The distribution and abundance of insect pests are influenced by landscape structure and composition, particularly through modifications to biocontrol services and the proportion of suitable habitats within the landscape. In addition, pest populations are affected by agricultural practices at different landscape scales, ranging from field-by-field to area-wide. Our study focuses on one of the world’s most invasive and polyphagous pests of fruits and vegetables: the Oriental fruit fly, Bactrocera dorsalis (Hendel, 1912) (Diptera: Tephritidae). We analysed how farmer practices, landscape composition, and mango varieties were related to B. dorsalis infestation in an insular tropical agroecosystem with disparate farming systems, where crop plots are of modest size and interconnected with various habitat types. Fruit infestations were regularly recorded during 18 months in different plots on all mango varieties of the study area. Agricultural practices were determined through semi-structured interviews and categorised according to the farm structure and practices related to B. dorsalis management. Landscape composition was determined from high-resolution satellite imagery and local surveys, and the area of landscape cover was calculated within a 500 m buffer around each sampled orchard plot. We demonstrate that both landscape and local factors influence the infestation indexes of B. dorsalis in mango orchards. At a landscape scale, B. dorsalis was favoured by habitat diversity, which probably provided complementary larval food resources and enabled populations to maintain throughout the year. On a local scale, individual farmers’ practices had a significant influence on infestation indexes. The proportion of infested fruits was lower in plots managed by farmers who practised sanitation.

Haritalodes derogata (Fabricius) (Lepidoptera: Crambidae), commonly known as the cotton leaf roller, is an important polyphagous pest that causes damage to various agricultural and forest plants, especially those of the Malvaceae family, but also to crops such as cotton, cashew, bamboo, oats, and jute. While microbial control agents are known for their efficacy and environmental friendliness, there are few studies demonstrating their effect on H. derogata. The aim of this study was to evaluate the bioefficacy of microbial agents from different pathogen groups against this pest. To this end, we investigated the insecticidal potential of fifteen indigenous microbial isolates from our entomopathogen collection. These included five Bacillus thuringiensis strains (Bn1, MnD, Mm2, Xd3, Lyd8), five entomopathogenic fungi (Metarhizium flavoviride As2, M. anisopliae KTU-51 and Beauveria bassiana Pa4, Pa5, Hp5), and five baculoviruses (HycuGV-Hc1, LdMNPV-T2, AcMNPV, DapuNPV-T1, SeMNPV-U), applied at concentrations of 1.8 × 109 cfu/mL, 1 × 107 conidia/mL, and 1 × 107 PIB/mL, respectively, against H. derogata larvae under laboratory conditions. Among these, B. thuringiensis subsp. kurstaki Bn1, B. bassiana Pa4, Hyphantria cunea granulovirus (HycuGV-Hc1), and Spodoptera exigua nucleopolyhedrovirus (SeMNPV-U) showed strong insecticidal activity and were selected for virulence assays, each achieving 100% mortality in third instar larvae. The median lethal concentrations (LC50) were determined to be 7.1 × 104 cfu/mL, 3.3 × 103 conidia/mL, 1.2 × 103 PIB/mL, and 1 × 103 PIB/mL, respectively. These results indicate that indigenous microbial agents are a promising environmentally friendly alternative to chemical pesticides in the control of H. derogata.

The European red spider mite, Panonychus ulmi Koch (Acari: Tetranychidae), is a major mite pest affecting a wide range of crops globally. Its rapid development and extensive dispersal enable P. ulmi to form large colonies through arrhenotokous reproduction, which subsequently produces bisexual offspring following oedipal phase mating. In this study, life tables for arrhenotokous and bisexual P. ulmi populations were constructed and assessed using the age-stage two-sex life table theory. To assess whether maternal age affects the offspring sex ratio, 3D life table analysis was conducted for both groups. Population projection for P. ulmi bisexual and arrhenotokous was based on life table data to evaluate the effect of arrhenotokous reproduction on population growth. Bisexual population parameters were r = 0.1828 d−1, λ = 1.2006 d−1, R0 = 44.80 offspring, and T = 20.79 d. The theoretical calculation of these parameters cannot be performed solely based on the survival rate and female fecundity of the P. ulmi arrhenotokous population, as only male offspring were produced during the first seven days before the arrival of the bisexual population. Although arrhenotokous parthenogenesis yields fewer offspring than bisexual reproduction, it significantly influences population dynamics by enabling a single virgin female to establish a bisexual population. Controlling offspring sex ratios enables rapid population growth and colonisation of new habitats. A comprehensive understanding of arrhenotokous reproduction is crucial for developing effective management strategies for P. ulmi. Future research should integrate genomic, ecological, and evolutionary perspectives to bridge the gap between laboratory and field conditions.

