Four invasive Mediterranean snails, i.e., Theba pisana (Müller, 1774), Cernuella virgata (da Costa, 1778), Cochlicella acuta (Müller, 1774) and Cochlicella barbara (Linnaeus, 1758) cost $170 million yearly to the grain industry in Australia. Their impact is mainly due to their estivation behavior: snails climb on cereal and legume stalks to rest during summer, which coincides with harvest, causing grain contamination issues in crops such as wheat, barley and canola. Diverse management methods have been developed to regulate snail populations, with limited success. Our study investigates the potential for a push–pull strategy to divert invasive snails from cultivated fields. A “push” part (i.e. using a repellent stimuli) was based on the use of a chemical deterrent repelling snails from the cultivated field, and a “pull” part (i.e. using an attractive stimuli) was based on offering attractive estivation supports for snails to aggregate outside the cultivated field. First, artificial estivation supports of different colors were tested under laboratory and field conditions and showed that red supports were the most attractive for these snails. Second, different substances were tested as potential snail deterrents (garlic, coffee, coffee grounds, copper). Garlic extracts were the most powerful snail deterrent and were shown to effectively protect an estivation support and food source from snails under laboratory conditions. These results, which were highly consistent for the four species, illustrate the potential of a push–pull strategy against invasive snails in Australia. It is the first attempt to develop a push–pull strategy relying on both visual and chemical stimuli to achieve results, as well as manipulating the estivation behavior of a pest.

Allium triquetrum L. (Amaryllidaceae), a bulbiferous monocot, is native to the Mediterranean. It was introduced to Australia in the early 1900s, where it has subsequently become a significant invader of temperate forests throughout south-eastern Australia. Intensive chemical and mechanical control methods can suppress A. triquetrum infestations at the local scale for short periods of time but remain ineffective at sustainably curtailing its invasion at landscape and regional scales. In this context, we undertook field surveys across the Mediterranean (mainland France, Corsica, Sardinia) to determine the feasibility of developing classical biological control solutions for A. triquetrum in Australia. Despite extensive sampling (i.e. 30 surveys at 18 sites over three growing seasons), very few phytophagous arthropod and fungal pathogen taxa were detected on A. triquetrum. The most common arthropod species were the flies Phytomyza gymnostoma and Delia hirticrura, the weevil Oprohinus consputus and the moth Hysterophora maculosana. All identified arthropod taxa were considered generalists, having been found on other plant species, and some are known pests of cultivated Allium species. Twenty-one different fungal isolates were recovered from A. triquetrum, with most considered as saprophytic, secondary/opportunistic pathogens that probably infected already-damaged A. triquetrum leaves. Only four fungal taxa were found to be primary pathogens of A. triquetrum but have been recorded to infect other plant species. None of these enemy taxa were deemed to be suitable candidate biocontrol agents to help manage A. triquetrum invasion in Australia. Future research directions for improved A. triquetrum management in Australia are discussed in this paper.

ABSTRACT Sonchus oleraceus L. (Asteraceae), an annual species native to Eurasia and northern Africa, is among the most widely distributed plant species on Earth. In Australia, S. oleraceus, is a common weed in disturbed areas such as crop fields, pastures, gardens and roadsides. In agricultural settings, it can dominate fallows and cultivated fields where it uses stored soil moisture and reduces crop yield. This weed has also developed herbicide resistance, predicating the need for alternative management solutions. In this context, we undertook field surveys and preliminary host range studies in the native range of S. oleraceus to determine the feasibility of developing classical biological control solutions for Australia. Fifty-nine phytophagous arthropod species were recorded and nine pathogenic fungi were recovered from disease symptoms. Four arthropod species were selected for initial host-specificity testing based on information available in the literature. Preliminary host-specificity tests were also performed with representative isolate(s) of six of the pathogenic fungi. All these candidate agents were shown in the tests to affect key native species in Australia in the same subtribe as S. oleraceus (i.e. Sonchus hydrophilus and Actites megalocarpus). The results of our investigations suggest that classical biological control may not be a feasible option for the management of S. oleraceus in Australia, and that alternative integrated weed management tactics may need to be pursued to mitigate the impacts of this weed.

Terrestrial snails that live in hot and dry climates have developed strategies to cope with high summer temperatures. Several species estivate during the warmest months of the years by resting on vertical supports, typically in groups. Understanding how snails choose their estivation sites and aggregate may lead to the development of new management tools in areas where these snails are invasive. Here, we investigated the preferences of four snail species for vertical supports varying in widths and heights under laboratory and field conditions, and tested whether the presence of conspecifics or snails of other species affected these preferences. The results show that the snails strongly preferred wider supports in laboratory dual-choice tests, and one species (Theba pisana) showed a consistent preference for taller supports as well. These results were confirmed in the field, where more snails were found on wider and taller supports 24 h after being placed in test quadrats. The percentage of snails found in groups on a support was strongly density-dependent. The presence of conspecifics or their mucus did not affect the choices of the snails, nor did the presence of snails of other species or their mucus. Taken together, these results could lead to the development of attractive supports that could be used to mass-capture snails in the field.

