engleski

Helicoverpa armigera (Hübn.) feeding preference for crop and weed plants

Helicoverpa armigera (Hübner, 1808), the cotton bollworm, is a highly polyphagous pest whose caterpillars feed primarily on crops, but can attack the weed plants in absence of food. The massive occurrence of this pest was recorded in the fall of 2016 in Lukač on the weed ambrosia. Feeding preference tests were carried out in laboratory in order to determine if ambrosia was preferable to oats, beans and sugar beet, crops on which this pest is important and common. For all test plants the amount of eaten leaves was measured, as well as the leaf surface, and the results were analyzed by ANOVA. If all the tested plant species ("choice test") were offered at the same time, the cotton bollworm caterpillars significantly preferred the ambrosia plants. If only one plant species in the test was offered ("no-choice test"), the cotton bollworm caused more damage on ambrosia, which was significantly higher only when compared to damages on the bean plants. In contrast to the damage, the "no-choice test" showed that cotton bollworm caterpillars had eaten significantly more ambrosia leaf suface than other plants in the study. Feeding preference tests have shown that the weed ambrosia is very acceptable plant host to cotton bollworm and that, in the absence of cultivated plants, it may serve as an alternative source of nutrition, thereby ensuring survival when crops are unavailable. This feeding preference study was made for the first time on cotton bollworm in Croatia. Therefore, it is recommended to carry out additional feeding preference tests on other plant species or investigate egg laying preferences of the cotton bollworm.

ambrosia, feeding preference tests, Helicoverpa armigera

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