64 Plant Protection Quarterly VoI.9(2) 1994 similar scales were described by Froggatt Biological control of the native shrubs Cassinia spp. (1903), no data on their biology were available. Thus observations began on using the native scale Austrotachardia sp. and Austrotachardia sp. in 1988 and Para­ Paratachardina sp. (Hemiptera: Kerriidae) in New tachardina sp. in 1991 to record their biol­ ogy and to ascertain whether they could South Wales be used for the biological control of Cassinia spp. M.H. Campbell', R.H. Holtkamp', L.H. McCormick', P.J. Wykes', J.F. Donaldson', P.J. Gulian' and P.S. Gillespie'. Life cycle of Austrotachardia sp. and Para tach ardin a sp. Austrotachardia sp. was s tudied at 1 NSW Agriculture, Agricultural Research and Veterinary Centre, Forest "0aydawn", Kerrs Creek and at the Agri­ Road, Orange, New South Wales 2800, . cultural Research and Veterinary Centre, ' NSW Agriculture, Agricultural Research Centre, Tamworth, New South Orange. Paratachardina sp. was studied in Wales 2340, Australia. the Tamworth and Manilla districts. ' NSW Agriculture, Manilla, New South Wales 2346, Australia. Fi rs t-instar nymphs (crawlers) of • "Daydawn", Kerrs Creek, New South Wales 2741, Australia. Austrotachardia sp. (Figure 1) (orange in ' Department of Primary Industries, lndooroopilly, Queensland 4068, colour and 0.5 mm long) emerged in De­ Australia. cember 1990 and established on stems of ' Division of Botany and Zoology, Australian National University, , C. arcuata. Initially, all second-instar ACT 2600, Australia. nymphs appeared identical. However, by February 1991, the red, oblong (1.5 x 0.6 ' Biological and Chemical Research Institute, Rydalmere, New South Wales mm) male tests were distinguishable 2116, Australia. &om the red, oval (1 mm diame ter) fe­ male tests (Figure 2). The red-coloured Summary soil or plant disturbance and become male fli es emerged in March 1991, but it is Naturally occurring populations of the weeds because they are unpalatable, com­ not known whether fertilization occurred native scale insects A ltstrotaC#,ardia sp. petitive, unproductive and difficult and a t this time because mating was not ob­ and Paratacharditra s p. killed large ar­ costly to control (Campbell el al. 1990). served. Sca le insects reproduce by a vari­ eas of native Cassi"ia s pp. in, respec­ They also p rovide harbour for noxious ety of means including hermaphroditism, tively, central and no rth-western New and make stock mustering diffi­ parthenogenesis and normal fertilization South Wales, from 1988 to 1993. These cult. The four main species are Cassinia (O'Brien el al. 1991). scales, which are specific to Cassi,Jia arcuala R.Br., C. IOll gifolia R.Br., C. lnevis Females of Austrotachardia sp. grew spp., have been wide ly spread through R.Br . and C. quinque/aria R.Br. C. arcuata slowly during winter 1991, increasing New South Wales by the transfer of in­ has invaded 616 000 hectares in central from 1.5 mm to 2.0 mm in diameter. As fested cuttings by humans. Observa­ and southern New South Wa les and is a the females matured, embryos appeared tions on one pro perty near Orange re­ declared noxious weed in 10 shires vealed that deliberate transfe r of (Campbell 1990, Campbell et al. 1990). A ustrotacltardia sp. assisted in killing Preliminary estimates indicate C. laevis 70% (255 ha) of C. arcuata on the prop­ and C. qUinquefaria are present on 250 000 erty between 1988 and 1993. Cassillia hectares in north-western New South spp. a re us ually re placed by native Wales. On arable land Cassinia spp. can grasses; however, poor management can be controlled by ploughing, sowing im­ lead 10 re-infes tation by woody weeds. proved pastures and applying fertilizers Both scales have a n annual life cycle and to overcome nutrient deficiencies and soil are spread b y transferring infected acidity (McGowen et al. 1990). On non­ cuttings to ne w plants 10 to 30 days be­ arable land conventional methods of con­ fo re firsl-instar nymphs e me rge. A com­ trol e.g., spraying and aerial distribution Figure 1. First·instar nymphs plex o