Background:

The date palm, or Phoenix dactylifera L., is a significant fruit crop and a source of income for many nations. The invasive bug Rhynchophorus ferrugineus (Olivier, 1790), often known as the red palm weevil (RPW), causes harm to the date palms all over the world via eating the internal stems of palm trees.

Aims:

The purpose of this study is to identify the susceptible and resistant kinds of R. ferrugineus and to investigate its population dynamics in three different imported date palm varieties: Dhakki, Bari, and Ajwa.

Methodology:

In a date palm orchard in Bahawalpur, Pakistan, red palm weevil (RPW) adults, larvae, and pupae were monitored. Using a stethoscope to listen for larval feeding sounds and by examining symptoms like yellowish discharges and disagreeable smells, infestations were found. As previously noted, three kinds of imported date palm were chosen, and monthly records of RPW population dynamics were made. Three orchards containing eighteen trees (three of each kind) were examined. Using a drill machine, immature and mature RPW stages were gathered, counted, and then put back into the trunk, which was sealed with soil paste containing 1 ml of chlorpyrifos water.

Results:

Our research findings indicate that the Dhakki variety of date palm experienced the highest levels of infestation across both age groups examined. Specifically, plants aged between ten and fifteen years, as well as those older than sixteen years, were significantly impacted by red palm weevil (RPW) infestations. The Dhakki variety was found to be particularly vulnerable to RPW infestations during the months of January to March, likely due to environmental conditions or the life cycle of the weevil during this period. This timing allows for proactive measures to be taken before the peak infestation period, thereby reducing the potential for significant damage to the Dhakki date palms.

Introduction: Deltamethrin (DTM) is widely used in forestry, professional agriculture, and amateur farming. However, its application presents specific risks to pollinating insects. DTM disrupts the physiology of honey bees (Apis mellifera), causing abnormalities in behaviors such as dancing and foraging, as well as issues like memory impairment, hypofertility, and hypothermia [1]. Antioxidant compounds incorporated into bee diets can defend bees against the adverse effects of various pesticide classes [2-3]. This study aimed to evaluate the potential of the polyphenolic fraction of bergamot (BPF) to mitigate the harmful effects of DTM exposure.

Materials and Methods: Twelve experimental groups consisting of 20 honey bees each were established. Under controlled laboratory conditions, honey bees were exposed to oral DTM administration for three days at a concentration of 21.6 mg/L. Additional experimental groups received BPF (1 mg/kg) in combination with the specified toxic DTM doses. Abnormal behaviors—including a curved-down abdomen, hyperactivity, apathy, motion coordination issues, and moribundness—were observed and recorded at 1, 2, and 3 days post-treatment. Survival rates were also assessed for each group.

Results: By day 3 of the experiment, all honey bees in the groups exposed solely to the highest DTM dose (21.6 mg/L) had perished. Conversely, in the groups treated with both BPF and DTM (21.6 mg/L), a survival rate of 46% was observed after 3 days. Overall, groups receiving only toxic DTM doses exhibited lower survival rates (day 1 = 38%, day 2 = 25%) compared to those treated with the BPF and DTM combination (BPF + DTM: day 1 = 86%, day 2 = 72%). Additionally, honey bees exposed to the BPF/DTM combination displayed fewer abnormal behaviors compared to those treated with DTM alone.

Conclusions: Oral administration of BPF can reduce the harmful effects of DTM. However, further research is necessary before recommending the inclusion of BPF in honey bee diets, despite the promising positive effects observed.

