Arthropod-Plant Interactions最新文献

Plant food such as pollen represents part of the diet of many predaceous coccinellids, exploited as a supplemental food source when prey is scarce. They can therefore suffer adverse effects when foraging on genetically modified plants expressing Cry1Ab toxin derived from Bacillus thuringiensis Berliner. The Variegated Lady Beetle, Hippodamia variegata Goeze, a very common and important aphid predator in the Mediterranean area, feeds preferably on aphids but can use plant pollen as a supplemental food source. Hence, it can be exposed to Cry proteins when foraging on insect-resistant Bt-maize. In the current study, an experimental methodology to provide pollen to the coccinellids and quantify the amount of pollen eaten was developed. Using this methodology, the potential effects of the consumption of Bt-maize pollen on the fitness of H. variegata were evaluated. Both standardized laboratory bioassays and demographic approach by means of an age-structured matrix population model were performed. Both biological and demographic parameters did not differ between coccinellids fed Bt- or non-Bt-maize pollen. However, demographic analyses showed that some effects of Bt pollen exposure on H. variegata occurred. Indeed, the Bt-pollen-fed females had a higher expected lifetime reproduction; however, a reduced life expectancy occurred early in life for their offspring. As a result, the consumption of Bt-maize pollen causes a lower increase in H. variegata population since a reduction of offspring survival seems only partially outweighed by increased female fecundity. Overall, this study shows that the consumption of Bt-maize pollen expressing Cry1Ab by adults of H. variegata does not significantly affect their fitness, but it also shows that this outcome is a result of a trade-off among vital rates such as age-specific fecundity and survival probability that are positively or negatively influenced. Moreover, the methodology proposed in this study provides a sound exposure system to supply pollen to the coccinellids and appears functional to quantify maize pollen consumption by H. variegata adults.

Morphological trait matching between flowers and the mouthparts of their visitors is important for the ecology and evolution of plant–pollinator interactions. Although both nocturnal and diurnal floral visitors are important pollinators, nocturnal visitors such as moths (Lepidoptera) remain less well studied. To elucidate the relationship between floral tube length and mouthpart length in nocturnal floral visitors, we examined moths visiting the flowers of 34 plant species (26 families) in Hyogo, Japan. A total of 970 adult moths representing 245 species (14 families) were observed. Hawkmoths (Sphingidae) and settling moths (mainly Crambidae, Noctuidae, and Geometridae) accounted for 4.0% and 96.0% of all individuals, and 3.3% and 96.7% of all species, respectively. Hawkmoths had longer proboscises (mouthparts/tongues) than settling moths. The relative proportions of hawkmoths and settling moths increased and decreased, respectively, with increasing floral tube length. Mean, minimum, and maximum proboscis lengths of all moths (hawkmoths and settling moths combined) were positively correlated with floral tube length. Among hawkmoths, maximum proboscis length was positively correlated with floral tube length, indicating that long-tongued hawkmoths avoid visiting short-tubed or nectar-exposed flowers. Among settling moths, minimum proboscis length was positively correlated with floral tube length, indicating that short-tongued settling moths avoid visiting long-tubed flowers. Consequently, long-tongued moths (hawkmoths) prefer to visit long-tubed flowers, whereas short-tongued moths (settling moths) prefer to visit short-tubed or nectar-exposed flowers.

Dim-light foraging is exhibited by the majority of the seven bee families (facultative behavior—five families; obligate behavior – four families) and represents an underappreciated aspect of pollination ecology. The most diverse adaptive radiations occur within the family Halictidae and while neotropical augochlorine bees (Halictinae) have been well studied, very little is known about an independent paleotropical origin of nomiine dim-light bee foraging (Nomiinae) restricted to Australasia (New Guinea and Australia). Here we provide the first molecular systematic hypothesis for the obligate dim-light genus Reepenia and its closest diurnal relatives derived from ultraconserved elements and whole genome sequence data: (Paulynomia, (Austronomia, (Mellitidia (Reepenia, Ptilonomia)))). Relaxed-clock divergence estimates suggest a Miocene origin for this Australo-Papuan endemic clade of Nomiinae (~ 20 mya, 95% CI 11–35) and the most recent common ancestor of Reepenia + Ptilonomia (~ 7 mya, 95% CI 2.82–16.7); with a Pleistocene/Pliocene crown age for Reepenia (~ 2 mya, 95% CI 0.83–6.22). Integrative taxonomic inference yielded the discovery of Mellitidia glossata Bossert sp. nov., which is described and illustrated herein.