f paras ito ids a nd pred ators, of pasture seed and fertilizers, are imprac­ (crawlers, 0.5 mm long) of Austro­ mainly small wasps, may limit the effec­ tical because herbicide treatments are un­ tachardia sp. emerge in summer or tiv~n ess of the scales in controlling economic and pasture establishment dif­ Cassinia spp. Pa rasito ids ca n be par­ ficult on the unploughed acid soils autumn ; transfer of infected tially contro lled by d estroying cuttings (Campbell 1990). cuttings should take place 10 to 30 immediately after crawler emergence Native scale insects have killed small days before crawler emergence. because they continue to eme rge for up a reas of C. arcuata and C. longifolia in cen­ to seven months after the crawlers. This tral New South Wales since 1979 O.j. study indicates thai if humans assist by Dell ow, NSW Agriculture, Orange, per­ spreading scale insects and controlling sonal communication) and patches of C. parasito id s and predators the scales laevis and C. quinquefaria in north-western could be useful biological agents for the New South Wales since 1988. However, control of Cassi"ia spp. between 1988 and 1993 relatively large ar­ eas of Cassinia spp. were killed by Introduction Austrotachardia sp (Hemiptera: Kerriidae) Cassillia spp. (Asteraceae), native shrubs in central New South Wales (Campbell widespread in New South Wales, Victo­ and Wykes 1991, 1992) and by Para­ ria and Queensland (Campbell 1977, tachardina sp. (Hemiptera: Kerriidae) in Figure 2. An oblong male nymph 1990), generally grow on infertile acid north-western New South Wales (Holt­ (centre) surrounded by six oval soils. They invade pastures in response to kamp and Campbell 1992). Although females of Austrotac1.ardia sp. Plant Protection Quarterly VoI.9(2) 1994 65 test and the adults emerge by cutting a Scott 1982). Although assist round hole in the test. Often female scale homopterans by carrying them (e.g., insects produce crawlers despite the pres- Pseudococcus spp.) to new habitats ence of a wasp larva. Wasps continue to (Strickland 1958, Way 1963) we have not emerge after crawler emergence has observed such assistance for Austro- ceased; for example, in the early autumn tachardia sp. and Paratachardina sp. 1993 Austrotachardia sp. population, 61% of wasps emerged in the two months af- Other insects and animals ter crawler emergence had ceased and Honeydew from Austrotachardia sp. and continued to emerge for a further seven Paratachardina sp_ attracted honeybees, Figure 3. A fully developed Austro­ months. This indicates that cuttings at­ ladybird beetles, hoverflies, wasps and tachardia sp. female one year old. tached to new plants to spread Austro­ blowflies which did not harm the scale tachardia sp. should be destroyed after insects. However, rabbits, hares, sheep inside and developed into crawlers that crawler emergence (Campbell and Wykes and goats often ate the scale insects which emerged in December 1991. Thus the life 1991, Campbell 1992) to reduce wasp was most detrimental when a new colony cycle of the population that began at numbers. was establishing. Kerrs Creek in December 1990 was ap­ The larvae of an undetermined moth proximately one year (Figure 3). Another (Lepidoptera: Coleophidae) predate on Fungi population, that began with crawlers in Austrotachardia sp., spinning a protective Austrotachardia sp. and Paratachardina sp. February 1991, had males emerging and web under which they feed. A dark are commonly covered by the black sooty females 1 mm in diameter in December brown beetle, Trogoderma sp., (Coleop­ mould, Capnodium walter; (Ascomyco­ 1991, and crawlers emerging in February tera: Dermestidae), a black and white tina), which does not seem to harm them 1992. These two populations repeated moth, Macrobathra sp. (Lepidoptera: because large numbers of crawlers are their respective life cycles in 1992/93 and Cosmopterigidae) and an unidentified produced from completely covered fe­ 1993/94; crawlers from the first popula­ case moth (Lepidoptera: Psychidae), are males. tion emerged in January 1993 and Decem­ often