The introduction and release of Chiasmia inconspicua and C. assimilis (Lepidoptera: Geometridae) for the biological control of Acacia nilotica in Australia

Two geometrid moths Chiasmia inconspicua and Chiasmia assimilis, identified as potential biological control agents for prickly acacia Acacia nilotica subsp. indica, were collected in Kenya and imported into quarantine facilities in Australia where laboratory cultures were established. Aspects of the biologies of both insects were studied and CLIMEX® models indicating the climatically favourable areas of Australia were developed. Host range tests were conducted using an approved test list of 74 plant species and no-choice tests of neonate larvae placed on both cut foliage and potted plants. C. inconspicua developed through to adult on prickly acacia and, in small numbers, Acacia pulchella. C. assimilis developed through to adult on prickly acacia and also in very small numbers on A. pulchella, A. deanei, A. decurrens, and A. mearnsii. In all experiments, the response on prickly acacia could be clearly differentiated from the responses on the non-target species. Both insects were approved for release in Australia. Over a three-year period releases were made at multiple sites in north Queensland, almost all in inland areas. There was no evidence of either insect’s establishment and both colonies were terminated. A new colony of C. assimilis was subsequently established from insects collected in South Africa and releases of C. assimilis from this new colony were made into coastal and inland infestations of prickly acacia. Establishment was rapid at one coastal site and the insect quickly spread to other infestations. Establishment at one inland area was also confirmed in early 2006. The establishment in coastal areas supported a CLIMEX model that indicated that the climate of coastal areas was more suitable than inland areas.     

Establishment of the biological control agent Hypocosmia pyrochroma for Dolichandra unguis-cati (Bignoniaceae) is limited by microclimate

Cat's claw creeper, Dolichandra unguis-cati (Bignoniaceae), a perennial woody vine native to tropical America, is a target for biological control in Australia and South Africa. The cat's claw creeper leaf-tying moth Hypocosmia pyrochroma (Lepidoptera: Pyralidae) from tropical South America was released as a biological control agent for cat's claw creeper in Australia from 2007 to 2010. A total of 2,277 adults, 837 pupae and 77,250 larvae were released at 40 sites in Queensland and New South Wales. Releases were made mostly in open fields (85%), and at limited sites (15%) in insect-proof cages erected over naturally occurring cat's claw creeper infestations in the field. Sampling was conducted annually in spring and autumn to monitor the establishment and dispersal of H. pyrochroma. Establishment of H. pyrochroma was first noticed in 2012 at three release sites and since then the number of established sites has increased to 80 in 2020. Establishment was evident on both ‘short-pod’ and ‘long-pod’ forms of cat's claw creeper and was more widespread in sites where releases were made within insect-proof field cages (50%) than in sites with open field releases (9%). The moth was active from late spring to late autumn with peak larval activity in late summer. To date, all field establishments have been in areas predicted by a CLIMEX model as climatically suitable but restricted mostly to riparian environment (93% of establishment), where the moth has continued to spread from 1.5 to 23 km from release sites. In contrast, there is the only limited establishment and spread in non-riparian corridors, highlighting the role of microclimate (riparian) as a limiting factor for establishment and spread. Future efforts will focus on redistribution of the agent to river/creek systems where the moth is currently not present.     

Status of Charidotis pygmaea (Coleoptera: Chrysomelidae) as a Biological Control Agent of Lantana montevidensis (Verbenaceae) in Australia

