The fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) has been a challenging pest of maize crops around the world. Novel, effective, eco-friendly and target-oriented approaches are needed to mitigate the damage of S. frugiperda. Farmers rely predominantly on extensive and repetitive use of synthetic insecticides, but they have unsatisfactory control because of the cryptic feeding style of the pest’s larvae and rapid decomposition of the applied insecticides. This study aimed to screen out available synthetic insecticides being used against different lepidopterous pests including S. frugiperda under field conditions, and then the two most effective insecticides were further formulated with silver nanoparticles and with sodium alginate hydrogel beads and bioassayed against the third larval instar of S. frugiperda under laboratory conditions using the standard leaf-dip method. Treatments included the following: T₁ = emamectin benzoate and chlorantraniliprole formulation at the recommended dose (90 mL/acre); T₂ = nanoformulated emamectin benzoate and chlorantraniliprole formulation; T₃ = nanoformulated emamectin benzoate and chlorantraniliprole at the recommended dose (90 mL/acre); T₄ = emamectin benzoate and lufenuron formulation at the recommended dose (400 mL/acre); T₅ = nanoformulated emamectin benzoate and lufenuron formulation; T₆ = nanoformulated emamectin benzoate and lufenuron formulation at the recommended dose (400 mL/acre); T₇ = nanoparticles alone (control); and T₈ = water (control). According to the results, the nanoformulated recommended dose of the emamectin benzoate and lufenuron formulation manifested the highest mortality (100%) at 24 h, followed by the nanoformulated recommended dose of the emamectin benzoate and chlorantraniliprole formulation (100%) at 48 h post-treatment. In other bioassays, alginate beads loaded with the recommended dose of emamectin benzoate and lufenuron formulations caused up to 50% more larval mortality compared to beads loaded with emamectin benzoate and chlorantraniliprole formulations, which resulted in 40% higher larval mortality than the control treatments. Overall, the findings of this laboratory study suggest further evaluation of such formulated application of synthetic insecticides combating S. frugiperda under semi-field and field conditions.

Pollinators' visits to flowers are guided by various factors, with nectar availability being one of them. Butterflies remain underexplored with respect to their contribution to pollination. Extensive field observations were conducted to gain insights into the floral morphology of 23 plant species from the northern Western Ghats (a globally recognized and threatened biodiversity hotspot), which are frequently visited by butterflies. Plants were observed during their peak flowering season. Parameters such as the pollen shape, apertural characters, and exine ornamentation were studied. In total, 91 butterfly species foraging on the 23 plant species were encountered. The Nymphalidae family, with 28 species, was the most abundant, followed by members of Lycaenidae (22), Hesperiidae (20), Papilionidae (11), and Pieridae (10). Plain tiger butterfly (Danus chryssipus) was recorded visiting eight different plant species, the highest amongst all the butterfly species. The highest average nectar quantity was recorded in Psydrax dicoccos (1.27 μl/flower). The maximum number of butterfly visitors (56 different species) were observed to be foraging on Ligustrum robustum subsp. perrottetii, which is an endemic tree species, followed by Mappia nimmoniana, which attracted 44 butterfly species. Butterflies were captured using swipe nets, and their bodies were screened for any pollen load. Pollens of an isopolar nature were predominant, while 12 species exhibited a monad dispersal unit. Triaperturate pollens was the most common type with a tricolpate aperture condition. The present study highlights the possible role of butterflies as contributors to pollination.

Introduction

The present study provides data on the ecological preferences and distribution of perlid stonefly Dinocras megacephala in Serbia in the 2012-2023 period. This species is often misidentified as the well-known perlid stonefly species, Dinocras cephalotes (Curtis, 1827). Males of D. cephalotes differ from D. megacephala by having patches of stronger sensilla basiconica on the ventral side of the abdomen (Hlebec et al, 2022).