present; their larvae are suspected ber 1993 and those from the second, in of feeding on crawlers, females, dead Distribution of the scale insects March 1993 and March 1994. The two lat­ scales or detritus. No detailed survey has been carried out ter emergences were later than in 1991/ Despite these predators and parasites, on the distribution of Austrotachardia sp. 92. Buckley (1987) recorded that climatic populations of Austrotachardia sp. and and Paratachardina sp. in New South and habitat factors may affect -plant­ Paratachardina sp. increased markedly Wales. However Austrotachardia sp. has homopteran interactions and regulate from 1988 to 1993 and the transfer of been observed on Cassinin spp. between population dynamics. Thus, lower than scales from infected plants to new plants Gulgong and Uarbry, north of Coolah, normal temperatures and higher rainfall was successful. throughout the Pilliga scrub, Bathurst, in 1992 (average daily mean 11.2·C and Hill End and in a 40 kilometre arc north total rainfall 1322 mm in 1992 compared Ants of Orange. Paratachardina sp. has been ob­ with the 100 year average of 12.1 °C and Ants observed tending Austrotachardia sp. served in the Tamworth, Armidale, 901 mm) may have increased the length included rufoniger (Lowne), Inverelt Tenterfield, Glen Innes, Bingara, of the life cycle of Austrotachardia sp. It 1. purpureus (F. Smith), Anonychomyra Barraba, BWldarra, Manilla and Merriwa was also observed that female itillerallS (Lowne) and CampO/lOtus sp. districts. Austrotachardia sp. grew more slowly, (: Formicidae); the first with a corresponding increase in length of three in daylight and the latter at night. A N alural dispersion of the scale life cycle, on retarded C. arcuata plants or healthy infestation of scale insects is often insects on plants growing in the shade. covered by a mass of ants feeding on hon­ Natural dispersal of Austrotachardia sp. Two years of observa tions in north­ eydew. The repetitive procedure for col­ and Paratachardina sp. relies on craw lers west New South Wales indicate that lecting honeydew was for the ant to shake walking or being transported by wind, Paratachardina sp. produces crawlers in a small bulb-shaped mass produced by water, insects or animals. Observations in November and has an annual life cycle. the female scale; in response a large bub­ the laboratory showed that crawlers walk Paratachardina sp. closely resembles ble was produced which the ant duly con­ at 2 m h-I across a flat surface. They ex­ Austrotachardia sp., the main external dif­ sumed. hibit negative geotaxis, phototaxis, or a ference being that Paratachardina sp. are It is possible that large numbers of ants combination of both, crawling upwards brown and Austrotachardia sp. are red. could assist Austrotachardia sp. and on plants in the field and to the top of Paratachardina sp. by discouraging preda­ cuttings standing upright in the labora­ Insects and fungi associated with tors and parasitoid, by preventing tory; if the cutting is horizontal the crawl­ Austrotachardia sp. and oviposition, eating eggs or attacking lar­ ers walk across the area in front, spread­ Paratachardina sp. vae or adults of predators and parasitoids ing out to cover the full width of the area (Buckley 1987). For example, attendance presented to them. As each 2 mm diam­ Predators and paras ito ids by ants raised the survival rate of tuliptree eter female produces about 300 crawlers, The major parasitoids of Austrotachardia scales in Pennsylvania from 8% to 47% and with 30 females per em on a heavily sp. and Paratachardina sp. are small (Burns 1973) and defence of the scale infested stem 2 cm in diameter, the maxi­ wasps: Dolichogenidea sp. (Hymenoptera: Toumeyella numismaticum by Formica mum reproduction rate is about 9000 Braconidae: Macrogastrinae) black wasp obscuripes was necessary for its survival crawlers per cm. In the field, crawlers es­ with long antennae; Encarsia sp. (Bradley 1973). On the other hand, ants tablish most successfully in cracks in the (Aphelinidae: Hymenoptera) small black did not reduce the mortality