Biocontrol efficiency of Zygogramma bicolorata at different growth stagesof Parthenium hysterophorus

摘要

Parthenium hysterophorus L. is a highly invasive plant of global significance. It is a herb of neotropical origin which now has spread to many parts of the world (Adkins and Shabbir 2014). The weed was accidentally introduced to India in 1955 throughthe imported food grains and at present it has invaded throughout India in about 35 million hactares of land (Sushilkumar and Varshney 2009, Sushilkumar 2014). It is notorious for causing allergic reacions (Kologi et al. 1997) besides a threat to biodiversity and loss of crop productivity (Adkins and Shabbir 2014, Sushilkumar, 2014). In Pakistan, this weed has been spreading very fast since last couple of decades and it has become a major weed of wastelands, fallow lands, roadsides and protected areas where it is rapidly replacing (he native flora (Shabbir et al. 2012, Mujahid 2015). It is also reported from some cereal and vegetable crops (Safdar et al. 2015, Javaid and Anjum 2005) and ornamental plant nurseries (Shabbir et al. 2012).