Molecular evidence that fireweed (Senecio madagascariensis, Asteraceae) is of South African origin

ITS1 sequence data was obtained for fireweed (Senecio madagascariensis) andS. lautus from Australia,S. madagascariensis andS. inaequidens from South Africa andS. madagascariensis from Madagascar. Despite the low level of variation (0.0–3.4%), these data further resolve the controversy concerning the identity and origin of fireweed. They confirm that fireweed is part of the South AfricanS. madagascariensis/S. inaequidens complex, and indicate that the infestation in Australia originated from South Africa as opposed to Madagascar. This will facilitate a resumption of biological control efforts in Australia and will direct surveys for control agents to South Africa.     

Simulated herbivory counteracts the effects of grass competition on the invasive fireweed (Senecio madagascariensis)

Competition, herbivory and their interaction play a significant role in determining the competitive ability and survival of individual plant species. Understanding these processes and interactions can improve the efficacy of biocontrol programs against invasive weeds. Senecio madagascariensis (fireweed) is an invasive weed of South African origin that reduces pastoral productivity and poisons livestock in several countries, notably Australia. Although competitive pastures can suppress the weed’s growth in Australia, its competitive nature is poorly understood in relation to its invasion success. This greenhouse study assessed the growth and reproductive yield of fireweed growing in competition with six native and introduced grasses present in both South Africa and Australia. Since fireweed is a target for biocontrol in Australia, we examined whether its response to grass competition changed with herbivory (simulated by 40% leaf removal). The effect of grass competition and herbivory on the weed’s biomass and floral productivity was examined during a 12‐week pot trial in South Africa. Floral numbers were unaffected by both grass competition and herbivory. Biomass was used to calculate Relative Interaction Indices (RII) to quantify the weed’s competitive or facilitative response. This index compares a specific measurable trait, such as biomass, of fireweed growing alone, to fireweed growing with grass to determine the level of competitive suppression or facilitation resulting from the interaction. Despite the lack of species‐specific effects of grass competition, the presence of grass suppressed fireweed’s foliar, root and whole plant biomass the most when herbivory was absent. With herbivory, fireweed did not suffer from any measurable competitive suppression. This lack of competitive suppression may be due to an induced allelopathic response, given the levels of pyrrolizidine alkaloids common in many Senecio species. Since this result may weaken the case for biocontrol, the weed’s competitive responses should be verified in relation to actual insect herbivory.     

Putative natural hybrid between Puccinia lagenophorae and an unknown rust fungus on Senecio madagascariensis in KwaZulu-Natal,South Africa

Several specimens of an aecial rust fungus were collected on Senecio madagascariensis during a field survey carried out in KwaZulu-Natal, South Africa. As telia were not present in the specimens collected, DNA sequence analyses were undertaken to determine the identity of the rust species. ITS and β-tub1 sequencing confirmed that one of the isolates recovered is Puccinia lagenophorae sensu lato. On the other hand, sequencing and RFLP analysis revealed the presence of two divergent copies of ITS and β-tub1 in all the other six isolates investigated. In both phylogenetic trees, one copy of the gene region grouped within a well supported clade with sequences of P. lagenophorae accessions from different geographical origins and hosts, and the Australian rusts Puccinia saccardoi and Puccinia stylidii. The other copy of these gene regions grouped within a separate clade comprising European accessions of Puccinia dioicae (ITS) and Uromyces sommerfeltii (β-tub1) that occur on Asteraceae hosts. Multiple copies of these gene regions were not observed in Australian isolates of P. lagenophorae. Our study provides some evidence that an interspecific hybrid rust fungus, with P. lagenophorae as one of its parents, may occur on S. madagascariensis in South Africa. The identity of the other parent remains unknown.     

Identification and genetic diversity of two invasive <Emphasis Type="Italic">Pissodes</Emphasis> spp. Germar (Coleoptera: Curculionidae) in their introduced range in the southern hemisphere