The western flower thrips (WFT, Thysanoptera: Thripidae) is an important pest worldwide that causes serious damage to commercial crops. To assess the impact of calcium chloride (CaCl₂) application and WFT infestation on the systemic resistance of kidney bean plant, a comparison was conducted about the contents of calcium ion (Ca²⁺) and activities of defensive enzymes in the upper, middle, and lower leaves after treating the middle leaves with either CaCl₂ application or H₂O and exposing them to WFT infestation or not. The development, feeding behavior, and leaf area damaged by WFT in different leaf positions were also observed. The results showed that the Ca²⁺ content was the highest on all leaf positions under CaCl₂ treatment plus WFT infestation. The activities of lipoxygenase (LOX), allene oxide synthase (AOS), phenylalanine ammonia-lyase (PAL), and β-1, 3-glucanase had no significant differences among leaf positions without WFT infestation, but they became significant after WFT infestation, WFT infestation could enhance the CaCl₂ treatment on all indexes. The immature period of WFT infestation on the upper, middle, and lower leaves of CaCl₂-treated plants were 0.8, 1.9, and 1.2 days longer than that of WFT fed on H₂O-treated plants, respectively. Electrical penetration graphs (EPG) showed that the total duration of long-ingestion probes (LP) of WFT on the upper, middle, and lower leaves of CaCl₂-treated plants obviously decreased than that in control plants. The feeding preference and feeding areas of WFT in CaCl₂-treated plants significantly reduced at all leaf positions. These results indicated that CaCl₂ application could weaken the development, feeding behavior, and damage areas of WFT, but WFT infestation triggered exogenous CaCl₂ application in activating the systemic defense of the whole plant.

Several pests, such as Bemisia tabaci and Tuta absoluta, can reduce tomato (Solanum lycopersicum L.) fruit production. Selection of resistant genotypes is one important pest management method. Thus, the objective of the present study is to evaluate the relationship between acylglucose levels, an allelochemical that activates resistance against tomato pests, leaf trichome types in tomato genotypes from two segregating populations, and their association with resistance to whitefly (Bemisia tabaci) and tomato leafminer (Tuta absoluta). The treatments were genotypes F₂BC₄ and F₂ ([M08 × F₂BC₃) S. pennellii × S. lycopersicum] with contrasting levels of acylglucoses, Solanum pennellii – LA-716 (resistance pattern) and Solanum lycopersicum lineage UEL M08 and S. lycopersicum cv. Redenção (susceptibility pattern). Evaluations of the genotypes were carried out by analyzing the densities and types of trichomes. Oviposition and nymphs of B. tabaci and damage severity of T. absoluta were evaluated. Densities of glandular trichomes are positively correlated to levels of acylglucoses. The advanced genotypes with high levels of the allelochemical reduced B. tabaci nymphs and eggs and the severity of T. absoluta damage, compared to commercial material. The desired characteristic of S. pennellii is inherited throughout backcrosses. The genotypes RVTA-2010-31319-214-238-pl#427 M and RVTA-2010-31-177-177-325-pl#42R demonstrate potential to advance the tomato breeding program to obtain pest-tolerant cultivars.

Urbanization promotes changes in the diversity of plants and pollinators which, in turn, result in novel ecological interaction networks that can be structurally different from those of natural habitats. Using published data from 32 studies across 18 ecoregions, we analyzed plant–insect networks from natural habitats and landscapes (‘natural networks’), natural habitats surrounded by urban matrices (‘natural–urban networks’), and urban networks in urbanized landscapes (‘urban networks’) to investigate the direct and indirect effects of urbanization on the structure of these networks. Through path analyses, we evaluate the effects of habitat type, proportion of exotic plant species, and pollinator richness on network connectance, nestedness, and modularity, while controlling for plant richness and ecoregion. We found that the effects of urbanization on network structure are primarily indirect, mediated by the decrease in pollinator richness, rather than directly or via the proportion of exotic plant species, underscoring the critical role of maintaining diverse pollinator populations in urban areas to sustain ecological network integrity. Our study highlights the need to consider direct and indirect effects when evaluating how urbanization affects plant–pollinator networks. This approach is especially important for conservation strategies aiming to mitigate the impact of urban development on plant–pollinator interactions.

Cabbage aphid, Brevicoryne brassicae L., is a key pest of canola (Brassica napus L.), all over the world. A few studies have focused on its field management using inducers or nutrients; however, none of them focused on aphid reproduction indices, phenolic defense, and economic returns. Induced resistance treatments were comprised of 0, 0.5, and 1 mM concentrations of SA—Salicylic Acid and CA—Citric Acid, while nutrient deterrence had 25 and 50 kg ha⁻¹ doses of Si—Silicon and AS—Ammonium Sulfate. Both approaches were compared to an insecticide (Carbosulfan 20 EC) and untreated control for two years in a field experiment. Although insecticide was an effective treatment, its impacts were not long-lived. The 1 mM SA reduced aphid reproduction the most, followed by 0.5 mM SA, 1 mM CA, and 0.5 mM CA. Similarly, in nutrient deterrence, Si 50 kg reduced the aphid reproduction indices followed by Si 25 kg and AS 25 kg. Seed yield was improved by 37.8% in AS 50 kg, followed by Si 50 kg (29.8%), and 1 mM SA (25.4%), over the insecticide. Other treatments were not performing well. Phenolic defense chemicals were highest in Si 50 kg, followed by Si 25, AS 25 kg, and 1 mM SA. Marginal analysis followed by residual analysis revealed AS 25 kg ha⁻¹ to be the most economical treatment followed by 0.5 mM SA for recommending to the farming community. Conclusively, both approaches showed the potential to manage cabbage aphids on canola and improved crop yield and phenolic defense; however, additional research is desired to explore their possible mechanism of resistance in plants.

