Arthropod Abundance Research Articles

Abundance and Diversity of Soil Arthropods in Major Plantation Crops under Different Farming Practices

Abundance and Diversity of Soil Arthropods in Major Plantation Crops under Different Farming Practices

Soil arthropod diversity, richness, and abundance in agroecological and conventional cotton production systems in Chaco, Argentina

In Argentina, agroecology has grown in last years as a scientific paradigm that seeks to design and evaluate agroecosystems considering sustainability, complexity, and uncertainty. Diversity is a key factor in the design and management of production systems and a necessary component for conservation biological control and the reduction of agrochemicals use. Cotton (Gossypium hirsutum) crop in northern Argentina is usually managed with high load of agrochemicals: agroecological production arises as an alternative. This study evaluated the diversity, richness, and abundance of soil arthropods using pitfall traps in two experimental cotton plots under conventional (CONV) and agroecological management (AE) in Chaco, Argentina. AE system presented higher diversity and richness of predators compared with CONV, even when natural preparations were used for pest control. The phytophagous arthropods showed higher diversity and richness in CONV, even when pyrethroid insecticides were applied for pest control and preventively. The abundance in AE was lower for predators and higher for phytophagous arthropods. Agroecological production of cotton can be a tool that favors conservative biological control and an alternative for areas where protecting the health of farmers and the ecosystem is a priority.

Short‐Term Grasslands in Agriculture Support Both Natural Enemy and Phytophagous Arthropod Populations

ABSTRACTSimplified agricultural land with high chemical input is increasingly replacing natural habitats in many parts of the world. This loss and fragmentation of natural areas may have profound impacts on an array of wildlife, including predatory arthropods that provide natural biocontrol of agricultural pests. There is increasing interest in utilising short‐term seminatural habitat restoration in agricultural systems to support populations of beneficial organisms. We assessed the impact of two types of short‐term set‐asides on the diversity and abundance/activity density of phytophagous and predatory arthropods. We found that flower‐enhanced set‐asides supported higher abundances of both phytophagous and predatory arthropods compared to control crop fields. In addition, we found that both set‐aside types (flower enhanced and traditional) supported a more active and diverse community of beneficial predatory carabid beetles, with particularly strong trends in set‐asides supplemented with flowering plants. These results suggest that small‐scale, temporary, seminatural habitats in agricultural systems provide support for a diverse and abundant community of both beneficial and phytophagous arthropods.

Enhancing ecosystem dynamics: organic and regenerative practices in rice–wheat systems and their impact on soil arthropod biodiversity

Arthropods may make a significant fraction of the total number of soil organisms. They function as plant litter transformers or ecosystem engineers, and thus contribute positively to soil health. The present study was conducted during the 2020–2022 at International Rice Research Institute, South Asia Regional Centre, Varanasi. Study investigates the impact of different farming methods-conventional (Scenario 1; Sc1), LINF- Low-input natural farming (Sc 2); BBEF- Biochar-based ecological farming (Sc 3); CROF- Climate-resilient organic farming (Sc 4); RF- Regenerative farming (Sc 5) practices on soil arthropod populations in rice-wheat systems. Study utilized pitfall traps across various experimental setups. The findings revealed a significant increase in arthropod diversity and abundance, particularly in organic farming scenarios, where the Formicidae family (ants) and the Araneae family (spiders) were most prevalent. In an organically rich soil system, the five most diverse groups (Isopoda, Myriapoda, Insecta, Acari, and Collembola) were reported. This increase can be attributed to the nutrient-rich amendments that positively influence soil organisms. This study highlights a gradual increase in specific taxa, such as cockroaches, spiders, ants, and grasshoppers, following the transition to organic farming. Principal component analysis (PCA) further revealed distinct arthropod distribution patterns in the different farming systems, indicating the unique ecological impact of each method. Interestingly, predator populations in zero-till wheat fields under regenerative agriculture were greater than those in conventionally tilled fields. These results underscore the substantial role of organic and regenerative farming practices in promoting sustainable agricultural ecosystems. This study reveals the complex interplay between farming practices and arthropod dynamics and highlights the ecological benefits of sustainable agricultural methods, emphasizing their potential to enhance biodiversity and ecosystem health.

