The importance of cryptic species and subspecific populations in classic biological control of weeds: a North American perspective

Smith, Lincoln; Cristofaro, Massimo; Bon, Marie‐Claude; Biase, Alessio De; Petanović, Radmila; Vidović, Biljana

doi:10.1007/s10526-017-9859-z

Cited by 38 publications

(24 citation statements)

References 61 publications

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“…Given the protracted problems facing weed biocontrol in the USA and Hawaii, especially, it is not surprising that the emphasis in this Special Issue is provided by authors from the USA writing on risk assessments, conflicts of interest and regulations, and on the considerable complications of dealing with agenthost-fidelity for taxa at sub-specific levels (Bean and Dudley 2018;Casagrande et al 2018;Smith et al 2018), and on innovations to expand host-specificity procedures, to help make them more definitive (Park et al 2018;Blossey et al 2018). Two papers in this Special Issue have wide applicability: Schaffner et al (2018) review and assess the use of open-field testing in risk assessments, and Blossey et al (2018) argue that the use of long-term, plant demographic data should be an essential practical and conceptual component in debates on host-specificity, risk assessments, and in the evaluation of weed biological control in management programs.…”

Section: Perceptions Of Risk In Weed Biological Controlmentioning

confidence: 99%

Constraints in weed biological control: contrasting responses by implementing nations

2018

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The compilation of papers in this Special Issue (SI) derives from a Symposium at the 25th International Congress of Entomology, in 2016, entitled ''Rise or demise? A global outlook on the future of classical biological weed control''. In the SIopening-paper, a summary of the 5th edition of the world catalogue of weed biocontrol agents and their target weeds provides a comprehensive international perspective. Weed biocontrol implementation is beleaguered by perceptions of risk and restrictive regulatory procedures, notably in the USA, and less so in Canada. Thus, most of the papers in this SI comprise accounts of innovative responses to these challenges from scientists in the USA. Political and funding issues have inhibited weed biocontrol in Australia over the past decade, but there appears to be a gradual reversal of this trend in recent years. In contrast, in New Zealand and in South Africa, the practice is flourishing, and there are significant recent initiatives in Europe. Overall, the contributions in the SI suggest an optimistic prognosis for weed biological control. Keywords World catalogue Á Successes and failures Á Non-target effects Á Risk assessments Á Hostspecificity Á Community involvement

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Section: Perceptions Of Risk In Weed Biological Controlmentioning

confidence: 99%

Constraints in weed biological control: contrasting responses by implementing nations

2018

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“…A program of classical biological control was initiated for the integrated management of common sowthistle (McCarren and Scott 2008, 2017. This program clearly relies on the correct identification of the target plant to search for specialist natural enemies to manage focal taxa (Goeden and Ricker 1985;O'Hanlon et al 2000;McFadyen 2003;Smith et al 2010Smith et al , 2018.…”

Section: Introductionmentioning

confidence: 99%

“…Indeed, the specificity relationship between the host plant and its natural enemies might be very tight, e.g. for pathogens and Eriophyidae spider mites, which is a crucial element in the science of weed biocontrol (McFadyen 2003;Smith et al 2010Smith et al , 2018. Misidentification of the target weed and selection of unadapted agents can cause incomplete control or failure of the establishment of the control agent in invasive range (Goeden and Ricker 1985;O'Hanlon et al 2000).…”

Section: Introductionmentioning

confidence: 99%

Using karyotyping and achene morphology to accurately identifySonchus oleraceus(Asteraceae) in the context of its biological control

Ollivier

Gauthier

Lesieur

et al. 2020

Preprint

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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.

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“…Cryptic species are more abundant than was originally thought (Bickford et al, 2007). The consequences of this abundance of cryptic species to the practice of weed biological control has recently been reviewed by Smith et al (2018). The positive implications are that more species are available as potential biological control agents, as many species that were thought to be polyphagous could be cryptic species complexes with restricted host ranges (Smith et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

“…The consequences of this abundance of cryptic species to the practice of weed biological control has recently been reviewed by Smith et al (2018). The positive implications are that more species are available as potential biological control agents, as many species that were thought to be polyphagous could be cryptic species complexes with restricted host ranges (Smith et al, 2018). There is, however, a potential danger in that cryptic species with broader host ranges could be introduced accidentally if biological control practitioners are not aware of their existence (Paynter et al, 2008;Paterson et al, 2016), which could result in unanticipated damage to non-target plants, with serious consequences to the science and practice of biological control.…”

Section: Introductionmentioning

confidence: 99%

Cryptic species of a water hyacinth biological control agent revealed in South Africa: host specificity, impact, and thermal tolerance

Paterson

Coetzee

Weyl

et al. 2019

Entomologia Exp Applicata

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The discovery that cryptic species are more abundant than previously thought has implications for weed biological control, as there is a risk that cryptic species may be inadvertently released with consequences for the safety of the practice. A cryptic species of a biological control agent released for the control of the invasive alien macrophyte, water hyacinth, Eichhornia crassipes (C. Mart.) Solms. (Pontederiaceae), was recently discovered in South Africa. The two species were considered a single species prior to genetic analysis and interbreeding experiments. The original biological control agent retains the name Eccritotarsus catarinensis (Carvalho) (Heteroptera: Miridae) whereas the new species has been described as Eccritotarsus eichhorniae Henry. In this study, we compared the host specificity, efficacy, and thermal physiologies of the two species. The host specificity of the two species within the Pontederiaceae was very similar and both are safe for release in South Africa. Comparison of the per capita impact of the two species indicated that E. eichhorniae was the more damaging species but this is likely to be influenced by temperature, with E. catarinensis being more effective under lower temperatures and E. eichhorniae being more effective under higher temperatures. Releasing the correct species for the thermal environment of each release site will improve the level of control of water hyacinth in South Africa. This example highlights the need to keep populations of biological control agents from different native range collection localities separate, and to screen for host specificity and efficacy.

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The importance of cryptic species and subspecific populations in classic biological control of weeds: a North American perspective

Cited by 38 publications

References 61 publications

Constraints in weed biological control: contrasting responses by implementing nations

Constraints in weed biological control: contrasting responses by implementing nations

Using karyotyping and achene morphology to accurately identifySonchus oleraceus(Asteraceae) in the context of its biological control

Cryptic species of a water hyacinth biological control agent revealed in South Africa: host specificity, impact, and thermal tolerance

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