Methods

Aquatic macroinvertebrate sampling was performed according to the AQEM protocol (AQEM, 2002). The semi-quantitative sampling was carried out using a hand net (25x25 cm, 500 μm mesh size), or the specimens were manually collected using tweezers. Samples were preserved using 70% ethanol solution and further processed in laboratories, where the specimens of D. megacephala were sorted from composite macroinvertebrate samples that were collected during Annual Water Quality Monitoring Programmes, conducted by the Serbian Environmental Protection Agency (SEPA), as well as other field research carried out by the Faculty of Biology in Belgrade.

Results

During the 2012-2023 period, the perlid stonefly Dinocras megacephala was recorded in a total of 30 sampling sites in Serbia. The majority of sampling sites are situated in southwestern and southeastern Serbia.

Conclusions

Dinocras cephalotes was hitherto the most common Dinocras species in Serbia, but we assumed that D. megacephala is more frequent than previously thought, and it is most likely that the species was erraneously identified as D. cephalotes. The species prefers well-oxygenated medium streams in submountaineous and mountainous regions of Serbia, dominated by rock and gravel riverbed substrate types. Furthermore, brachypterous males of D. megacephala also occur at higher elevations (Illies, 1966), so brachyptery cannot be used as a characteristic to distinguish this species from D. cephalotes (usually at higher elevations). In addition, larvae of D. megacephala were used to estimate the effects of trout farms on the mass of the larvae and their antioxidative defense under pollution stress conditions (Mirčić et al, 2016).

The myrmecofauna of Bulgaria is diverse, including Central and Northern European species as well as thermophilic and xerophilic Mediterranean species. Potential corridors for thermophilic fauna penetration include the valleys of the Struma, Mesta, and Maritsa rivers. Here, we consider the species diversity and the availability of thermophilic species in the Mesta river valley. Three sampling plots were situated in the Mesta river biocorridor, from the southernmost point in the Bulgarian territory up north to where Mediterranean influence is still significant. A total of 30 pitfall traps and 2 mesovoid shallow substratum (MSS) traps were set. The myrmecofauna was additionally sampled by hand collection, leaf litter sifting, and sweep netting. Only five species were reported in the literature for the region of Mesta Valley prior to our study. Twenty species were recorded in total during the survey in Mesta Valley. Fifteen species are new to the area, and fourteen are thermophilic species. The collected specimens were preserved in 70-80% ethanol and deposited in the Institute of Biodiversity and Ecosystem Research collection at the Bulgarian Academy of Sciences (IBER). Additional studies will clarify the rates of penetration of thermophilic species after qualitative and quantitative comparison of the composition of the myrmecofauna, along the south–north gradients. This study is a part of the Project “Monitoring the effects of global climate changes through qualitative and quantitative analysis of model animal groups in selected corridors of thermophilic fauna penetration in Bulgaria” (funded by the National Science Fund of Bulgaria under grant contract number KP-06-N61/6 – 14.12.2022).

Introduction:

The present study aimed to reveal the complexity of the spatio-temporal population dynamics of merolimnic and hololimnic insect species in terms of sampling site precision relevant to aquatic macroinvertebrate community metrics used for ecological status assessment/potential assessment of certain waterbodies.

Methods:

Aquatic insect taxa were identified in the laboratory, together with other taxa from composite macroinvertebrate samples collected using the AQEM protocol (AQEM, 2002) covering all microhabitats with at least 5% distribution at the sampling site during Annual Water Quality Monitoring Programmes conducted by the Hydrometeorological Service of Serbia (2009 and 2010) and the Serbian Environmental Protection Agency (2011-2023), resulting in approx. 1700 samples in total.

Results:

Data on aquatic insect taxa collected during a 15-year period (2009-2023) revealed the difficulties in determining the sampling locations of both insect groups. These difficulties can be attributed to the species’ complex annual spatio-temporal variability in population dynamics, comprising cumulative effects of intrinsic (insect behavior, age, and life history traits) and extrinsic factors (primarily microhabitat conditions and heterogeneity).