The objective of this experiment was to evaluate the resistance of advanced tomato genotypes resulting from an interspecific cross between Solanum lycopersicum and Solanum pennellii to Tetranychus urticae and Phthorimaea absoluta. The plant materials included nine lines, 14 hybrids, Leblon F1 (commercial control), and the wild accession S. pennellii LA716 as a resistance standard. Acylsugar content was then determined. For mite bioassays, oviposition, adult mortality/survival, egg hatching, and nymphs were evaluated using a no-choice bioassay. For P. absoluta bioassays, the oviposition, intensity of damage, type of lesions, and percentage of damaged leaflets were evaluated. F1 (TOM-808 × BPX-443E-03-02-113-02), F1(TOM-810 × BPX-443E-03-02-113-02), F1(TOM-808 × TOM-717), F1(TOM-808 × TOM-757), and F1(TOM-810 × TOM-717) were the most resistant to the mite, exhibiting higher female mortality, reduced oviposition, and no nymph emergence observed. The genotypes F1(TOM-808 × TOM-667), F1(TOM-808 × TOM-717), F1(TOM-810 × TOM-615), and several lines, which exhibited reduced oviposition and foliar damage. The results of the bioassays indicated that high acylsugar content reduced oviposition and foliar damage of the tested pests. The hybrid F1(TOM-808 × TOM-717) is the most promising at this stage of the breeding program, as it shows resistance to both tested pests.

The study systematically investigated the key biological and ecological characteristics of Cyamophila willeti, a major pest of the tree species Styphnolobium japonicum. We focused on its circadian mating rhythm, oviposition preference, and the effects of temperature on population parameters. Using the age-stage, two-sex life table approach, we compared the development, reproduction, and population growth potential under different temperature conditions. Results showed that mating activity peaked at 12:00 and 17:00, with females significantly preferring shoot tips for oviposition. At 25°C, female and male adult longevities were 39.88 ± 0.93 and 46.71 ± 1.69 days, respectively, and the mean fecundity per female was 647.75 ± 52.94 eggs. At 29°C, longevity was significantly reduced to 11.88 ± 4.10 days for females and 13.89 ± 4.31 days for males, while fecundity decreased to 47.63 ± 4.26 eggs. Most nymphs did not develop beyond the fifth instar at 33°C. These findings indicate that the optimal temperature for population growth of C. willeti is around 25°C, whereas high temperatures (≥29°C) significantly suppress survival and reproduction. This study establishes a foundation for monitoring C. willeti and developing effective control strategies.

Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) is one of the most serious pests of rice. The variations in phytoconstituents of rice cultivars (Miniket, Cottondora Sannalu, Gobindobhog, Swarna, and Tulaipanji) that led to differences in population growth of S. cerealella were studied. Fitness of the moth was approximated in terms of mean generation time (Tc), net reproductive rate (NRR or R0), intrinsic rate of population increase (rm), etc. Considering potential fecundity (Pf), growth rates, mortality coefficient (MC), and expected population size in the second generation (PF2), we classified the susceptibility of the rice cultivars to S. cerealella in the order as M > C > G > S > T. This was despite the higher concentrations of all the tested primary metabolites (PMs) in C and T. The least susceptibility of T and lower susceptibility of C than M can be attributed to their higher levels of secondary metabolites (SMs). M was highly susceptible due to its lowest SM content and sufficient levels of PMs. Now, G and S contained lower amounts of SMs, but they were moderately susceptible owing to the lower PM content. This emphasises the role of SMs, such as phenols, flavonoids, tannins, saponins, alkaloids, phytates, and oxalates, in determining the susceptibility of crop cultivars. Although none of the rice cultivars were entirely resistant, it can be stated that Miniket requires more protection measures against S. cerealella during storage than the others.

