The hypothesis of this study was that different plant hosts of the medfly Ceratitis capitata may cause variability as a prerequisite for its invasiveness. The main objective was to determine ...population variability based on medfly wing shape in three favorable medfly host plants (peach, fig and mandarin) from different agroecological growing areas with different pest management practices, and to evaluate phenotypic plasticity as a basis for future expansion into new areas and new hosts. Using geometric morphometric methods across 14 specific landmarks on the medfly wings, 10 populations were tested from infested peach, fig and mandarin fruits, as well as laboratory-grown sterile populations. The studies led to the following main findings: (1) all of the medfly populations that were studied exhibited sexual dimorphism in wing shape; (2) the hosts in which the medfly develops influence wing shape and condition its variability; (3) there is significant variability between laboratory mass-reared sterile and wild individuals in male and female populations; (4) a high phenotypic plasticity of medfly populations was observed along the study sites. Even the low but clearly detected variability between different agroecological conditions and localized variability indicate genotypic stability and high phenotypic plasticity, which can be considered as a prerequisite for medfly invasiveness and dispersal to new areas.
Two-year (2014-2015) study aimed to determine the effectiveness of entomopathogenic nematode (EPN) Heterorhabditis bacteriophora Poinar, 1976 (Nematoda: Heterorhabditidae) infective juveniles (IJs) ...on sugar beet weevil (Bothynoderes punctiventris Germar, 1824 (Coleoptera: Curculionidae)) larvae and to assess its potential for use in practice. In field experiments, three doses of nematodes were used and an untreated control. In the conditions of moderate larval attack (average infestation of 0.28 larvae per plant), EPNs showed clear dose response being highly effective (92.86% control) when applied in the highest dose. Although the results indicated that H. bacteriophora could have a satisfactory mortality effect on sugar beet weevil larvae, further investigations are needed in order to better determine the optimal dose and application timing. If effective, EPNs could be used as one of the tools in a strategy which aims to reduce sugar beet weevil population levels in a wider area.
Overwintering success and weather conditions are the key factors determining the abundance and intensity of the attack of the first generation of European corn borers (ECB). The tolerance of maize to ...the 1st generation of ECB infestation is often considered to be connected with the maize maturity time. The aims of this research were (I) to examine the reactions of different maize FAO maturity groups in term of the damage caused by ECB larvae, (II) to analyze the influence of four climatic regions of Croatia regarding the damage caused by ECB larvae, and (III) to correlate observed damage between FAO maturity groups and weather conditions. First ECB generation damage has been studied in the two-year field trial with 32 different hybrids divided into four FAO maturity groups (eight per group) located at four locations with different climatic conditions. The results showed a lack of correlation between the FAO maturity group and the percent of damage. The percent of damage was positively correlated with the average air temperature in June (r = 0.59 for 2017 and r = 0.74 in 2018, p = 0.0001) within the range from 20 to 24.5 °C and was negatively correlated with the relative air humidity (r = −0.58 in 2017 and r = −0.77 in 2018, p = 0.0001) within the range of 50% to 80%. Our results provide a better understanding of the different factors that influence ECB damage. The obtained data could be used to predict the damage from the first generation of ECB under the weather conditions of different regions.
Carrots are among the top ten vegetable crops in the world, with an annual world production of about 428 million tonnes grown on about 11.5 million hectares. The investment per unit area is not high ...and with good cultivation techniques yields of up to 50 t/ha can be achieved, together with major economic benefits from winter cultivation. During the growing season, carrots are susceptible to numerous pests. The most important are the carrot root fly (Psila rosae, Fabricius), whose root-feeding fly larvae reside in the soil or plant tissue, and the carrot cyst nematode (Heterodera carotae Jones), which is responsible for the decline of carrots in many countries and requires strict sanitation measures if crops are infected. As insecticides become less available in Europe, the appropriate use of non-chemical methods in integrated pest management (IPM) needs to be emphasised, highlighting the importance of developing new tolerant varieties. This review addresses the approaches to monitor and predict the occurrence of two important carrot pests and the main control measures according to the strategies of IPM.
Different rearing environments produce dissimilar stress level in insects, which can be reflected on the ability of an individual to overcome these pressures and spread further. Sugar beet weevil, ...Bothynoderes punctivnetris Germar. (Coleoptera: Curculionidae) is one of the most harmful pests of sugar beet, infesting agricultural fields in different parts of Croatia. It is highly invasive being able to inhabit diverse environments across the country. The aim of this study was to assess the association between different environmental and rearing conditions and the morphological variation observed in the sugar beet weevil body shape. The present results showed significantly different eco-morphs related to different environmental conditions, thus suggesting that the observed ecomorphological changes could be associated to the ability of this pest to spread further.