of bark on new stems. wasp; and undetermined Encyrtidae (Hy­ Pulvinarius mesembryanthemi or Pseudo­ Natural dispersal of Austrotachardia sp. menoptera) brown backed and yellow coccus macrozamiae in Western Australia was studied by deliberately infecting 12 wasps. These wasps lay eggs either in or despite the presence of significant num­ previously uninfected plants at Orange in under an establishing nymph; the larvae bers of predators and parasitoids (Majer December 1990. The resultant females feed on female scales, pupate under the 1982, Collins and Scott 1982, Dolva and prod uced craw lers in December 1991 66 Plant Protection Quarterly VoI.9(2) 1994 which further infected the 12 plants but emerged from late November to late De­ spp. on their properties and subsequent also moved to adjacent plants. By No­ cember. There was no external indication transfers were made fr om within their vember 1992, 43 of the 96 adjacent plants of impending emergence; it was best as­ properties. Using cuttings to spread scale we re infected with Austrotachardia sp.; certained through dissecting females and insects restricts the time of transfer to the 91 % on the main stem or on branches tracing embryo d evelopment. Cuttings 30 days before emergence. One way to ex­ within 20 em of the ground, indicating that produced the most crawlers were tend the transfer period is to transplant that crawlers walked across the ground those taken 10 to 30 days before emer­ infected plants which aUows the scale in­ and to the new plants. Seventy-six percent gence. Taking cuttings 30 days before sects to be spread at any time of the year. of the newly infected plants we re within emergence appeared to hasten emergence Transfer of cuttings in large infestations 2 m of a previously infected plant; the in response to desiccation of the cutting. of Cassinia spp. could be facilitated by greatest distance crawlers spread was In eight days at Orange, large cuttings (12 aerial application; in New Zealand 6 m. No Austrotachardia sp. were found cm long x 1.2 cm diameter) of C. arcuata cuttings infected with E. oran·eflsis were more than 20 em above ground level on stems lost 70% and small cuttings (3 cm distributed by aircraft with successful re­ new plants indicating that wind was not long x 0.3 cm diameter) lost 89% of their sults (Hoy 1961). responsible for their spread. Scale insects moisture in a laboratory at room tempera­ are often spread by wind, for example, in ture. It w ould thus appear that female Effectiveness of scales in killing 11 years E. orariellsis was carried 140 km scales survive on cuttings for up to 30 Cassinia spp. north, 46 km east and 53 km south of a days, mainly on moisture stored in their Although Auslrotachardia sp . had killed large infestation in New Zealand by pre­ bodies. small areas of Cassinia spp. on the central vailing winds (Hoy 1961). The failure of In s ummers from 1990/91 to 1993/ 94 tablelands since 1979, it was not until 1988 wind to spread Austrotachardia sp. in the deliberate transfer of scale insects took that large areas were killed . Even then the above observations may have been due to place in New South Wales by supplying failed to spread in some situations the small infestation supplying limited Austrotachardia sp. infected cuttings from after killing small patches. Thus the effec­ numbers of crawlers and the short time Kerrs Creek to 400 landholders; cuttings tiveness of Austrotachardia sp. at Kerrs over which spread was measured . were taken approximately 10 days before Creek (Table 1) could be due to a particu­ estimated crawler emergence. Para­ larly lethal strain. As scale insects kill Deliberate Iransfer of the scale tachardina sp. inJected cuttings were dis­ plants by sucking out nutrients, transmit­ insects by humans persed to landholders in north-western ting viruses, rickettsia, bacteria or If we are to rely on nature to spread na­ New South Wales from infestations in the mycoplasma, or injecting toxins (O'Brien tive sca Ie insects, then the possibility of Manilla and Barraba districts. Many et al. 1991), it is