Sonchus oleraceus L. (Asteraceae), an annual species native to Eurasia and northern Africa, is among the most widely distributed plant species on Earth. In Australia, S. oleraceus, is a common weed in disturbed areas such as crop fields, pastures, gardens and roadsides. In agricultural settings, it can dominate fallows and cultivated fields where it uses stored soil moisture and reduces crop yield. This weed has also developed herbicide resistance, predicating the need for alternative management solutions. In this context, we undertook field surveys and preliminary host range studies in the native range of S. oleraceus to determine the feasibility of developing classical biological control solutions for Australia. Fifty-nine phytophagous arthropod species were recorded and nine pathogenic fungi were recovered from disease symptoms. Four arthropod species were selected for initial host-specificity testing based on information available in the literature. Preliminary host-specificity tests were also performed with representative isolate(s) of six of the pathogenic fungi. All these candidate agents were shown in the tests to affect key native species in Australia in the same subtribe as S. oleraceus (i.e. Sonchus hydrophilus and Actites megalocarpus). The results of our investigations suggest that classical biological control may not be a feasible option for the management of S. oleraceus in Australia, and that alternative integrated weed management tactics may need to be pursued to mitigate the impacts of this weed.

French broom (Genista monspessulana) (Fabaceae) is a perennial species native to the Mediterranean basin. Introduced in the 19th century as an ornamental plant, it is currently invasive in California and Australia. The current research is focused on biocontrol with the use of the phytophagous weevil Lepidapion argentatum (Brentidae). Its capacity to develop both in the stem galls and pods of French broom makes it a promising candidate. The impact on the reproduction of French broom was studied in Southern France and revealed that it could effectively reduce the number of viable seeds by 18.8%, but also increased the number of aborted seeds by 10% within the attacked pods. To evaluate the specificity of L. argentatum, choice and no-choice tests were performed in 2012 and 2015 on a total of 36 non-target closely related species. Results revealed the presence of galls and larvae in the stems of seven species, including two endemic Californian lupines; i.e., Lupinus arboreus blue and Lupinus chamissonis. In the future, new tests will be conducted to determine if L. argentatum is able to complete its entire development lifecycle on the non-target species where galls have previously been observed.

The conical snail,Cochlicella acuta, is an introduced pest of grain crops in Australia. Biological control ofC. acutahas been attempted using the parasitoid fly,Sarcophaga villeneuveana, sourced from southern France, but has failed. Molecular genetics of the snails and climatic matching have suggested greater success might be realised using flies from southern Iberia (Spain and Portugal) or Morocco. We measured levels of parasitism ofC. acutabyS. villeneuveanaat several sites within southern Iberia, and near the previous fly release site in Australia. Emergence of flies was slightly higher in Iberia, compared with Australia, but 31% of theS. villeneuveanathat reached pupal stage withinC. acutain Iberia were hyperparasitised (up to 63% at individual sites). No hyperparasites emerged from Australian collections ofC. acuta. These data encourage further searches in southern Iberia for more effective populations ofS. villeneuveanafor use as biological control agents.

Testing the specificity of candidate agents is a key component of risk analysis in weed biological control. This step is often time‐consuming due to the numerous plant species that need to be tested under quarantine conditions in the invaded country of the weed species. Here, we examined whether an abridged phylogenetically based test list could be used in the weed's native range to quickly screen the host specificity of candidate agents. Ten plant species were used to test the host specificity of a promising candidate for the biological control of Sonchus oleraceus in Australia, the gall midge, Cystiphora sonchi. No‐choice and choice tests were carried out in the native Mediterranean range of the midge. The results showed the midge has potential to threaten native Australian species, as those species showed high infestation levels in no‐choice tests and produced significantly higher numbers of galls in choice tests. As a result of this approach, C. sonchi was rapidly discarded from the list of agents to be imported into Australian quarantines for further tests. This study demonstrates that testing a few key phylogenetically related species in the native range may save cost and effort in a weed biological control programme.

