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Intensive agriculture and crop production lead to a significant decline in biological control agents, their abundance and diversity. Ground beetles are important in reducing populations of pests and weeds. They are often used in environmental research as biological indicators of different habitats. The aim of this research was to analyse biocenotic and synecological indices of ground beetle populations collected from two remote sites differing in weather conditions, tillage, and types of arable crops. After detailed identification, 64 species were distinguished and classified according to the Catalogue of Palearctic Coleoptera. Biocenotic synecological analysis per crop in both Vukovar-Syrmia and Virovitica-Podravina counties showed that H. rufipes, P. melas, P. melanarius melanarius and P. cupreus cuperus were the most abundant species in the studied crops. Catches in Virovitica-Podravina County were significantly higher than catches in Vukovar-Syrmia County. Compared to the other crops, maize had significantly the highest. The highest catches were recorded in September, while catches were significantly lower in July. Catches were affected by location site, crop, and sampling date, as well as their combinations, proving that the abundance of ground beetles was significantly different at the two sites.

The effectiveness of pest control depends on monitoring methods, most of which are outdated and irrelevant. For example, the pear leaf blister moth (Leucoptera malifoliella (O. Costa, 1836)) is an important apple pest whose larvae damage leaves. Its monitoring is done with pheromone traps, which are time-consuming to inspect and may result in delayed pest control. The most effective time for its control is an early stage of damage occurrence (mines), which is difficult to detect with classical monitoring techniques. Artificial neural networks (ANN) have recently been used for pest monitoring. Therefore, the aim of this study was to develop automatic systems for monitoring pear leaf blister moth and its damage using ANNs. The two ANNs were trained to detect the pear leaf blister moth and its damage using photographs collected in three apple orchards in Zagreb County. The model was developed for use in two prototype smart monitoring devices (pest monitoring device and vegetation monitoring device). The model was tested and the results were processed using a confusion matrix. The developed models showed high accuracy and precision in detecting pear leaf blister moth and its damage, while the monitoring devices showed good functionality in apple orchards. The developed system is effective for automatic monitoring of pear leaf blister moth and its damage, and therefore can significantly improve pest control and apple production in general.

The codling moth is an economic pest of apple production in Croatia and has a cosmopolitan distribution. We have been working on CM biology, ecology, and genetics for over a decade to better understand how this pest has only changed its distribution, abundance, and movement patterns and what this means for improving control practices and management of the species in Croatia. Our initial work commenced with a study into the biology and ecology of CM under different treatments. Our findings showed that in the untreated orchard, two generations of CMs were observed per year, whereas an additional third flight period of the moths was observed in the treated orchards. This work was followed by a population genetic study which showed no genetic differentiation was found. Our most recent work on CM population genetics using SNPs found evidence that population sub-structuring may be occurring as a result of improved integrated control practices in Croatian apple orchids over the last decade. To further investigate population sub-structuring we investigated phenotypic traits under selection (ie. wings) using geometric morphometric (GM) methods. GM methods showed a reliable pattern of differences related to the type of control practice CM was subjected to. The combined use of SNPs and GM to detect resistant variants is a completely new approach and provides new insights into CM control. Recent innovative methods we’ve undertaken involve the use of structural engineering numerical modeling using the finite element method (FEM) to investigate the dispersal capabilities of CM in Croatia by modeling wing deformation against different wind speed moths experienced in the field. Our findings showed CM from the ecological orchards displayed the least wing deformation as the wind speed increased and had the most structurally sound wings compared to CM from integrated control orchids that had wings that were less structurally sound.