Effects of sown and spontaneous inter-row vegetation on weeds and beneficial arthropods in vineyards

The intensification of crop management has resulted in a decline of biodiversity in the last decades, in particular through habitat loss, fragmentation and degradation. Semi-natural habitats within agricultural landscapes such as hedges, grasslands or herbaceous field margins, provide resources and refuge to beneficial arthropods. In vineyards, extensively used inter-row vegetation may be functionally equivalent to such semi-natural habitats and sowing of plant species rich in floral resources may improve habitat functions. In this study, three types of vineyard inter-row vegetation treatments were compared in 15 vineyards of South-eastern France: (1) sowing a high-diversity seed mixture (HD) with a high number of nectariferous plant species, (2) spontaneous vegetation, and (3) tilled inter-rows. We monitored the inter-row vegetation including problematic weeds, the abundance of beneficial arthropods, and the predation of sentinel prey. The invasive weedy grass species Cynodon dactylon showed a lower cover in HD inter-rows than in spontaneous vegetation, whereas no differences were found for the invasive herb Erigeron sumatrensis. Both weed species were still best controlled in tilled inter-rows. Beneficial arthropods were less abundant in tilled than in spontaneously vegetated and sown inter-rows. Day predation was higher in HD inter-rows than in spontaneous vegetation although no significant differences were found for observed predators. Over all treatments, plant species richness, flower and grass cover had a positive influence on several beneficial arthropod groups. Our results highlight the positive effects of species-rich inter-row vegetation on weed control, beneficial arthropod abundance and predation but also showed that further research is needed to improve the efficiency beyond services already provided by spontaneous vegetation.

Regional and local patterns of soil arthropod diversity are explained by different processes in southwest China

Understanding the distribution patterns and underlying mechanisms of community assembly at different spatial scales is crucial for the ecology and conservation of organisms, yet little is known about soil arthropods. In this study, we tested the relative importance of the two hypotheses that could explain soil arthropod distribution patterns at local and regional scales: (1) the habitat heterogeneity hypothesis (spatial complexity and variability of a habitat allow the coexistence of many species), and (2) the more-individuals hypothesis (the amount of resources per se, regardless of its spatial heterogeneity, increases overall soil arthropod abundance and richness). We extensively collected soil arthropods (identified to families or subfamilies) and measured soil physicochemical properties in four forests distributed across latitudes in Yunnan Province, China. We found that soil arthropod abundance and taxon richness increased with increasing latitudes, contrasting with the generally known pattern for plants and aboveground animals. Litter biomass (resources) explained the taxon richness and abundance at the regional scale, which aligned with the more-individuals hypothesis. Other soil physicochemical properties (e.g., Ca, TP, Mg, Mn, and pH) were more important at the local scale, underpinning the habitat heterogeneity hypothesis. However, the relative importance of individual soil properties was highly location-specific, suggesting that the environmental factors operating in one location do not necessarily reflect those operating in others at different latitudes. These findings improve our understanding of the community assembly and ecological processes of soil arthropods at different spatial scales, which is vital for predicting the future of soil biodiversity.

Tree species richness suppresses red imported fire ant invasion in a subtropical plantation forest

Abstract The ecological resistance to the invasion of alien species has been extensively researched at the within‐trophic level; however, the effect of cross‐trophic interactions remains largely unknown. The red imported fire ant (RIFA, Solenopsis invicta) is a globally invasive species, and a cross‐trophic interaction study between RIFAs and plants may provide a more comprehensive understanding and management of its invasion. We hypothesized that the diversity of trees, which are the primary producers supporting terrestrial ecosystems, could suppress the invasion of omnivorous RIFAs by regulating food resources (e.g. plants and arthropods) and the microenvironment (e.g. soil microclimate) as well as enhancing competition with other carnivorous ants. To test this hypothesis, we investigated RIFA abundance and mound numbers across tree species richness gradients in a subtropical plantation forest. Using structural equation models, we discovered that tree species richness had contrasting effects on RIFA abundance and mound numbers. RIFA abundance directly decreased with higher tree species richness because of the dilution effect (i.e. lower abundance of preferred tree species). In contrast, RIFA mound numbers indirectly increased with tree species richness via an increase in arthropod abundance (excluding ants) (i.e. more ample food resources for RIFA). Moreover, warmer soil temperatures decreased RIFA abundance, whereas other carnivorous ant species richness and abundance negatively affected RIFA abundance and mound numbers. Synthesis and applications: Our findings demonstrate that the ecological resistance to RIFA invasion is influenced by tree species richness in a complex manner; specifically, the relative strengths of the effects of tree species characteristics, native competitors and environmental conditions are likely to impact the power of ecological resistance. This highlights the importance of cross‐trophic interactions underlying the resistance of complex ecosystems to alien species invasion; therefore, maintaining diverse tree communities in controlled systems (e.g. suburban and urban green spaces) should be viewed as a potential strategy for controlling RIFA invasion.

