Although case-bearing leafmining larvae of Coleophora klimeschiella Toll were released on Russian thistles, Salsola australis R. Brown (Chenopodiaceae), at 13 locations in southern California during 1977-85, this biological control agent remained tenuously established at only one site by late 1986. Neither insectary-reared or field-collected stocks released in field cages or in the open in numbers of 100-600 per site appeared to foster colony establishment. Poor host-plant adaptation as well as predation and parasitism by indigenous natural enemies are identified as possible sources of biotic resistance to the establishment of this imported insect. The predator, Phylobacnus atriplexus (Foster) (Coleoptera: Cleridae), and the primary parasite, Macroneura sp. (Hymenoptera: Eupelmidae), found attacking C. klimeschiella, also are known from gall-midge hosts on native saltbushes (Atriplex spp., also Chenopodiaceae

Goeden, R. D.

Müller, H.

Ricker, D. W.

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Introduction~ Recovery~and Limited Establishment ofColeophora klimeschiella (Lepidoptera: Coleophoridae) onRussian Thistles~ Salsola australis, in Southern CaliforniaR. D. GOEDEN, D. W. RICKER, AND H. MULLER'Division of Biological Control, Department of Entomology,University of California, Riverside, California 92521Environ. Entomol. 16: 1027-1029 (1987)ABSTRACT Although case-bearing leafmining larvae of Coleophora klimeschiella Tollwere released on Russian thistles,Salsola australis R. Brown (Chenopodiaceae), at 13locationsin southern California during 1977-85, this biological control agent remained tenuouslyestablished at only one site by late 1986. Neither insectary-reared or field-collected stocksreleased in field cages or in the open in numbers of 100-600 per site appeared to fostercolony establishment. Poor host-plant adaptation as well as predation and parasitism byindigenous natural enemies are identified as possible sources of biotic resistance to theestablishment of this imported insect. The predator, Phylobacnus atriplexus (Foster) (Co-leoptera: Cleridae), and the primary parasite, Macroneura sp. (Hymenoptera: Eupelmidae),found attacking C. klimeschiella, also are known from gall-midge hosts on native salthushes(Atriplex spp., also Chenopodiaceae).KEYWORDS Salsola, Coleophora, biological control, colonization, natural enemiesColeophora klimeschiella Toll (Lepidoptera: Co-leophoridae) is the second species of phytophagousinsect, besides C. parthenica Meyrick, to be intro-duced into the western United States from Pakistanby ARS-USDA entomologists for the biologicalcontrol of the Russian thistle, Salsola australis R.Brown (Chenopodiaceae) (Hawkes et al. 1975, Ju-lien 1982). The biology and host specificity of thiscase-bearing leaf miner was described by Khan &Baloch (1976) and Hawkes & Mayfield (1978), re-spectively. This report describes our experience withC. klimeschiella in southern California since 1977,including where and when it first was introducedby us as collaborators, while others handled intro-ductions in central and northern California (Hawkes1978, Julien 1982).Materials and MethodsInsectary Culture. Sixty-four late instars and pu-pae of C. klimeschiella were received at Riversidefrom the ARS-USDA Biological Control of WeedsLaboratory, Albany, Calif., on 14 April 1977. Thesespecimens were collected from a culture main-tained at Albany that originated from material col-lected in Pakistan on Salsola ruthenica Iljin (Khan& Baloch 1976, Hawkes & Mayfield 1978). Uponreceipt, these larvae and pupae were caged in theinsectary of the Division of Biological Control onvegetative Salsola australis greenhouse-grown fromtransplanted, field-collected seedlings. Glass-topped1 Current address: Zoologiches Institut der Universitiit Basel,Hheinsprung 9, CH-4051 Basel, Switzerland.sleeve cages (34 by 32 by 35 em), each containinga single potted plant as described by Gilstrap &Goeden (1974), were used exclUSively for insectaryrea rings at 26 ± 1°C and a 15:9 (L:D) photoperiodduring 1977 and 1978.Approximately half-grown fourth instars weretransferred to fresh plants individually, with for-ceps, by pinching off the leaves with the larvaeattached whenever their feeding damage on plantsbecame severe. New cagings were initiated witheggs oviposited by insectary-reared moths. In No-vember 1977, insectary-cultured, fully grown lar-vae and pupae were stored for the winter in a coldroom in darkness at 2°C while attached within theirtubular cases to branches of basally excised plants.Each infested plant was individually placed in alarge paper bag that was taped shut basally andhung from a wall hook. Moths emerging from someof these overwintered individuals were used to re-start insectary cultures in April 1978, and thesecultures were maintained as described