New biological control agent for Parthenium!

An application was recently submitted for the release of the stem-boring weevil into Pakistan. It was approved with permission for CABI to release Listronotus setosipennis in phases in Pakistan. This new biological control agent will be used for the management of the invasive Parthenium hysterophorus (white top) as it has spread throughout both urban and rural areas.

Parthenium is an invasive weed, native to tropical America and has been accidentally introduced to several countries. It is a threat to animal and human health; it now covers thousands of hectares of rangeland in Pakistan. This invasive species has spread so far due to its high seed production, for which its seeds have longevity and its wide adaptability.

CABI started host range testing at a new quarantine facility at CABI’s Central and Western Asia (CWA) offices in Pakistan. CABI applied for the importation of this weevil and with CABI’s Dr. Philip Weyl and with the help of Lorraine Strathie (ARC-PHP), 200 adult Listronotus setosipennis were successfully imported.

After conducting a multitude of tests in other countries, the results concluded that this weevil is a safe biological control agent against parthenium. The weevil controls the parthenium by ‘’laying its eggs primarily in the flowers where newly hatched larvae tunnel into the stem and continue to feed, eventually exiting at the base of the stem to pupate in the soil.’’

The weevil is in the process of being mass-reared by CABI for planned releases in spring 2023. This new biocontrol agent will help manage the spread of the invasive parthenium without the use of machinery or chemicals. This is a sustainable way that will not have any impacts negatively on the environment.

Read more about this here!