidelines of the In- and M. Chau for maintaining the cultures of ßies and assisting in taking down the tests and analyzing the results. The helpful ternational Code of Best Practices for Classical Bio- comments, on early drafts of this manuscript, by T. Dudley and logical Control of Weeds emphasizes that only effec- L. Smith, as well as those from the subject editor and two tive agents be released (Balciunas 2000, Balciunas and anonymous referees, have improved this manuscript. Coombs 2004). Accordingly, Balciunas and Smith (2006) conducted, in the Albany quarantine, prere- lease efÞcacy assessments (PREA) of the potential References Cited impact of P. regalis and found that, even at low infes- Balciunas, J. K. 2000. Code of best practices for classical tation rates, they cause a signiÞcant reduction in biological control of weeds, p. 435. In N. R. Spencer (ed.), height and nongall biomass. The modeling studies of Proceedings, X International Symposium on Biological McClay and Balciunas (2005) indicated that PREAs Control of Weeds, 4Ð14 July 1999, Bozeman, MT. Mon- would be most cost-effective if they were conducted tana State University, Bozeman, MT. before the host-speciÞcity trials. The PREAs evaluat- Balciunas, J. 2001. Viable seed production by Cape-ivy in ing P. regalis impact were done during the Þrst year of California Þnally conÞrmed. CalEPPC News 9: 13. our host range testing, and the positive outcome en- Balciunas, J. K. 2004a. Delairea odorata Lemaire. Crop couraged us to complete the Þnal four years of host protection compendium, 2004 edition. (http:cabi.org/ range evaluations of this ßy. compendia/cpc/). Balciunas, J. K. 2004b. Are mono-speciÞc agents necessarily In conclusion, we feel that both the host speciÞcity safe? The need for pre-release assessment of probable and the potential efÞcacy of P. regalis have now been impact of candidate biocontrol agents, with some exam- shown. Therefore, a petition, summarizing our studies ples, pp. 252Ð257. In J. M. Cullen, D. T. Briese, D. J. and results, has been submitted to the Technical Ad- Kriticos, W. M. Lonsdale, L. Morin, and J. K. Scott (eds.), visory Group for Biological Control of Weeds, better Proceedings, XI International Symposium on Biological Control of Weeds, 27 April to 2 May 2003, Canberra, Australia. CSIRO, Canberra, Australia. Table 2. Comparison of the mean no., per plant, of different Balciunas, J. K., and E. M. Coombs. 2004. International code gall types, and the no. of P. regalis puparia produced from these of best practices for biological control of weeds, pp. 130Ð galls on two varieties of Cape-ivy 136. In E. M. Coombs, J. K. Clark, G. L. Piper, and A. F. Astipulate Stipulate Cofrancesco, Jr. (eds.), Biological control of invasive Cape-ivy Ϯ SE Cape-ivy Ϯ SE plants in the United States. Oregon State University Press, Corvallis, OR. Under-developed galls 1.85 Ϯ 0.36 1.75 Ϯ 0.37 Balciunas, J., and L. Smith. 2006. Prerelease efÞcacy assess- Ϯ Ϯ Fully developed galls 0.90 0.31 0.90 0.29 ment, in quarantine, of a Tephritid gall ßy being consid- w/o windows Fully developed galls 5.25 Ϯ 0.78 5.30 Ϯ 0.94 ered as a biological control agent for Cape-ivy (Delairea w/ windows odorata). Biol. Control 39: 516Ð524. Puparia and Adults 30.35 Ϯ 5.02 29.35 Ϯ 6.91 Balciunas, J. K., and B. Villegas. 2007. Laboratory and real- ized host ranges of Chaetorellia succinea (Diptera: Te- Twenty replicates each of both the astipulate and stipulate varieties phritidae), an unintentionally introduced natural enemy of Cape-ivy were exposed to eight P. regalis females. of yellow starthistle. Env. Entomol. 36: 849Ð857. 848 ENVIRONMENTAL ENTOMOLOGY Vol. 39, no. 3