The Asian pear moth (Grapholita molesta) is one of the most significant pests affecting pear orchards in China, causing extensive damage to fruit production. Over the past few decades, the widespread use of organophosphate and pyrethroid insecticides to control this pest has led to concerns about the evolution of pesticide resistance. This study investigates G. molesta populations' development of resistance to these two major classes of insecticides commonly used in Chinese pear orchards. We conducted a series of laboratory bioassays to evaluate the susceptibility of G. molesta larvae and adults from multiple orchards in key pear-growing regions of China to a selected organophosphate (chlorpyrifos) and pyrethroid (deltamethrin). The study also examines the underlying mechanisms of resistance, including metabolic detoxification through cytochrome P450 enzymes, esterase activity, and mutations in the target site of the insecticides. Our results show a significant increase in resistance ratios among G. molesta populations to both organophosphates and pyrethroids, with some populations exhibiting resistance levels up to 20-fold higher than susceptible strains. Resistance was most pronounced in regions where chemical control has been heavily relied upon for multiple seasons. Enzyme assays revealed elevated levels of P450-mediated detoxification in resistant populations, and molecular analysis identified key mutations in the voltage-gated sodium channels of pyrethroid-resistant individuals. These findings highlight the adaptive potential of G. molesta to pesticide pressure and underscore the risks of prolonged chemical use without rotation or integrated pest management (IPM) strategies. This study provides a comprehensive understanding of the mechanisms driving resistance in G. molesta and emphasizes the need for sustainable pest management practices in pear orchards. To mitigate further resistance development, we recommend the adoption of IPM approaches that integrate biological control, alternative insecticides with novel modes of action, and resistance monitoring to ensure the long-term viability of chemical control in pear production.

Lucilia cuprina Wiedemann and Lucilia sericata Meigen (Diptera: Calliphoridae) are blowflies that may cause cutaneous myiasis in sheep, among other wild and domestic animals, leading to major economic losses in the sheep industry. The mitochondrial cytochrome c oxidase subunit 1 (cox1) gene has been considered ineffective for species identification when used alone. Some Lucilia (Phaenicia) cuprina exhibit mitochondrial DNA haplotypes that closely resemble those of Lucilia sericata, suggesting a paraphyletic relationship between L. cuprina and L. sericata. To address this, we examined both the nuclear 28S rRNA gene and the mitochondrial cox1 gene to differentiate between L. cuprina and L. sericata using new DNA data from Northwest Africa. This study provides the first evidence of L. cuprina in Northwest Africa.

Adult flies were captured from Tipaza Province, North Algeria (36°33'11.254"N, 1°48'5.749" E). We sequenced both the cox1 and 28S genes and constructed phylogenetic trees using the maximum likelihood method with 1000 bootstrap replicates. The sequencing generated approximately 675 base pairs (bp) for cox1 and 633 bp for 28S. All sequences were identified using BLASTn and deposited in GenBank (accession numbers PP918012- PP918014, PP922527- PP922529, PP922531- PP9225333, and PP916230- PP916232). No intraspecific differences were observed among the sequences. The 28S analysis confirmed the monophyly of the two species, while the cox1 analysis revealed that L. cuprina is divided into two distinct clades, paraphyletic with respect to L. sericata. The 28S sequences clustered together without showing any consistent geographic patterns.

Despite the paraphyletic relationship between L. sericata and the two forms of L. cuprina, mitochondrial DNA appears useful in distinguishing these species. However, the subspecies L. cuprina cuprina (Wiedemann) and L. cuprina dorsalis Robineau-Desvoidy cannot be differentiated using the 28S and cox1 genes, nor can their differences be inferred based on geographic location, particularly in areas where both subspecies coexist.

Diptera is one of the most diverse insect orders in the world, possibly ranking second or third in terms of estimated species diversity, and it requires a significant time investment in order to be studied even within one geographic area, with many new taxa being reported or described throughout the decades. This is the case for Bulgaria, where the systematized and extensive Catalog by Hubenov (2021) highlights the need for further research, creating a good baseline for future studies. We have caught or photographed multiple fly species new to the fauna of Bulgaria from multiple families, four of which are discussed here. The hyper-diverse family Empididae is represented by Rhamphomyia anfractuosa, collected from the region of Kyustendil. The family Micropezidae is represented by Rainieria calceata, which was observed and photographed near Vidin. From Rhinophoridae, Melanophora roralis was observed near Vidin and collected in the region of Sofia, where it is common in urban parks and green areas. From the family Sarcophagidae, the species confirmed to be among the fauna of Bulgaria are Sarcophaga belanovskyi and S. schusteri Lehrer, 1959. The former species was collected twice in the city of Sofia in 2022. It may have been previously reported under the name of S. ancilla, but these are currently considered to be separate species. Sarcophaga schusteri has been collected from different parts of Vitosha Mts in 2022 and 2023. Its taxonomic status is not fully clear, as it is similar to other montane taxa from the Alps. This species is likely not synonymous with Sarcophaga subvicina, as it was compared to material of S. subvicina from Czechia and Slovakia and shows differences. Povolny and Verves (1990) expressed suspicion about the older records of Sarcophaga subvicina in Bulgaria. This study is a part of the project under Grant contract number KP-06-N61/6 – 14.12.2022).