During the first half of the twentieth century, two accidental cases of introduction of Pissodes weevils were recorded from the southern hemisphere. The weevils in South Africa were identified as the deodar weevil (Pissodes nemorensis) and those in South America as the small banded pine weevil (Pissodes castaneus). Wide distribution of the two species in their invasive range, general difficulty in identifying some Pissodes spp., and the varying feeding and breeding behaviours of the species in South Africa has necessitated better evidence of species identity and genetic diversity of both species and population structure of the species in South Africa. Barcoding and the Jerry-to-Pat region of the COI gene were investigated. Morphometric data of the South African species was analysed. Our results confirmed the introduction of only one Pissodes species of North American origin to South Africa. However, this species is not P. nemorensis, but an unrecognized species of the P. strobi complex or a hybrid between P. strobi and P. nemorensis. Only P. castaneus, of European origin, was identified from South America. We identified ten mitochondrial DNA haplotypes from South Africa with evidence of moderate genetic structure among geographic populations. Terminal leader and bole-feeding weevils did not differ at the COI locus. A single haplotype was identified from populations of P. castaneus in South America. Results of the present study will have implications on quarantine, research and management of these insect species.     

Spread and potential distribution of Senecio madagascariensis Poir. (fireweed) in Australia

Abstract The potential distribution of the herbaceous weed Senecio madagascariensis Poir. (fireweed) in Australia was estimated using the Bioclimate Prediction System, BIOCLIM. Climate profiles for S. madagascariensis predicted that suitable areas occurred only in the south-eastern region of Australia. Its potential to spread outside these areas was assessed by comparing the present African and South American distributions of this species with that observed in Australia. The rate of spread of S. madagascariensis in New South Wales was exponential, although in some regions, such as the Gloucester River Valley, the rates had decreased because all farms had become infested. The results indicate that S. madagascariensis may spread and increase in abundance along the far south coast of New South Wales and in south-eastern Queensland. Coastal areas in eastern Victoria and as far north in Queensland as the Tropic of Capricorn may be invaded.     

Resolving the native provenance of invasive fireweed (Senecio madagascariensis Poir.) in the Hawaiian Islands as inferred from phylogenetic analysis

Accurate identification of weedy species is critical to the success of biological control programs seeking host-specific control agents. Phylogenetic relationships based on internal transcribed spacer region (ITS1, ITS2) DNA sequence data were used to elucidate the most likely origin and taxonomic placement of Senecio madagascariensis Poir. (fireweed; Asteraceae) in the Hawaiian archipelago. Putative S. madagascariensis populations from Madagascar, South Africa, Swaziland, and Hawaii were included in the analysis. Different phylogenetic models (maximum parsimony and maximum likelihood) were congruent in suggesting that Hawaiian fireweed is most closely related to populations from the KwaZulu-Natal region in South Africa. Phylogenetic divergence and morphological data (achene characteristics) suggest that the S. madagascariensis complex is in need of revised alpha-level taxonomy. Taxonomic identity of invasive fireweed in Hawaii is important for finding effective biological control agents as native range populations constitute different biotypic variants across a wide geographical area. Based on our phylogenetic results, research directed at biological control of Hawaiian infestations should focus on areas in the KwaZulu-Natal region in South Africa where host-specific natural enemies are most likely to be found. Our results show that phylogeographical analysis is a potential powerful and efficient tool to address questions relevant to invasion biology of plants.     

Using molecular methods to determine the origin of weed populations of Pereskia aculeata in South Africa and its relevance to biological control

New biological control agents are required in order to reach and sustain an adequate level of control of the declared environmental weed Pereskia aculeata Miller (Cactaceae) in South Africa. Identifying the origin of weed genotypes has been important in a number of biological control programmes and is likely to be of importance for the control of P. aculeata due to its disjunct native distribution and morphological polymorphisms between plants from different regions of the native and introduced distribution. DNA sequencing of the trnL chloroplastic intron and the phyC nuclear gene indicate that the South African weed population’s origin was in the southern region of native distribution. Inter-Simple Sequence Repeats (ISSRs) confirmed this result and added resolution to the analysis indicating that the native plants with the closest genetic distance to the South African weed population were found in Rio de Janeiro Province, Brazil. The relationship between the South African weed population and garden variety plants as well as the large genetic distance between the South African plants and the native plants suggests that the South African population may be the progeny of escaped garden variety plants that have been cultivated and possibly hybridized. The low levels of genetic variation within the South African population and the monophyly of the South African plants indicates that these plants are the progeny of a single introduction or multiple introductions from the same source. Rio de Janeiro Province in Brazil is the most appropriate region in which to survey for new biological control agents.     