The snail, Cochlicella acuta (Müller), is an introduced pest of grain crops in southern Australia, and native to Europe and north-west Africa. Parasitoid flies ( Sarcophaga villeneuveana (Enderlein)) have previously been sourced from France to attempt biological control of the pest in Australia, but have failed. Cochlicella acuta has three mitochondrial lineages ( CO1 & 16S based) within its native distribution. The snails now found in Australia belong to just one of these lineages. Their origins most likely lie in the southern Iberian Peninsula or Morocco, not in France. We collected S. villeneuveana attacking C. acuta in France, Spain, Portugal, Morocco and Australia. Genetic structure ( CO1 ) was not found within the fly that aligned with the lineages recorded for the snail host in the same regions. However, geographical patterns were detected amongst haplotypes of S. villeneuveana which encourage further, better targeted searches in Morocco and the southern Iberian Peninsula for a more effective biological control agent(s).

In weed biocontrol, accurate identification of the target weed is essential to select effective and host-specific biocontrol agents. This study focuses on the biocontrol of an invasive weed species in Australia, native from Europe, the common sowthistle, Sonchus oleraceus L. (Asteraceae). During field surveys, the distinction between S. oleraceus and a morphologically related species ( S. asper L.) was difficult because of specimens bearing intermediate morphological features. These observations raised questions about the reliability the morphological characters used for distinguishing between these species and the identity of the intermediate phenotypes. First, cytological analyses coupled with morphological comparisons were carried out on specimens collected in Europe and Australia. Results showed that specimens morphologically described as S. oleraceus and S. asper possessed, in accordance with literature 32 and 18 chromosomes, respectively. Specimens with intermediate morphotypes had 32 chromosomes, showing that they belong to S. oleraceus species. The variability of characters used for diagnosis is discussed and for a particular feature, achene ornamentation, an inquiry among 30 people was carried out to determine how this character might be relevant for distinguishing the two species herein considered. The successful identification rate was 92.2% (SE ± 0.77) showing the practical interest of this feature for diagnosis.

There is growing evidence that rapid adaptation to novel environments drives successful establishment and spread of invasive plant species. However, the mechanisms driving trait adaptation, such as selection pressure from novel climate niche envelopes, remain poorly tested at global scales. In this study, we investigated differences in 20 traits (relating to growth, resource acquisition, reproduction, phenology and defence) amongst 14 populations of the herbaceous plant Sonchus oleraceus L. (Asteraceae) across its native (Europe and North Africa) and introduced (Australia and New Zealand) ranges. We compared traits amongst populations grown under standard glasshouse conditions. Introduced S. oleraceus plants seemed to outperform native plants, i.e. possessing higher leaf and stem dry matter content, greater number of leaves and were taller at first flowering stage. Although introduced plants produced fewer seeds, they had a higher germination rate than native plants. We found strong evidence for adaptation along temperature and precipitation gradients for several traits (e.g. shoot height, biomass, leaf and stem dry matter contents increased with minimum temperatures, while germination rate decreased with annual precipitations and temperatures), which suggests that similar selective forces shape populations in both the native and invad- ed ranges. We detected significant shifts in the relationships (i.e. trade-offs) (i) between plant height and flowering time and (ii) between leaf-stem biomass and grain yield between native and introduced plants, indicating that invasion was associated with changes to life-history dynamics that may confer competitive advantages over native vegetation. Specifically, we found that, at first flowering, introduced plants tended to be taller than native ones and that investment in leaf and stem biomass was greater in introduced than in native plants for equivalent levels of grain yield. Our study has demonstrated that climatic conditions may drive rapid adaption to novel environments in invasive plant species.

The conical snail, Cochlicella acuta, is a major introduced pest of grain crops in southern Australia. In particular, C. acuta aestivates on the heads and upper stalks of crop plants thus fouling grain harvests in late spring - early summer. Previous attempts to control this snail pest included the release, during the early 2000s, of parasitic flies (Sarcophaga villeneuveana) sourced from southern France, within the perceived native distribution of C. acuta. The flies established in southern Australia, but only in very low numbers, such that there was no significant reduction in the snail's pest status. Sequencing of the snail's COI and 16S mitochondrial genes has now identified three main maternal lineages within C. acuta, across its distribution in south-western Europe and Morocco. The 1st lineage was only found in north-eastern Spain (near the Pyrenees), throughout southern France and in northern Italy. Both the 2nd and 3rd lineages were found in the U.K., western France, northern and southern Spain, Portugal and Morocco. The 3rd lineage was also collected throughout eastern Spain and just into southern France (near the Pyrenees). All the C. acuta found in Australia belong to the 3rd lineage. Highest levels of genetic diversity in C. acuta were found in the 3rd lineage, in particular in Morocco. A plausible explanation for the poor performance of the biological control agent previously released to control C. acuta in Australia is a mismatch between snail host and selected parasitoid. A different biotype or sub-species of S. villeneuveana, or even a different parasitoid species altogether, that attacks the 3rd lineage of C. acuta in south-western Europe or Morocco, could prove to be a more effective biological control agent than the S. villeneuveana previously released from southern France. Climates in southern Spain, southern Portugal and northern Morocco also best match those areas in southern Australia where C. acuta is a pest, suggesting further searches for effective natural enemies should be focussed there.