A preliminary recording of insects on the island of Farwa Northwest of Libya

The study aimed to present the first record of insect families in Farwa Island. Farwa Island is the largest and most important island in Libya; located in Northern west part of Libya in the Mediterranean, its insect fauna is poorly studied. Short time intensive collection of insect samples was conducted in four areas (mouth of the valley, bay of containers, center of the Island, and Ras-Attalgha) in February, March and April 2021. Different methods were used for insect collection, sorting, preservation and later identification to the lowest taxonomic level and verification. 9 orders, 31 families, 40 genera and 58 insect species were collected in the study; the center of the Island had the highest numerical density and diversity of insect fauna due to its diverse vegetation compared to other areas. Diverse suitable habitats and absent insect control measures provided suitable environmental conditions for insects breeding, feeding and hiding from enemies. This study constitutes the first comprehensive survey of insect fauna on Farwa Island and adds significant value to the ongoing assessment of insect diversity in Libya. A long-term study has to be conducted to investigate detailed information about the abundance and diversity of insects and other arthropods on Farwa Island.

Millets and sorghum as promising alternatives to maize for enhancing climate change adaptation strategies in the Mediterranean Basin

ContextClimate change is increasingly requiring the adoption of both climate-resilient alternative crops and sustainable management practices. Millets and sorghum are increasingly recommended as alternatives to maize in addressing these issues, yet there are no studies comparing the environmental impacts of food-crop millets and sorghum with maize, under sustainable management in Mediterranean area. ObjectiveThe present study examined for the first time the environmental and economic impacts, as well as agronomic performances, of rainfed cultivated proso millet, sorghum and maize over a three-year period under challenging climatic conditions in Emilia-Romagna region, Italy. MethodsDifferent kinds of trials were realized during three years of experimentation in one location in Ravenna province. The first trial aimed to compare proso millet, sorghum and maize agronomical performances and water use efficiency in a low-input system. The second trial aimed to compare soil fertility and biodiversity impacts of two different agronomical management systems (low-input and high input) for the summer crops previously described. Soil basic fertility parameters were monitored and ground dwelling arthropods were collected and analyzed using pitfall traps. The last trial of this study intended to evaluate the environmental and economic performances of the previous cereal crops cultivated in the low-input and high-input systems, applying the Life Cycle Assessment (LCA) and the Life Cycle Costing (LCC) methodologies. ResultsBoth organic sorghum and millet showed high potential as viable summer-crop alternatives, not only to organic maize, based on yield, water use efficiency, disease tolerance and weed competition, but also to conventional maize, based on reduced environmental and economic impacts. Positive land impacts including improved beneficial arthropod abundances and preserved soil fertility were evident under organic management. In fact, the comparative LCA and LCC, carried out with primary data from conventionally cultivated maize and sorghum within central-north Italy and the organic experimental field under investigation, showed that the Global Warming and Eutrophication Potential, were comparable between the organically cultivated crops and significantly lower than conventional maize and sorghum. ConclusionsThe results highlighted the potential of sorghum and millet cultivation as rainfed summer-crop alternative to maize in climate-change context, especially in low-input agronomical systems. In particular, under rainfed, organic management over three years, proso millet yielded consistently. ImplicationsUnder the sustainable practices of the present study, proso millet outperformed maize for yield and WUE stability, as well as potential costs saved, related to the production amount per unit area and potential revenue.