On the Presence of Five Species of Naupactini (Coleoptera: Curculionidae) Damaging Soybean in Brazil

We report five broad-nosed weevils of the tribe Naupactini, Naupactus leucoloma Boheman, Naupactus minor (Buchanan), Naupactus peregrinus (Buchanan), Naupactus tremolerasi Hustache and Pantomorus viridisquamosus (Boheman) (Coleoptera: Curculionidae) damaging soybean plants in the state of Rio Grande do Sul, Brazil. Some of these species are recorded for the first time in Brazil, and they all belong to species groups naturally distributed in the prairies of southern Brazil, Uruguay, Central Argentina and Paraguay. Three of them have been introduced, established and expanded in other countries outside South America. The five species in conjunction with other native species of Naupactini could cause severe damages to soybean crops if the root-feeding larvae attack young growing plants.     

Taxonomic notes on the genus Otoptera (Phaseoleae, Fabaceae) in southern Africa

A taxonomic study of the genus Otoptera (tribe Phaseoleae) is presented. This distinct genus consists of two species, O. burchellii in southern Africa (Namibia, Botswana, South Africa and Zimbabwe) and O. madagascariensis endemic to Madagascar. The two species differ in the shape and size of leaflets, size and orientation of the spur located at the base of the wing petal, and also by size of the pod. A key to the two species is provided. This study focuses mainly on the southern African O. burchellii DC., which is described and illustrated. The species name is lectotypified and the known geographical distribution is recorded for the first time.     

Two Distinct Triatoma dimidiata (Latreille, 1811) Taxa Are Found in Sympatry in Guatemala and Mexico

Approximately 10 million people are infected with Trypanosoma cruzi, the causative agent of Chagas disease, which remains the most serious parasitic disease in the Americas. Most people are infected via triatomine vectors. Transmission has been largely halted in South America in areas with predominantly domestic vectors. However, one of the main Chagas vectors in Mesoamerica, Triatoma dimidiata, poses special challenges to control due to its diversity across its large geographic range (from Mexico into northern South America), and peridomestic and sylvatic populations that repopulate houses following pesticide treatment. Recent evidence suggests T. dimidiata may be a complex of species, perhaps including cryptic species; taxonomic ambiguity which confounds control. The nuclear sequence of the internal transcribed spacer 2 (ITS2) of the ribosomal DNA and the mitochondrial cytochrome b (mt cyt b) gene were used to analyze the taxonomy of T. dimidiata from southern Mexico throughout Central America. ITS2 sequence divides T. dimidiata into four taxa. The first three are found mostly localized to specific geographic regions with some overlap: (1) southern Mexico and Guatemala (Group 2); (2) Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica (Group 1A); (3) and Panama (Group 1B). We extend ITS2 Group 1A south into Costa Rica, Group 2 into southern Guatemala and show the first information on isolates in Belize, identifying Groups 2 and 3 in that country. The fourth group (Group 3), a potential cryptic species, is dispersed across parts of Mexico, Guatemala, and Belize. We show it exists in sympatry with other groups in Peten, Guatemala, and Yucatan, Mexico. Mitochondrial cyt b data supports this putative cryptic species in sympatry with others. However, unlike the clear distinction of the remaining groups by ITS2, the remaining groups are not separated by mt cyt b. This work contributes to an understanding of the taxonomy and population subdivision of T. dimidiata, essential for designing effective control strategies.     

Isolation and characterization of polymorphic microsatellite markers from fireweed,Senecio madagascariensis Poir. (Asteraceae)

Ten polymorphic microsatellite loci were isolated and characterized from invasive fireweed (Senecio madagascariensis) populations in the Hawaiian archipelago. These loci provided markers with polymorphism of six to 24 alleles per locus within 96 individuals collected from two populations from the island of Maui. The expected and observed heterozygosities ranged from 0.31 to 0.91 and from 0.056 to 1. These markers should be useful to study the importance of genetic diversity in invasion success of this species.     

Sesquiterpene lactones in various populations of Parthenium hysterophorus

Samples of 31 populations of Parthenium hyserophorus from varius areas of its world distribution were examined for their sesquiterpene lactone composition. On the basis of the occurrence of sesquiterpene lactones the samples were divided into seven chemical types. The most common is a type represented by plants containing parthenin as a major sesquiterpene lactone, and coronopilin and tetraneurin-A. All samples from North and Central America, Venezuela, South Africa, India, Australia, and one sample from Jamaica belong to this type. This suggests that P. hysterophorus recently introduced to South Africa, India and Australia originates in North and (or) Central America. On the other hand, there is a great diversity among examined South American populations. Plants from these populations usually contain hymenin which is their major sesquiterpene lactone. Some populations may also contain coronopilin, hysterin, and dihydroisoparthenin. A high diversity in the sesquiterpene lactone chemistry and the morphological differences between individual South American populations of this species indicate the possible existence of several taxa.     