The establishment of the leaf-feeding beetle Charidotis pygmaea Klug and its potential to control Lantana montevidensis (Sprengel) Briquet, a serious pasture weed of central and southern Queensland, Australia, were assessed. C. pygmaea was collected in Brazil from Lantana fucata Lindley, a plant morphologically similar to L. montevidensis. Over 40,000 beetles were released over 3 years by use of caged and uncaged techniques at 25 sites throughout southeast and central Queensland. At 6 of the sites where detailed and frequent monitoring occurred, no adults were found 6 months after the release. At another 2 sites, adults were present for only 12 months. Only a small number of eggs were laid at any single site and few larvae completed development to the adult stage. No signs of insect activity were found at any site after 24 months. Comparative laboratory and experimental field plot trials with both the weedy (field host) and the ornamental (glasshouse host) forms of L. montevidensis did not show significant differences in insect performance. Assessment of nitrogen, phosphorous, potassium, and water contents, leaf hairiness, and leaf toughness of both the weedy and the ornamental forms of L. montevidensis grown under glasshouse and field plot conditions did not show differences between the two plant forms. There were, however, differences in the percentage of adults that developed in the glasshouse trials compared to the field plot trials (55% vs 5%). Field observations in Brazil showed that C. pygmaea was found only on L. fucata and L. tiliifolia Chamisso and was not seen on L. montevidensis growing in the same region. Climate matching with CLIMEX showed that most areas in Australia where L. montevidensis is a major problem are not climatically similar to the collection sites of C. pygmaea in Brazil. Whereas populations of C. pygmaea can be maintained on L. montevidensis under glasshouse conditions, it performs poorly on that species under field conditions. Unsuitable climatic conditions and an incompatible target plant are the most likely factors affecting the poor performance of C. pygmaea. Consequently, field releases of the agent in Australia have ceased and C. pygmaea is not recommended as a biological control agent for L. montevidensis in Australia.     

Biology and Host Specificity of the Stem Galling Weevil Conotrachelus albocinereus Fiedler (Col.: Curculionidae), a Biocontrol Agent for Parthenium Weed Parthenium hysterophorus L. (Asteraceae) in Queensland, Australia

The stem-galling weevil Conotrachelus albocinereus Fiedler has been investigated as a potential biological control agent against parthenium weed ( Parthenium hysterophorus L.) in Australia. Adults were tested in multiple-choice feeding and oviposition tests on 56 plant species in 51 genera. No feeding or oviposition was recorded on any non-target plant except annual ragweed ( Ambrosia artemisiifolia L.), a closely related weed. Field releases of the weevil in Queensland, Australia, commenced in 1995 and establishment has been recorded at several sites.     

Biology and host specificity ofPlatphalonidia mystica (Lep.: Cochylidae) introduced into queensland to biologically controlParthenium hysterophorus (Asteraceae)

Platphalonidia mystica (Razowski &; Becker) has been studied as a potential biological control agent against parthenium weed (Parthenium hysterophorus L.). During host specificity testing, larval feeding damage occurred on sunflower (Helianthus annuus L.) and to a lesser extent onDahlia sp., but risk of damage to sunflower crops under field conditions is considered negligible. In view of the very great problem thatP. hysterophorus is causing, and the threat of its continued southward spread into Southern Queensland, New South Wales and Victoria, field release ofP. mystica was authorised and commenced in Queensland in late 1992.     

The host range and biology of <Emphasis Type="Italic">Cometaster pyrula</Emphasis>; a biocontrol agent for <Emphasis Type="Italic">Acacia nilotica</Emphasis> subsp. <Emphasis Type="Italic">indica</Emphasis> in Australia

Prickly acacia, Acacia nilotica subsp. indica (Benth.) Brenan, a major weed of the Mitchell Grass Downs of northern Queensland, Australia, has been the target of biological control projects since the 1980s. The leaf-feeding caterpillar Cometaster pyrula (Hopffer) was collected from Acacia nilotica subsp. kraussiana (Benth.) Brenan during surveys in South Africa to find suitable biological control agents, recognised as a potential agent, and shipped into a quarantine facility in Australia. Cometaster pyrula has a life cycle of approximately 2 months during which time the larvae feed voraciously and reach 6 cm in length. Female moths oviposit a mean of 339 eggs. When presented with cut foliage of 77 plant species, unfed neonates survived for 7 days on only Acacia nilotica subsp. indica and Acacia nilotica subsp. kraussiana. When unfed neonates were placed on potted plants of 14 plant species, all larvae except those on Acacia nilotica subsp. indica and Acacia nilotica subsp. kraussiana died within 10 days of placement. Cometaster pyrula was considered to be highly host specific and safe to release in Australia. Permission to release C. pyrula in Australia was obtained and the insect was first released in north Queensland in October 2004. The ecoclimatic model CLIMEX indicated that coastal Queensland was climatically suitable for this insect but that inland areas were only marginally suitable.     

