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The combined impact of biocontrol agents on the seed regenerative capacity, i.e. seed production, seed-rain, soil seedbank, seed germination and seedling density, of Lantana camara L. (sensu lato) (Verbenaceae), was measured in the field in an inland area of South Africa. The study was conducted on 10 plots (20 × 50 m each) along part of the Sabie River catchment. The most prevalent biocontrol agents at the site were Aceria lantanae (Cook) (Acari: Trombidiformes: Eriophyidae), Hypena laceratalis Walker (Lepidoptera: Noctuidae), Octotoma scabripennis Guérin-Méneville (Coleoptera: Chrysomelidae), Ophiomyia camarae Spencer (Diptera: Agromyzidae) and Teleonemia scrupulosa Stål (Hemiptera: Tingidae). Using the insecticidal exclusion method, comparisons of seed regenerative capacity were made between exclusion (insecticide treated) and biocontrol (untreated) plants over a three-year period. Lantana camara seed production per plant was slightly lower in biocontrol (5831 ± 844 seeds) compared to exclusion plants (6718 ± 1571 seeds), seed-rain density was significantly lower in biocontrol (1080 ± 122 seeds m−2) compared to exclusion plants (1419 ± 154 seeds m−2). Seed germination was lower in biocontrol (98 ± 41 seeds m−2) compared to exclusion plants (116 ± 38 seeds m−2). Seedling density was higher in biocontrol (36 ± 14 seedlings m−2) compared to exclusion plants (32 ± 11 seedlings m−2). Adult plants appeared to suppress their own seedlings. This study showed that the impact of the current suite of biocontrol agents on the recruitment potential of L. camara is minimal, emphasising the need for additional agents, better adapted to the cooler high altitude inland environmental conditions. [ABSTRACT FROM AUTHOR]

This laboratory-based study sought to determine the efficacy of using carbofuran in an exclusion experiment aimed at assessing the impacts of biocontrol agents on Lantana camara L. (sensu lato) (Verbenaceae). Two separate experiments were conducted, the first one on insect-free plants, to determine the effects of carbofuran solely on plant growth; and the second one, on Teleonemia scrupulosa Stål (Hemiptera: Tingidae) infested plants, with the objective of determining the impact of carbofuran on this biocontrol agent, as well as its impacts on plant growth. Carbofuran granules (10% a.i.) were applied at 7 g/m2 a.i. to the potting medium. It was found that carbofuran did not have a significant effect on plant growth. Total removal of T. scrupulosa from exclusion plants (carbofuran-treated plants) was not achieved; however the low level of leaf feeding lesions on those plants indicated that carbofuran had considerably reduced the insect's population density. Results from a bioassay showed 100% and 40% T. scrupulosa mortality on leaves collected from carbofuran-treated and control plants, respectively, within three weeks of exposure. Analysis of chemical residue levels in the leaf material revealed that carbofuran potency only persisted for about three weeks, and was detectable at trace levels (<0.1 mg/kg). It was therefore concluded that carbofuran was effective at reducing the population of T. scrupulosa on its host plant, but only briefly. Carbofuran should be applied at least once every three weeks or at a higher dosage in order to maintain a low insect population for the duration of an experiment or to achieve total exclusion. For better insect removal, one should consider combining carbofuran and foliar insecticides. [ABSTRACT FROM AUTHOR]

A host specificity study conducted in South Africa between 2000 and 2004 showed that the leafhopper, Barela parvisaccata Young, performed as well on some of the indigenous Lippia spp. as on the target weed Lantana camara L. During adult no-choice tests, B. parvisaccata reproduced on eight species of the two closely related genera, Lantana and Lippia . Although B. parvisaccata has a restricted host range, its reproductive performance on the indigenous Lippia scaberrima Sond. during the adult multiple-choice tests was unacceptably high. It was therefore concluded that B. parvisaccata was not sufficiently host-specific to be released against L. camarara in Africa. [ABSTRACT FROM AUTHOR]