Mrkva je među deset najznačajnijih povrtarskih kultura u svijetu. Godišnja svjetska proizvodnja iznosi 428 milijuna tona proizvedenih na oko 11,5 milijuna hektara. Ulaganje po jedinici površine nije ...veliko, a dobrim tehnikama uzgoja mogu se postići prinosi do 50 t/ha. Zimski uzgoj mrkve značajno povečava ekonomsku dobit ove kulture. Tijekom vegetacije mrkva je osjetljiva na brojne štetnike, od kojih su najvažniji mrkvina muha (Psila rosae, Fabricius), čije se ličinke nalaze u tlu ili krojenu unutar kojeg se hrane i mrkvina cistolika nematoda (Heterodera carotae Jones), koja je uzročnik drastičnog pada uzgoja mrkve u mnogim zemljama i zahtijeva stroge sanitarne uvjete u slučaju zaraze usjeva. Uz sve manje insekticida dostupnih u Europi, valja naglasiti pravilnu uporabu nekemijskih metoda u kontekstu integriranog suzbijanja štetočina (IPM), ističući važnost razvoja novih tolerantnih sorti. U radu su prikazane metode praćenja i prognoze navedenih štetnika te glavne mjere suzbijanja u skladu sa strategijama IPM -a.
Fireflies (Coleoptera: Lampyridae), with more than 2 000 species in 100 genera worldwide, are a charismatic nocturnal species. Although popular in different cultures because of their association with ...warm summer evenings in childhood, fireflies are an under-researched insect. Like numerous other insects worldwide, fireflies have experienced declines in their distribution and abundance. Anthropogenic impacts and climate change are likely to influence their development, reproduction, and survival. A project called “Krešo Krijesnica” (eng. “Krešo the Firefly”), used a Citizen Science model of data collection, to determine where are the fireflies located and how abundant are they throughout Croatia. Citizen Science involves the participation of the general or non-scientific public in data collection so determining the basic demographic profile of the citizen scientists involved was also one of the project goals. During the first phase of the project (2019-2021), data on fireflies were provided by citizen scientists through a formal survey on social media (Facebook, Instagram). Phase two aims to open the fireflies’ datasets to the public through various open data portals. In the three years of the project, more than 16 000 records of fireflies were collected and analysed from over 1800 sightings. Descriptive statistics showed that the highest firefly population density was found in central Croatia, which is consistent with the greater number of people living in this area and thus a greater chance of firefly detection. Higher number pf female reporters were noted during the project. The dataset collected in this Citizen Science project presents a valuable source of information to the scientific community, especially in the field of entomology, conservation biology and ecology.
This study evaluated the use of fluctuating asymmetry (FA) of shape, as a bio-indicator developmental stability (DS) in multiple populations of two different agricultural productions a) perennial ...(orchard) and b) annual (arable) crops on the carabid beetle Pterostichus melas melas (Creutzer, 1799) morphology. Shape variation and FA levels were estimated using geometric morphometrics. The results obtained using geometric morphometric analyses such as regressions (FA scores vs Shape) and partial least squares showed that carabids that inhabited the perennial agro-ecosystem seem to have adapted to the strong anthropogenic influence (i.e. IPM practices) at the phenotypic level, while the carabids inhabiting annual agro-ecosystems experience more unstable environments and their phenotypes seem to have been changed more recently. It was expected that phenotypes of the annual agro-ecosystems would be more variable than the long-established ones. Different IPM practices in agro-ecosystems generate different disturbance degrees in insect communities, and these effects can be successfully quantified by applying geometric morphometric techniques.
Citrus fruits, particularly mandarins, are highly valued globally for their nutritional benefits and versatile culinary uses. However, the challenge of post-harvest decay, primarily due to blue mold ...(Penicillium italicum) infections, results in significant food losses and necessitates effective preservation strategies. Traditional methods often rely on fungicides, raising concerns about chemical residues and environmental impact. This study investigates the efficacy of ozone as an alternative approach to controlling blue mold in mandarins. Various gaseous ozone treatments were tested, including single, double, and triple treatments, with durations ranging from 10 to 60 min and concentrations from 3.3 to 20 ppm. Additionally, ozonated water treatments were evaluated with concentrations of 2, 4, and 6 ppm. To simulate a realistic infestation scenario, mandarins were artificially infected with P. italicum spores before undergoing both gaseous ozone and ozonated water treatments. The storage conditions for the mandarins were meticulously controlled, maintaining a humidity level of 50–60% and a temperature range of 10–12 °C. Each fruit was analyzed, and the presence of P. italicum infection was determined two and three weeks after the ozonation. Results indicated that ozone treatments significantly reduced mold growth, with gaseous ozone demonstrating efficacy rates up to 97.5% and ozonated water treatments achieving preservation rates between 95% and 97%. These results underscore ozone’s potential as a safe, efficient, and sustainable alternative to conventional fungicides, offering promising solutions for extending the shelf life of mandarins. Further research is recommended to optimize ozone treatment parameters, assess long-term effects on fruit quality and nutritional content, and refine application techniques to harness ozone’s potential in citrus fruit preservation fully. This approach not only addresses food security challenges but also aligns with global efforts to reduce chemical inputs in agriculture and promote environmentally sustainable practices.
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