Biological control of parthenium (Parthenium hysterophorus): the Australian experience

ABSTRACT

Parthenium is a Weed of National Significance in Australia. Biological control of parthenium in Australia commenced in 1977 and since then nine insect species and two rust fungi have been introduced and established. Seven of them are widespread, however the time taken for field establishment varied widely between various agents, ranging from one to 15 years. Among them, the stem-galling Epiblema moth, the stem-boring Listronotus weevil, the seed-feeding Smicronyx weevil and the root-feeding Carmenta moth occur in all parthenium-infested areas at high population densities. The leaf-feeding Zygogramma beetle occurs only in central and southern Queensland, and not in northern Queensland. The parthenium summer rust occurs seasonally in central and northern Queensland, while the parthenium winter rust is more widespread in southern Queensland than in central Queensland, but does not occur in north Queensland. The sap-feeding Stobaera planthopper and the leaf-mining Bucculatrix moth established and are widespread, but their damage levels remain very low. The stem-galling Conotrachelus weevil and the stem-boring Platphalonidia moth are believed to be established, but at very low abundance. Biological control has resulted in significant reductions in the abundance and impact of parthenium in Australia. As a result, the area infested with parthenium in central Queensland has declined since the mid-1990s. Due to the absence of many of the effective agents in southern and south-eastern Queensland, agents from central Queensland are being redistributed there. Additionally, based on Australian success, many of these agents have also been introduced into other countries around the world.     

The leaf-tying moth Hypocosmia pyrochroma (Lep., Pyralidae), a host-specific biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia

Abstract:  Cat's claw creeper, Macfadyena unguis-cati , a major environmental weed in coastal and sub-coastal areas of Queensland and New South Wales, Australia is a target for classical biological control. Host specificity of Hypocosmia pyrochroma Jones (Lep., Pyralidae), as a potential biological control agent was evaluated on the basis of no-choice and choice larval feeding and survival, and adult oviposition preference tests, involving 38 plant species in 10 families. In no-choice tests, larval feeding and development occurred only on cat's claw creeper. In choice tests, oviposition and larval development was evident only on cat's claw creeper. The results support the host-specificity tests conducted in South Africa, and suggest that H. pyrochroma is a highly specific biological control agent that does not pose any risk to non-target plants tested in Australia. This agent has been approved for field release by relevant regulatory authorities in Australia.     

Introduction, Rearing, and Host Range of Aerenicopsis championi Bates (Coleoptera: Cerambycidae) for the Biological Control of Lantana camara L. in Australia

The biology and host range of the cerambycid beetle Aerenicopsis championi Bates, a potential biological control agent for the weed Lantana camara L., were studied. A. championi is a univoltine species associated with L. camara, L. urticifolia, and L. hirsuta in Mexico and Central America. In Mexico, adult emergence occurred in May and June at the start of the rainy season. Larvae fed within the stems over a 9- to 12-month period and caused damage to the plant. The insect was imported into Australia, where a procedure for rearing it in the laboratory was developed. Host-range tests indicated that adults oviposited and larvae commenced development in L. camara and L. montevidensis but not in any of 57 other species tested. A CLIMEX model indicated that most areas infested with lantana in Australia would have a favorable climate for A. championi. Permission to release this insect in Australia was obtained and three small releases were made in southern Queensland in February 1995.     

