sodininkystė ir daržininkystė 25(4)

SCIENTIFIC WORKS OF THE LITHUANIAN INSTITUTE OF
HORTICULTURE AND LITHUANIAN UNIVERSITY OF AGRICULTURE.
SODININKYSTË IR DARÞININKYSTË. 2006. 25(4).
TOXICITY OF ABAMECTIN TO FRUIT TREE
RED SPIDER MITE, PANONYCHUS ULMI
(ACARI: TETRANYCHIDAE) IN APPLE TREE SITE
Laimutis RAUDONIS
Lithuanian Institute of Horticulture, Laboratory of Plant Protection,
LT-54333 Babtai, Kaunas distr., Lithuania.
E-mail l.raudonis@lsdi.lt
The effect and toxicity of Abamectin 18 g l -1 to the fruit tree red spider mite (Panonychus
ulmi Koch) was studied in apple tree under field conditions in 2005–2006. Abamectin
18 g l -1 at the rates 27 g AI ha -1 and 18 g AI ha -1 was very toxic (mortality ranged
from 92.9 to 99.0%) to the mites 2–5 and 7 days after treatment and from moderately
to very toxic (mortality – 54.4–89.7%) 31 days after treatment. Abamectin 18 g l -1 ,
13.5 g AI ha -1 was rated as very toxic (mortality – 89.0–91.4%) 2–5 and 7 days after
treatment and only moderately toxic (mortality – 51.1–62.4%) 31 days after treatment.
Spirodiclofen 240 g l -1 , 96.0 g AI ha -1 was rated as very toxic 2–5, 7 days and 31 days
after treatment and showed long term of action, meanwhile Lambdacihalotrin 50 g l -1 ,
25.0 g AI ha -1 was very toxic to the mites 2–5 and 7 days after treatment, but from
non-toxic to moderately toxic 31 days after treatment.
Key words: Abamectin, apple tree, rates, Panonychus ulmi, toxicity.
Introduction. Fruit tree red spider mite is the key pest of apple tree in many
countries (Edland, 1994; Raudonis, 2001; Hardman et al., 2003). Though tree red
spider mites are sensitive to the low temperature during hibernation, warm and dry
climate stimulates mite development in high numbers (Raudonis, 2001). The toxicity
of pesticides on mites and insects has been widely studied in many countries, using
a range of different pesticides at different rates on various developmental stages
(Zon, Geest, 1980; Tuovinen, 1992; Sterk et al., 1999; Nauen et al., 2001; Kim, Yoo,
2002; Choi et al., 2003; Hardman et al., 2003; Cuthbertson, Murchie, 2003, Marcic,
2003; Bostanian et al., 2004; Raudonis et al., 2004; Martînez-Villar et al., 2005).
There is data that most organophosphates are very detrimental to predatory mites,
except strains, which have developed resistance to organophosphates (Cranham,
1979). The widely used synthetic pyrethroids are very effective against pest insects,
but it has not any effect on mites and it causes increasing phytophagous mite populations
that induce severe damage of plants (Edland, 1994; Raudonis 2004). On the
other hand, frequent acaricide applications against the increased phytophagous mite
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