Phytogeography of the Kaieteur Falls, Potaro Plateau, Guyana: floral distributions and affinities

Aim The plant diversity of one location on the Guiana Shield, Kaieteur National Park in Guyana, is used to examine the various hypothesized origins of the flora and to evaluate which may best explain the current plant distributions. Location Kaieteur National Park is located on eastern edge of the Potaro Plateau in central Guyana, South America. The species examined have distributions that vary from local to global. Methods The distribution patterns of the families, genera and species known from Kaieteur are examined using generalized distribution patterns. Results Data on distribution patterns, elevation and habitat were gathered from 131 flowering plant families, 517 genera and 1227 species. These plants represent all taxa that are currently known to occur in the area of the original Kaieteur National Park. Families tend to have cosmopolitan or pantropical distribution, genera are mostly neotropical and at the species level, most species are restricted to the Guiana Shield (c. 40%), northern South America (69%) or neotropical (96%) in distribution, each level inclusive of the previous. Conclusions The flora at the study site in Kaieteur National Park has its strongest affinity with the Guiana Shield; 42.1% of the species have a distribution that corresponds with the Shield or is more restricted within the Shield. There is a distinct flora on the Guiana Shield and its affinities lie with the flora of northern South American and beyond that, the neotropics. The flora is not closely affiliated with the floras of the Brazilian Shield, the Amazon, the Andes, the eastern coastal forests of Brazil, southern South America, or Africa as has been previous suggested.     

The biogeography of Gunnera L.: vicariance and dispersal

Aim The genus Gunnera is distributed in South America, Africa and the Australasian region, a few species reaching Hawaii and southern Mexico in the North. A cladogram was used to (1) discuss the biogeography of Gunnera and (2) subsequently compare this biogeographical pattern with the geological history of continents and the patterns reported for other Southern Hemisphere organisms. Location Africa, northern South America, southern South America, Tasmania, New Zealand, New Guinea/Malaya, Hawaii, North America, Antarctica. Methods A phylogenetic analysis of twenty‐six species of Gunnera combining morphological characters and new as well as published sequences of the ITS region, rbcL and the rps16 intron, was used to interpret the biogeographical patterns in Gunnera. Vicariance was applied in the first place and dispersal was only assumed as a second best explanation. Results The Uruguayan/Brazilian Gunnera herteri Osten (subgenus Ostenigunnera Mattfeld) is sister to the rest of the genus, followed sequentially upwards by the African G. perpensa L. (subgenus Gunnera), in turn sister to all other, American and Australasian, species. These are divided into two clades, one containing American/Hawaiian species, the other containing all Australasian species. Within the Australasian clade, G. macrophylla Blume (subgenus Pseudogunnera Schindler), occurring in New Guinea and Malaya, is sister to a clade including the species from New Zealand and Tasmania (subgenus Milligania Schindler). The southern South American subgenus Misandra Schindler is sister to a clade containing the remaining American, as well as the Hawaiian species (subgenus Panke Schindler). Within subgenus Panke, G. mexicana Brandegee, the only North American species in the genus, is sister to a clade wherein the Hawaiian species are basal to all south and central American taxa. Main conclusions According to the cladogram, South America appears in two places, suggesting an historical explanation for northern South America to be separate from southern South America. Following a well‐known biogeographical pattern of vicariance, Africa is the sister area to the combined southern South America/Australasian clade. Within the Australasian clade, New Zealand is more closely related to New Guinea/Malaya than to southern South America, a pattern found in other plant cladograms, contradictory to some of the patterns supported by animal clades and by the geological hypothesis, respectively. The position of the Tasmanian G. cordifolia, nested within the New Zealand clade indicates dispersal of this species to Tasmania. The position of G. mexicana, the only North American species, as sister to the remaining species of subgenus Panke together with the subsequent sister relation between Hawaii and southern South America, may reflect a North American origin of Panke and a recolonization of South America from the north. This is in agreement with the early North American fossil record of Gunnera and the apparent young age of the South American clade.     

