The effect of plant extract on mortality, feeding and oviposition of Frankliniella occidentalis Pergande, 1895

Kalifornijski trips (Frankliniella occidentalis Pergande, 1895) jedan je od najvažnijih polifagnih štetnika zaštićenih prostora diljem svijeta. Problem u suzbijanju ovog štetnika javio se razvojem rezistentnosti izazvan nepravilnom primjenom kemijskih sredstava. Jedna od alternativnih i ekološki povoljnih metoda u suzbijanju jest primjena biljnih ojačivača. S obzirom na vrlo mali broj podataka o izravnom utjecaju biljnih ojačivača na štetne kukce, cilj ovog istraživanja je utvrditi utjecaj biljnih ekstrakata na mortalitet, ishranu i ovipoziciju kalifornijskog tripsa te na debljinu stanične stijenke i epiderme lista krastavca. Rezultati pokazuju kako biljni ojačivači nemaju izravan utjecaj na mortalitet drugog stadija ličinke niti na ovipoziciju ženki. Kod odabira odraslog oblika tripsa između listova krastavca tretiranim biljnim ekstraktima i listova tretiranih vodom nema signifikantne razlike. Ishrana tripsa po listu signifikantno je veća na listovima tretiranim ekstraktom koprive. Signifikantne razlike u debljini stanične stijenke nisu utvrđene dok je debljina epiderme signifikatno veća kod listova tretiranim ekstraktom koprive i preslice. The western flower thrips (Frankliniella occidentalis Pergande, 1895) is one of the most important polyphage pests in greenhouse production worldwide. A problem with the control of this pest has arisen through the development of resistance caused by the improper use of chemicals. One of the alternative and environmentally friendly methods of suppression is the use of plant extracts. Due to the lack of literature on the direct impact of plant extract on insect pests, the aim of this study is to determine the effect of plant extracts on mortality, feeding and oviposition of western flower thrips as well as the effect on thickness of the cell wall and epidermis of cucumber. The results show that plant extracts do not have a direct effect on second-stage larval mortality nor on oviposition of females. There is no significant difference in the choice of adult thrips form between plant extract treated cucumber leaves and water treated leaves. The feeding of thrips per leaf is significantly higher on leaves treated with stinging nettle extract. There is no significant difference in the thickness of the cell wall, whereas the thickness of the epidermis is significantly higher in leaves treated with stinging nettle and horsetail extract.