Box tree moth (Cydalima perspectalis, Walker) is an invasive species present in Croatia since 2012 where causes great damage to plants of the genus Buxus. The pest spreads rapidly, has high reproductive potential and good adaptability. Its known natural dispersal velocity is up to10 km per year. Understanding flight characteristics of insect pests is essential for designing effective strategies and programs for their management. The aim of this study was to asses wing shape variability, flight propensity and of C. perspectalis and to evaluate its invasive character using geometric morphometric methods and flight mill technology. An inter-sites analysis was performed, and the dataset was divided by geographic area, with intraspecific variation detected independently. Results show wing shape influenced by agroecological factors, with forewings found to be more plastic than hindwings. In terms of sexual differentiation, multivariate regression of wing shape revealed minimal differences between male and female forewings, yet female wing shapes were more variable and covered a large percentage of the shape space. C. perspectalis flew a maximum distance of 15.6 km (virgin females) and spent a maximum time in flight of 241 minutes (4 hours). The average speed of C. perspectalis ranged from 1.1 m/s to 1.6 m/s. Knowledge of C. perspectalis wing characteristics and flight performances are of great importance in assessing dispersal and provide important insights into migratory activities.

Trgovina biljem i biljnim proizvodima uvelike je povećala rizik i mogućnost širenja štetnika. Broj unesenih vrsta raste kao posljedica globalizacije (povećanje prijevoza, turizma, trgovine), ali i klimatskih promjena. Invazivna vrsta je strana vrsta za koju je utvrđeno da njezino unošenje ili širenje ugrožava ili štetno utječe na bioraznolikost i povezane usluge ekosustava. Nove strane vrste redovito se pojavljuju i u Hrvatskoj, a neke od njih uspiju se udomaćiti te uzrokuju velike štete u poljoprivredi. Veliki broj štetnih invazivnih vrsta ipak još nije prisutan u Hrvatskoj. Zato je iznimno važno na vrijeme informirati znanstvenike i poljoprivrednike o štetnosti i važnosti invazivnih vrsta kukaca kako bi ih mogli prepoznati i suzbiti na vrijeme. Cilj je opisati biologiju i štetnost nekoliko važnih invazivnih vrsta koje trenutno nisu prisutne u Hrvatskoj, ali s obzirom na povoljne klimatske uvijete predstavljaju visoki fitosanitarni rizik. Naglasak će biti na važnomu štetniku kukuruza, jesenskoj sovici (Spodoptera frugiperda) koja se posljednjih godina širi velikom brzinom te bi ubrzo mogla stići u Hrvatsku. Također ukratko će biti opisane najvažnije karakteristike smeđe mramoraste stjenice (Halyomorpha halys), invazivne vrste koja je prisutna u Hrvatskoj te su zabilježene štete na poljoprivrednim kulturama.

