Composition of Essential Oils in Needles and Barks of Turkish Red Pine (Pinus brutia Ten.) Infested by Marchalina hellenica Genn

The scale insect Marchalina hellenica Genn. plays a key role in pine honey production and is hosted mainly by Turkish red pine (Pinus brutia Ten.). The needles of Turkish red pine are rich in essential oils. Moreover, essential oils can affect the host selection of insects. The essential oils in the needles and barks of Marchalina hellenica-infested and non-infested Turkish red pine were obtained via water distillation and their composition was determined by GC-MS analyses. The composition of the essential oils was found to differ in the needles of non-infested Turkish red pine and in those of pine infested by Marchalina hellenica. The Mann-Whitney U test results showed that the β-caryophyllene level was higher in the needles of Turkish red pine infested by Marchalina hellenica, whereas the junipen level was higher in the essential oil of non-infested Turkish red pine bark. Pimaral and α-guaiene were detected only in the needles of infested trees, but were absent in the needles of non-infested trees. These components may be markers that can act on their own or as part of the whole in the host tree selection of Marchalina hellenica. In addition, the cis-verbenone component found in Turkish red pine bark might play a role in attracting Marchalina hellenica. This phenomenon should be further investigated through additional studies. Ljuskavica Marchalina hellenica Genn. ima ključnu ulogu u proizvodnji meda od borovine, a uglavnom živi na turskome crvenom boru (Pinus brutia Ten.). Iglice tog bora bogate su eteričnim uljima. Štoviše, eterična ulja za insekte mogu biti presudna pri odabiru domaćina na kojemu će se nastaniti. Eterična ulja iz iglica turskoga crvenog bora zaraženoga i nezaraženoga ljuskavicom Marchalina hellenica dobivena su vodenom destilacijom, a njihov je sastav određen GC-MS analizama. Utvrđeno je da je sastav eteričnih ulja u iglicama ne-zaraženoga turskoga crvenog bora i u iglicama bora zaraženoga s Marchalina hellenica različit. Rezultati Mann-Whitneyjeva U-testa pokazali su da je razina β-kariofilena veća u iglicama crvenoga turskog bora zaraženoga s Marchalina hellenica, dok je razina kleke viša u eteričnom ulju nezaražene kore turskoga crvenog bora. Pimaral i α-guaiene otkriveni su samo u zaraženim iglicama stabala, ali ih nije bilo u iglicama nezaraženih borova. Te komponente mogu biti markeri koji pri selekciji stabla domaćina Marchaline hellenice mogu djelovati sami ili kao dio cjeline. Osim toga, komponenta cis-verbenon, pronađena u k