Bulletin of Entomological Research最新文献

In tritrophic interactions, host plants could influence not only the population of insect pests but also that of their natural enemies. This study examined the effect of three wheat cultivars on demographic parameters of Schizaphis graminum Rondani (Hemiptera: Aphididae) and its predator, Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae). Furthermore, the secondary metabolites, photosynthetic pigments, and defence enzymes of wheat cultivars were evaluated at different times. According to the results, the highest and lowest developmental times of S. graminum were found on cultivar (cv.) Morvarid and cv. Ehsan, respectively. However, it was vice versa for the predator, being highest on cv. Ehsan and lowest on cv. Morvarid. Adults of S. graminum lived shorter on cv. Morvarid, while males and females of H. variegata lived longer on this cultivar. The intrinsic rate of natural increase (r) of S. graminum ranged from 0.347 to 0.456 day^-1, and that of H. variegata from 0.118 to 0.176 day^-1 on different cultivars. The value of this parameter was lowest for aphids but highest for their predator on cv. Morvarid. Based on the results, cv. Morvarid at 120 hours post-infestation by S. graminum contained the greatest concentrations of secondary metabolites and enzyme activities. The time-dependent loss of photosynthetic pigments occurred in each tested cultivar. The results revealed that cv. Morvarid had a suitable potential for reducing the population of S. graminum and enhancing the performance of H. variegata. However, further studies are needed to evaluate the complementary interactions of cv. Morvarid and H. variegata in controlling S. graminum population under natural conditions.

Predatory mites are important biological control agents of spider mites in various crops. Long-term mass rearing on alternative foods, such as plant pollen, may affect their predatory efficiency, but data on Euseius scutalis are scarce. Therefore, this study aimed to evaluate whether long-term rearing of E. scutalis on cattail pollen influences its functional response when fed on Tetranychus turkestani. Functional and numerical responses of the predatory mite E. scutalis reared on cattail (Typha latifolia) pollen over 30 generations on different densities (2, 4, 8, 16, 32, 64, and 128) of T. turkestani were evaluated. The results indicated a type II functional response for E. scutalis on T. turkestani in all generations (G1, G10, G20, and G30) tested. The attack rate (a) of E. scutalis increased as the number of generations increased. The handling time decreased as the number of generations increased from G1 (0.330 h) to G10 (0.318 h), then increased in G20 (0.572 h) and then decreased again in G30 (0.385 h). In G1 and G30, the number of eggs deposited by the predator increased as prey density increased. However, in G10 and G20, egg deposition increased up to 64 prey and then slightly decreased at 128 prey. The results indicated that the quality of E. scutalis did not lessen against T. turkestani after different periods of rearing on cattail pollen. Based on this study, we recommend cattail pollen as a good candidate for the large-scale rearing of E. scutalis for use in biological control programmes against T. turkestani.

Parasitoids play a key role in biological control, regulating pest populations in natural and agricultural ecosystems. Their efficiency depends on a thorough understanding of host-parasitoid interactions. Among these, the functional response, the relationship between parasitism rate and host density, plays a critical role. Despite a well-established background, challenges remain in experimental design, model selection, and parameter estimation for functional response analysis in parasitoids. This study aims to provide a practical guide to addressing these challenges. We outline key considerations in experimental design, including the selection of model organisms and initial host densities. For model selection, we present methods to differentiate between Type II and Type III functional responses, identifying the best-fitting models for parasitoids. In parameter estimation, we present an example demonstrating the application of functional response models for each type, including parameter estimation to guide model choice. Additionally, we provide equations and code based on published data to facilitate parameter comparisons. This guide provides a structured framework for experimental design, parameter estimation, and model selection in functional response studies, which is adaptable to various host-parasitoid interactions. By enhancing methodological rigour, we aim to support researchers in improving the precision and applicability of functional response analyses in parasitoid research.

Soybean aphids (Aphis glycines) (Hemiptera: Aphididae) pose a serious threat to global soybean production, necessitating sustainable control strategies. This study investigated silica nanoparticles (SiNPs) as an eco-friendly alternative, hypothesising they would suppress aphid populations while enhancing plant growth. Soybean plants were foliar-sprayed with SiNPs (0-1 mmol/L), and aphids were assessed across six assays: fecundity, survival, feeding preference, weight gain, olfactory response, and plant morphometrics. SiNPs significantly reduced aphid nymphal production and population growth at all concentrations but did not affect survival, weight gain, or host-seeking behaviour. Plant responses were mixed: leaf width increased at higher SiNPs doses, but plant height decreased, with no effects on leaf length, root/shoot biomass, or root length. These findings suggest that SiNPs could disrupt aphid reproduction without triggering behavioural avoidance. The absence of biomass reduction indicates potential for crop compatibility. This laboratory study reveals a novel, reproduction-targeted mode of action for SiNPs, highlighting its potential as a candidate for future development in sustainable IPM strategies. Further field-scale validation is required to confirm these effects under real-world conditions.

Lygus hesperus is an economically important pest of many crops. An effective monitoring method for the early detection of L. hesperus could improve its management. A recently developed pheromone lure has been shown to attract L. hesperus males, however, fewer males were captured than expected. It is unknown whether this was an effect of pheromone responsiveness or the type of trap used. Thus, we compared the efficacy of the previously used white delta sticky traps to red cylindrical sticky traps in strawberry fields in California and cotton fields in Arizona. Collections were made 1 and 2 weeks after trap deployment. In strawberry, pheromone baited traps captured more L. hesperus males than unbaited traps. More males were collected from baited red cylindrical sticky traps compared with either type of unbaited trap. In cotton, baited red cylindrical traps captured more males than unbaited traps after 1 week of field exposure, but not after 2 weeks of deployment. Overall, red cylindrical traps caught more L. hesperus males than white delta traps. Diminished trap captures during the second week of monitoring may be attributed to high temperatures in cotton that likely shortened the lure's longevity and windy conditions in both strawberry and cotton that may have decreased the effectiveness of the trap's adhesive. Additional work to clarify the lure's field longevity and distinguish various elements of trap design (e.g. colour, adhesive, and shape) may further increase the operational effectiveness of pheromone-baited traps for L. hesperus.

Aphids pose a significant threat to crop production, highlighting the need for sustainable pest management strategies. Plant-derived compounds are well-known as eco-friendly alternatives to synthetic pesticides. However, the role of methyl chavicol (MC), a phenylpropanoid found in several plant species, in inducing plant defence through exogenous application remains unexplored, despite its demonstrated insecticidal properties against various pests on direct exposure. This study aims to investigate the impact of exogenous MC applications on Brassica assessing performance and behaviour of Myzus persicae Sulzer (Aphididae) and its parasitoid Aphidius gifuensis Ashmead (Braconidae). Therefore, we assessed aphid survival and fecundity on MC-treated and untreated (control) plants using clip cages and evaluated behavioural responses through settlement and Y-tube olfactometer assays. Additionally, we conducted foraging and parasitism bioassays to examine performance of the natural enemy A. gifuensis on MC-treated plants. Our results showed that M. persicae exhibited higher fecundity on MC-treated plants compared to controls, indicating that MC treatment made the plants more favourable for aphid reproduction. Similarly, A. gifuensis demonstrated enhanced preference and parasitism behaviour towards MC-treated plants, suggesting that MC could help recruit the parasitoid. These findings suggest that MC may act as a modulator of plant defence, altering insect-plant interactions while maintaining compatibility with beneficial insects, offering a promising approach for Integrated Pest Management (IPM) programs in Brassica crops.

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.