Repin buhač (Chaetocnema tibialis Illinger) radi velike štete u toplim i sušnim godinama na mladom usjevu šećerne repe. Izgrizanjem rupica na lišću dovodi do propadanja biljaka i prorjeđivanja sklopa. Tretiranje sjemena insekticidima iz skupine neonikotinoida davalo je zadovoljavajuće rezultate, no zbog mogućeg negativnog učinka na pčele i pojave rezistentnosti, ti insekticidi su zabranjeni odlukom Europske komisije od 27. travnja 2018. za sve poljoprivredne usjeve na otvorenom uključujući i šećernu repu. U 2020. i 2021. godini omogućena je hitna autorizacija tiametoksama za tretiranje sjemena šećerne repe u RH. U sklopu projekta Monitoring rezistentnosti štetnih organizama na sredstva za zaštitu bilja u Republici Hrvatskoj (2018. - 2021.) provedena su trogodišnja istraživanja rezistentnosti repina buhača na piretroide. Ukupno je u istraživanje bilo uključeno 27 lokaliteta (3-9 lokaliteta/godini). Pokusi su provedeni po metodi IRAC 011 (piretroidi), IRAC 021 (neonikotinoidi), IRAC 025 (organo-fosforni insekticidi). Utvrđivana je učinkovitost preporučene doze, dvostruke doze i 1/5 preporučene doze insekticida u četiri repeticije. U istraživanje su uključeni piretroidi (lambda cihalotrin, organofosforni insekticidi (klorpirifos) i neonikotinoidi (tiakloprid). Klasifikacija rezultata provedena je temeljem utvrđene učinkovitosti, a populacije su razvrstane kao visoko osjetljive, osjetljive, umjereno rezistentne, rezistentne i visoko rezistentne. Rezultati provedenih istraživanja pokazuju da se udio lokaliteta na kojem repin buhač pokazuje smanjenu osjetljivost na piretroide povećava iz godine u godinu. U 2018. godini jedna je populacija buhača (11, 1%) razvrstana kao rezistentna, pet je populacija (55, 5%) razvrstano kao osjetljivo dok su tri populacije (33, 3%) razvrstane kao visoko osjetljive. U 2019. godini dvije su populacije (22, 2%) razvrstane kao umjereno rezistentne, šest populacija (66, 6%) razvrstano je kao osjetljivo i jedna populacija (11, 1%) kao visoko osjetljiva. U 2020. godini tri su populacije (50%) razvrstane kao umjereno rezistentne, a tri su populacije (50%) razvrstane kao rezistentne dok niti jedna populacija nije bila osjetljiva ili visoko osjetljiva. U 2021. godini jedna je populacija (33, 3%) razvrstana kao umjereno rezistentna, a dvije su populacije (66, 6%) razvrstane kao osjetljive. Iz dobivenih rezultata razvidno je da je udio umjereno rezistnetnih i rezistentnih populacija repina buhača na lambda cihalotrin u porastu. Hitna autorizacija je privremena mjera koja je bila moguća u 2020. i 2021. no upitno je dovela je do nešto manjeg udjela umjereno rezistentnih populacija u 2021. Ne može očekivati da će hitna autorizacija biti moguća kroz duži period, a zbog zabrane klorpirifosa i neonikotinoida piretroidi su trenutno jedina dozvoljena skupina insekticida za suzbijanje repine buhača. Rezultati istraživanja ukazuju da bi nemogućnost suzbijanja repina buhača uskoro mogla postati još jedan u nizu ograničavajućih čimbenika za uzgoj ove vrijedne ratarske kulture.

Grain foods are the most important staple foods throughout the world. Meeting the food needs of a growing population remains a global problem, especially considering that losses can be as high as 30% due to pest infestation and inadequate facilities. Storage facilities such as silos or containers are a perfect environment for pests to develop. It is becoming increasingly difficult to control pests in stored products due to fewer products available on the market, environmental and safety concerns, developing resistance to pesticides, and cryptic insect behavior. Ozone, a highly reactive and a strong oxidizing agent, has demonstrated its effectiveness against a wide range of pests. The objective of the study was to determine: i) the effect of ozone on insect mortality, mobility, and velocity ; ii) the correlation between mortality and time elapsed after ozone treatment. The efficacy of ozone was tested on Sitophilus granarius, Tenebrio molitor and Blatta lateralis. The efficacies of all variants were subjected to analysis of variance (ANOVA) to determine the difference in the effect of ozone on insects at different exposure times. ANOVA was performed on insect velocity and mobility data to determine the effect of ozone on the above parameters. Ozonation showed 85-100% efficacy with inhibitory effect on insect mobility and speed. The efficiency of ozone treatment (mortality) increases with increasing ozone duration. Ozone has a harmful effect on storage pests and could be used for pest management, primarily for post-harvest treatment of stored grain, either alone or as an adjunct to other methods.

Colorado potato beetle, CPB, (Leptinotarsa decemlineata Say) is the most important potato pest. Over the past 60 years, more than 300 cases of CPB resistance to 56 active ingredients have been detected in potato-growing regions of the world. Understanding population structure, gene flow, and variability is particularly important for CPB management because insecticide resistance is widespread in this species. A detailed genomic description could potentially give us an answer to genetically driven population evolution, which is often related to the evolution of resistance. Therefore, in our study, we used single nucleotide polymorphism markers (SNPs) and geometric morphometric (GM) methods to investigate the population structure and variability of CPB populations. We used 16 CPB populations from the main potato growing areas in continental Croatia. In addition, the morphology of hindwings of the same CPB individuals was studied using geometric morphometric techniques based on vein patterns. Regardless of the low genetic structure found in all CBP populations without significant variability, a single panmictic population or genetic cluster has emerged that characterizes CPB in Croatia. This suggests that control practices are successfully reducing genetic diversity, genetic structure, differentiation, and gene flow, and thus ultimately reducing the potential for the development of mutations associated with CPB resistance.