The distribution and abundance of Ophiomyia camarae was determined in three ecological regions, i.e., highveld, middleveld, and lowveld of Swaziland. Within each region, sites were selected based on Lantana camara L. density, with 10 plants randomly chosen per sampling site. Ten leaves from each shrub were collected and assessed for any damage caused by the herringbone leaf-miner. Relative abundance, based on the number of shrubs damaged by the herringbone leaf-miner, was scored per site. Three lantana varieties were observed during the sampling period. There were significant differences in mean leaf damage due to leaf-miner activity between varieties (P=0.0162), with 46±4.89% leaves of the pale pink variety damaged compared to 23±5.56 and 21±3.53% leaves of the orange and pink varieties, respectively. While there were no restrictions in terms of distribution, the highest levels of O. camarae populations were observed in the middleveld (P=0.0012), suggesting that this region had the most suitable environmental conditions for this natural enemy. Overall, the abundance was significantly different between regions (P=0.006) and months (P=0.000), with April scoring the highest population levels. Based on our observations, the variation in environmental conditions has an influence on the activity of O. camarae, with the middleveld having the most suitable conditions [ABSTRACT FROM AUTHOR]

Compatibility between the root-feeding agent Longitarsus bethae Savini & Escalona and the varieties of the target weed Lantana camara L. could influence the chances of successful establishment and effectiveness of this agent as a biocontrol agent of lantana in South Africa. Laboratory experiments were conducted to determine the influence of major South African lantana varieties on feeding, colonization, oviposition preference and larval survival of L. bethae. Feeding preference and the number of adults per plant varied among the varieties. The most damaged and colonized varieties were 150 Orange, 009 Light Pink and 113 Dark Pink. Variety 018 Dark Pink was the least damaged, while 021 Total Pink and 029 White Pink were the least colonized. Females laid the highest number of eggs on variety 150 Orange. The lowest number of eggs was recorded on Australian Richmond Pink and the closely related species Lippia wilmsii. Larval survival differed significantly among the varieties. The highest survival was recorded on 150 Orange. Duration of development also varied significantly among the varieties, with the slowest rate of development recorded on variety 029 Light Pink and the quickest on variety 015 White Yellow. Although variations in female body size were less significant among varieties, males emerging from variety 150 Orange were slightly smaller than those emerged from other varieties. There was a significant tendency for females to select varieties that enhanced the survival of their offspring, which met the predictions of the preference-performance hypothesis. The data suggest that the chances of establishment and successful control of the weed are expected to be much greater on those varieties that were preferred for oviposition and provided better larval performance. [ABSTRACT FROM AUTHOR]

An 8-month study was conducted to determine the effect of herbivory by the herringbone leafminer Ophiomyia camarae Spencer (Diptera: Agromyzidae) and the lace bug Teleonemia scrupulosa Stål (Heteroptera: Tingidae) on growth and reproductive capacity of their host plant, Lantana camara L. (Verbenaceae), Ophiomyia camarae adults were released into field cages at two population densities while T. scrupulosa, a widespread and naturalised biocontrol agent in South Africa, colonised and attacked uncaged plants of similar size grown under similar field conditions. At lower initial density, O. camarae reduced stem height, stem diameter, leaf density, flower density and above-ground biomass by 5, 22, 54, 100 and 41%, respectively. At higher initial density of O. camarae, stem height, stem diameter, leaf density, flower density and above-ground biomass were substantially reduced by 19, 28, 73, 99 and 49%, respectively. Teleonemia scrupulosa also reduced stem height, stem diameter, leaf density, flower density and above-ground biomass by 37, 34, 75, 100 and 50%, respectively. The root development was less affected by both O. camarae and T. scrupulosa. Whilst higher densities of O. camarae exerted noticeable herbivore pressure, T scrupulosa herbivory substantially hampered plant growth and reproductive capacity even at lower population levels. These findings suggest that O. camarae, released in 2001 for the control of lantana, would be effective as part of a complementary guild of biological control agents. The profound effect of herbivory by T. scrupulosa on plant growth and reproductive capacity suggests that it is making a much greater contribution to the biological control of lantana in South Africa than was previously thought. [ABSTRACT FROM AUTHOR]