possible that successful controlling Cassinia spp. is low because of landholders transferred the cuttings more strains may transmit toxic substances that the deleterious effects of native predators than 300 km in one day, thus greatly ac­ unsuccessful strains d o not. and parasitoids. But, if humans aid the celerating the rate of spread over that of It is also possible that the habitat at spread of scales and enemies are control­ natural dispersion. Transfer of cuttings is Kerrs Creek may provide the nutrient sta ­ led , the chances of s uccess could be im­ best done in a dry, cool box as moisture tus in C. arcuata that increases its suscepti­ proved. Scale insects have been spread by and high temperature adversely affect the bility to sca le insects (McClure 1985) or humans in India (Froggatt 1899), New scale insects. Crawlers in the laboratory at that the ecotype of C. arcuata is preferred Zealand (Hoy 1961) and Australia Orange existed without food for up to 16 by the scales to other ecotypes in the cen­ (Hosking et al. 1988, Campbell and Wykes days at 2 - S' C, but died within two days tral tablelands. Not only can ecotypes af­ 1992). In the latter case P.). Wykes spread at 32' C. fect homopteran preference but indi­ cuttings infected with Austro fnchnrdia sp. Aust rotac/tardia sp . were transferred by vidual plants, within the one ecotype, can through his property "Daydawn", Kerrs tying 10 ern long infected cuttings to differ in their susceptibility to scale in­ Creek from 1985 to 1992 which resulted in uninfected plants 0.5 to 1 m above the sects (Edmunds and Alstad 1978). the control of 70% of the C. arcuntn on the ground (Campbell 1992). By taking property (Table 1). The role of natural dis­ cuttings 10 to 30 d ays before crawler Host specificity of Allstrotacliardia persal in this example is not known but it emergence at Kerrs Cree k, 50% of new sp. is thought to have been important par­ plants were infected at Orange. To facili­ Although Austrotadwrdia spp. have a ticularly in population increases of tate control of Cassillia spp. on their prop­ wide host range, the Austrotacltardia sp. Austrotnc/1nrdin sp. before deliberate erties, landholders need to transfer referred to in this paper has only been transfer began in 1985. cuttings annually until most plants are in­ found on C. arcuata, C. quinquefaria and C. To determine the best time to transfer fected. The insects could be obtained from longifolia, despite access to a varied plant AuslrotacJmrdia sp. to new plants, cuttings introduced cuttings or from recently es­ community over thousands of hectares in were taken weekly from Kerrs Creek be­ tablished colonies on their own proper­ the Kerrs Creek district. tween October and December 1991, ties. Some landholders who received In a laboratory experiment conducted stored dry in a laborato ry at room tem­ cuttings in 1990 and 1991 recognized that over seven days at Orange, Austro­ perature and observed . Crawlers the scale was already present on Cassillia tachardia sp. crawlers were allowed a choice of 10 cm cuttings from eight plant species spaced at random in four replica­ Table 1. Cumulative amount of Cassinia spp. killed annually by tions 10 cm apart. This resulted in means Allstrotachardia sp. on "Daydawn", Kerrs Creek, New South Wales. of 24 and 16 nymphs per cutting on C. arcuata and C. longifolia respectively, but Year Hectares of dead % of property w ith none on Acacia con currens Pedley Cnssinia spp. dead Casshzia spp. (Fabaceae), Eucalyptus albell s Benth. 1985-87 0 0 (Myrtaceae), Hypericum peiforalum L. 1988 3 1 (Clusiaceae), Pinus radiatn D. Don 1989 18 5 (Pinaceae), Rosa rubigil10sa L. (Rosaceae) 1990 172 47 and Rubus fruticosus L. (Rosaceae). The 1991 255 70 plant species used were chosen because 1992 255 70 they are trees or shrubs that commonly Plant Protection Quarterly VoI.9(2) 1994 67

