1 Outdoor trials were carried out during 2001â02 on strawberries grown in
commercial growing bags naturally infested with black vine weevil larvae
(BVW) Otiorhynchus sulcatus in Co. Wexford, Ireland.
2 The two nematode isolates used in these trials were Heterorhabditis megidis
(UK211) and Heterorhabditis downesi (K122), both laboratory cultured.
Growing bags received nematodes either once (May 2001), twice (May and
October 2001) or three times (May, October 2001 and May 2002). Ten days
after each application date, nine blocks (of the total 27) were randomly
selected, destructively assessed and discarded.
3 The single application (May 2001) resulted in a mortality of black vine weevil
larvae, of 93.4% with H. megidis and 51.3% with H. downesi, compared with
the control treatment at that date. Respective figures after the double application
(May 2001 and October 2001) were 78.9 and 77.6% and after the triple
application (May 2001, October 2001 and May 2002) the figures were 93.7 and
88.1%.
4 Results from these trials clearly indicate that entomopathogenic nematodes are
good alternatives to chemical control of the black vine weevil on strawberries
grown in growing bags in Ireland
