| Arable
More consistent vine weevil
control from the high quality
formulation, Nemasys L
New experimental work has confirmed that Nemasys L (Steinernema kraussei) provides better control of black vine
weevil at a range of temperatures compared with other species of nematodes used to control this pest. Nemasys L is
manufactured in the innovative, state of the art production facility at Littlehampton, which prides itself as being one of
the best in terms of quality.
ob Storer of BASF explains that
the trials on black vine weevil
compared Nemasys L with a
number of other parasitic
nematode products. “We
initiated this work originally to
prove once and for all that Nemasys L works
just as well at warmer temperatures as at lower
ones. The temperature data for this trial ranged
from a high of 40°C down to below minus 5°C.
Nematodes were applied at 25,000 per plant,
and Met 52 OD at 0.05 ml/plant on the 31st
August 2017. The untreated suffered nearly 6
vine weevils per plant; Nemasys L reduced this
to less than 1 per plant, which was the best
treatment in the trial. Met52 resulted in 5.2
weevils per plant, Nemtrident H 5 per plant,
Nema-top 4.2, Larvanem 4.1 per plant.”
Nemasys L really outshone the other
treatments. We were surprised at the results for
the competitors, none of which performed as
we expected. This could possibly be down to
formulation as the BASF product is well known
to be of particularly high quality.”
“Nemasys L (Steinermema kraussei) is
nematode that controls the immature stages of
the black vine weevil in strawberries and other
crops under a wide range of temperatures.
Nemasys L is effective at all times and across a
soil temperature range of 5 ºC to 30ºC, when
the larvae are active and feeding,” says Rob.
Black vine weevil (Otiorhynchus sulcatus) is
R
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a devastating pest of many plants, particularly
soft fruits, glasshouse ornamentals and nursery
stock. It feeds on over 140 different plant
species. In strawberries alone they are thought
to be responsible for losses of over £10 million
each year. The adult feeds on the foliage
producing characteristic notches, which is a
problem in nursery stock such as Azaleas,
Camellias, Fuschsias and Rhododendrons
where cosmetic damage can make plants
unmarketable. “Larvae in the soil or growing
medium feed on roots, leading to wilting or
even death of the plant. When applied as a
drench or through irrigation systems, Nemasys
L controls the damaging larvae rapidly and
safely.”
“This assured activity across a wide
temperature range added to its high quality
formulation is what differentiates Nemasys L
from other nematode products,” comments
Rob.
Adult vine weevils are active from May to
October. The female lays 500 eggs in the soil or
compost from July to September. Eggs are
1mm across, white turning brown and are
difficult to see. The larvae hatch after 2 weeks
and start feeding on roots. The beneficial
nematodes, usually applied from February to
November, seek out the larvae and once inside
release symbiotic bacteria, quickly killing the
insect pest. The microscopic nematodes
reproduce inside the insect and release a new
generation of infective juveniles that seek
further larvae, providing long lasting effects.
Nemasys L persists in the soil for four weeks.
“Nemasys L (Steinermema kraussei) is
nematode that controls the immature
stages of the black vine weevil in
strawberries and other crops under a wide
range of temperatures”
Nemasys L can be applied using standard
spray applicators. Drench application is
preferred, particularly where canopies are
dense. New plant material coming into the
nursery should always be treated as it may
contain vine weevil larvae. As well as being
effective at warm and low temperatures,
Nemasys L has no resistance problems, no
residue concerns, no re-entry interval, no
requirement for protective clothing and no
disposal restrictions.
Rob Storer notes that “there is increasing
pressure for effective pest and disease control
in specialist crops, particularly fruit crops, but
there are more legislative and practical
challenges for growers. We need effective
alternative options in speciality crops and
Nemasys L provides this. BASF are developing
market-leading science in both conventional
and biological approaches.”
February 2018 | Farming Monthly | 15