High soil moisture promotes the emergence of ground beetles and spiders from soils in wheat fields

Promoting arthropods in agricultural landscapes can contribute substantially to stop their decline and enhance pest control. Higher soil moisture and the presence of field margins can increase the abundance of arthropods in agricultural landscapes and influence their distribution within crop fields. However, little is known about the influence of soil moisture and distance from field margins on the overwintering of arthropods in arable fields. We investigated the influence of soil moisture and distance from a field margin on the numbers of arthropods, ground beetles and spiders emerging from soil in winter wheat fields. We established transects in winter wheat fields away from two different types of field margins: (i) around small standing water bodies (kettle holes) to capture a wide range of soil moisture values and (ii) other semi-natural landscape elements. At three distances (1 m, 20 m, 50 m), we sampled arthropods with emergence traps and measured soil moisture between March and June. We found that soil moisture had a positive effect on the emergence numbers of arthropods in general and ground beetles and spiders in particular. Distance from field margins generally had negative effects on the emergence numbers of ground beetles, but positive effects on the emergence numbers of spiders. Emergence numbers and soil moisture content did not differ significantly between the two types of field margins. The high emergence numbers inside the fields indicate that arable fields are important overwintering habitats for beneficial arthropods. Proper management of arable soils to promote soil water holding capacity and soil moisture content may have the added benefit of promoting the production of beneficial natural enemies from local soils.

Differences in phenology across three trophic levels between two Afrotropical sites separated by four degrees latitude.

Birds time their life cycle events to favourable windows in environmental conditions. In tropical environments, where photoperiod variation is small, birds show high variability in the timing of life cycle stages, yet these species have been severely underrepresented in phenology research. Here, we investigated temporal patterns in bird life cycles and resource availability in two sites in tropical Africa: Weppa (Nigeria, 7° N) and Elat (Cameroon, 3° N). In these sites we captured common bulbuls (Pycnonotus barbatus), a widespread generalist, and recorded breeding and moult over a 12-month period. Simultaneously, we surveyed fruiting tree and arthropod abundance. Our aim was to quantify seasonal patterns in moult and breeding in bulbuls at both sites, and link them to fluctuations in local fruit and arthropod abundance and precipitation. Moult was more seasonal than breeding in both sites, and seasonality of both life cycle events was stronger in Nigeria than Cameroon. The peak timing for moult was 1.5 months earlier in Nigeria than Cameroon. Seasonal variation in abundance of fruiting trees and arthropods was different between sites, as were the associations with breeding and moulting. In Nigeria, we found a positive association between moult and arthropod abundance, and a negative one with fruiting tree abundance. In contrast, in Cameroon moult was associated with higher precipitation, while breeding occurred at times with higher fruit abundance. Our results provide evidence that, even in similar habitats separated by four degrees in latitude, seasonal patterns across three trophic levels are variable. Understanding links between environmental conditions and life cycle events can reveal potential vulnerabilities of tropical species, and guide conservation efforts.

Leaf Shelters Facilitate the Colonisation of Arthropods and Enhance Microbial Diversity on Plants.

Shelter-building insects are important ecosystem engineers, playing critical roles in structuring arthropod communities. Nonetheless, the influence of leaf shelters and arthropods on plant-associated microbiota remains largely unexplored. Arthropods that visit or inhabit plants can contribute to the leaf microbial community, resulting in significant changes in plant-microbe interactions. By artificially constructing leaf shelters, we provide evidence that shelter-building insects influence not only the arthropod community structure but also impact the phyllosphere microbiota. Leaf shelters exhibited higher abundance and richness of arthropods, changing the associated arthropod community composition. These shelters also altered the composition and community structure of phyllosphere microbiota, promoting greater richness and diversity of bacteria at the phyllosphere. In leaf shelters, microbial diversity positively correlated with the richness and diversity of herbivores. These findings demonstrate the critical role of leaf shelters in structuring both arthropod and microbial communities through altered microhabitats and species interactions.

