The Laguna del Ojo is located in the Pampean plain, San Vicente Municipality, Buenos Aires Province. Since 2009, it has been invaded by water hyacinth, endangering the lagoon’s cultural, recreational and tourist value, as well as the ecosystem services it provides as a natural reservoir of the biodiversity of the region’s lagoon system in the Pampas.

The rapid growing and coverage of water hyacinth on the lake increased from 1 to more than 25 ha in two years. This invasion directly affected society and fundamentally the biodiversity of the system. A multi-stakeholder control strategy has been launched, where the main lines of action are to investigate, in order to transfer and apply know-how and raise awareness through community engagement. The use of integrated management (biological and mechanical) consists of establishing the massive breeding of the insects.

Students and teachers of the Agrarian School No. 1 are in charge of the small mass-rearing facility, and are supervised by FuEDEI’s researchers. Insects are released in the lake in periodic activities. Biological Weed Control is now an optional subject at school, through professionalizing practices, where students not only learn concepts about environmental education but are also actors and promoters of a solution for their community and the transference of acquired knowledge. Furthermore, the project was declared of Cultural, Scientific and Legislative Interest by the Municipality of San Vicente and more recently by Buenos Aires Province authorities.

Staff:
Alejandro Sosa, Tomás Righetti, Ana Faltlhauser, Mariel Guala, Guillermo Cabrera Walsh, M. Cristina Hernández, Fernando Mc Kay, Marina Oleiro

Cooperators:
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
Municipalidad de San Vicente
Martin P. Hill y J. Coetzee, Rhodes Univ., Sudáfrica.

Chromolaena odorata (L.) R.M.King & H.Rob. (Asteraceae: Eupatorieae), a herbaceous plant native to the Neotropical Region, has become a widespread weed in South Africa and other tropical and subtropical regions of the world. The stem borer Recchia parvula (Lane) (Coleoptera: Cerambycidae) is a host-specific biocontrol agent for C. odorata in South Africa.

Chromolaena odorata (L.) R.M.King & H.Rob. (Asteraceae: Eupatorieae) is a herbaceous plant native to the Neotropical Region (Argentina, Paraguay and Bolivia) that has become a widespread weed in South Africa and other tropical and subtropical regions of the world.  The univoltine stem borer Recchia parvula (Lane) (Coleoptera: Cerambycidae) was selected as a promising biological control agent against this weed. After extensive host range field and laboratory studies, R. parvula was approved as a biocontrol agent of C. odorata in South Africa. Climate matching studies indicate that the northwestern Argentina R. parvula populations would be best adapted to control C. odorata in the invaded areas of Africa.

Personal a cargo:
Fernando Mc Kay.

Cooperadores:
Costas Zachariades (Agricultural Research Council, Plant Protection Research Institute, South Africa).

Bellyache bush (Jatropha gossypiifolia) has become a major and expanding weed of rangelands and riparian zones in Australia.  In February 2018, an agreement was signed with DAFF (Queensland Department of Agriculture and Fisheries) to test two species of gall midges (Prodiplosis spp.) (Cecidomyiidae) as biological control agents of Bellyache bush. The no-choice trials carried out so far show the midge develops exclusively on J. gossypiifolia.

Jatropha gossypiifolia (Euphorbiaceae) is native to Mexico, South America, and the Caribbean. It has become an invasive weed in grasslands and riparian zones in Australia. Given that Prodiplosis longifila is a pest species on several crops from different families, and the phylogenetic proximity of the pest species with the species found on J. gossypiifolia, specificity tests were started on the cultivated hosts of P. longifila. Between February 2018 and March 2020, no-choice trials were carried out with 11 commercial species, two euphorbiaceae (non-commercial species), and J. gossypiifolia as a control species. Of all the species tested, we only obtained adult damage and emergence in the control species, while none of the other 13 species suffered any kind of damage.

Personal a cargo:
Marina Oleiro, Willie Cabrera, Mariel Guala

Cooperadores:
Dhileepan Kunjithapatham, Invasive Plant & Animal Science, Biosecurity Queensland, Department of Agriculture and Fisheries, Brisbane, Australia.

Saltcedar, Tamarix spp. is native to Eurasia and Africa. In Argentina, saltcedars affect the social and economic value of both highly productive land and subsistence agriculture areas. They also threaten biodiversity and conservation in dry ecosystems, including national parks and several protected areas.

The taxonomic isolation of Tamarix spp. in Argentina, their widespread distribution, negative impact on natural areas, and lack of impact from existing natural enemies, all indicate that Tamarix is an ideal candidate for classical biological control (CBC). CBC of Tamarix spp. has been rapid and highly successful in the USA after the introduction of four Diorhabda spp. (Coleoptera: Chrysomelidae). CBC of Tamarix spp. in Argentina could be implemented easily, rapidly, and at a low cost by utilizing the information developed in the USA. In 2019, we initiated a project to document arthropods and pathogens associated with Tamarix spp. in Argentina to determine the convenience of introducing natural enemies from the weed’s native range. In a second phase, we may recommend the importation of D. sublineata from USA to initiate a colony of the insect at the National Institute of Agricultural Technology (INTA) quarantine facility, and evaluate the risk of utilizing D. sublineata as a biocontrol agent against Tamarix spp. in Argentina.

Staff:
Guillermo Cabrera Walsh
Fernando Mc Kay
Alejandro Sosa
Mariel Guala.

Cooperadores:
Evangelina Natale (Universidad Nacional de Río Cuarto), Freda Anderson (Centro de Recursos Naturales Renovables de la Zona Semiárida, Bahía Blanca). Paul Pratt USDA, ARS, WRRC, Invasive Species and Pollinator Health Research Unit.

Brazilian peppertree (BP), Schinus terebinthifolius, native to South America, is an invasive weed in the USA, Australia and South Africa. The main objective of the project is to search for natural enemies of BP in South America and evaluate their potential as biocontrol agents for this invasive exotic weed.

Surveys in northeastern Argentina revealed the presence of 40 phytophagous insects associated with BP, providing valuable biological diversity and species distribution information for Argentina. In 2019, Pseudophilothrips ichini (Hood) (Thysanoptera: Phlaeothripidae) was released in Florida for the biocontrol of BP. We are currently studying the biology and host specificity of the sawfly Heteroperreyia hubrichi (Hymenoptera: Pergidae), a potential biocontrol agent for BP.

Staff:
Fernando Mc Kay

Cooperators:
Greg Wheeler (USDA-ARS-Invasive Plant Research Lab, Fort Lauderdale, Florida, USA); Marcelo Diniz Vitorino (Universidade Regional de Blumenau, Santa Catarina, Brasil).