Laura Varone

Fundación Para El Estudio De Especies Invasivas

The cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) is native to South America and has been used as a biocontrol agent of Opuntia (Cactaceae) in Australia and South Africa. Its invasion in North America has raised concerns for the native Opuntia in the USA and Mexico. We investigated the reproductive biology and rearing procedure...

Novel host plant–insect interactions often arise from human-mediated introductions of potential hosts to areas inhabited by native insects, or invasive insects to regions with suitable hosts. These novel interactions may drive ecological and evolutionary change in native species. Here we investigate the role of the introduction of the prickly pear...

Opuntia ficus-indica, commonly known as prickly-pear, tuna, or nopal, is a cactus species of economic significance. It is widely cultivated for its fruits and cladodes, used as both fodder and human food. The species would have been domesticated in pre-Hispanic Mexico. In Argentina, two forms are present: the horticultural (spineless, f. ficus-indi...

Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), the cactus moth, is native to South America with a widespread distribution in Argentina. The larvae consume the interior of Opuntia spp. (Cactaceae) plants. The moth was used as a biocontrol agent against invasive non-native Opuntia spp. in many countries around the world. The cactus moth arriv...

Landscape heterogeneity and the host plant use are factors suggested to play determinant roles in shaping the evolutionary history of herbivorous insects. However, the role of the reconfiguration of host plants distributions linked to Quaternary climate oscillations as drivers of contemporary population genetic structure is still poorly understood....

Biological control (BC) can occur naturally (without human intervention), or by being applied intentionally when it is the result of research and the scientific selection of antagonists. It consists of the reduction in the population density of one species through the action of another. Although the adoption of applied BC in Argentina started at th...

Landscape heterogeneity and the reconfiguration of host plant distributions as a consequence of Quaternary climate oscillations are suggested to play a determinant role in shaping the evolutionary history of herbivorous insects. The cactus moth, Cactoblastis cactorum, is a southern South American phytophagous insect specialized in the use of cacti...

Surveys of patterns of genetic variation in natural sympatric and allopatric populations of recently diverged species are necessary to understand the processes driving intra and interspecific diversification. The South American moths Cactoblastis cactorum, Cactoblastis doddi and Cactoblastis bucyrus are specialized in the use of cacti as host plant...

Surveys of patterns of genetic variation in natural sympatric and allopatric populations of recently diverged species are necessary to understand the processes driving intra and interspecific diversification. The South American moths Cactoblastis cactorum, Cactoblastis doddi and Cactoblastis bucyrus are specialized in the use of cacti as host plant...

Argentina is considered megadiverse for Cactaceae, and Jujuy province, with a high proportion of cacti ende-mism, is a critical region for their preservation. Cacti deterioration is mainly associated with habitat degradation, agricultural frontier advance, urbanization, illegal collection and trade. Of the three species of columnar cacti within Tri...

The cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), is an invasive species in North America where it threatens Opuntia native populations. The insect is expanding its distribution along the United States Gulf Coast. In the search for alternative strategies to reduce its impact, the introduction of a natural enemy, Apanteles opun...

Cactoblastis cactorum's unintended arrival to Florida and its expansion in North America represent a threat to Opuntia‐based agriculture and natural ecosystems in the United States and Mexico. Apanteles opuntiarum attacks C. cactorum and is a potential biocontrol agent due to its specificity, wide distribution and occurrence. Laboratory rearing met...

Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) is native to South America and has been used successfully as a biocontrol agent against invasive species of Opuntia (Cactaceae). After its release in the Caribbean, it entered North America, dispersed to southeastern USA, and may reach Mexico threatening native cacti biodiversity and industry ba...

Summary Field exploration in Argentina for cactophagous lepidopteran hosts parasitized by the recently described braconid parasitoid Apanteles opuntiarum Martínez & Berta (Hymenoptera: Braconidae) revealed a host range restricted to Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) and C. doddi. Field collections of cactophagous larvae parasiti...

The cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), is a pest that threatens native Opuntia spp. in North America. Control tactics developed and implemented against this invasive pest successfully eradicated the moth in Mexico and on barrier islands in the United States. However, with the cancellation of the regional management...

A central aspect in biology and ecology is to determine the combination of factors that influence the distribution of species. In the case of herbivorous insects, the distribution of herbivorous species is necessarily associated with their host plants, a pattern often referred to as “host use”. Novel interactions that arise during a biological inva...