Effect of habitat management on arthropod community in crab apple orchards (Malus sylvestris (L.) Mill.) in Indonesia

ABSTRACT Crab apple (Malus sylvestris (L.) Mill.) is native to Central Europe and successfully commercially grown in Indonesia. Management practices that increase biodiversity in agroecosystems are essential for mediating the negative impacts of intensive agriculture. This study aims to compare arthropod abundance and diversity between grass ground cover and Hydrangea intercropping in crab apple orchards and assess their impact on arthropod functional groups providing ecosystem services. In this study, arthropods were sampled using three types of traps, i.e. pitfall trap, yellow sticky trap, and pan trap. Arthropod specimens were identified by order and family, then categorised by their ecological role: detritivore, omnivore, herbivore, the natural enemy (predator and parasitoid), and pollinator. Our study collected 164 families belonging to the five examined functional groups. We found that the family composition of arthropods was significantly different between Hydrangea intercropping and grass ground cover in crab apple orchards. Grass ground cover supports the increase of herbivore and natural enemy populations and it’s related to enhancing biological control. In addition, Hydrangea intercropping increases pollinator species richness and contributes to pollination services. Pest management in crab apple orchards may benefit from a combination of grass ground cover to encourage natural enemies and Hydrangea intercropping to increase pollinators.

Changes in soil arthropods and litter nutrients after prescribed burn in a subtropical moist pastureland

Plant litter decomposition is driven by soil biota and biophysiochemical conditions as well as substrate quality. Prescribed burns can affect the abundance and diversity of soil arthropods and the biophysiochemical conditions in terrestrial ecosystems. In this study, we examined the effects of a prescribed burn on soil arthropods and litter chemistry in decomposing litter during a total of 469-days field incubation using litter from two grasses, Dichanthium annulatum and Megathyrsus maximus, in a subtropical moist pastureland of Puerto Rico. We found the prescribed burn substantially elevated ultraviolet (UV) radiation and soil temperature; and significantly decreased the diversity of litter total arthropods, especially predators and Mesostigmata mites, during the initial 5 months after the burn. However, the prescribed burn had no effect on either the biophysical environment nor on arthropod abundance and diversity during the subsequent incubation period of >5 months after the burn. Furthermore, the prescribed burn substantially increased the immobilization of iron (Fe) and manganese (Mn), and decreased sulfur (S) concentration in the decomposing litter. Prescribed burn had no interactions with substrate quality for percent mass remaining (PMR) and elemental release or accumulation. Low substrate quality D. annulatum litter with a carbon to phosphorus (C/P) ratio of 614 was associated with higher microbivore diversity and higher predator density than higher substrate quality M. maximus litter with a C/P ratio of 266 during the entire incubation period. Lower initial concentration of litter P, magnesium (Mg) and calcium (Ca) in D. annulatum resulted in higher immobilization of these elements in decomposing litter than in M. maximus. Our study suggest that prescribed burn can impose short-term changes in biophysiochemical conditions and the diversity of arthropods in litter decomposition during the initial recovery period of about 5 months after a burn, thus highlighting a high resilience of the grassland ecosystem to fire disturbance, and that it can bring lasting changes in the cycling of Fe, Mn, and S in subtropical moist pastureland that can alter ecosystem productivity.

Arthropod traits as proxies for abundance trends in the Azorean Islands

Human activities drive ecological transformation, impacting island ecosystems from species diversity to ecological traits, mainly through habitat degradation and invasive species. Using two unique long‐term datasets we aim to evaluate whether species traits (body size, trophic level, dispersal capacity and habitat occupancy) can predict temporal variations in the abundance of endemic, indigenous (endemic and native non‐endemic) and exotic arthropods in the Azores Islands. We found that body size is crucial to predict arthropod abundance trends. Small‐bodied herbivorous arthropods showed a decrease in abundance, while large‐bodied indigenous arthropods increased in abundance, mainly in well‐preserved areas. Also, large‐bodied exotic arthropods increased in abundance across the entire archipelago. Moreover, endemic canopy dwellers increased in abundance, while endemic ground‐dwellers decreased in abundance. Simultaneously, exotic arthropods showed the opposite result, increasing in abundance in the ground while decreasing in abundance in the canopy. Finally, habitat influenced both endemic and exotic spider abundance trends. Endemic spiders that occupy solely natural habitats experienced a decline in abundance, while exotic spiders in the same habitats increased in abundance. Our study underscores the significance of arthropod species traits in predicting abundance changes in island ecosystems over time, as well as the importance of monitoring species communities. Conservation efforts must extend beyond endangered species to protect non‐threatened ones, given the increased extinction risk faced by even common species on islands. Monitoring and restoration programs are essential for preserving island ecosystems and safeguarding endemic arthropod populations.

