Host Plant Research Articles

Effects of host plants on aphid feeding behavior, fitness, and Buchnera aphidicola titer.

Aphids are sap-feeding plant pests that depend on their symbiotic relationships with the primary endosymbiont Buchnera aphidicola to adapt to impoverished diets. However, how the host plant affects the aphid primary symbiont and aphid adaptation to host plant transfer are poorly known. In this study, aphid symbiont screening and genotype identification were used to establish 2 aphid strains (Rhopalosiphum maidis [Rm] and Rhopalosiphum padi [Rp] strains) containing only Buchnera without any secondary symbionts for both wheat aphid species (R. maidis and R. padi). Aphid fitness and Buchnera titers were unstable on some of these host plants after transferring to novel host plants (G1-G5), which were influenced by host plant species and generations; however, they stabilized after prolonged feeding on the same plants for 10 generations. The electropenetrography (EPG) records showed that the allocation of aphid feeding time was significantly distinct in the 6 host plants; aphids had more intracellular punctures and spent more nonprobing time on green bristlegrass which was not conducive to its growth compared with other plants. The content of soluble sugar, soluble protein, and amino acid in the leaves of the 6 host plants were also clearly separated. The correlation coefficient analysis showed that the nutrient contents of host plants had significant correlations with aphid feeding behaviors, fitness, and Buchnera titers. In the meantime, aphid fitness, and Buchnera titers were also affected by aphid feeding behaviors. Also, Buchnera titers of aphid natural populations on 6 host plants showed a visible difference. Our study deepened our understanding of the interaction among aphids, endosymbionts, and host plants, indicating that the host plant nutrient content is a predominant factor affecting aphid adaptation to their diet, initially affecting aphid feeding behaviors, and further affecting aphid fitness and Buchnera titers, which would further contribute to exploiting new available strategies for aphid control.

Plant infection by the necrotrophic fungus Botrytis requires actin-dependent generation of high invasive turgor pressure.

The devastating pathogen Botrytis cinerea infects a broad spectrum of host plants, causing great socio-economic losses. The necrotrophic fungus rapidly kills plant cells, nourishing their wall and cellular contents. To this end, necrotrophs secrete a cocktail of cell wall degrading enzymes, phytotoxic proteins and metabolites. Additionally, many fungi produce specialized invasion organs that generate high invasive pressures to force their way into the plant cell. However, for most necrotrophs, including Botrytis, the biomechanics of penetration and its contribution to virulence are poorly understood. Here, we use a combination of quantitative micromechanical imaging and CRISPR-Cas-guided mutagenesis to show that Botrytis uses substantial invasive pressure, in combination with strong surface adherence, for penetration. We found that the fungus establishes a unique mechanical geometry of penetration that develops over time during penetration events, and which is actin cytoskeleton dependent. Furthermore, interference of force generation by blocking actin polymerization was found to decrease Botrytis virulence, indicating that also for necrotrophs, mechanical pressure is important in host colonization. Our results demonstrate for the first time mechanistically how a necrotrophic fungus such as Botrytis employs this 'brute force' approach, in addition to the secretion of lytic proteins and phytotoxic metabolites, to overcome plant host resistance.

Evaluation of host plant species for a trap cropping strategy in integrated pest management of pineapple mealybug (Dysmicoccus brevipes)

Pineapple mealybugs are responsible for the emergence of pineapple wilt disease and the subsequent transmission of the pineapple disease virus. This study aimed to evaluate the alternate host plants as potential trap crops for pineapple mealybug. A total of nine host plant species, banana, pumpkin, roselle, hibiscus, ground fig, okra, java grass, goose grass and rhodes grass were selected for the study. Thirty adult females of pineapple mealybug were reared on a pumpkin for two months. Three replicates of a plot (area covered with black netting measuring 3 m × 3 m) were set up. Nine host plant species, approximately 2–3 feet in a 16 inch × 16 inch polybag were arranged in a circle around the pumpkin. The effectiveness of the host plant species was determined by calculating the infestation of each plant species for six months (with two-week observations). Our findings revealed that the pineapple mealybug prefers banana with the greatest mean and SD value (621.7±172.7), followed by pumpkin (237.0±45.6) and the lowest one is rhodes grass (2.00±26.5). ANOVA results show that there is a significant difference between host plant species (F-value of 26.87 and a P-value < 0.00). The observations suggest that banana has the potential to be utilized as trap crops for pineapple mealybug, and can be considered in IPM strategy to control pineapple mealybug.