Conclusions:

Based on the data obtained, it was concluded that the merolimnic insect life cycle is seasonally dependent. The duration of the stage periods varied from year to year, particularly in light of recent climate change. Due to active dispersion, they can reach the most suitable stretches for their emergence.

On the other hand, hololimnic insect species spend their whole life cycle in the water and can only disperse via drift, active swimming, or phoresy (Li et al, 2016), but some aquatic beetle species have flying adults (macropterous forms) and disperse in the ways mentioned above. They can also have mixed populations consisting of both forms (including brachypterous forms).

Both insect group species can be passively carried by heavy rainfall and torrents in downstream stretches, which is also a problem for the determination of their precise sampling location.

Declines in post-harvest loss during storage due to insect pests require the development of eco-friendly bio-insecticide formulations such as plant-derived essential oils (EOs). Despite their advantages, the transient nature and high volatility of EOs are addressed through nanoemulsion (NE) formulations, enabling sustained release, enhanced stability, and prolonged bioefficacy. Considering the above, the contact insecticidal and repellent activity of 6% (v/v) of Piper nigrum corn EO (PNEO)-based NEs (PNNEs) were evaluated on Tribolium castaneum. The NEs were prepared using the high-shear emulsification method, witha single surfactant of Tween80 at three EO:Tween80 combinations, PNNE1 (1:5), PNNE2 (1:8), and PNNE3 (1:10). The chemical profile of PNEO was analyzed via GC-MS. The effect of cutaneous exposure of the treatments on antioxidant systems and acetylcholinesterase (AChE) in T. castaneumwas was further assessed. The chemical constitution of PNEO was dominated by (+/-)-alpha-thujene. With increasing Tween80 levels, PNNE particle sizes decreased from 11.66 nm through 10.5 nm to 9.581 nm. Correspondingly, the PDI values were0.210, 0.153, and 0.130, resulting in zeta potential values of -10.65mV, -17.87 mV, and -11.27 mV for PNNE1, PNNE2, and PNNE3, respectively. In comparison to PNEO treatments, the insecticidal activity of PNNE increased by ~2-fold, ~3-fold, and ~7-fold for PNNE1, PNNE2, and PNNE3, respectively, after 12 h of post-treatment, while all PNNEs showed ~2 times more repellency than PNEO. The results revealed that PNNEs significantly depleted the levels of glutathione (GSH), catalase (CAT), and peroxidase (POD), along with an augmenting effect on oxidized glutathione (GSSG) levels and Acetylcholinesterase (AChE) inhibition rates after cutaneous application compared to that of PNEO. Consequently, the encapsulation of PNEO in NEs improved the stability and bio-effectiveness of PNEO, thereby making it a potentially applicable bio-insecticide against T. castaneum.

Glycine max (Fabales: Fabaceae) is a key global crop, with over 17 million hectares dedicated to soybean production in Argentina, making it a cornerstone of agricultural systems. To promote sustainable agriculture practices, farmers increasingly use plant-based biostimulants, yet their effects on pest interactions remain unclear. This study evaluates the impact of a polyphenol-based biostimulant applied to soybean seeds on two pests: Spodoptera frugiperda (Lepidoptera: Noctuidae) and Nezara viridula (Hemiptera: Pentatomidae). Yield traits were assessed, while insect bioassays measured the survival and weight gain of larval S. frugiperda and nymphal N. viridula. Additionally, protease inhibitor (PI) levels in leaves and seeds were measured after 24 and 72 hours of herbivory. Biostimulant-treated plants exhibited improved yield parameters, including seed count and plant height. Serine PIs (defensive against lepidopterans) increased in the treated plants’ leaves, but cysteine PIs (defensive against stink bugs) showed no significant differences, even after feeding. The survival and weight gain of S. frugiperda were significantly affected by the treatment, whereas no effect was observed for N. viridula. The results suggest that biostimulant-treated soybeans enhance lepidopteran resistance while having limited effects on stink bugs. These findings highlight the potential of polyphenol-based biostimulants to improve integrated pest management and boost crop productivity in sustainable soybean farming systems.