A biotype of the flower-galling mite, Aceria lantanae (Cook) (Trombidiformes: Eriophyidae) collected in Florida (U.S.A.) was released in South Africa in 2007 against Lantana camara L. (Verbenaceae) but has displayed patchy establishment. The occurrence of different L. camara varieties and their susceptibility to A. lantanae were assessed across four provinces with dense infestations. Surveys were undertaken at 113 sites during the mite’s peak infestation period (April-May) in 2013-2015. The occurrence of 13 recorded L. camara varieties differed substantially across and within these provinces. Overall, five varieties accounted for 7-45% of the sampled plants at 9-51% of the surveyed sites. The remaining eight varieties accounted for <1-4% of the plants at 2-9% of the sites. The establishment and impact of A. lantanae differed significantly between L. camara varieties. The mite established best on three varieties (163 LP, 021 WP and 015 OR), with 60-90% of plants infested. Reduced establishments were observed on seven varieties, with 18-50% of plants infested, while no establishment was recorded on three varieties. Where established, A. lantanae inflicted considerable levels of damage (i.e. 51-75% of buds infested) on the most widespread and abundant L. camara variety (163 LP) and on one less common variety (021 WP). Two uncommon varieties (015 OR, 021 P) suffered moderate levels of damage with the remainder suffering only trivial levels. The mite’s impact in South Africa could be improved by complementing the established biotype with others from Central and South America that are better matched with the poorly attacked L. camara varieties. [ABSTRACT FROM AUTHOR]

The invasive macrophyte water hyacinth, Pontederia crassipes (Mart.) Solms (Pontederiaceae), was first introduced in India at the Acharya Jagadish Chandra Bose Indian Botanic Garden, near Kolkata in 1889 from where they spread throughout the sub-continent. An extensive systematic survey of water bodies in and around Kolkata, India, was done for the first time to assess the natural occurrence of indigenous phytopathogenic fungi of the weed between 2014 and 2019. The study brings into light several species, along with some first reports, of naturally occurring native phytopathogenic fungi and their evolutionary-related lineages. The occurrence and frequency of pathogens varied from site to site. Around 150 fungal pathogens isolated from water hyacinth were evaluated for their disease-causing potential against the weed. The isolated fungi were identified using morphological and molecular techniques. Fusarium Link followed by Alternaria Nees were the highest and most consistently isolated genera. Seven potential fungi that caused more than 90% disease in whole plant pathogenicity bioassay were subjected to host-range evaluation against 67 plant species selected based on ecological nearness or economic significance. Among these Fusarium oxysporum f. sp. lycopersici (WHK-59) was found to have a narrow host range and be effective against water hyacinth. With further studies on their impact assessment, environmental viability and tolerance, few of them, especially F. oxysporum (WHK- 26, 106) may effectively reduce population growth of water hyacinth by themselves or in conjunction with other introduced biocontrol agents, including insects and other plant pathogens. [ABSTRACT FROM AUTHOR]

After initially building up to high densities, populations of a promising biological control agent, Falconia intermedia (Distant) (Hemiptera: Miridae), imported to control the invasive plant Lantana camara L. (Verbenaceae) in South Africa, disappeared at almost all release sites in the Eastern Cape, Mpumalanga, KwaZulu-Natal and Limpopo provinces. In an attempt to explain this phenom-enon, laboratory trials were conducted to determine the effect of previous feeding on the subsequent performance of F. intermedia on L. camara varieties from two of the Eastern Cape release sites; Lyndhurst Farm and Whitney Farm. F. intermedia feeding damage, number of adults, number of nymphs and oviposition on Whitney Farm, L. camara plants were 40.8% (p <0.001), 106% (p <0 .001), 81.5% (p <0.001) and 80% (p <0.001) higher, respectively, than on Lyndhurst Farm, indicating the superior suitability and quality of Whitney Farm plants for F. intermedia performance. A defence response was observed by plants from Lyndhurst Farm that were previously fed on (i.e. induced). The induced plants had significantly lower F. intermedia feeding damage (21.4% less, p =0.007), numbers of adults (187.5% less, p =0.034), numbers of nymphs (110% less, p =0.071) and oviposition (99.8% less, p =0.021) than plants that were not previously fed on. The defence responses were elicited and expressed throughout the plant in both damaged and undamaged leaves within five weeks after insect release (rapidly induced response). The significant decrease in herbivore performance suggests that some L. camara varieties possess factors that enable them to resist subsequent feeding activity, offering us some under-standing of one of the factors that might have contributed to the failure of F. intermedia in South Africa. [ABSTRACT FROM AUTHOR]

The stem-galling fly, Eutreta xanthochaeta , was evaluated as a potential agent for biocontrol of the invasive alien plant, Lantana camara, in Africa. Multi-choice trials showed an approximately equal oviposition preference for indigenous Lantana and Lippia species, and the target weed. They were also found to be about equally suitable for fly development. Finally, population sustainability studies indicated that the fly has about as much potential to persist on these indigenous plants as on the target weed. It was concluded that E. xanthochaeta is insufficiently host specific to use for biocontrol of L. camara in Africa. [ABSTRACT FROM AUTHOR]