Figure 4. Cassinia arCllata infesting land near Boorowa. Figure 5. A dense stand of Cassinia arcltata killed by Altstrotaclwrdia sp. near Kerrs Creek. occur in areas infested by Cassillia spp. effectiveness as a bio-control agent has seedlings occur (Campbell el al. 1990). For Paratachardina sp. ha s on ly been ob­ not been studied. example, after slashing a dense infesta­ served on C. [nevis and C. quinquefaria in tion of C. arcuata in autumn 1989 at MuJ­ northern New South Wales, despite ac­ Replacement of Cassinia spp. lion Creek, New South Wales, 170 seed­ cess to many other plant species. killed by scale lings per square metre reinfested by Sep­ At Kerrs Creek, native perennial grasses tember 1989. Most of these seedlings, and Other insects that attack Cassinia and Acncia denlbnta replaced large areas of those of subsequent reinfestations in 1990 spp. C. arcuatn killed by Austrotachnrdia sp. and 1991, died due to competition for In the central tablelands of New South (Figure 5). An 800 m2 experimental area moisture and nutrients, but sufficient sur­ Wales the sca le Chi01taspis sp. (Hemiptera: complete ly infested with C. nrcuntn in vived to ensure complete reinfestation Diaspiclidae) occurs on C. arcuata with or 1988, was partly repla ced by Dnllthonin (Table 3). without Austrotachardia sp. At Kerrs spp., and some other useful species in In north-western New South Wales, ob­ Creek crawlers observed in October and 1991 and 1992 (Table 2). Few C. amlnla servations on two properties where January develop into brown nymphs and seedlings (0.01 m·' ) reinfested after the Paratachardinn sp. had killed C. laevis re­ reside in cracks in the bark. Later, the fe­ death of the mature plants because the vealed that red grass (Bothriochlon rnacra) males produce a soft white cover under seed lings were killed by Austrotachnrdia replaced the weed at Bingara, but sticky which she lays her eggs. The male is a sp. This contrasts with other con trol daisy bush (Olen ria eITiptica) became small red fly similar to th e male of methods where heavy reinfestations of dominant at Barraba, due to a large rabbit Austrotachardia sp. The time taken for the life cycle has not been determined. Table 3. Regeneration of C. arcltata from seed in the soil, in winters 1989, Chiollaspis sp. does not appear to kill C. 1990 and 1991 and subsequent decline in plant numbers, after mature arcuata. plants were killed by slashing in April 1989 at Mullion Creek, New South A dark brown sca le, Coccus sp. Wales. (Hemiptera: Coccidae), has killed a few A 2 Plants (m· ) establishing in plants of C. arcuata nea r Orange and C. Observation lon gifolia near Crookwell. date 1989 (s.d.') 1990 (s.d.) 1991 (s.d.) A native pine looper Chlenias sp. (Lepidoptera: Geometridae) de foliated September 1989 170 (1.8) 100 ha of C. arcuata near Boorowa in the May 1990 23 (1.5) 62 (1.6) southern tablelands (F igure 4) in 1989 and October 1990 19 (1.4) 24 (1.5) killed a few plants, but is not considered a June 1991 8 (1.3) 2 (1.2) 47 (1.5) possible bio-control agent because it also January 1992 8 (1.3) 1 (1.1 ) 35 (1.5) attacks Pinu s radiata . June 1992 7 (1.3) 1 (1.1 ) 22 (1.5) Larvae of a jewel beetle (Coleoptera: June 1993 6 (1.3) 1 (1.1 ) 10 (1.4) Buprestidae) have killed small areas of C. A measured in a 5 ha paddock on 48 x 0.25 m2 randomly selected permanent quadrats. arcuata on th e central tablelands but its B standard deviation. Table 2. Botanical composition before and after C. arcltata was killed by AltstrotaclIardia sp. in 1988--90 at Kerrs Creek, New South Wales. Ground cover (%) Spring Danthonia Microlaemfl Annual Broadleaved Cassinia Moss Bare spp. stipoides and legumes and plants arcuata and ground other perennial grasses litter grasses 1987 9 2 7 8 53 2 19 1991 34 3 10 7 <1 23 23 1992 42 6 3 8 <1 30 11 68 Plant Protection Quarterly VoI.9(2) 1994 population. On both properties C. lnevis Campbell, M.H. (1992). Spreading scale (1992). Biological control of ClISsi,,;a did not reinfest. in sects to control sifton bush (Cassinia spp. (Asteraceae). Eds. E.S. Delfosse These investi gations indicate that arcuata) and other Cassinia spp . Pro- and R.R. Scott. Proceedings 8th interna­ Austrotachardia sp. and Paratachardina sp. ceedings 7th Confe rence Grasslands So- tional Symposium on Biological Con­ are capable of controlling infestati ons of ciety of New South Wales, Tamworth, trol of Weeds, Lincoln, New Zealand. Cassinia spp. However, this control must pp.82-3. Hosking, I.R., McFadyen, R.E . and be augmented by a program to re-estab- Ca mpbell , M.H ., McGowen, 1.1., Milne, Murray, N.D. (1988). Distribution and \ish and maintain a pasture of perennial B.R. and Vere, D.T. (1990). The Biology biological contro l of cactus species in grasses and annual legumes to prevent re- of Australian Weeds. 