Invasion origin,rapid population expansion,and the lack of genetic structure of cotton bollworm (Helicoverpa armigera) in the Americas

In 2013, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) was officially declared as present in Brazil and, after two years, the species was detected in the Caribbean and North America. Information on genetic features and accurate distribution of pests is the basis for agricultural protection policies. Furthermore, such knowledge is imperative to develop control strategies, understand the geographical range, and genetic patterns of this species in the Americas. Here, we carried out the widest sampling of H. armigera in the South American continent and Puerto Rico, after we estimated the diversity, demographic parameters, and genetic structure. The Internal Transcribed Spacer 1 (ITS1) nuclear marker was used to investigate the presence of putative hybrids between H. armigera and H. zea, and they were observed at a frequency of 1.5%. An ABC analysis, based in COI gene fragment, suggested Europe as the origin of South America specimens of H. armigeraand following a movement northward through the Caribbean. Three mtDNA genes and three nDNA markers revealed high genetic diversity distributed without the defined population structure of H. armigera in South America. Most of the genetic variation is within populations with a multidirectional expansion of H. armigera among morphoclimatic regions. High genetic diversity, rapid population expansion, and hybridization have implications for pest management since they suggest that adaptive alleles are spread through wide areas in South America that favor rapid local adaptation of H. armigera to new and disturbed environments (e.g., in agricultural areas).     

Tour around the globe: The case of invasive tapeworm Atractolytocestus huronensis (Cestoda: Caryophyllidea), a parasite of common carp

The monozoic tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea), an intestinal parasite of the common carp, is characterized by its invasive character and potential to colonize new territories. It was initially described from North America and has also been found in several European countries. The most recent findings of A. huronensis originated from China and South Africa; however, no data on genetic relationships of these populations were available. The current study provides the first molecular characterisation of A. huronensis from South Africa and China using a partial sequence of mitochondrial cytochrome c oxidase subunit 1 (cox1) and a complete ribosomal ITS2 spacer. Ribosomal and mitochondrial data were applied for phylogenetic analyses in order to assess the genetic interrelationships among global A. huronensis populations. Divergent intragenomic copies of ribosomal ITS2 were detected in all analysed specimens; the structure and frequency of the ITS2 variants of tapeworms from China and South Africa corresponded with the data on ITS2 paralogues observed previously in A. huronensis from Slovakia, the United States and the United Kingdom. The phylogenetic analysis of cox1 indicated that A. huronensis exist in two slightly differentiated clusters; one cluster was supported by all phylogenetic approaches (NJ, ML, BI) and was represented by samples from China, the USA and the UK. A second cluster was represented by tapeworms from continental Europe (Slovakia, Hungary, Romania, Croatia) and South Africa. Haplotype network analysis revealed that the highest population diversity occurs in China. The results provide useful pilot information about the interrelationships of A. huronensis on four continents and indicate that China, or the eastern Palaearctic, served as the original source population for the global expansion of this invasive tapeworm. Data on the origin and distribution of the common carp, the only specific host of A. huronensis, are also discussed.     

A hotspot of Toxoplasma gondii Africa 1 lineage in Benin: How new genotypes from West Africa contribute to understand the parasite genetic diversity worldwide

Through international trades, Europe, Africa and South America share a long history of exchanges, potentially of pathogens. We used the worldwide parasite Toxoplasma gondii to test the hypothesis of a historical influence on pathogen genetic diversity in Benin, a West African country with a longstanding sea trade history. In Africa, T. gondii spatial structure is still non-uniformly studied and very few articles have reported strain genetic diversity in fauna and clinical forms of human toxoplasmosis so far, even in African diaspora. Sera from 758 domestic animals (mainly poultry) in two coastal areas (Cotonou and Ouidah) and two inland areas (Parakou and Natitingou) were tested for T. gondii antibodies using a Modified Agglutination Test (MAT). The hearts and brains of 69 seropositive animals were collected for parasite isolation in a mouse bioassay. Forty-five strains were obtained and 39 genotypes could be described via 15-microsatellite genotyping, with a predominance of the autochthonous African lineage Africa 1 (36/39). The remaining genotypes were Africa 4 variant TUB2 (1/39) and two identical isolates (clone) of Type III (2/39). No difference in terms of genotype distribution between inland and coastal sampling sites was found. In particular, contrarily to what has been described in Senegal, no type II (mostly present in Europe) was isolated in poultry from coastal cities. This result seems to refute a possible role of European maritime trade in Benin despite it was one of the most important hubs during the slave trade period. However, the presence of the Africa 1 genotype in Brazil, predominant in Benin, and genetic analyses suggest that the triangular trade was a route for the intercontinental dissemination of genetic strains from Africa to South America. This supports the possibility of contamination in humans and animals with potentially imported virulent strains.     