Barkley, T. M. 1999. The segregates of Senecio, S.L., and Judd, W. S., C. S. Campbell, E. A. Kellogg, P. F. Stevens, and Cacalia, S.L., in the ßora of North America north of M. J. Donoghue. 2002. Plant systematics: a phylogenetic Mexico. Sida 18: 661Ð72. approach. Sinauer, Sunderland, MA. Bossard, C. C. 2000. Delairea odorata, pp. 154Ð158. In C. McClay, A. S., and J. K. Balciunas. 2005. The role of pre- Bossard, J. Randall, and M. Hoshovsky (eds.), Invasive release efÞcacy assessment in selecting classical biologi- plants of CaliforniaÕs wildlands. University of California cal control agents for weedsÑapplying the Anna Kare- Press, Berkeley, CA. nina principle. Biol. Control 35: 197Ð207. Bremer, K. 1994. Asteraceae: cladistics and classiÞcation. Munro, H. K. 1929. New Trypetidae from South Africa Timber Press, Portland, OR. (Dipt.). Bull. Entomol. Res. 20: 391Ð401. de la Torre-Ferna´ndez, F., and R. A´ lvarez-Arbesu´. 1999. Con- Munro, H. K. 1935. Biological and systematic notes and trol of noxious weeds in sensitive areas, pp. 203Ð208. In records of South African Trypetidae (fruit-ßies, Diptera) Proceedings, Invasoras Lenhosas, 16Ð18 November 1999. with descriptions of new species. Entomol. Mem. S. Afr. Sociedade Portuguesa Ciencias Florestais, Geres, Spain. Dep. Agric. 9: 18Ð59. Flora of North America Editorial Committee. 2006. Flora of Munro, H. K. 1939. On certain South African gall-forming North America, vol. 20, Magnoliophyta: Asteridae (in part): Trypetidae (Diptera), with descriptions of new species. Asteraceae, part 2. Oxford University Press, New York. J. Entomol. Soc. South. Afr. 2: 154Ð164. Grobbelaar, E. 2000. Delairea odorata surveyÑphase 2: a Munro, H. K. 1940. Further South African gall-forming Try- survey of selected biological control agents of Delairea petidae (Diptera) with descriptions of new species. J. odorata Lemaire on closely related plants occuring sym- Entomol. Soc. South. Afr. 3: 76Ð87. patrically in South Africa. Agricultural Research Council, Munro, H. K. 1952. Les Trypetides, Dipteres cecidogenes Pretoria, South Africa. de la serie Eutreta-Oedaspis a propos de deux nouvelles Grobbelaar, E., J. K. Balciunas, O. Neser, and S. Neser. 2003. especes malgaches. Mem. Inst. Sci. Madagascar, Ser. E 1: 217Ð225. South African insects for biological control of Delairea Munro, H. K. 1953. Records of some Trypetidae (Diptera) odorata, pp. 16Ð28. In M. Kelly (ed.), Proceedings of the collected on the Bernard Carp Expedition to Barotseland, CalEPPC Annual Symposium, 2000Ð2002. California 1952, with a new species from Kenya. J. Entomol. Soc. Exotic Pest Plant Council, Sacramento, CA. South. Afr. 16: 217Ð226. Haselwood, E. L., and G. G. Motter. 1983. Handbook of National Botanical Institute. 1993. Plants of southern Af- Hawaiian weeds, 2nd ed. University of Hawaii Press, Ho- rica: names and distribution. In Arnold, T. H., and B. C. de nolulu, HI. Wet (eds.), National Botanical Institute, Pretoria, South Heard, T. A., and R. D. van Klinken. 1998. An analysis of Africa. designs for host range determination of insects for bio- Pearson, D. E., and R. M. Callaway. 