Bulletin of Entomological Research最新文献

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 (T_c), net reproductive rate (NRR or R₀), intrinsic rate of population increase (r_m), etc. Considering potential fecundity (P_f), 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.

Leaf epicuticular waxes play a crucial role in host selection of Spilosoma obliqua, Amsacta albistriga, Spodoptera litura, and Spilarctia luteum. The leaf epicuticular waxes of groundnut, soybean, mikania, and parthenium indicated the presence of 25 different n-alkanes (C₁₄ to n-C₃₆) and 15 free fatty acids (FFAs) (C_12:0 to C_22:0). All the chemical analysis and bioassays were conducted by using the standard protocols. The attraction index (AI %) and oviposition preference index (OPI %) of each pest species towards the combined-synthetic-mixtures of respective leaf wax chemicals (4 n-alkanes [n-C₁₆, n-C₁₈, n-C₂₀, n-C₂₂] + 4 FFAs [C_14:0, C_16:1, C_16:0, C_20:0]) were more preferred due to respective wax chemicals. The AI (%) and OPI (%) towards the said mixture (C3) of the selected host plants (groundnut > soybean > parthenium > mikania) were in the order of S. obliqua > S. litura > S. luteum > A. albistriga for better survival and growth of their neonates because of the respective amounts of leaf wax chemicals including other phytoconstituents. The said synthetic mixture in respective leaf equivalent amount (µg leaf^-1) acted as the most preferred lure to develop baited trap and or groundnut as trap crop for soybean to support integrated pest management of such crops (groundnut and soybean). It also supports the use of such pest species as biocontrol agent for the exotic weeds (mikania and parthenium). This finding promotes sustainable pest and weed management for climate smart agriculture to maintain and sustain quality of our planet in the near future.

Aphis gossypii Glover (Hemiptera: Aphididae) is a significant pest of Capsicum annuum (Solanales: Solanaceae) and exhibits intraspecific differentiation within populations. To investigate the adaptability of Hap3 and Hap17 A. gossypii to various C. annuum varieties, including 'Lvzhou101' (LZ), 'Lashen' (LA), 'Saierweilvtianjiao' (SE), 'Haimaihongri' (HM), 'Chaotianjiao' (CT), and 'Luosijiangjun' (LS), we employed life tables to analyse growth and population parameters post-feeding and conducted petri dish host choice experiments to assess the host plant preference of A. gossypii. Survival rates of A. gossypii varied significantly across C. annuum varieties. Notably, Hap3 and Hap17 thrived on 'LZ' but failed to establish populations on 'LA'. The net reproductive rate (R₀), average generation time (T), and intrinsic rate of increase (r_m) differed markedly between Hap3 and Hap17 across C. annuum varieties. Feeding on 'LZ' resulted in a significantly higher R₀ value (26.49) for Hap3 relative to other varieties. The T (7.60 days) and r_m (0.27) values for Hap3 on 'SE' were superior to those observed on other C. annuum varieties. These findings indicate that 'SE' is the optimal host for Hap3 growth, while 'LZ' best supports Hap17. Both haplotypes exhibited the lowest adaptability to 'LA'. Therefore, the utilisation capacity of A. gossypii populations on C. annuum demonstrates differentiation, and the resistance levels among C. annuum varieties to A. gossypii vary. This differentiation can inform targeted management strategies for aphid infestations on pepper crops.

Bombyx mori Tryptophanyl-tRNA synthetase (BmWARS) belongs to the family of Ic-like aminoacyl-tRNA synthetases (aaRSs), whose specific recognition of the substrate Trp, tRNA, maintains the fidelity of protein synthesis. In this study, BmWARS was cloned and characterized from the midgut of the silkworm, Bombyx mori, resulting in an open reading frame (ORF) with a full length of 1,149 bp, which can encode 382 Aa. BmWARS is localized in the cytoplasm, and is expressed in all tissues of the silkworm, with higher expression in the testis, ovary, silk gland and malpighian tubule. The expression of BmWARS was significantly up-regulated in the midgut and silk gland after infection with Bombyx mori nuclear polyhedrosis virus (BmNPV). In addition, overexpression of BmWARS inhibited BmNPV infection and replication extremely significantly, while interference with BmWARS expression promoted BmNPV infection and replication. Analysis of the immune pathways in which BmWARS may be involved revealed that the expression of the key genes of the PI3K-Akt pathway, BmPI3K, BmAkt, BmPDK1, BmeIF4E, BmS6, and p-Akt protein was significantly reduced, whereas the expression of BmPTEN, BmFoxO, and BmCaspase9 was significantly increased in the cells that overexpressed BmWARS and were infected with BmNPV. Meanwhile, the results of the study interfering with the expression of BmWARS were completely opposite to those of the study overexpressing BmWARS. This is the first report that BmWARS has antiviral effects in Bombyx mori. Moreover, BmWARS inhibits BmNPV infection and replication in Bombyx mori cells by promoting apoptosis and inhibiting cell proliferation.

Data from three and half years' nightly light-trap catches of 25 Afrotropical ant species were examined by Fourier analysis. Between 8 and 72 % of the seven-day-moving-average logarithmically transformed catches were accounted for by two to four terms. All 25 species showed significant annual periodicity and all, but Dorylus fulvus and Camponotus foraminosus, six monthly. Four species had wavelengths of between two and four years, and Tapinoma melanocephalum of 289 days. Twenty-three species showed two peak catches annually, contemporaneous with the two rainy seasons, with the higher peak corresponding with the main rains for 21 of them, while D. fulvus and C. foraminosus had single annual peaks during the main rains. Catches of 14 species with lunar periodicities were lowest around full moon and highest near new moon, contrasting with Hypoponera dulcis and Plagiolepis brunni whose catches were highest at full moon, and near the first quarter, respectively. Gynes and males of eight species were sufficiently numerous for comparisons of their separate responses to lunar illuminance. Catches of males peaked ca. six and three days later than gynes for Tapinoma cf. carininotum and Tetramorium aculeatum, respectively; whereas males of Crematogaster africana, Cr. depressa, Tetramorium sericeiventre, Oecophylla longinoda, Tapinoma melanocephalum, and Technomyrmex andrei peaked from ca. one to six days earlier than their respective gynes.