## 5 Biopesticides and Inert Materials in IPM  
As already discussed above, current legislation and recommendations on IPM emphasises the reduction in chemical products, promoting natural products that are used in organic agriculture and that are useful in insect control. The first forms of control in olive groves included the anticipation of the harvest and the use of mixtures based on copper, cobalt, potassium/sodium arsenite, or tar [160]. In fact, some of these, although valuable [161], are not approved under the CE N\({}^{\circ}\)1107/2009 regulation or are candidates for replacement in some European countries, such as Spain [10]. Among the approved substances is spinosad. It is a molecule with a potent larvicidal effect discovered in the 1980s that has gained popularity in the field of IPM due to its effectiveness against a wide range of insect pests, including caterpillars, leaf miners, thrips, fruit flies, spider mites, and certain beetles. Spinosad, produced by the bacterium _Saccharomyces sponge_, has a similar efficacy to pyrethroid insecticides and is superior to organophosphates [162]. It contains two active ingredients, spinosyn A and spinosyn D, which target the nervous systems of insects. Spinosad acts on nicotinic acetylcholine receptors in insect nerve cells, leading to the overstimulation and paralysis of the insects, ultimately causing their deaths [163; 164]. The use of spinosad (a commercial mixture of spinosins) provides enormous benefits compared to other traditional chemicals. It is also worth noting that spinosad has a relatively short residual activity, i.e., it degrades relatively quickly in the environment. This property reduces the risk of long-term environmental impact when used properly, and it allows for a flexible approach to IPM, including the timely release of beneficial organisms after spinosad application. However, mutations in detoxification enzyme genes that confer resistance to this product have already been described in some insect species such as _Drosphila suzukii_, _Zeugodacus cucurbitea_, _Ceratitis capitata_, _Musca domestica_, _Tribolim castaneum_, or _Plutella xylostella_, among many others [165; 166; 167; 168; 169; 170], maybe as a consequence of treating consecutive insect generations with the same mode of action that therefore result in the evolution of insecticide resistance [171]. Despite the fact that spinosad's unique mode of action makes it less prone to insect resistance compared to some other classes of insecticides, it is still essential to practise responsible use and to avoid over-reliance on any single pest control method to prolong its effectiveness. Until recently, one of the most promising key advantages of spinosad in IPM is its selectivity and low toxicity to beneficial insects and non-target organisms, such as bees, butterflies, and predators like ladybugs and lacewings. However, spinosad has an undesirable effect on populations of natural enemies of the olive fly, mainly on predatory arthropods inhabiting the tree canopy but also pollinators such as _Apis mellifera_ or natural enemies of some other pests [172; 173; 174; 175; 176]. Nevertheless, sustainable olive grove management holds the potential to alleviate this adverse impact, as it distinctly enhances various soil quality parameters, encompassing the abundance and diversity of microbial and pedofaunal communities [160; 177; 178]. Next, particle film technologies refer to aqueous formulations of chemically inert clay or mineral particles specifically designed for coating purposes. These clays are widely used to reduce damage from insects, diseases, and solar radiation [179]. Kaolin is an aluminosilicate mineral that disperses readily in water and is chemically inert over a wide pH range [180]. It is often applied to plants as a thin film that does not interfere with plant respiration, and once the water evaporates, it forms a protective barrier that acts as a physical barrier to pests [181].