2005. Indirect nontarget logical control of weeds, pp. 539Ð546. In M. P. Zalucki, effects of host-speciÞc biological control agents: impli- R.A.I. Drew, and G. G. White (eds.), Proceedings, Sixth cations for biological control. Biol. Control 35: 288Ð298. Australasian Applied Entomology Research Conference, Pearson, D. E., and R. M. Callaway. 2006. Biological control 29 September to 2 October 1998, Brisbane, Australia. agents elevate hantavirus by subsidizing deer mouse pop- University of Queensland Printery, Brisbane, Australia. ulations. Ecol. Lett. 9: 443Ð450. Hill, R. L. 1998. Minimising uncertaintyÑin support of no- Robison, R. 2001. Cape ivy germinating in California and choice tests, pp. 1Ð10. In T. M. Withers, L. Barton Browne, Oregon. CalEPPC News 1: 8Ð9. and J. Stanley (eds.), Host speciÞcity testing in Australa- Robison, R., E. Grotkopp, and R. Yacoub. 2000. Cape ivy sia: towards improved assays for biological control. Sci- (Delairea odorata) distribution in California and Oregon, entiÞc Publishing, Indooroopilly, Queensland, Australia. pp. 82Ð84. In M. Kelly, M. Howe, and B. Niell. (eds.), Hilliard, O. M. 1977. Compositae in Natal. University of Proceedings, California Exotic Pest Plant Council Sym- Natal Press, Pietermaritzburg, South Africa. posium, 15Ð17 October 1999, Sacramento, CA. California Holt, R. D., and M. E. Hochberg. 2001. Indirect interactions, Exotic Pest Plant Council, Sacramento, CA. community modules and biological control: a theoretical Simberloff, D., and P. Stiling. 1996. How risky is biological perspective, pp. 13Ð37. In E. Wajnberg, J. K. Scott, and control? Ecology 77: 1965Ð1974. P. C. Quimby (eds.), Evaluating indirect ecological ef- Snedecor, G. W., and W. G. Cochran. 1967. Statistical meth- fects of biological control. CABI Publishing, New York. ods. Iowa State University Press, Ames, IA. [ITIS] Integrated Taxonomic Information System. 2009. Statistix. 2005. Version 8.1. Statistix, Tallahassee, FL. The Integrated Taxonomic Information System on-line [TAG] Technical Advisory Group. 2003. ReviewerÕs man- database. (http://www.itis.gov). ual for the technical advisory group for biological control Jacobi, J. D., and F. R. Warschauer. 1992. Distribution of six of weeds. USDAÐAPHISÐPPQ, Riverdale, MD. alien plant species in upland habitats on the island of [USDA–NRCS] U.S. Department of Agriculture–Natural HawaiÕi, pp. 155Ð188. In C. P. Stone, C. W. Smith, and J. T. Resources Conservation Service. 2009. The PLANTS Tunison (eds.), Alien plant invasions in native ecosystems database. (http://plants.usda.gov). of HawaiÕi management and research. University of Ha- Wapshere, A. J. 1974. Host speciÞcity of phytophagous or- waii Cooperative National Park Resources Studies Unit, ganisms and the evolutionary centres of plant genera or Honolulu, HI. sub-genera. Entomophaga 19: 301Ð309. Jeffrey, C. 1986. The Senecioneae in East Tropical Africa. Webb, C. J., W. R. Sykes, and P. J. Garnock-Jones. 1988. Kew Bull. 41: 873Ð943. Flora of New Zealand. Volume IV. Naturalized Pterido- Jeffrey, C. 1992. Notes on Compositae, VI: the tribe Sene- phytes, Gymnosperms, Dicotyledons. Botany Division, cioneae (Compositae) in the Mascarene Islands with an D.S.I.R., Christchurch, New Zealand. annotated world check-list of the genera of the tribe. Kew Bull. 47: 49Ð109. Received 21 August 2008; accepted 23 December 2009.