Predicting the potential geographical distribution of the harlequin ladybird, Harmonia axyridis, using the CLIMEX model

Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) is a ladybird beetle native to temperate and subtropical parts of Asia. Since 1916 populations of this species have been introduced throughout the world, either deliberately, or by accident through international transport. Harmonia axyridis was originally released as a classical biological control agent of aphid and coccid pests in orchards and forests, but since 1994 it is also available as a commercial product for augmentative control in field and greenhouse crops. It is a very voracious and effective natural enemy of aphids, psyllids and coccids in various agricultural and horticultural habitats and forests. During the past 20 years, however, it has successfully invaded non-target habitats in North America (since 1988), Europe (1999) and South America (2001) respectively in a short period of time, attacking a wide range of non-pest species in different insect orders. Becoming part of the agricultural commercial pathway, it is prone to being introduced into large areas across the world by accident. We use the CLIMEX programme (v2) to predict the potential geographical distribution of H. axyridis by means of matching the climate of its region of origin with other regions in the world and taking in account biological characteristics of the species. Establishment and spread seem likely in many regions across the world, including those areas which H. axyridis has already invaded (temperate Europe, North America). Based on the CLIMEX prediction a large part of Mediterranean Europe, South America, Africa, Australia and New Zealand seem highly suitable for long-term survival of H. axyridis as well. In addition we evaluate CLIMEX as a strategic tool for estimating establishment potential as part of an environmental risk assessment procedure for biological control agents we discuss biological and ecological aspects necessary to fine-tune its establishment and spread in areas after it has been introduced.     

Size of the first spring generation of Helicoverpa punctigera (Wallengren) (Lepidoptera: Noctuidae) and winter rain in central Australia

Serious infestations of Helicoverpa punctigera are experienced yearly in the eastern cropping regions of Australia. Regression analysis was used to determine whether the size of the first generation in spring (G₁), which is comprised mostly of immigrants from inland Australia, was related to monthly rainfall in inland winter breeding areas. Data from two long series of light-trap catches at Narrabri in New South Wales (NSW) and Turretfield in South Australia (SA) were used in the analyses. The size of G₁ at Narrabri in each year was significantly regressed on the amount of rainfall in western Queensland and NSW in May and June. The size of G₁ at Turretfield each year was significantly regressed on the amount of rain in May, June and July in western Queensland and NSW and also in the desert of central Western Australia. Low r ² values of the regressions suggest that rainfall data for more sites, as well as biological and other physical factors, such as temperature, evaporation, and prevailing wind systems, may need to be included to improve forecasts of the potential magnitude of the infestations in coastal cropping regions.     

Use of CLIMEX modelling to identify prospective areas for exploration to find new biological control agents for prickly acacia

Abstract  Selection of biocontrol agents that are adapted to the climates in areas of intended release demands a thorough analysis of the climates of the source and release sites. We present a case study that demonstrates how use of the CLIMEX software can improve decision making in relation to the identification of prospective areas for exploration for agents to control the woody weed, prickly acacia Acacia nilotica ssp. indica in the arid areas of north Queensland.     

The biology and host specificity of the stem-boring weevilListronotus setosipennis [Col.: Curculionidae] A potential biocontrol agent forParthenium hysterophorus [Asteraceae]

The stem-boring weevilListronotus setosipennis (Hustache) is widespread and damaging to its hostParthenium hysterophorus L. in northern Argentina and southern Brazil. In detailed host-testing it was shown to have a restricted host-range and, despite some feeding and development on sunflower in tests, to be a safe biological control agent againstP. hysterophorus. Field releases in Queensland, Australia took place from 1982 to 1986 and the weevil has established over several thousand hectares at numerous sites. Spread is however slow and the effect on the plant still negligible.      

