Kartulimardika (Leptinotarsa decemlineata Say) populatsiooni arvukuse prognoosi võimalikkus Eestis
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Kuupäev
2017
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Ajakirja pealkiri
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Kirjastaja
Estonian Academic Agricultural Society
Abstrakt
On the basis of phenological observations and overwintering
mortality data in 2015/2016 we tried to predict the population
density of Colorado potato beetle (Leptinotarsa decemlineata Say) (CPB)
for the following season. Because of the late and cool spring in 2015, the
beetles started to emerge from the soil at the end of May and, because of
the low temperatures, did not start to reproduce immediately. The first egg
clutches did not appear until the end of June. The low density of larvae
and beetles in mid-summer lead us to expect low damage for the whole
season. However, very warm weather in August and September induced
the beetles to lay eggs and the population density increased sharply. A lot
of the summer beetles managed to terminate their development in time and
to dig into the soil for overwintering. Consequently, we expected the
beetles to be abundant the following spring. However, a short, snowless,
very cold period in January when air temperature fell to –30 °C and soil
temperature to –6.6 °C nullified this prediction as over 90% of overwintering
beetles perished. In spring 2016, very few beetles were found on
the field and the potato plants remained undamaged until the end of June.
Then, due to south-east storms at the end of June, very large migrations
occurred and, some weeks later, various development stages of CPB were
very abundant in potato fields. Thus, none of our predictions came true.
The main reason for this was our extremely unstable weather conditions
during summer and the overwintering period and the unpredictable large
migrations from southern regions.
Kirjeldus
Saabunud / Received 22.12.16 ; Aktsepteeritud / Accepted 10.03.17 ; Avaldatud veebis / Published online 20.03.17 ; Vastutav autor / Corresponding author: Külli Hiiesaar ; e-mail: kylli.hiiesaar@emu.ee
Märksõnad
population density, prediction, phenology, overwintering, weather conditions, articles