Honey bee (Apis mellifera) pollination is an essential ecological service, particularly in South Africa’s growing blueberry industry. Honey bees may, however, also act as vectors of Botrytis cinerea, a destructive fungal pathogen causing blossom blight and grey mould in blueberries. This study investigated B. cinerea occurrence on blueberry flowers, fruits, honey bees, and hive entrances across six blueberry farms in Western Cape province, South Africa. The blueberry farms were categorized by historical Botrytis pressure (farm status), namely, high, medium, or low. Samples were collected from two farms per status, and two variety blocks per farm. The samples were plated onto Botrytis-selective media, and isolates were identified morphologically and molecularly. The effect of farm status, variety, and tissue type on the presence of B. cinerea was tested using generalized linear fixed effects models, whereas a simple linear regression was used to test the relationship between the presence of the pathogen on blueberry plants and honey bees and hives. The results showed that B. cinerea presence was the highest in the two high-pressure farms and on swabs collected from hives, specifically on the farm where hives were placed near the soil surface. Botrytis cinerea presence on swabs was significantly affected by farm status, while the other variables did not have a significant effect. Additionally, there was no significant relationship between B. cinerea on blueberry plants and honey bees or hive swabs. These findings suggest that honey bees can carry B. cinerea spores to blueberry plants, but the risk of infection depends on multiple factors, particularly environmental ones. The role of honey bees in B. cinerea transmission in blueberries, and biological control agents for the pathogen, warrants further investigation. Cultural control methods such as field sanitation may reduce the build-up of inoculum sources, particularly overwintering structures, while strategic hive placement can further minimise exposure.

The survival of any species depends on how efficiently it can thrive during unfavourable seasons. Diapause in Sternochaetus mangiferae, a monophagous pest of mango in India and other mango-growing countries of the world, was achieved by it remaining in a dormant phase during its adult stage. The diapause in the weevil was studied based on an extensive survey carried out in pest-infested areas of Kannur and Kozhikode districts of Kerala from the year 2023 to 2024.The mangoes that were collected from the field were cut open to identify the presence of the different immature stages of the pest and studied using a stereo zoom microscope. The pulps of the ripened mangoes were removed to expose the nuts, and 500 nuts were placed in plastic containers with small holes at the bottom and top. The nuts were observed regularly for the emergence of the weevil. Sudden falls in temperature and relative humidity, rainfall, and the onset of flowering in mango trees were recorded regularly to study their effects on the onset of diapause and its termination. The details of the life cycle, including the immature stages, were studied and discussed. This work showed that in Kerala (India), the emergence of the adult from the nut depended on the humidity, fall in temperature, and rainfall. Under the cage conditions, all the adults entered the diapause stage by the second week of July, which was influenced by heavy rainfall, humidity, and a fall in temperature. Meanwhile, the break in diapause was observed to occur along with the flowering of mango. In the study area of of Kerala during the years of 2023 and 2024, the exit from diapause was achieved in the months of January and February of the year 2024. Various factors involved in diapause and its termination are discussed.

