Šumarski list, Vol. 136 No. 5-6, 2012.
Izvorni znanstveni članak
Foliar treatments against horse chestnut leaf miner (Cameraria ohridella)
Aleksandar Mešić
orcid.org/0000-0003-3102-5078
; Sveučilište u Zagrebu, Agronomski fakultet
Tihomir Miličević
; Sveučilište u Zagrebu, Agronomski fakultet
Dinka Grubišić
; Sveučilište u Zagrebu, Agronomski fakultet
Baris Duralija
; Sveučilište u Zagrebu, Agronomski fakultet
Ante Marić
; Grad Petrinja
Anamarija Popović
; Grad Sisak
Sažetak
Horse chestnut leaf miner (Cameraria ohridella) is the most important pest of horse chestnut (Aesculus hippocastanum), common tree in European parks. The pest regularly develops high populations of larvae which damage leaves. It could be controlled with foliar spraying or with trunk injections of insecticides (endotherapeutical method).
The paper presents results of in-city trials with foliar treatments against horse chestnut leaf miner’s larvae. Knapsack mist-blower was used for insecticides application (dates of applications are presented in Table 2) on trees higher than 15 m. Insect growth regulators (IGRs), imidaclopride, spinosad and Bacillus thuringiensis (Table 1) were applied with liquid rate of 3 l per one tree.
Each year, leaves were examined five times; each time 400 leaves were examined for each trial variant and numbers of mines per leaf were counted and statistically analyzed.
The best results were achieved after two applications in one season (with average period between two applications of 43 days) with imidaclopride (91.4–97.2 % efficacy) and insect growth regulators (IGRs) – diflubenzuron (89.5–94.9%), hexaflumuron (84.6–96.3 %), methoxyfenozyde (85.6–94.9 %) and lufenurone (85.8–94.4 %). Single application of imidaclopride (88.9–97.7%) and diflubenzuron (85.9–95.3 %) did not achieved statistically different efficacy in horse chestnut leafminer control than two applications in one season. Efficacy of spinosad (67.4–89.3%) and combination of B. thuringiensis and imidaclopride (52.4–91.6 %) did not satisfy. Even lower efficacy was achieved after two applications of B. thuringiensis in one season (52.2–83.7 %) and after single application in one season (30.3–84.7 %) (Table 8). In this period untreated control trees were infected with average of 22.4 –84.2 larvae/leaf (Tables 3–7), depending on date of examination.
Results of those five-year trials results show that is possible to protect horse chestnuts if foliar insecticides application is provided in period of first generation’s larvae hatching. The most suitable insecticides were insect growth regulators (IGRs), while imidaclopride is not appropriate in urban area due to its high toxicity. B. thuringiensis provides very good initial protection, but it has very poor residual effect so it is advisable to apply B thuringiensis twice or more times in one season (Tables 3–8).
Ključne riječi
Bacillus thuringiensis; efficacy; foliar threatment; horse chestnut protection; IGRs; imidaclopride; insect growth regulators; spinosad
Hrčak ID:
84709
URI
Datum izdavanja:
30.6.2012.
Posjeta: 3.470 *