Here we present the first records and new data on the biology of flesh flies (Diptera: Sarcophagidae) emerging from terrestrial snails belonging to the families Cochlicellidae, Helicidae and Hygromiidae collected from eight sites on the Moroccan Atlantic coast over the period May 2015 to May 2016. We successfully identified 271 adults of these flies. Five of them represent new records for the Moroccan fauna. With these new records, the number of known species belonging to the family Sarcophagidae in Morocco has been increased from 51 to 56.

s: Theme 3 – Risk analysis 355 native Senecio plants. Damage was notable for 54.5% of the native Senecio plants sampled with 15.3% of this damage caused by the native moth Patagoniodes farinaria and the rest by other unidentified insect agents. Of the ragwort plants damaged, definite attack (presence of an agent) by C. atricapitana or P. isodactyla occurred upon 100% of the rosettes and 51% of the damaged bolting and flowering ragwort plants. The results from this study support the results obtained during detailed host-specificity studies, which indicated that C. atricapitana and P. isodactyla are host-specific to S. jacobaea and therefore pose a very low risk to the native flora. Host specificity of Megamelus scutellaris (Hemiptera, Fulgoromorpha, Delphacidae), a potential agent for the biological control of waterhyacinth A.J. Sosa,1 H.A. Cordo,1 M.A. Szudruk,1 M.C. Hernandez1 and M. Hill2 1South American Biological Control Laboratory, USDA–ARS, Bolivar 1559 (B1686EFA) Hurlingham, Buenos Aires, Argentina 2Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown, 6140, South Africa The host range of Megamelus scutellaris was studied in the laboratory using two types of multiplechoice test (including and excluding water hyacinth), and one type of non-choice test. In the first multiple-choice test, plants other than Pontederiaceae were used, whereas in the second one only Pontederiaceae were used. For the non-choice test, five species and two varieties in the Pontederiaceae were included, and this test included maize and rice. These last two plants were included because they are host of many species of Delphacidae. Feeding damage was difficult to quantify, so the preference for each plant was indirectly measured using an index that related the number of insects on a given plant and the number of insects alive in the cage used. Mortality was also measured. When given a choice, M. scutellaris significantly preferred waterhyacinth to other plants and it did not show preference to a particular plant when waterhyacinth was absent. The mortality after 48 hrs in the tests where waterhyacinth was present was significantly lower than those where waterhyacinth was absent. In the nonchoice trial, M. scutellaris reached the adult stage on only three plants: waterhyacinth, Pontederia cordata lancifolia and P. rotundifolia. However, nymphal mortality was lower, and the duration of the whole immature stage was significatively shorter in waterhyacinth than on the other two plants. These results, along with the fact that, despite extensive surveys, M. scutellaris has been recorded from waterhyacinth in only Argentina and Brazil, indicate that the insect is monophagous and a safe agent to be introduced into other countries for the biological control of this weed. Realized host-specificity testing of Bruchidius villosus (Coleoptera: Chrysomelidae) in Europe Thierry Thomann and Andy Sheppard CSIRO European Laboratory, Campus International de Baillarguet, 34980 Montferrier-sur-Lez, France Bruchidius villosus, a broom seed feeder, was introduced into New Zealand in 1987 from the UK and from New Zealand into Australia in 1995 as a biological control agent against Scotch broom ( Cytisus scoparius) a leguminous shrub native to Europe. Introduction followed extensive testing in the UK, New Zealand and Australia that showed it to be host specific. Contrary to test results, Bruchidius villosus was found emerging from pods of tagasaste (Chamaecytisus palmensis), an exotic fodder species closely related to broom, in New Zealand in 1999. The same year, a field trial of the host range

Fumaria species are increasingly problematic in the cropping regions of southern Australia, and one fumitory, Fumaria densiflora DC, has developed populations with herbicide resistance. Consequently, the potential for biological control was assessed. Nine species of fungi were found associated with Fumaria spp. in a survey of 33 sites in southern France. According to the literature, species potentially host specific to fumitory include Cladosporium brachormium Berk. and Broome, Entyloma fumariae J. Schröt. and Peronospora affinis Rossmann. Of the insects detected on Fumaria spp. in France, the stem weevil, Sirocalodes mixtus Mulsant and Rey has potential as a biological control agent because it is thought to be host specific. None of these species were detected amongst the six pathogen species found during surveys of 64 locations in southeastern and southwestern Australia. The absence of pathogens and insects associated with Fumaria species in Australia, the lack of Fumaria spp. native to Australia, and few closely related crops or ornamental species, indicate that there are opportunities for research into the development of natural enemies for the biological control of fumitory.