Collembola and ants: Influence of trails of red wood ants (Formica lugubris) on the community of soil springtails

Red wood ants are keystone species in forest ecosystems. Because ants are active polyphagous predators, they control the abundance of other arthropods. In addition to direct effects on other species, there are a number of indirect effects caused by ants. In our study, we investigated the influence of ants on springtails, which they rarely come into contact with. Springtails have been set as a model group to assess the state of soil animals, since they are one of the most numerous and widespread groups of soil microarthropods. They are characterized by high sensitivity to environmental changes. The basic characteristics (abundance, species richness, and species diversity) of the springtail community and the response of certain species to the presence of ant trails have been studied. The total abundance and species richness of springtails decreased along ant trails. Among occurred species Parisotoma ParIsotoma notabilis, Lepidacyrtus lignorum, Isotomiella minor, Desoria tigrina, and Pseudasinella alba are the most numerous species both along ant trails and in control samples. There are no significant changes in species diversity (assessed by the Shannon-Weaver index). Species structure of springtail communities along ant trails and in control is different. Two groups of common Collembola species are identified: (1) increasing their numbers in the presence of ants, (2) on the contrary, decreasing. The presence of ants in a forest ecosystem influences the soil springtail community, although ant-Collembola interactions are indirect.

Are evergreen mistletoes on deciduous hosts arthropod winter refugia?

ABSTRACT Deciduousness is rare among native New Zealand trees, however, non-native deciduous trees now dominate many landscapes. The native evergreen mistletoe Ileostylus micranthus parasitises many non-native deciduous trees, so may be a critically important winter refuge for foliage-dwelling arthropods in deciduous trees. We compared arthropod communities on mistletoes and their evergreen or deciduous hosts in Dunedin, Otago. Foliage samples of 19 hosts and 19 mistletoes parasitising them were collected in summer and winter. Summer samples harboured 1335 arthropods including 1216 mites (Arachnida: Acari), mostly in domatia of two hosts. Winter samples harboured 60 arthropods including 19 mites. Mites were only identified to order but the 160 non-mite arthropods recovered were identified to 26 species or morphospecies in 23 families and 11 orders. The most common non-mite arthropods on hosts were mealybugs (Hemiptera: Pseudococcidae), while bark lice (Psocoptera) were most common on mistletoes. Mistletoes hosted 13 non-mite taxa not found on hosts, which were more likely to be native than those also or only found on hosts. Significantly more non-mite arthropods were found on mistletoes in winter than on their deciduous hosts. There was no difference between mistletoes and evergreen hosts in non-mite arthropod abundance. Mistletoes on deciduous hosts supported higher non-mite arthropod taxonomic richness in winter and over both seasons than their hosts. Despite the small number of non-mite arthropods recovered, our study adds to evidence that mistletoes are important habitat refugia for arboreal arthropods during suboptimal climatic periods, which in our study was during winter on deciduous host trees.

The day after mowing: Time and type of mowing influence grassland arthropods.

Recent losses in the abundance and diversity of arthropods have been documented in many regions and ecosystems. In grasslands, such insect declines are largely attributed to land use, including modern machinery and mowing regimes. However, the effects of different mowing techniques on arthropods remain poorly understood. Using 11 years of data from 111 agricultural grassland plots across Germany, we analyzed the influence of various grassland management variables on the abundance and abundance-accounted species richness of four arthropod orders: Araneae, Coleoptera, Hemiptera, and Orthoptera. The analysis focused on detailed mowing information, for example, days after mowing and mower type, and compared their effect with other aspects of grassland management, that is, rolling, leveling, fertilization, and grazing. We found strong negative effects of mowing on all four arthropod orders, with arthropod abundance being lowest directly after mowing and steadily increasing to three to seven times the abundance after 100 days post-mowing. Likewise, Hemiptera and Coleoptera species richness was 30% higher 100 days after mowing. Mower width showed a positive effect on Orthoptera abundance, but not on the other arthropods. Arthropod abundance and Coleoptera species richness were lowest when a mulcher was used compared to rotary or bar mowers. In addition to mowing, intensive grazing negatively affected Orthoptera abundance but not the other orders. Mowing represents a highly disturbing and iterative stressor with negative effects on arthropod abundance and diversity, likely contributed by mowing-induced mortality and habitat alteration. While modifications of mowing techniques such as mower type or mowing height and width may help to reduce the negative impact of mowing on arthropods, our results show that mowing itself has the most substantial negative effect. Based on our results, we suggest that reduced mowing frequency, omission of mowing in parts of the grassland (refuges), or extensive grazing instead of mowing have the greatest potential to promote arthropod populations.