The Biogeography of Cladocera (Crustacea) in Tropical Australia

Ninetysix species of Cladocera, comprising 8 Sididae, 50 Chydoridae, 17 Macrothricidae, 5 Moinidae, 2 Bosminidae, and 14 Daphniidae, occur in tropical Australia. Of this number 38% are cosmopolitan including so-called cosmopolitan species, 13.5% are circumtropical, 13.5% occur as well innear by countries, and 35% are endemic. North Queensland is a major area of speciation. Species richness varies from north to south and from wetter coastal areas to the drier inland. Major factors influencing richness and distribution are the relative proportion of floodplain billabongs in an area, coupled with rainfall reliability. The most common species include Alonella clathratula, Chydorus nr. pubsecens, Macrothrix triserialis, Oxyurella singalensis, Ephemeroporus nr. barroisi, Dadaya macrops, Diaphanosoma sarsi, Ceriodaphnia cornuta, and Dunhevedia crassa.     

New species of Choleoeimeria (Apicomplexa: Eimeriidae), coccidia of bile-bladders of reptiles, illustrating a multiplicity of host cell-parasite interrelations

Oocyst characteristics and histological features of the endogenous development of bile-bladder coccidia of the genus Choleoeimeria Paperna and Landsberg, 1989 are described and the main features for species differentiation are discussed for the following new species: C. allogamae n. sp. from Agama sp., Cameroon, West Africa; C. allogehyrae n. sp. from Gehyra australis, Magnetic Island (type) and mainland N Queensland, Australia; C. boulii n. sp. from Gehyra variegata, SW Queensland, Australia; C. calotesi n. sp. from Calotes mystaceus, Xiang-Mai, Thailand; C. heteronotis n. sp. from Heteronotia binoei, N Queensland, Australia; C. lygosomis n. sp. from Lygosoma buringi, Kon-Kaen, Thailand; C. sylvatica n. sp. from Carlia rhomboidalis, N Queensland, Australia, and C. xiangmaii n. sp. from Hemidactylus frenatus, Xiang-Mai, Thailand. Oocyst characteristic of Choleoeimeria are also reported from Oedura castelnaui, N Queensland. The described species demonstrate a diversity of associations with the bile-bladder epithelial lining, from a single parasite in a single hypertrophic host cell to multiple infections inducing the hypertrophied cells to form stratified layers, or merge into branched clumps.     

Potential distribution of the Asian disease vector Culex gelidus Theobald (Diptera: Culicidae) in Australia and New Zealand: a prediction based on climate suitability

Abstract  Culex gelidus has a wide distribution throughout Asia, where it is a vector of Japanese encephalitis. It was first detected in Australia in 1999, with archived material revealing an introduction sometime prior to 1994. It is currently widely distributed throughout northern and particularly north-eastern Australia. Using climate matching software (CLIMEX Version 1.1) and the known distribution of Cx. gelidus throughout Asia, a predicted distribution for Australasia based on current climate was developed. A potentially wide distribution throughout coastal Australia, particularly in tropical and subtropical areas, was revealed. Few inland locations were suitable, except in tropical areas of the Northern Territory and Queensland. The predicted distribution presented here is concordant with most recent collection records of Cx. gelidus in Australasia. However, there are a small number of exceptions which highlight some of the limitations of this approach for predicting mosquito distributions. The presence of Cx. gelidus in a large artificial swamp in Alice Springs is one such example. The predicted Cx. gelidus distribution incorporates highly populated areas, in which people may experience an increased risk of mosquito-borne viral encephalitis should this mosquito spread throughout its entire predicted range.     