The fungus Beauveria bassiana (Unioeste 76) was tested against the soybean pest Euschistus heros in laboratory, greenhouse, and field. In the laboratory, insects were sprayed with pure conidia (TC) suspended in distilled water or in an oil dispersion formulation (OD; vegetable oil) at a concentration of 109 conidia/mL. The UV-B radiation and heat tolerance of the conidia were also assessed. After 12 days, the mortality rates in the laboratory were 70% for the TC treatment and 80% for the OD treatment. In the greenhouse pre-infestation bioassay, which used soybean plants in cages, the fungal treatments resulted in 52% and 47% mortality for the TC and OD formulations, respectively. In the post-infestation bioassay, both fungal treatments caused 83% mortality. In the field trial conducted on soybean plots (14 × 18 m), the treatments included: (i) biological: OD (109 conidia/mL); (ii) chemical insecticide; (iii) biological + chemical, all applied at 150 L/ha. Insect numbers were evaluated using beating-sheet sampling. In the final population sample, the biological treatment showed a population density similar to the chemical treatment (0.94 and 0.83 insects/m, respectively), both below the economic threshold. Conidia tolerance to UV-B radiation was similar across both treatments, but conidia in oil were less tolerant to heat. These results suggest that strategically combining both approaches (B. bassiana with chemical insecticides), with careful consideration of application intervals, could provide a sustainable and effective method for managing natural populations of E. heros.

This study investigates the gut microbiota of newly emerged adult females and males of five economically important Anastrepha species (Tephritidae) – A. ludens, A. obliqua, A. serpentina, A. striata, and A. fraterculus – by analyzing 16S rRNA amplicon sequences from 36 samples collected from ecologically relevant fruit hosts and locations in Mexico. We chose to concentrate only on newly emerged adults to identify bacteria that females could potentially transmit vertically to progeny via oviposition, a topic that remains poorly studied. Results revealed that Proteobacteria dominated the microbiota in all species, but substantial variation was observed in genus-level composition. Differentially abundant genera included Enterobacter, Gluconobacter, Tatumella, Providencia, Ochrobactrum, Siccibacter, Sphingobacterium, and Sphingobium. Significant differences in alpha diversity were observed between species, particularly between A. obliqua and A. striata, and between A. obliqua and A. serpentina based on the Shannon index. Anastrepha ludens, A. obliqua, and A. striata males exhibited higher species richness than females, although these differences were not statistically significant within individual species likely due to limited sample size. Interestingly, across all species, significant differences in microbiota composition were observed between males and females. Our findings suggest that morphological, physiological (i.e., metamorphosis) and ecological factors, such as possible gut structural differences and host fruit preferences, may influence the composition of the gut microbiota, potentially affecting the ecological adaptability and pest behavior of these flies.

Understanding predator-prey dynamics is pivotal for advancing sustainable pest management strategies. This study examined the functional response of Harmonia axyridis across six developmental stages when preying upon the eggs of two destructive lepidopteran pests including Spodoptera litura and Spodoptera frugiperda. Using logistic regression and Holling’s disc equation, a clear Type II functional response was observed across all stages except first instars, indicating a density-dependent predation pattern constrained by handling time at higher prey densities. Adult females consistently emerged as the most potent predators, demonstrating the highest effectiveness of predation (1.591 on S. litura; 1.736 on S. frugiperda) and maximum predation rates (113.7 and 120.9 eggs, respectively). Adult males and fourth instar larvae also showed high predation capacities, with maximum consumption nearing 99 and 95 eggs. In contrast, first instars exhibited minimal predatory potential (effectiveness <0.017; maximum consumption <10 eggs), highlighting the critical role of developmental maturity in predation performance. Notably, predation on S. frugiperda eggs slightly surpassed that on S. litura, suggesting host-specific traits may modulate predator efficiency. The functional response curves confirmed a classic decelerating intake rate at high prey densities, characteristic of Type II predators. These findings affirm the high consumptive potential of H. axyridis, particularly adult females, as efficient natural enemies against Spodoptera spp. eggs, and provide actionable insights for their integration into targeted, stage-specific biological control programs.

Rice water weevils (RWWs) (Lissorhoptrus oryzophilus) and rice weevils (RW) (Echinocnemus squameus) (both Coleoptera: Curculionidae) are major rice pests that cause significant economic losses in China. Understanding their potential distribution areas is crucial for effective management. This study used the Biomod2 package in R to simulate and predict the current and future potential distributions, changes in suitable areas, shifts in distribution centres, and overlaps under climate change for both pests under three greenhouse gas emission scenarios. By 2023, the suitable areas for RWWs and RWs were 538.52 × 104 km2 and 376.05 × 104 km2, respectively. The suitable area for the former pest expanded southwestward and northeastward across China, whereas the latter spread mainly into Northeast China. The suitable area for RWWs is projected to remain stable, whereas that for RWs is expected to decline. The distribution centroid of RWWs is anticipated to shift toward southeastern or southwestern Shaanxi, whereas RWs are likely to migrate toward central-eastern or northeastern Shaanxi. The niche overlap between the two pests is high (Schoener’s D = 0.658, I = 0.816), with overlap concentrated in central, eastern, and southern China. The key factors influencing their distributions include precipitation of the wettest month (Bio13), mean temperature of the warmest quarter (Bio10), and precipitation of the driest month (Bio14). This study provides a theoretical basis for the prediction of the potential distribution of both pests, which offers valuable insights for the development of effective pest control strategies in China.