Lantana camara is a poisonous, bushy shrub from South and Central America that has invaded much of the moist, warm sub-tropical areas of South Africa. In the last decade, evidence of a conspicuous and damaging mycobiota on lantana in the Neotropics has persuaded biocontrol researchers to consider fungi as potential biocontrol agents for this plant. Samples of diseased L. camara leaves were collected during field surveys in South, North and Central America from 1987 to 1997. Pathogenicity tests showed the leaf spot fungus, Mycovellosiella lantanae var. lantanae to be a promising biocontrol pathogen. Inoculations onto South African biotypes of L. camara and a number of closely related species within the family Verbenaceae were made under quarantine conditions to determine the pathogenicity and host specificity of the fungus. Inoculation of L. camara biotypes resulted in necrotic, grey lesions (20-60 per leaf), necrosis of flower buds and stalks, as well as defoliation of certain biotypes after three weeks. None of the other plant species tested showed any disease symptoms. This indicates a very restricted host range, making this pathogen a suitable candidate for application as a biological control agent. It is expected that the fungus will reduce the vigour and reproductive potential of L. camara. Due to the variation in virulence of M. lantanae var. lantanae when tested on South African lantana biotypes, release strategies may include the use of combinations of the isolates to target a wider range of lantana biotypes in the field. Permission to release M. lantanae var. lantanae in South Africa was granted in September 2001. The pathogen will be released as a classical biocontrol agent in South Africa. [ABSTRACT FROM AUTHOR]

Invasive alien plants (IAPs) are considered one of the greatest threats to biodiversity in South Africa and are often associated with negative socio-economic and human health consequences. Biocontrol is seen as an effective strategy for managing IAPs however it can realistically only be considered for a subset of such plants given the limited funding resources available. Some plants are also better targets for biocontrol than others. This paper develops a prioritisation system to create an objective, transparent and easily usable method in which to target IAPs plants that are most suited to biocontrol in South Africa. The Biological Control Target Selection (BCTS) system builds on twelve previously developed prioritisation systems. The system uses three sections encompassing thirteen attributes that are combined to present the highest predicative powers to rank potential target IAPs as biocontrol targets. [ABSTRACT FROM AUTHOR]

Australia and South Africa have a long history of sharing successful biocontrol agents for cactus weeds but other countries, such as Namibia, could also benefit. There are four biological control agents that are widely utilised in South Africa and/or Australia for the control of 10 invasive alien Cactaceae in Namibia. [ABSTRACT FROM AUTHOR]

Sagittaria platyphylla (Engelmann) J.G. Smith (Alismataceae) was first recorded in South Africa in 2008 and is considered to be an emerging weed with naturalised populations occurring throughout the country. A biological control programme was initiated in Australia and surveys conducted between 2010 and 2012 yielded potential agents, including the crown feeding weevil, Listronotus sordidus Gyllenhal (Coleoptera: Curculionidae). The potential of L. sordidus as a candidate biological control agent against S. platyphylla in South Africa was examined. Although adult feeding was recorded on a number of plant species, oviposition and larval development indicated a narrow host range restricted to the Alismataceae. In South Africa, S. platyphylla populations are primarily found in inundated systems. However, laboratory studies showed that L. sordidus did not oviposit on inundated plants, potentially nullifying the impact of the insect on South African populations. It is suggested that even though L. sordidus is a damaging, specific agent, its limited impact on inundated plant populations in South Africa does not justify the inherent risk associated with the release of a biological control agent. [ABSTRACT FROM AUTHOR]

