The plantain weevil, Mecinus pascuorum (Gyllenhal), an introduced species associated with narrow leaf plantain, has become a regular and common post-harvest contaminant of kiwifruit in South Auckland. Here we describe its life history in New Zealand for the first time, based on surveys of narrow leaf plantain, shelter trees and kiwifruit vines, light trapping and ovarian dissections. Adult plantain weevils were captured in light traps from October to mid-November, and appeared on narrow leaf plantain in early October with numbers peaking in early November before declining in December. Ovarian and oocyte development occurred approximately 3 weeks after adults first appeared on narrow leaf plantain, and eggs were probably laid throughout November. Newly emerged adults were found from late December, and the majority emerged from narrow leaf plantain seed heads in January before dispersing by flight. Adults were subsequently found in crevices in tree and vine bark, coarse shelterbelt litter and foliage from January until mid-September. Adults were also found in the distal end of kiwifruit from late January until at least March. We conclude there is one generation per year with a relatively brief immature stage of 2 months and a long-lived adult stage of about 11 months.
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