22 . Cassinia eastern AustraHa. Plant Protection Quar­ infestation by Cassinia spp in case all the arcuata R. Br. Plant Protection Quarterly terly 3, 115-23. scale insects die as a result of killing all 5, 162-8. Hoy, I.M. (1 961). Eriococcus oraTiensis Hoy the host ClISsill in spp. Ca mpbell , M.H. and Wykes, P.I. (1991). and other Coccoidea (Homoptera) as­ Possible bie-control of sifton bush by sociated with Forst. spe­ Acknowledgments scale insects. Proceedings 6th Confer­ cies in New Zealand. New Zealand De­ We thank Dr. C.W. Watson, International ence Grassland Society of New South partment of Science Industry Research Institute of Entomology, London, for the Wales, Orange, pp. 101-2. Bulletin 141. identifi ca tion of Chionaspis sp. Campbell, M.H. and Wykes, P.I. (1992). Majer, I.D. (1 982). Ant-plant interactions Possible bio--control of native weeds by in the Darling Botanical District of References native insects. Proceed ings 1st mtema­ Western AustraHa . In 'Ant-Plant Inter­ Bradley, G.A. (1973). Effect of Fortllicn tional Weed Control Cong ress, Mel­ actions in Australi a', ed. R.C. Buckley, obscuripes (Hymenoptera : Formicidae) bourne 2, 106-8. pp. 45-62. Ounk, The Hague). on the predator-prey rela tionship Collins, L. and Scott, I.K. (1982). interac­ McClure, M.S. (1985). Patterns of abun­ between Hyperaspis congressis (Coleop­ tion of ants, predators and the sca le in­ n.ance, s urvivorship and fecundity of tera : Coccinellidae) and Toum eyeIla sect Pu /villariella mesembryanthemi on Nuculaspis tsugae (Homoptera : Dia­ num ismaticum (Homoptera: Coccidae). Carpobrotus etiuIis, an exotic plant natu­ spididae) on Tsuga species in Japan in Cmwdinll ElllolI/ologist 105, 111 3-ll. rali zed in Western Australia. Australian rela tion to eleva tion. EnviromllentaJ En ­ Buckley, R. (1987). Ant-plant- Eutomo!ogical Magazine 8, 73-8. tomology 14, 41 3-5. Ho mopteran interactions. Advances in Dolva, I.M. and Scott, I.K. (1982). The as­ McGowen, LI ., Campbell, M.H. and Ecologicnl Resenrch 16,53-85. sociation between the Milne, B.R. (1 990). Sifton bush. NSW Burns, D.P. (1973). The foraging and tend­ PseudococCliS macroznm ine, ants and the Agriculture Agfact P7.6.49. ing behaviour of Dolichorderus taschen­ cycad Macrozamia reidlei in a fire-prone O'Brien, L.B ., Stoetzel, M.B. and Miller, R. berg; (Hymenoptera: Formicidae). Ca­ environment. Journal of the Royal Society (1991). Order Homoptera, Ch. 30. III //Iulinll Ell lolI/ ologisl 105,97-104. of Western Auslralia 65, 33-6. 'Immature Insects', ed . F.W. Stehr Campbell , M.H . (1 977). Assessing the Edmunds, G.F . and Alstad, D.N. (1978). (Kendall / Hunt, Iowa, USA). area and distribution of serra ted tus­ Coevolution in insect herbivores and Strickland, A.H. (1958). The entomology sock (Na ssel1a trichotoma) , St John's conifers. Scie ll ce 199, 941-5. of swollen shoot of cacao. I. The insect wort (Hypericum perforatum) and sifton Froggatt, W.W. (1 899). Sca le insects that species involved, w ith notes on their bi­ bush (Cass jnia arcuata) in NSW. NSW prod uce lac. Agricultural Gazette New ology. Bulletin of Entomological Research Agriculture Technica l BuJletin 18. 50ulh Wnles 10, 11 59-61. 41,725-748. Ca mpbell , M.H. (1990). Distribution, Froggatt, W.W. (1903). 'Australian in­ Wa y, M.I. (1963). Mutualism between ecology and control of Cass j'lia arcua ta sects'. (William Brooks and Co. Ltd ., ants and honeydew·producing in New South Wales. Australian Journal ). Homoptera. Annual Review of Entomol­ of Experimell tal Agn'cuIture 30, 215-20. Holtkamp, R.H. and Campbell, M.H. ogy 8, 307-344.