above untilAugust 1978. An additional 150 larvae, reared frommaterial collected in Pakistan in the fall of 1977,were received from the Albany laboratory on 17May 1978 and added to stock already in culture atRiverside. A total of 98 potted plants was cagedwith adults or half-grown larvae in 1977; 120 plantswere similarly caged in 1978. These rearings yield-ed the 918 larvae or pupae and 13 adults releasedin southern California in 1977, and the 600 larvaeor pupae released in 1978 (Table 1).Colonizations. Table 1 lists release data for C.klimeschiella at 13 locations in southern California.Thirteen moths reared from the initial shipmentfrom Albany were introduced into field cages cov-10271028 ENVIRONMENT AL ENTOMOLOGY Vol. 16, no. 4Table 1. Release data for C. klimeschiella in southernCaliforniaa Colony survived at low densities from 1979 to 1983. See text.b Apparently heavily parasitized. See text.larvae or pupae, and with as many as 600 unpar-asitized, insectary individuals, i.e., Del Mar in 1978,failed to become established. This poor perfor-mance partly may be the result of poor adaptationof this insect to S. australis, because it originatedon another host-plant species, S. ruthenica, in Pa-kistan (Khan & Baloch 1976, Hokkanen & Pimentel1984, Goeden & Kok 1986). Field observations dur-ing four consecutive years at Indio site 1 indicatedthat < 10% of the plants were infested by C. klime-schiella at prevailing generally low populationdensities. Moreover, this colony never spread morethan 200 m from the colonization point during the4 yr of its tenuous existence, again indicative of apoor adaptation of this moth to Russian thistle.A single plant bearing 2,453 larval cases at Indiosite 1 provided material for releases in east andwest Indio in late 1983 and early 1984, respectively.However, this field-collected material apparentlywas heavily parasitized. A sample of 10 branchesrepresenting about 1% of the crown of this plantbore a total of 121 larval cases, of which 17 (14%)showed lateral exit holes of parasites and 19 (16%)contained active C. klimeschiella larvae. The re-maining 85 cases held in individual gelatin capsulesyielded 7 (6%) moths, 4 (3%) Phyllobaenus atri-plexus (Foster) (Coleoptera: Cleridae, a predator),and the following hymenopterous parasites: 30(25%) Macroneura sp. (Eupelmidae), 20 (17%)Hockeria sp. (Chalcididae), 5 (4%) Catolaccusaeneoviridis (Girault) (Pteromalidae, probably ahyperparasite), 3 (2%) Cerambycobius sp. (Eupel-midae), and 2 (1%) unidentified Ichneumonidae).Fourteen (12%) cases contained larvae that diedfrom unknown causes. This suggests a parasitiza-tion and predation rate of at least 66% in over-W. Indio no. 2BanningRiversideTotalNo. released ColonyLarvae/ estab-Adults \ished?pupae1322100 No100 No110 No177142 No267600 No278 2 Noll684b No1,65d} No400400 No600250 No600 No600 No800 ?7,780Date(s)26 Apr. 197731 May 197721 June 19778 July 197715 Aug. 197715 Aug. 197722 Sept. 197722 Sept. 197724 Aug. 197825 June 197915 Nov. 198329 Mar. 19842 Oct. 198521 Oct. 198517 Oct. 19856 Nov. 198517 Oct. 198517 Oct. 198522 Oct. 1985ReleaseSiteE. Indio no. 1E. Indio no. 2W. Indio no. 1HighgroveE. Indio no. 3Lake PerrisBonsallRamonaMorenoDel MarResults and Discussionered with fine-mesh fiberglass window screen (1.2by 1.8 by 0.5 m) previously positioned over vig-orous, young Russian thistles at the University ofCalifornia Moreno Valley Field Station. Last instarsand pupae were subsequently also introduced intothis field cage and a second field cage, respectively(Table 1). The cages were removed in July 1977when the actively growing thistles occupied abouthalf of the interior of the cages. Subsequent releasesduring 1977 and 1978 involved transporting insec-tary-reared larvae or pupae to preselected sites inice-cream cartons filled with loosely bunched papertoweling within cold chests in an air-conditionedvehicle. Toweling and open cartons were carefullytucked into the crowns of vigorous Russian thistlesinto which the larvae readily moved.The larvae or pupae released at the east and westIndio sites in 1983 and 1984 (Table 1), were ob-tained from a single large plant bearing most ofthe larval survivors of a 4-yr-old colony tenuouslyestablished at east Indio site 1. The latter site hadbeen colonized by the direct release of larvae andmoths received from Albany on 25 June 1979 (Ta-ble 1).All the insects for the 1985 releases were ob-tained from a colony of C. klimeschiella estab-lished since 1977 by ARS-USDA entomologists atCoalinga, Fresno County, in the San Joaquin Valleyin central California. Nine early-fruiting-stageplants with dense blue-green leaves that bore mostof the current-generation larvae (darker and gray-ish versus whitish to light tan empty larval cases)at this site were measured and then cut off basallyat the central, main stem just