The biology and host range of the defoliating beetlePhysonota maculiventrisBoheman (Chrysomelidae: Cassidinae) were studied in quarantine to determine its suitability for release as a biological control agent against Mexican sunflower,Tithonia diversifolia(Hemsl.) A. Gray (Asteraceae), in South Africa. Females laid 5.25 ± 0.25 (mean ± SE) egg batches during their lifetimes, with each batch consisting of approximately 33 eggs. Larvae were highly gregarious as early instars and both larvae and adults fed voraciously, often defoliating the plants completely. The life cycle of the beetle was completed in 67.5 ± 7.5 days under quarantine conditions. Among the 58 test plant species subjected to no-choice tests,P. maculiventrisdeveloped successfully onT. diversifoliaand some sunflower (Helianthus annuusL.) cultivars. However, only minor damage was recorded on non-target species, notably the exotic weedXanthium strumariumL. and someH. annuuscultivars. Also, survival to adulthood was considerably lower on sunflower cultivars than on the target weed during these tests. During choice tests,P. maculiventrisoviposited and developed successfully onT. diversifoliaonly, with only minor feeding damage on someH. annuuscultivars, suggesting that the beetle’s field host range will be confined to the target weed. Risk analysis also showed thatP. maculiventrispresents an extremely low risk to non-target plant species (e.g. within the tribe Heliantheae and other close relatives). The study concluded thatP. maculiventrisis safe for release in South Africa and an application for its release is being considered by the relevant South African regulatory authorities. [ABSTRACT FROM PUBLISHER]

The gall flyCecidochares connexa(Diptera: Tephritidae) is a potential biological control agent forChromolaena odoratain Australia. Its host specificity was determined against 18 species in the tribe Eupatorieae (Family Asteraceae) in whichC. odoratabelongs, in quarantine in Brisbane, Australia. Oviposition occurred and flies developed on onlyC. odorataandPraxelis clematidea, both of which are in the subtribe Praxelinae.P. clematideais considered a weed outside tropical America. In both multiple-species-minus-C. odoratachoice tests and single-species no-choice tests, the mean number of galls/plant was significantly greater onC. odorata(48 and 41, respectively) than onP. clematidea(2 and 9, respectively). There were also significantly more adults emerging fromC. odorata(mean 129 and 169, respectively) in the two types of tests than fromP. clematidea(1 and 8, respectively). Paired choice, multiple generation (continuation) and time dependent tests further clarified the extent thatC. connexacould develop onP. clematidea. In these tests, the mean number of galls formed and the mean number of emerging adults were consistently less forP. clematideathanC. odorataand populations ofC. connexacould not be maintained onP. clematidea. Galls were not seen on any other plant species tested. This study supports the results of host specificity testing conducted in seven other countries and confirms thatC. connexaposes little risk to other plant species in Australia.C. connexahas been released in 10 countries and an application seeking approval to release in Australia has been submitted to the Australian Government. [ABSTRACT FROM PUBLISHER]

The leaf-mining flyCalycomyza eupatorivoraSpencer (Diptera: Agromyzidae) has become widely established in the eastern regions of South Africa, following its release for the biological control of the invasive shrubChromolaena odorata(L.) King and Robinson. This study was conducted to gain some insight into the impact ofC. eupatorivorapopulations, by assessing their seasonal activity, habitat preferences, levels of leaf exploitation and extent of larval mortality in the field over a 1-year period. Leaf mining intensity was poorly synchronised with leaf availability, with leaf exploitation peaking at the end of the growing season ofC. odorata. Although significantly more mines were recovered on plants growing in shaded situations, the percentage of available leaves that were exploited for mining was not significantly different between plants growing in shaded versus open situations. Overall, the levels of leaf damage were trivial with mines recovered from <5% of available leaves that were sampled during the study. Besides leaf-quality requirements, these low levels of leaf exploitation may have been influenced by high larval mortality which varied between 60 and 83%, depending on whether lower or higher estimates were used. These evaluations have verified the results of earlier laboratory studies which suggested that the impact ofC. eupatorivoraon mature populations ofC. odoratain South Africa will be negligible. [ABSTRACT FROM AUTHOR]

The leaf-mining flyCalycomyza eupatorivoraSpencer (Diptera: Agromyzidae) was released in the eastern coastal regions of South Africa for the biological control of the invasive shrubChromolaena odorata(L.) King and Robinson. Despite widespread establishment, its ability to inflict sufficient foliar damage has been questioned. This laboratory study was initiated to provide some insight into how increasing fly populations (represented by 1, 5 and 10 mating pairs per plant) are likely to influence leaf-mining intensity and the levels of damage. On average, individual plants exposed to five mating pairs displayed significantly more larval mines (248) than those exposed to single pairs (69), while plants exposed to 10 mating pairs were intermediate (125). Similarly, at densities of five mating pairs per plant, the percentages of available leaves that were exploited peaked at 36%, while the percentages of available leaf area that were removed by larval leaf mining peaked at 22%. The non-linear relationship between leaf mining and fly density and the high percentages of unexploited leaves suggest that leaf mining may be influenced by leaf quality, the nature of which is currently unconfirmed. These results also suggest that the levels of leaf exploitation byC. eupatorivorawill be too low to have any meaningful impact in the field. Field evaluations, to be reported in a later contribution, have indeed confirmed that the impact ofC. eupatorivoraon mature populations ofC. odoratais negligible. [ABSTRACT FROM PUBLISHER]