Katydids (order: Orthoptera) are nocturnal insects that use species-specific calls for acoustic communication. Katydid communities are affected by variations in environment and habitat. However, very little is known about the biogeographic patterns of katydid communities from the biodiverse regions of the Indian subcontinent. It is important to understand biogeographical patterns in the rapidly changing environment due to climate change and invasive species. The objective of my study was therefore to understand the latitudinal patterns in acoustic assemblages of katydids from the Indian subcontinent. Field studies were conducted from 2015 to 2024 in three geographical locations from Western Ghats to Central India and the Western Himalayas in an increasing latitudinal gradient. A total of 26 call types were recorded from the study sites located across the three latitudes. This study also provides the first description of acoustic communities from Central India and the Western Himalayas. I also included eight call types from previously described acoustic assemblage data, making a total of 34 call types, to understand the latitudinal patterns. Preliminary analysis shows distinct community composition in the biogeographic areas. Only few species inhabited all three areas, and most call types were observed in a specific geographical area. The study indicated that the acoustic diversity of katydids follows the general pattern of a latitudinal biodiversity gradient. Given that katydids are important ecological indicators of ecosystem health, my study can help in understanding ecological processes that drive diversity and predicting how recent anthropogenic changes will affect species interactions and diversity.

In Tunisia, the Mediterranean fruit fly (or medfly), Ceratitis capitata (Wiedemann), is one of the most damaging insect pests in horticulture. It is primarily managed with the application of organophosphate insecticides, notably malathion. In this work, we investigate the toxicological and biochemical effects of malathion application on C. capitata adults from the Gafsa oasis, south Tunisia. This toxicological study was carried out by contact testing, and the biochemical activities were analyzed via acetylcholinesterase (AChE) activity, as well as catalase (CAT), glutathione S- transferase (GST), and malondialdehyde (MDA) levels as oxidative stress biomarkers in the whole bodies of adult Mediterranean fruit flies. For toxicological effects, the highest concentrations (50 ppm) generated 66.66% mortality after 24 h of exposure, whereas the lowest concentration (3.125 ppm) achieved 30% mortality for the same duration. For biochemical activities, malathion application increased the MDA content. In addition, the results indicated that malathion caused decreased AChE activity, decreased CAT activity, and increased GST activity compared to the control (non-treated flies). We infer that while malathion resistance in C. capitata populations from Gafsa oasis has not been described, marked increases in Glutathione S-transferase levels after exposure of Medfly adults, compared to the control, strongly suggest that oasis' Medfly populations tend to acquire resistance to malathion. Therefore, safer control alternatives should be implemented.

The genus Cotesia (Hymenoptera: Braconidae: Microgastrinae) comprises koinobiont endoparasitoid wasps specialized in lepidopteran hosts. This research aimed to investigate the potential to identify Cotesia species associated with hosts from the tribe Melitaeini based on their fore wing morphology. Additionally, the intraspecific diversification within the C. melitaearum aggregation was explored. Parasitoids were reared from twelve broods of Melitaea didyma, M. ornata, M. phoebe and Euphydrias aurinia, collected primarily in Serbia, as well as in Croatia and Spain. Emerged parasitoids were identified as C. bignellii, C. hispanica, C. lycophron and C. melitaearum agg. The females' fore wings were analyzed using geometric morphometrics to evaluate the interspecific and intraspecific morphological variation. The results of this study revealed significant differences in the forewing shape among the Cotesia species. The Principal Component Analysis (PCA) identified four distinct species, supporting species-level differentiation based on identification keys. Cotesia hispanica was distinguished by the slight widening and elongation of the distal part of its wings. The evidence suggests the existence of a potential biotype within the C. melitaearum aggregation, which may represent a distinct subgroup, requiring further investigation. This study enhances the identification of morphologically similar species within the highly diverse genus Cotesia based on forewing morphology, particularly those utilizing Melitaeini caterpillars as hosts.