Parasitoids are effective biocontrol agents against Spodoptera frugiperda. Here, we studied four egg parasitoids (Trichogramma chilonis, Trichogramma pretiosum, Trichogrammatoidea bactrae, and Telenomus remus) on S. frugiperda eggs under laboratory conditions [25 ± 1 °C, 70 ± 5% RH, 14/10-h (L:D) photoperiod]. Then, Tr. chilonis (the best trichogrammatid species in the laboratory) was studied inside cages (1 m × 1 m) under maize-field conditions. Egg-to-adult periods (days) were recorded among different species, with Te. remus having the longest (10.00 ± 0.89 days) and Tr. bactrae the shortest (7.80 ± 0.66 days) periods. Furthermore, Te. remus exhibited the greatest adult longevity (days) for both males and females, with and without food. Lifespan parasitism under laboratory conditions was the highest for Te. remus (73.60 ± 7.23 eggs), followed by Tr. chilonis (45.40 ± 2.56 eggs) and Tr. pretiosum (42.00 ± 3.70 eggs). Adult emergence (%) was always higher than 90% and the sex ratio was higher than 0.60 for the studied egg parasitoid species. In the cage experiments set up in uncontrolled field conditions, different release densities of Tr. chilonis (50,000, 100,000, and 150,000 parasitoids/ha) were studied. Release densities of 100,000 and 150,0000 parasitoids per hectare were the most effective rates for managing S. frugiperda, with recorded egg parasitism of 71.36% and 72.88%, respectively. These findings provide crucial insights into the biological attributes and parasitism potential of these parasitoids, indicating the optimal release density of 100,000 Tr. chilonis/ha as an integrated pest management strategy against S. frugiperda in maize ecosystems.

Many species of spittlebugs (Auchenorrhyncha: Cercopidae) use sugarcane and other grasses as host plants, and when damage is extensive they are considered pests leading tom economic losses. Mahanarva fimbriolata and Mahanarva spectabilis are the most common in sugarcane and can be distinguished mainly by genital morphology. Recently, another morphotype of Mahanarva occurring in sugarcane fields that did not match the morphologies of either of these Mahanarva species mentioned above has been widely collected in Brazil, raising doubts on the identification of Mahanarva species using sugarcane. Accurate specimen identification is critical for sugarcane pest management, because misidentifications can lead to economic losses and inefficient control strategies. Thus, we combined morphology, geometric morphometrics, and molecular techniques to investigate the hypothesis that this morphotype could be considered a new species of Mahanarva. Morphological analyses included examination of male genitalia and tegminal colouration patterns. We also quantified hindwing shapes using geometric morphometrics; and performed a phylogenetic analysis using the mitochondrial COI gene. Morphological evidence distinguished the new morphotype through unique traits in male genitalia. Geometric morphometrics reliably separated species, with over 89% classification accuracy. Molecular analyses confirmed the morphotype as a distinct lineage closely related to M. fimbriolata and M. spectabilis. Thus, we describe M. diakantha sp. n., demonstrating the effectiveness of an integrative approach in resolving taxonomic challenges. Additionally, we provide formal diagnoses for M. fimbriolata and M. spectabilis. This work underscores the importance of precise taxonomy in agroecosystems, supporting sustainable pest management practices.