Florivory can affect plant reproduction by altering pollinator behavior, especially in species with specialized floral structures. We investigated these effects using Senna aversiflora, an enantiostylous species susceptible to floral damage, as a species model. The objective of this study was to analyze the influence of floral damage on the frequency of pollinator visits and the quality of reproduction. We tested the following hypotheses: (a) flowers with damaged petals and anthers are less visited than flowers without damage; (b) healthy flowers have a higher fruit set than flowers with damaged petals and anthers; and (c) healthy flowers present higher quantitative aspects of fruits and seeds than damaged flowers. The study was carried out with ten individuals and three treatments (intact flowers, flowers with damaged petals and flowers with damaged anthers). We conducted focal observations of visitors to the flowers of each treatment. The flowers visited were monitored until fruiting, and the collected fruits were analyzed for size, weight, number, and weight of seeds per treatment. Intact flowers received more visits (43%) than flowers with damaged petals (30%) and damaged anthers (26%). Fruit set was similar between intact flowers (86%) and flowers with damaged petals (83%), but lower in flowers with damaged anthers (70%). However, the quality of fruits and seeds did not differ significantly between treatments. Florivory affected the frequency of visits, but did not influence the size of the fruits or the number and weight of the seeds, possibly due to the species capacity for reproductive compensation that allows the plants to produce fruits and seeds with unchanged characteristics despite the stress caused by florivory.

Tephritid fruit flies cause significant losses in global agriculture, particularly in fruit and vegetable production. Conventional pest control methods are increasingly scrutinized for their environmental and health impacts, leading to growing interest in alternative strategies. Bacterial symbionts offer a promising avenue for pest management by playing crucial roles in the biology and ecology of fruit flies, including nutrition, reproduction, immunity, and environmental adaptability. The manipulation of symbionts, such as Wolbachia, has been explored for reproductive control through cytoplasmic incompatibility, while Providencia rettgeri has been shown to enhance male mating competitiveness, improving the efficacy of the Sterile Insect Technique (SIT). Symbionts like Enterobacter spp. and Klebsiella spp. produce microbial volatile organic compounds (mVOCs) with potential applications in attract-and-kill strategies, offering a targeted pest control approach. Furthermore, probiotic applications of symbionts in SIT programs have demonstrated enhanced fitness and survival of sterile flies, reducing reliance on chemical pesticides. Despite these advancements, the integration of bacterial symbionts into pest management faces challenges, including non-target effects, environmental variability, and regulatory constraints. Addressing these challenges requires further research into symbiont-host molecular interactions, ecological dynamics, and effective integration into Integrated Pest Management (IPM) systems. This review explores the potential of bacterial symbionts to revolutionize Tephritid fruit fly control, emphasizing their diverse biological roles and practical applications. It further highlights the need for continued research to optimize and validate symbiont-based strategies for sustainable and effective pest management in agricultural systems.

Mosquitoes, like many other insects, are dependent on plant-derived nutrients as adults. Arid lands in particular create a challenge for mosquitoes to find resources consistently. In the United States, the arid, high elevation floodplains around the Great Salt Lake present a rich environment where salt desert shrublands meet alkaline freshwater wetlands, while plant communities contain a diversity of native and invasive flower species. We investigated survivorship on 15 flowering plants representing the common ephemeral wildflowers found through the aforementioned habitats using local Culex pipiens (L.) under laboratory conditions. Four native angiosperm species, Cleome serrulata Pursh (Brassicales: Cleomaceae), Asclepias incarnata L. (Gentianales: Apocynaceae), Asclepias speciosa Torrey, and Verbena hastata L. (Lamiales:Verbenaceae) had the highest mosquito mean percent survival in 10-day assays. Mosquito survival was significantly better on native flowers than on non-native flowers. Endemic mosquitoes in the field were also sampled for frequency of sugar feeding at six sites across 11 weeks. Flower phenology data of the aforementioned four flowers with highest mosquito mean percent survival were taken from iNaturalist and compared to the abundance of sugar-fed mosquitoes from the wild. Flower phenology and sugar-fed mosquito abundance followed the same trends, with increased flower sightings co-occurring with increased sugar feeding. The short-lived blooming intervals in the arid landscape result in time periods when both flower sightings and sugar feeding in mosquitoes are low, highlighting elevated risks to exposure and malnutrition for wild populations. Sustainable research and management of mosquitoes require answers to basic biological and ecological questions such as flower dependence and resource scarcity in the field.