Pereskia aculeataMiller (Cactaceae) is an invasive alien species in South Africa that is native in Central and South America. In South Africa,P. aculeataoutcompetes native plant species leading to a reduction in biodiversity at infested sites. Herbicidal and mechanical control of the plant is ineffective and unsustainable, so biological control is considered the only potential solution. Climatic matching and genotype matching indicated that the most appropriate regions in which to collect biological control agents were Santa Catarina and Rio de Janeiro provinces in Southern Brazil. Surveys throughout the native distribution resulted in 15 natural enemy species that were associated with the plant. Field host range data, as well as previous host plant records, were used to prioritise which of the species were most likely to be suitably host specific for release in South Africa. The mode of damage was used to determine which species were most likely to be damaging and effective if released. The most promising species prioritised for further study, including host specificity and impact studies, were the stem-wilterCatorhintha schaffneriBrailovsky & Garcia (Coreidae); the stem boring speciesAcanthodoxus machacalisMartins & Monné (Cerambycidae), Cryptorhynchussp. (Curculionidae) andMaracayia chlorisalis(Walker) (Crambidae) and the fruit gallerAsphondyliasp. (Cecidomyiidae). By prioritising the potential biological control agents that are most likely to be host-specific and damaging, the risk of conducting host specificity testing on unsuitable or ineffective biological control agents is reduced. [ABSTRACT FROM AUTHOR]

The host range ofMada pollutaMulsant (Coleoptera:Coccinnellidae) was studied to assess its suitability as a biological control agent ofTecoma stans(L.) Juss ex Kunth var stans (Bignoniaceae), an invasive weed in South Africa. Biology ofM. pollutaand its host range were determined in the laboratory using no-choice and multi-choice feeding, oviposition and larval survival tests. Out of 36 plant species from 12 plant families (Bignoniaceae, Acanthaceae, Asteraceae, Verbenaceae, Lamiaceae, Oleaceae, Cucurbitaceae, Fabaceae, Scrophulariaceae, Solanaceae, Apiaceae, Chenopodiaceae and Poaceae) within the order Lamiales that were tested during the host specificity testing,M. pollutashowed a very strong preference forT. stans, depositing its eggs onT. stansand none on non-target plant species. In no-choice tests, an average of 246 eggs was laid onT. stans, and from these, 133 larvae developed to adulthood. The beetle also showed very promising biological attributes that will contribute to its success as a biological control agent ofT. stans. These attributes include highly damaging larvae and adults, high fecundity (532 eggs/female) and a short life cycle (four weeks). The short life cycle will enable multiple generations per year and rapid population increase in the field. It is concluded thatM. pollutais sufficiently host-specific to be released againstT. stansin South Africa. It is, therefore, strongly recommended that permission be granted to release this beetle from quarantine for biological control ofT. stansin South Africa. [ABSTRACT FROM AUTHOR]

The life history and host range of the herringbone leaf-mining fly Ophiomyia camarae, a potential biological control agent for Lantana spp., were investigated. Eggs were deposited singly on the underside of leaves. Although several eggs can be laid on a single leaf and a maximum of three individual mines were seen on a single leaf, only one pupa per leaf ever developed. The generation time (egg to adult) was about 38 days. Females (mean 14 days) lived longer than males (mean 9 days) and produced about 61 mines. Oviposition and larval development occurred on all five lantana phenotypes tested. Eleven plant species representing six families were tested to determine the host range. Oviposition and larval development occurred on only lantana and another nonnative plant Lippia alba (Verbenaceae), with both species supporting populations over several generations. A CLIMEX model showed that most of the coastal areas of eastern Australia south to 30°16' S (Coffs Harbour) would be suitable for O. camarae. O. camarae was approved for release in Australia in October 2007 and mines have been observed on plants at numerous field sites along the coast following releases. [ABSTRACT FROM AUTHOR]