Effect of Micronutrients on Incidence, Damage Severity of Sucking Insect Pests of Sunflower and its Impact on Yield and other Arthropods

An experiment was conducted in a field on 23074/N latitude and 90035/E longitude at the central farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh from November 2021 to April 2022. The experiment of eight treatments as follows: T1 = Urea @ 210 gm/plot + TSP @ 84gm/plot + MoP @ 98gm/plot [recommended doses (RD) of Urea, TSP and MoP] +Boron @ 7.0 gm/ Plot+ ZnSo4 @ 8.4 gm/ Plot ;T2 = RD of Urea, TSP and MoP +Spraying 0.2% Borax @ 2gm/ L of water; T3= RD of Urea, TSP and MoP +Spraying 0.2% ZnSo4 @ 2gm/ L of water; T4= RD of Urea, TSP and MoP +Spraying 0.5% Borax @ 5gm/ L of water; T5 RD of Urea, TSP and MoP +Spraying 0.2% Borax + 0.2% ZnSo4 @ 2gm/ L of water; T6 = Urea @ 210 gm/plot+ TSP @ 180 gm/plot+ MoP @ 150gm/plot + Spraying 0.5% ZnSo4 @ 5gm/ L of water; T7 = Urea @ 210 gm/plot+ TSP @ 180gm/plot+ MoP @ 150gm/plot+ MgSo4 @ 12 gm/ Plot and T 8= control. The experiment was laid out in a Randomized Complete Block Design (RCBD) with 8 treatments and 3 replications. The overall result indicates that the combination of different micronutrients decreased the incidence of sucking insect pests of sunflower and increased the abundance of beneficial arthropods compared to T8 treatment. In T1 treatment, the lowest leaf infestation percentage caused by aphid 17.49 and 19.50 %; Jassid 14.19 and 14.89 % and White fly 26.18 and 30.83 % at the vegetative and reproductive stages respectively. The highest number of beneficial arthropods per plot of lady bird beetle both adults and grubs ((3.63 and 5.53 respectively); honey bee (22.36), ant (3.55), spider (1.42) was also recorded in T1 treatment. The highest yield contributing characters of sunflower, the highest of head/ capitulam diameter (9.75cm), height of plant per plot (179.73 cm), leaf width (14.24 cm), leaf length (21.05 cm), area of leaves per plant (62.29 cm) and number of leaf per plant (21.93), number of total head per plot (29.83), number of seed per head (725.56), weight of single seed (1.03 mg), and weight of seed per head (54.96 gm) of sunflower were observed in T1 treatment which was statistically different from among all other treatments. The highest sunflower yield (1.92 kg /plot) and oil content (0.93 liter/2kg and 46.5%) were also observed from T1 treatment. Among the different micronutrient treatment combinations, different micronutrients using in T1 treatment were more effective for the reducing the incidence of sucking insect pests on sunflower. In the term of effect of micronutrients, T1= Recommended doses of Urea, TSP and MoP + Boron @ 7.0 gm/ Plot+ ZnSo4 @ 8.4 gm/ Plot; was an eco-friendly pest management practice for sunflower by which one can significantly reduce pest infestation without use of any chemical insecticides.

Does biodiversity affect Olive fly populations? Evidence from different understorey treatments

The agricultural industry is intensifying production methods to increase crop yields. Olive cultivation, the prevalent permanent crop in Europe and the Mediterranean area, involves intense practices with heavy agrochemical use. This significantly impacts agroecosystem biodiversity and its ecosystem services. In this study, we explore how biodiversity influences the adult olive fly (Bactrocera oleae (Rossi)) population in Lesvos Island, Greece, under different understorey management practices in olive groves. Our findings show that increased plant and arthropod abundance and diversity negatively affect the olive fly. The results suggest that maintaining undisturbed plant cover enhances olive grove biodiversity, ecosystem services, and biological control of the olive fly. Moreover, this practice is in line with Integrated Pest Management principles and Conservation Biological Control approach.