Box tree moth Cydalima perspectalis (Walker) (Lepidoptera: Pyralidae) is an invasive moth originating from East Asia and present in Croatia since 2012. Its natural dispersal velocity of up to10 km per year is of particular concern. Understanding flight characteristics of insect pests is essential for designing effective strategies and programs for their management. The aim of this research was to use a flight mill to test flight propensity, performance and flight patterns of the box tree moth. The flight-testing mill consisted of a flight mill, a testing chamber and a data logging and processing unit. Flight characteristics such as duration and number of flights as well as velocity and distance of individual flights were monitored by four flight mill chambers in a C. perspectalis population under naturally occurring conditions. In 24-hour experiments, C. perspectalis flew a maximum distance of 15.6 km (virgin females) and spent a maximum time in flight of 241 minutes (4 hours). The average speed of C. perspectalis ranged from 1.1 m/s (the slowest flying/virgin females) to 1.6 m/s (laboratory males). The performed flight- testing systems proved to be efficacious and useful tools in unveiling essential flight characteristics of invasive flying insects. Flight mills contribute to the understanding of physiological traits and provide important insights into migratory activities ; this is of particular importance for the highly invasive C. perspectalis.

Colorado potato beetle (CPB) is a serious pest of potato worldwide, which became difficult to control due to resistance developed to many classes of inseciticides. In Croatia, resistance to organophosphorus insecticides and pyrethroids was established in mid 1990s, and recent research has shown that it has developed resistance to newer generation insecticides (e.g. neonicotinoids) in some areas. Due to the resistance development and restrictions on the registration and use of plant protection products in the EU as well as in Croatia, the spectrum of available insecticides for CPB control is limited. Efficacy of spinosad and metaflumizone was investigated in laboratory bioassays on 35 populations collected from 2017-2019 in Croatia. Efficiency of recommended dose, half, 1/5 and 1/10 of the recommended dose were determined. Populations were classified according to IRAC method No. 1132 into five categories based on the efficacy. Efficacy data were subjected to Probit analysis to generate LC50 estimates for each insecticide and population 48 and 72 hours after the treatment. Results have showed that all populations are susceptible or highly susceptible to spinosad and metaflumizone. However, the differences among populations in LC50 have been established, indicating that at some locations resistance development is in progress. Due to the limited availability of insecticides for CPB control, spinosad and metaflumizon could be recommended in areas where CPB developed resistance to other classes of insecticides. But, the monitoring of the resistance development to these active ingredients is required

Kukuruzna zlatica, (Diabrotica virgifera virgifera LeConte) najvažniji je štetnik kukuruza na području SAD-a i Europe. Već više od desetljeća populacijska genetika koristi se za evaluaciju učinkovitosti provedenih mjera suzbijanja ovoga štetnika u Hrvatskoj, a pokazala se korisnim i u razumijevanju invazijskog širenja štetnika kroz Hrvatsku i u druge susjedne države. Provedena genetska istraživanja kukuruzne zlatice utvrdila su osnovne informacije vezane uz njene alele i haplotipove u SAD-u i Europi. Polimorfizam pojedinačnog nukleotida (SNP, od engl. single nucleotide polymorphism) novija je metoda analize cijelog genoma utvrđivanjem polimorfizma. Primjena SNP-ova u nemodelnim organizmima postala je pristupačno i lako dostupno sredstvo za generiranje važnih podataka o brojnim vrstama što bi inače bilo nemoguće zbog visokih troškova i često nedostatka stručnosti laboratorijskog osoblja. Zbog velikog broja SNPs-a (od tisuće do milijuna) koji se lako generiraju u jednom slijedu, nadmašili su mikrosatelite u izboru istraživačkog alata kada je u pitanju utvrđivanje populacijske genetike neke vrste. S obzirom na najnoviju tehnologiju u sekvenciranju i sada već rutinsku upotrebu genotipizacije sekvenciranjem SNPs-a, analizirali smo veći broj uzoraka iz više populacija kako bi dobili bolje rezultate koji bi detektirali promjenu genoma kukuruzne zlatice na malim (intra-populacijski) i velikim (inter- populacijski) geografskim površinama. U radu će biti prikazani preliminarni rezultati SNP analize te genetska struktura, diferencijacija i protok gena unutar i između populacija kukuruzne zlatice.