Forecasting Helicoverpa populations in Australia： A comparison of regression based models and a bioclimatic based modelling approach

Abstract Long-term forecasts of pest pressure are central to the effective management of many agricultural insect pests. In the eastern cropping regions of Australia, serious infestations of Helicoverpa punctigera (Wallengren) and H. armigera (Hübner)(Lepidoptera: Noctuidae) are experienced annually. Regression analyses of a long series of light-trap catches of adult moths were used to describe the seasonal dynamics of both species. The size of the spring generation in eastern cropping zones could be related to rainfall in putative source areas in inland Australia. Subsequent generations could be related to the abundance of various crops in agricultural areas, rainfall and the magnitude of the spring population peak. As rainfall figured prominently as a predictor variable, and can itself be predicted using the Southern Oscillation Index (SOI), trap catches were also related to this variable. The geographic distribution of each species was modelled in relation to climate and CLIMEX was used to predict temporal variation in abundance at given putative source sites in inland Australia using historical meteorological data. These predictions were then correlated with subsequent pest abundance data in a major cropping region. The regression-based and bioclimatic-based approaches to predicting pest abundance are compared and their utility in predicting and interpreting pest dynamics are discussed.     

The potential geographical distribution of the Old World screw-worm fly, Chrysomya bezziana

The potential geographical distribution and relative abundance of the Old World screw-worm fly, Chrysomya bezziana Villeneuve (Diptera: Calliphoridae) as determined by climate, was assessed using CLIMEX, a computer program for matching climates. CLIMEX describes the relative growth and persistence of animal populations in relation to climate. The observed global distribution of C.bezziana was compared with the potential distribution predicted by CLIMEX. The differences in the two distributions indicate the areas at risk of colonization, with particular reference to Australia and the Americas. According to the model, the potential area of permanent colonization in Australia extends south to the mid-coast of New South Wales. Comparison of areas suitable for permanent establishment with the potential summer distribution indicates that large additional areas, carrying most of the continent's livestock, could be colonized in the summer months. Seasonal population growth indices are presented for three ports in Australia at which screw-worm fly specimens have been collected by quarantine authorities. They indicate the relative risk associated with introductions at different places in different seasons and so provide valuable planning information for quarantine authorities. The CLIMEX predictions for C.bezziana in North America are shown to be similar to the recorded distribution limits of the New World screw-worm fly, Cochliomyia hominivorax (Coquerel). The fly could also colonize South America, as far south as southern Brazil and midway through Argentina.     

Complementing biological control with plant suppression: Implications for improved management of parthenium weed (Parthenium hysterophorus L.)

Parthenium hysterophorus L. is a weed of global significance that has become a major weed in Australia and many other parts of the world. A combined approach for the management of parthenium weed using biological control and plant suppression, was tested under field conditions over a two-year period in southern central Queensland. The six suppressive plant species, selected for their demonstrably suppressive ability in earlier glasshouse studies, worked synergistically with the biological control agents (Epiblema strenuana Walker, Zygogramma bicolorata Pallister, Listronotus setosipennis Hustache and Puccinia abrupta var. partheniicola) present in the field to reduce the growth (above ground biomass) of parthenium weed, by between 60–86% and 47–91%, in Years 1 and 2, respectively. The biomass of the suppressive plants was between 6% and 23% greater when biological control agents were present than when the biological control agents had been excluded. This shows that parthenium weed can be more effectively managed by combining the current biological control management strategy with selected sown suppressive plant species, both in Australia and elsewhere.     

The synonymy and distribution of the crenaticeps-group of Atractomorpha Saussure, 1862 (Orthoptera, Acridoidea, Pyrgomorphidae)

The general distribution of Atractomorpha australis Rehn, A. similis Bolívar and A. crenaticeps (Blanchard) in Australia and the South Pacific is discussed. Detailed synonymies and lists of known localities are given for each species, together with a distribution map. A. australis is confined to cooler, moister regions of Australia from eastern Victoria to south-western Queensland; A. similis is more tropical, occurring in the southern Moluccas, Timor, southern New Guinea and associated islands to northern and eastern Australia, but it extends, in suitable localities, as far south as central New South Wales, and, in inland areas, even to north-western Victoria and south-eastern South Australia; A. crenaticeps , formerly thought to embrace both the above species, is restricted to the northern Moluccas, western and other parts of New Guinea north of and including the central mountain chains and associated islands to the north and west, and to the Bismarck Archipelago and the Solomon Islands.