Brazilian peppertree (Schinus terebinthifolius Raddi), native to South America, is invading many ecosystems in south and central Florida. The defoliating tortricid moth Episimus unguiculus Clarke was selected as a potential biocontrol agent of Brazilian peppertree in Florida. The objective of this study was to examine the effect of different levels of herbivore damage on growth and biomass allocation of Brazilian peppertree seedlings in the laboratory. Three treatments were established: (1) no herbivory (control), (2) low herbivory (~4 larvae/plant), and (3) high herbivory (~12 larvae/plant). High levels of herbivory significantly reduced the number of leaflets, plant height, foliar biomass, foliar relative growth rate (RGR) and shoot: root ratio of Brazilian peppertree seedlings. Moreover, plants were not able to recover from herbivory after 2 months. The performance of Brazilian peppertree subjected to low herbivory levels did not differ from the control plants (no herbivory). The potential effectiveness of the biocontrol agent E. unguiculus to suppress this noxious weed is examined. [ABSTRACT FROM AUTHOR]

Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), a biological control agent of Parthenium hysterophorus L. (Asteraceae), was feeding on leaves of Helianthus annuus in India, raising concerns of its host range. Based on the age grading technique, it was shown that the majority of Z. bicolorata on sunflower plants at any time were reproductively immature. This establishes that Z. bicolorata does not pose any risk to sunflower in India. [ABSTRACT FROM AUTHOR]

Miconia calvescens DC. (Melastomataceae) is an invasive tree considered one of the greatest threats to natural ecosystems of Hawaii and other Pacific islands. The potential for using the defoliator Antiblemma leucocyma (Lepidoptera: Noctuidae) as a biological control agent of M. calvescens was evaluated in the native habitat of the insect in Brazil. Impact assessment in the field showed that 37.2% of leaves presented damage by A. leucocyma, and among damaged leaves, 1.5-51.9% of the leaf area (16.3% on average) was affected. Damage was found in young to fully expanded leaves (28-915 cm2 in area). Individual A. leucocyma developing as third through sixth instars in the laboratory consumed an average of 1348 cm2 of M. calvescens leaf material in about 11 days. Populations of A. leucocyma in the field were heavily impacted (up to 83% parasitism) by a braconid parasitoid. Observations in the field and single- and two-host choice tests in the laboratory indicated that A. leucocyma has a narrow host range restricted to M. calvescens. Usefulness of this herbivore for biological control in Hawaii appears low, however, because of its probable susceptibility to generalist parasitoids. [ABSTRACT FROM AUTHOR]

The fungus, Alternaria alternata (Fr.) Keissler Strain 501, has been evaluated as a bioherbicide for control of Eupatorium adenophorum Spreng., but the biology of the pathogen–host interaction and the optimal environmental conditions for disease development and effective weed control are unknown. Disease development of A. alternata Strain 501 mycelia on E. adenophorum was assessed under several factors including pathogen inoculum concentration, plant age, dew period duration, post-dew temperature, storage temperature and duration. The minimum inoculum concentration required to kill E. adenophorum seedlings was 3.2×10 6 mycelial fragment mL -1 . E. adenophorum seedlings at the four-leaf-pair stage were more susceptible than the older plants, especially those at the older than seven-leaf-pair stage. With a dew period of at least 14 h, 100% mortality occurred. The optimal post-dew temperature for disease development was 18–25°C. Storage at [ABSTRACT FROM AUTHOR]

The life history and host specificity of Falconia intermedia in Australia were investigated. Adults and nymphs feed on the intercellular tissue on the underside of Lantana camara leaves. Eggs are deposited singly or in small clusters alongside veins and, on average, hatch in 12 days. Development to adult takes about 15 days and there are 5 instars. Females live for approximately 30 days and lay an average of 1.5 eggs/day. Oviposition occurred on all five L. camara phenotypes tested but subsequent development was significantly poorer on the pink-flowering phenotype. Forty-six plant species were tested to determine host specificity. The only species upon which adults fed and oviposited were L. camara and another introduced weed, Lippia alba. Both plant species supported populations of F. intermedia over several generations. F. intermedia did not display any predatory behaviour towards eggs, nymphs or larvae of either Aconophora compressa or Ectaga garcia, two other introduced biocontrol agents of L. camara. F. intermedia was approved for release in Australia in 2000. [ABSTRACT FROM AUTHOR]

Examines the life cycle and host range of Charidotis pygmaea to assess its use as a biological control agent for Lantana montevidensis. Life history of C. pygmaea specie; Determination of host specificity and choice oviposition in larval feeding trials; Capabilities of C. pygmaea to survive in dry season.