Despite their recognized importance in the literature, the contribution of native-range species interactions to invasion success has been inadequately studied. Previous authors have suggested that biases in the sampling of propagules from the native range might influence invasion success, but most contemporary invasion hypotheses focus on the devel...

Solenopsis invicta virus 1 (SINV-1) was found regularly and prevalently in S. invicta. In sampled locations where S. invicta and S. geminata are sympatric (specifically, Gainesville, FL and Travis, TX), SINV-1 was detected in S. geminata. Conversely, in areas in which S. geminata and S. invicta are allopatric, SINV-1 was not detected in S. geminata...

The cactus moth, Cactoblastis cactorum (Berg), is native to South America. Since its unintentional arrival to the United States in 1989 and to Mexican islands in 2006, it has become a serious threat to the diversity of both wild and cultivated species of Opuntia Mill, in North America. The native ecological host range of C. cactorum has not been di...

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A field exploration was conducted to confirm the southern distribution of Cactoblastis cactorum in Argentina. The distribution of the moth was found to be extended to the south (40° 10'S) and west (66° 56'W). The native species Opuntia penicilligera was recorded as a host for the first time. These findings should be useful in improving bioclimatic...

We review the fire ant research conducted by the ARS-South American Biological Control Laboratory (SABCL) since 1987 to find a complex of natural enemies in southern South America and evaluate their specificity and suitability for field release as self-sustaining biological control agents. We also include those studies conducted by the ARS-Center f...

Environmental niche models (ENMs) have gained enormous popularity as tools to investigate potential changes in species distributions resulting from climate change and species introductions. Despite recognition that species interactions can influence the dynamics of invasion spread, most implementations of ENMs focus on abiotic factors as the sole p...

The gregarious species of Apanteles that attack cactus-feeding phycitine moths (Lepidoptera : Pyralidae) from Argentina are identified using DNA barcodes and morphological data. Sequences of specimens from 10 different populations were generated. Corrected genetic divergences showed two clusters of specimens separated by COI divergences higher than...

Orasema minutissima (Hymenoptera: Eucharitidae) has been proposed as a biological control agent of the Little Red Fire Ant, Wasmannia auropunctata. Our results suggest that there is some confusion of species boundaries and biological differences with the closely related species O.costaricensis and O.smithi. We examine differences between species us...

Parasitoid wasps of the genus Orasema Cameron have been considered as potential candidates for biological control of imported fire ants in the United States. Surveys were conducted for their occurrence in fire ant colonies across southern South America. In Argentina, 443 ant colonies were excavated at 57 sites and 11 positive sites were revisited t...

The RNA-dependent RNA polymerase (RdRp) region of Solenopsis invicta virus 1 (SINV-1) was sequenced from 47 infected colonies of S. invicta, S. richteri, S. geminata, and S. invicta/richteri hybrids collected from across the USA, northern Argentina, and northern Taiwan in an attempt to infer demographic information about the recent S. invicta intro...

Solenopsis invicta virus 3 (SINV-3) is a recently described positive-strand RNA virus that infects the red imported fire ant, S. invicta. The genome of an Argentinean isolate of Solenopsis invicta virus 3 (SINV-3ArgSF ) obtained from the Santa Fe region of Argentina was sequenced in entirety. Assembly of nine overlapping fragments yielded a consens...

Several species of Orasema are known to attack both Solenopsis and Wasmannia (Myrmicinae), and have been proposed as biological control agents of fire ants (Heraty 1993). Two species complexes are known to attack fire ants; the Orasema xanthopus group attack Solenopsis in southern South America, and species in the costaricensis group are parasitoid...

Multiplex reverse transcription and polymerase chain reaction (PCR) methods were developed to detect Solenopsis invicta viruses -1, -2, and -3 simultaneously in their host, the red imported fire ant, S. invicta. cDNA synthesis was conducted in a single reaction containing an oligonucleotide primer specific for each virus. Multiplex PCR was subseque...

Biological characteristics of the parasitoid Orasema simplex Heraty (Hymenoptera: Eucharitidae), a potential candidate for the biological control of fire ants in the United States were investigated. Female survivorship, fertility and oviposition preferences were studied in the laboratory. Naturally parasitized colonies were examined to determine of...