The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a major invasive pest threatening maize production in India. Temperature strongly influences its development, reproduction and population dynamics. This study evaluated the biological performance of S. frugiperda on maize across seven constant temperature regimes (14 ± 1°C to 38 ± 1°C) under controlled laboratory conditions, using the age-stage, two-sex life table approach. Developmental time decreased significantly with rising temperatures, while survival and fecundity peaked at 26 ± 1°C and 30 ± 1°C. The highest values of net reproductive rate (R0 = 499.91 females/female), intrinsic rate of increase (rm = 0.25 females/female/day), and finite rate of increase (λ = 1.28 females/day) were recorded at 30 ± 1°C, followed by 26 ± 1°C (R0 = 467.32, rm = 0.24, and λ = 1.26, respectively). In contrast, thermal extremes delayed development and adversely affected both survival and reproduction. No development occurred at 38 ± 1°C. Population projections indicated rapid generational turnover at optimal temperatures, with up to nine generations annually at 26 ± 1°C. The temperature range of 26–30 ± 1°C was found to be optimal for both survival and reproduction of S. frugiperda, aligning with kharif season temperatures in North India, particularly Punjab. These conditions promote multiple generations annually, whereas extreme summer or winter temperatures may limit population development. The findings advocate for temperature-informed, location-specific pest control strategies. Intervening during critical developmental windows, especially at the egg and larval stages, can limit population buildup. Insights into the pest’s thermal adaptability contribute to the advancement of climate-resilient, sustainable pest management frameworks for maize systems in North India and similar agroclimatic regions.

Natural enemies serve a crucial role in crop protection through the regulation of pest population dynamics. Cyrtorhinus lividipennis is an important natural enemy of rice planthoppers. Fatty acid synthase (FAS), a multifunctional enzyme crucial for fatty acid biosynthesis, serves as a vital energy source for insect reproduction. However, the function of FAS in the reproductive processes of C. lividipennis remains incompletely understood. In this study, the ClFAS gene was successfully cloned from C. lividipennis. The open reading frame of ClFAS was 7224 bp, encoding a putative protein of 2407 amino acids. The expression levels of ClFAS were notably elevated in the fifth-instar nymphs, adults, as well as in the fat body and ovaries of female individuals. Silencing of ClFAS resulted in a reduction of 58.4%, 34.6%, and 49.0% in the expression levels of ClVg at 1-, 2-, and 3-days post-dsRNA injection, respectively. Furthermore, RNA interference (RNAi)-mediated depletion of ClFAS not only suppressed the Vg protein expression but also significantly impaired oocyte maturation and ovarian development. The fecundity of dsFAS-treated C. lividipennis females was markedly reduced by 49.5%, accompanied by significant decreases of 32.7% in oviposition duration and 26.3% in female adult lifespan. Our findings showed that ClFAS positively regulates the reproduction of C. lividipennis by promoting vitellogenesis and ovarian development, which provides valuable insights into how lipid metabolism governs fecundity in predatory insects.

The host plant associations of the bird cherry-oat aphid, Rhopalosiphum padi (L.), a major pest of wheat, before and after wheat harvest remain poorly understood. Overlapping growth of maize and wheat may promote R. padi survival and movement between crops. We examined population dynamics and constructed life tables for R. padi reared on wheat seedlings, maize husks, and maize leaves. Field-collected R. padi survived on both maize tissues, but aphid abundance declined sharply on aging maize leaves, while aphids on maize husks developed successfully. Aphids reared on wheat exhibited the fastest development, longest lifespan (27.89 ± 1.20 days), highest fecundity (98.59 ± 5.61 nymphs), and lowest mortality (2.56%). In contrast, aphids transferred to maize leaves showed reduced longevity (19.62 ± 1.16 days), lower fecundity (33.55 ± 2.47 nymphs), and higher mortality (23.73%). No significant differences in some reproductive parameters were observed between wheat- and maize husk-reared aphids, indicating relatively good performance on maize husks. Aphids transferred from wheat to maize experienced fitness costs, while aphids moved from maize husks back to wheat exhibited improved performance. These findings suggest that maize husks offer a comparatively favourable resource microhabitat for R. padi, potentially serving as a secondary host that supports population persistence after wheat harvest.

This study presents the first record of Miyalachnus sorini Kanturski & Lee, 2024 (Aphididae: Lachninae) in South Korea, thereby extending its known distribution beyond Japan and identifying a new host plant, Prunus sargentii (Rosaceae). We describe diagnostic morphological traits across multiple life stages and compare them with those of Japanese populations. Comparative analyses with Japanese populations demonstrated consistent morphological differentiation, notably elevated ratios of the ultimate rostral segment to antennal segments across multiple morphs in the Korean population, indicating potential ecological adaptation. DNA barcoding using the mitochondrial cytochrome c oxidase I gene revealed low intraspecific divergence (average 0.2%) and interspecific divergence (average 10.5%) between Miyalachnus sp. and M. sorini. Haplotype analysis was performed to investigate the relationship between host plants and cryptic genetic diversity. These findings enhance our understanding of the morphological and genetic diversity of M. sorini and underscore the importance of monitoring its spread for informed pest management strategies.