Neotropical nymphoides (Menyanthaceae): Meso-American and west indian species

Studies ofNymphoides (Menyanthaceae) in Mexico, Central America, and the West Indies indicate that three species are present in this region, all of which are members of theNymphoides indica complex. White-flowered plants of Meso-America, the Antilles, and South America traditionally have been referred toN. humboldtiana but are identical to the otherwise Old WorldN. indica and must be called by the latter name. The Mexican and GuatemalanNymphoides fallax, described in this paper, differs fromN. indica in having winged yellow petals with a stipitate basal tuft of hairs, consistently yellow anthers, larger seeds, and higher altitudinal occurrence. Yellow-flowered plants of the Bahamas and Cuba are considered to represent a third species,N. grayana, which resembles plants of southern Brazil and southern Africa in flower color and morphology. However, because of the geographic distribution and unique ultraviolet-light emittance characters ofN. grayana and the still uncertain relationships of the Brazilian and African populations, this third taxon is provisionally retained at the specific level pending further study of those populations.     

Biogeography of mutualistic fungi cultivated by leafcutter ants

Leafcutter ants propagate co‐evolving fungi for food. The nearly 50 species of leafcutter ants (Atta, Acromyrmex) range from Argentina to the United States, with the greatest species diversity in southern South America. We elucidate the biogeography of fungi cultivated by leafcutter ants using DNA sequence and microsatellite‐marker analyses of 474 cultivars collected across the leafcutter range. Fungal cultivars belong to two clades (Clade‐A and Clade‐B). The dominant and widespread Clade‐A cultivars form three genotype clusters, with their relative prevalence corresponding to southern South America, northern South America, Central and North America. Admixture between Clade‐A populations supports genetic exchange within a single species, Leucocoprinus gongylophorus. Some leafcutter species that cut grass as fungicultural substrate are specialized to cultivate Clade‐B fungi, whereas leafcutters preferring dicot plants appear specialized on Clade‐A fungi. Cultivar sharing between sympatric leafcutter species occurs frequently such that cultivars of Atta are not distinct from those of Acromyrmex. Leafcutters specialized on Clade‐B fungi occur only in South America. Diversity of Clade‐A fungi is greatest in South America, but minimal in Central and North America. Maximum cultivar diversity in South America is predicted by the Kusnezov–Fowler hypothesis that leafcutter ants originated in subtropical South America and only dicot‐specialized leafcutter ants migrated out of South America, but the cultivar diversity becomes also compatible with a recently proposed hypothesis of a Central American origin by postulating that leafcutter ants acquired novel cultivars many times from other nonleafcutter fungus‐growing ants during their migrations from Central America across South America. We evaluate these biogeographic hypotheses in the light of estimated dates for the origins of leafcutter ants and their cultivars.     

Sequence data reflect the introduction pathways of the Sirex woodwasp parasitoid,Ibalia leucospoides (Ibaliidae,Hymenoptera)

1. The parasitoid wasp Ibalia leucospoides is native to the northern hemisphere and has been introduced to the southern hemisphere as a biological control agent for the invasive woodwasp Sirex noctilio. Two subspecies of the parasitoid, Ibalia leucospoides leucospoides (Palearctic distribution) and Ibalia leucospoides ensiger (Nearctic distribution), were introduced and are reported to have hybridized.
2. Despite extensive records of the numbers and origins of the wasps imported into the southern hemisphere, nothing is known regarding their current population diversity. We investigated the genetic variation of I. leucospoides in its native and introduced ranges using mitochondrial (COI) and nuclear (ITS) markers.
3. Mitochondrial DNA diversity in the introduced range was limited, with only five haplotypes, although sequence divergence between these haplotypes was high. Similarly, the ITS rDNA sequences revealed multiple clades present in the introduced range.
4. These results reflect introductions from a wide geographical range but where genetic bottlenecks have possibly reduced the genetic diversity. The data further reflect the origin of the I. leucospoides populations in South America and South Africa from New Zealand or Australia. We found no evidence of hybridization between the two subspecies of the parasitoid in its introduced range, and no evidence that I. leucospoides ensiger has established outside its native range.