above the ground.The intact infested shoots were transported by anair-conditioned vehicle to Riverside and stored at2°C. The cases were placed at room temperaturein closed ice-cream cartons containing paper tow-eling upon which the active larvae climbed. Thelarval cases that remained on the container floorswere examined after a few days for parasite exitholes, and those found to be intact but not emptywere held for possible parasite emergence in in-dividual gelatin capsules in the insectary. The 3,650active, field-collected larvae or newly formed pu-pae were liberated by inserting the toweling andopen cartons in crowns of vigorous Russian thistlesat five locations in Riverside County through 22October 1985 (Table 1).Recovery. Recovery efforts at each release siteconsisted of careful examination of plants, mainlyfor larval cases, but also for adults. Visits were madeas time permited, but rarely at intervals <1 moduring 1977-86.As of September 1986, C. klimeschiella larvaecontinued to be recovered in small numbers onlyat our Riverside colonization site (Table 1). Thismeant that colonies started within field cages or inthe open, with insectary reared or field-collectedAugust 1987 GOEDEN ET AL.: INTRODUCTION OF Coleophora klimeschiella 1029wintering C. klimeschiella and another apparentreason for the poor performance of this biologicalcontrol agent in southern California. Hawkins &Goeden (1984) reported P. atriplexus and the sameMacroneura sp. as natural enemies of native Cec-idomyiidae forming galls on the salt bushes, Atri-plex canescens (Pursh) Nuttall and Atriplex poly-carpa (Torrey) Watson (Chenopodiaceae). Thesegalled halophytes are common associates of Russianthistle in southern California (Hawkins et al. 1986).This documented source of biotic resistance to thecolonization of C. klimeschiella provides anotherexample of a phenomenon reviewed by Goeden &Louda (1976) for other species of phytophagousinsects imported for biological control of weeds.We have no further plans to introduce C. klime-schiella in southern California, and conclude fromour efforts to date that this species is an ineffectivebiological control agent.AcknowledgmentOur sincere thanks to the Biological Control of WeedsLaboratory (ARS-USDA, Albany, Calif.) for supplyingC. klimeschiella. We also thank the following taxono-mists for identifications of adopted natural enemies ofC. klimeschiella: W. F. Barr (Department of Entomol-ogy, University of Idaho, Moscow); G. Gibson (Depart-ment of Entomology, University of Alberta, Edmonton);and E. E. Grissell (Systematic Entomology Laboratory,ARS-USDA, Beltsville, Md.). J. A. McMurtry and E. R.Oatman provided helpful comments on a draft of themanuscript.References CitedGilslrap, F. E. & R. D. Goeden. 1974. Biology ofTarachidia candefacta, a Nearctic noctuid intro-duced into the U.S.S.R. for ragweed control. Ann.Entomol. Soc. Am. 67: 265-270.Goeden, R. D. & L. T. Kok. 1986. Comments on aproposed "new" approach for selecting agents for thebiological control of weeds. Can. Entomo!. ll8: 51-58.Goeden, R. D. & S. Louda. 1976. Biotic interferencewith insects imported for weed control. Annu. Rev.Entomol. 21: 325-342.Hawkes, R. B. 1978. Biological control of Russianthistle along California highways. Calif. Dep. Transp.Pub!. T 900 B55.Hawkes. R. B. & A. Mayfield. 1978. Coleophoraklimeschiella, biological control agent for Russianthistle: host specificity testing. Environ. Entomol. 7:257-271.Hawkes. R. B.• R. D. Goeden. A. Mayfield & D. W.Ricker. 1975. Biological control of Russian thistle.Calif. Agric. 29(4): 3-4.Hawkins, B. A. & R. D. Goeden. 1984. Organizationof a parasitoid community associated with a complexof galls on Atriplex spp. in southern California. Ecol.Entomol. 9: 271-292.Hawkins, B. A., R. D. Goeden & R. L. Gagne. 1986.Ecology and taxonomy of the Asphondylia spp. (Dip-tera: Cecidomyiidae) forming galls on Atriplex spp.(Chenopodiaceae) in southern California. Entomog-raphy 4: 55-107.Hokkanen, H. & D. Pimentel. 1984. New approachfor selecting biological control agents. Can. Entomol.ll6: ll09-ll21.Julien, M. H. 1982. Biological control of weeds: aworld catalogue of agents and their target weeds.Unwin, Surrey, England.Khan, A. G.& G. M. Baloch. 1976. Coleophora klime-schiella (Lep.: Coleophoridae), a promising biocon-trol agent for Russian thistles, Salsola spp. Entomo-phaga 21: 425-428.Received for publication 19 November 1986; accepted24 April 1987.

Introduction, Recovery, and Limited Establishment of Coleophora klimeschiella (Lepidoptera: Coleophoridae) on Russian Thistles, Salsola australis, in Southern California

Introduction, Recovery, and Limited Establishment of Coleophora klimeschiella (Lepidoptera: Coleophoridae) on Russian Thistles, Salsola australis, in Southern California

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