Natural enemies from South Africa for biological control of Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae) in Europe

Abstract

The non-native invasive plant, Lagarosiphon major (Hydrocharitaceae) is a submersed aquatic macrophyte that poses a significant threat to water bodies in Europe. Dense infestations prove difficult to manage using traditional methods. In order to initiate a biocontrol programme, a survey for natural enemies of Lagarosiphon was conducted in South Africa. Several phytophagous species were recorded for the first time, with at least three showing notable promise as candidate agents. Amongst these, a leaf-mining fly, Hydrellia sp. (Ephydridae) that occurred over a wide distribution causes significant leaf damage despite high levels of parasitism by braconid wasps. Another yet unidentified fly was recorded mining the stem of L. major. Two leaffeeding and shoot boring weevils, cf. Bagous sp. (Curculionidae) were recorded damaging the shoot tips and stunting the growth of the stem. Several leaffeeding lepidopteran species (Nymphulinae) were frequently recorded, but are expected to feed on a wide range of plant species and are not considered for importation before other candidates are assessed. The discovery of several natural enemies in the country of origin improves the biological control prospects of L. major in Europe.

Ocean Sprawl: Challenges and Opportunities for Biodiversity Management In A Changing World

“…Atalah et al (2014) advocated that many of the limitations could be overcome with biocontrol (i.e., control by natural predators, either native or non-indigenous) as effective control agents will have a sustained effect on all life stages of target species or multispecies assemblages. This method of control of non-indigenous species is relatively well established in terrestrial and freshwater aquatic systems (e.g., Newman et al 1996, Baars et al 2010, Mangan & Baars 2013. Despite the promising preliminary results to date, this field is very much in its infancy in the marine environment (but see Atalah et al 2013aAtalah et al ,b, 2014Atalah et al , 2015, and further research is needed in this area.…”

A new species of Hydrellia (Diptera: Ephydridae) mining Hydrilla verticillata (Hydrocharitaceae) leaves in Singapore

“…The fly was discovered in South Africa during surveys for candidate biological control agents for L. major in Europe (Baars et al . ). Hydrellia egeriae Rodrigues Júnior, Mathis & Hauser mines the leaves of dense water weed, Egeria densa Planchon (Hydrocharitaceae), in Argentina (Cabrera Walsh et al .…”

Management of <i>Lagarosiphon Major</i> (Ridley) Moss in Lough Corrib—A Review

“…The possibility of using biological control, where natural enemies from L. major's country of origin (southern Africa) are targeted against it, is being explored (Baars et al 2010;2011). The life cycle and adventive traits of L. major are also being studied in anticipation of finding a 'weak link' in the plant's life cycle that could become the target of strategic control operations.…”