The western corn rootworm (WCR) is a highly invasive pest of maize. It has developed resistance to insecticides and established management strategies. The objective of this study is to determine the differences between WCR laboratory populations from the United States that are resistant to various Bt toxins and non- resistant population by combining genetic and geometric morphometric analyzes. For the morphometric analyzes, 775 hindwings of Bt- resistant and susceptible WCR populations from laboratory cultivation in the USA were used. Fourteen specific points (markers) were used to assess variability in hindwing shape and size. Principal component analysis (PCA) and canonical discriminant analysis (CVA) were used. The research results showed the significant differences in US populations resistant to different Bt toxins. To confirm these results, we used the single nucleotide polymorphisms (SNPs) method for a detailed whole genome analysis. Forty-five WCR individuals were genotyped. Individuals were subjected to standard population genetic analyzes, and the resulting genotypic data were analyzed for: expected (HE) and observed (HO) heterozygosity, FIS and θ (FST) to determine the alteration of individual alleles as a possible consequence of mutations and the development of resistance to some of the Bt toxins. After quality filtering of the SNP data, we retained 7, 229 SNPs for further data analysis. Preliminary results based on the one- population model showed moderate observed heterozygosity (HO = 0.3206). Moderate genetic diversity estimated by expected heterozygosity (HE = 0.302). Moderate inbreeding was also observed (FIS = 0.1271). There were no significant deviations from HWE on all loci. The low value of pairwise FST = 0.0179 estimated suggests a lack of genetic differentiation and structuring among the putative populations. The use of these modern and innovative techniques (i.e., SNPs and geometric morphometrics) to detect resistant variants is a completely novel approach and provides new insights into a very important area of pest management.

Poznavanje evolucijskih promjena i ukupne promjene genetske varijabilnosti populacije nekog štetnika može pružiti korisne informacije za razumijevanje genetskih promjena povezanih sa stupnjem razvoja rezistentnosti štetnika, pa se tako praćenje i suzbijanje mogu prilagoditi pojedinoj vrsti štetnika. Tehnologija nizova raznolikosti (engl. Diversity Array Technology (DArT)) metoda je za analizu DNK polimorfizma. Predstavlja jeftin i postojan sustav s minimalnom potrebnom količinom DNK koji omogućuje sveobuhvatnu pokrivenost genoma. DArTseq tehnologija ujedinjeni je postupak utvrđivanja i genotipizacije polimorfizma pojedinačnog nukleotida (engl. Single Nucleotide Polymorphisms (SNPs)) u jednom koraku ; omogućuje analizu SNPs-a u širokom rasponu nemodelnih organizama i utvrđuje genetsku varijabilnosti unutar glavnih genetskih skupina. S obzirom na vrlo velik broj SNPs-a (od tisuće do milijuna) koji se lako generiraju u jednom slijedu, nadmašili su mikrosatelite u izboru istraživačkog alata kada je u pitanju utvrđivanje populacijske genetike neke vrste. Upotreba SNPs-a nužna je za bolje razumijevanje populacijske genetike kukuruzne i krumpirove zlatice te jabukinog savijača. U radu će biti prikazani preliminarni rezultati SNP analize te genetska struktura, diferencijacija i protok gena unutar i između populacija kukuruzne i krumpirove zlatice te jabukina savijača. Takvi podaci ključni su za provedbu antirezistentnih programa kao sastavnog dijela integrirane zaštite bilja od štetnika.