Leaf-cutting ants represent a significant threat to forests and agriculture. In this context, the use of plant-derived substances has garnered growing interest as an alternative to synthetic insecticides. This study aimed to evaluate the effects of different concentrations of diphenyl disulfide and lyral, compounds present in the essential oil of Tropaeolum majus (Brassicales: Tropaeolaceae), on the leaf-cutting ant Atta sexdens and its symbiotic fungus Leucoagaricus gongylophorus. First, we assessed the effects of these compounds on fungal growth. Subsequently, we evaluated the impact of topical application and exposure to the compounds through an artificial diet on the survival of gardener and forager worker ants. We also analyzed worker ant interactions using a software tool for behavioral assessments, to evaluate the spread of the compounds via topical application. No significant changes were observed in the mass or growth area of fungi exposed to diphenyl disulfide or lyral. Through topical application, diphenyl disulfide demonstrated a toxic effect that increased with higher concentrations of the compound, while lyral showed no toxic effect on any ant caste. No significant effects on ant mortality were observed when the compounds were administered via artificial diet, nor was there inhibition of ant feeding, indicating that the compounds did not directly influence food consumption. Diphenyl disulfide increased interactions between treated and untreated ants compared to lyral and the control. However, this increase in interactions did not compromise colony activities. Thus, the results suggest that diphenyl disulfide is a compound with characteristics worth exploring to assess its potential for managing Atta sexdens.

Introduction: Rhyzopertha dominica, Sitophilus oryzae, Trogoderma granarium, and Tribolium castaneum are serious stored-product pests. The pyrethroids inhibit neurotransmission by affecting the function of sodium channels in the nervous system. The anthranilic diamides disturb calcium homeostasis and cause arthropod mortality by specifically activating arthropod ryanodine receptors. The use of combinations of insecticides with different modes of action is more effective compared to single applications.

Methods: A formulation containing the active ingredients λ-cyhalothrin (pyrethroid) plus chlorantraniliprole (anthranilic diamide) was tested in various doses (0.01–5 ppm) against S. oryzae, T. granarium, T. castaneum, and R. dominica on wheat, rice, and maize in laboratory mortality and persistence mortality/progeny production bioassays.

Results: In all bioassays (laboratory and persistence), S. oryzae and R. dominica proved to be the most susceptible species, followed by T. castaneum and T. granarium. The same pattern was noted for progeny production in laboratory and persistence bioassays. Among the tested commodities, wheat led to higher mortality rates compared to rice and maize.

Conclusions: The efficiency of λ-cyhalothrin plus chlorantraniliprole was affected by various biotic and abiotic parameters, such as insect species, commodities, exposure intervals, and doses. The need for innovative and efficient techniques to improve protection in storage facilities is growing because of the limited number of approved grain protectants used in stored products. This research has shed light on the possible application of λ-cyhalothrin plus chlorantraniliprole in storage conditions by combining various parameters.

Leaf trichomes have been extensively studied as physical defensive structures against abiotic and biotic stress in plants. Climate change-driven stresses such as drought and/or herbivory can aggravate crop morpho-physiology as well as physical and chemical defenses. However, the interactions of such stresses on trichomes, as well as their impact on herbivores, remain poorly understood. To study the effects of drought and herbivory (D×H) on leaf trichomes, we introduced soybean looper (SBL) (Chrysodeixis includens Walker), a polyphagous herbivore, to drought stressed soybeans. After assessing trichome density, the trichomes were extracted and incorporated into artificial diets to examine SBL growth traits under various leaf-diet concentrations (10% and 20%) and trichome diets (high and low). Following that, a time-to-feed experiment was performed to evaluate the effects of trichomes on SBL feeding initiation. We found that SBL started feeding faster on shaved leaves with trichomes removed than on unshaved leaves that had intact trichomes. The results also revealed that D×H induced trichomes in new leaves, which led to cascading effects on SBL growth traits. Although SBL showed a positive mass gain under the leaf diet from stressed plants, they had early pupation and eclosion under D×H leaf diet. Post-ingestion effects were evident from frass pellets under trichome diets, since the caterpillars that fed on high trichome diet also had a higher number of trichomes in their frass. In conclusion, trichomes are substantially induced by D×H and have cascading effects on SBL growth and development, exhibiting both pre- and post-ingestive effects. The highly inducible nature of trichomes in response to abiotic and biotic stresses provides the potential for future investigation in defensive priming and integration into resistance-breeding programs.