Natural products in stored product pest control: challenges and opportunities

Abstract

Postharvest losses of stored grains are recognized as a major constraint in food security. The losses caused by stored product pests (insects, microorganisms and rodents) amount from 20 to 80%, depending on the region, thus their reduction can increase available food supplies. The control of pests in storage and processing industry is mainly relying on the use of chemically synthesized pesticides and toxic fumigants. However, the inadequate and frequent use of these compounds has led to a development of pest resistance (to residual insecticides, fumigants and some fungicides), residues in food and feed, environmental and health hazards and other adverse impacts. The mentioned has resulted in a ban or restriction of a number of pesticide compounds in recent years, particularly insecticides, enabling the expansion of natural products (NPs) use in stored product pest management. Although NPs have long been used as pesticides and have served as an inspiration for numerous commercial synthetic products, at some point in history they were neglected. NPs originate from natural sources, and are i) mineral-derived (inert dusts: diatomaceous earth, kaolin clay, boric acid, zeolite, silver nanoparticles etc.) or ii) plant-derived compounds (terpenes, phenolics, steroids, alkaloids etc.).

Posležetveni gubici uskladištenih zrnastih proizvoda prepoznati su kao glavno ograničenje u raspoloživosti hrane. Gubici koje uzrokuju štetočine uskladištenih proizvoda (insekti, mikroorganizmi i glodari) iznose od 20 do 80%, u zavisnosti od regiona, te smanjenje istih može doprineti povećanju zaliha hrane. Suzbijanje štetočina u skladišnim objektima i prehrambenoj industriji, uglavnom se zasniva na upotrebi hemijski sintetisanih pesticida i toksičnih fumiganata. Međutim, neadekvatna i česta upotreba ovih jedinjenja dovela je do razvoja rezistentnosti štetnih organizama prema rezidualnim insekticidima, fumigantima i nekim fungicidima, do pojave ostataka u hrani za ljudsku ishranu i životinje, opasnosti po životnu sredinu i zdravlje i drugih negativnih posledica. Navedeno je rezultiralo zabranom ili restrikcijom primene brojnih pesticidnih jedinjenja, posebno insekticida, usled čega se intenzivirala razvoj i upotreba prirodnih proizvoda (PP) u zaštiti od skladišnih štetočina. Iako su PP dugo korišćeni kao pesticidi i služili su kao model jedinjenja za brojne komercijalne sintetičke proizvode, u nekom trenutku u prošlosti, su zanemareni. PP potiču iz prirodnih izvora i mogu biti i) mineralnog (dijatomejska zemlja, kaolin glina, borna kiselina, zeolit, nanočestice srebra itd.) ili ii) biljnog porekla (terpeni, fenoli, steroidi, alkaloidi itd.).