Pectin Remodeling and Involvement of AtPME3 in the Parasitic Plant–Plant Interaction, Phelipanche ramosa–Arabidospis thaliana

Phelipanche ramosa is a root parasitic plant fully dependent on host plants for nutrition and development. Upon germination, the parasitic seedling develops inside the infected roots a specific organ, the haustorium, thanks to the cell wall-degrading enzymes of haustorial intrusive cells, and induces modifications in the host’s cell walls. The model plant Arabidopsis thaliana is susceptible to P. ramosa; thus, mutants in cell wall metabolism, particularly those involved in pectin remodeling, like Atpme3-1, are of interest in studying the involvement of cell wall-degrading enzymes in the establishment of plant–plant interactions. Host–parasite co-cultures in mini-rhizotron systems revealed that parasite attachments are twice as numerous and tubercle growth is quicker on Atpme3-1 roots than on WT roots. Compared to WT, the increased susceptibility in AtPME3-1 is associated with reduced PME activity in the roots and a lower degree of pectin methylesterification at the host–parasite interface, as detected immunohistochemically in infected roots. In addition, both WT and Atpme3-1 roots responded to infestation by modulating the expression of PAE- and PME-encoding genes, as well as related global enzyme activities in the roots before and after parasite attachment. However, these modulations differed between WT and Atpme3-1, which may contribute to different pectin remodeling in the roots and contrasting susceptibility to P. ramosa. With this integrative study, we aim to define a model of cell wall response to this specific biotic stress and indicate, for the first time, the role of PME3 in this parasitic plant–plant interaction.

Comparison of different attract-and-kill device densities to control the adult population of Popillia japonica (Coleoptera: Scarabaeidae).

Popillia japonica Newman is a scarab beetle native to Japan that is considered a serious pest outside its native range. It can feed on more than 400 host plants and spread about 10 km per year in invaded territories, therefore it is considered the second most important quarantine pest in Europe. Both chemical and biological insecticides have been used for control, with variable results. Despite ongoing efforts, P. japonica remains a threat in invaded countries, and it is necessary to test more effective and sustainable solutions in the context of integrated pest management. Here we present a study on long-lasting insecticide-treated nets (LLINs) assembled in semiochemical-baited attract-and-kill devices (A&Ks) as a means to control adults of P. japonica with low environmental impact. This study complements previous ones in which we first evaluated the effectiveness of the LLINs in the laboratory and then tested both effectiveness and duration in field-exposed A&Ks against P. japonica. In the present work we compared the effectiveness of three different densities of A&Ks per hectare in areas where the population of P. japonica was numerically homogeneous. The different densities of A&K (1, 2, 4 A&Ks per ha) resulted in an overall reduction of the population of P. japonica by about two thirds in comparison to the control area. This study suggests that the use of one A&K per hectare, requiring minimal management effort, is an effective ratio for reducing local populations of P. japonica. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Pseudomonas syringae pv. actinidiae Unique Effector HopZ5 Interacts with GF14C to Trigger Plant Immunity.

The bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is the most devastating disease threaten-ing the global kiwifruit production. This pathogen delivers multiple effector proteins into plant cells to resist plant immune re-sponses and facilitate their survival. Here, we focused on the unique effector HopZ5 in Psa, which previously has been reported to have virulence functions. In this study, our results showed that HopZ5 could cause macroscopic cell death and trigger a serious immune response by agroinfiltration in Nicotiana benthamiana, along with up-regulated expression of immunity-related genes and significant accumulation of reactive oxygen species and callose. Subsequently, we confirmed that HopZ5 interacted with the phosphoserine-binding protein, GF14C, in both the nonhost plant N. benthamiana (NbGF14C) and the host plant kiwifruit (AcGF14C), and silencing of NbGF14C compromised HopZ5-mediated cell death, suggesting GF14C played a crucial role in the detection of HopZ5. Further studies showed that overexpression of NbGF14C both markedly reduced the infection of Sclerotinia sclerotiorum and Phytophthora capsica in N. benthamiana and overexpression of AcGF14C significantly enhanced the re-sistance of kiwifruit against Psa, indicating that GF14C positively regulates plant immunity. Collectively, our results revealed that the virulence effector HopZ5 could be recognized by plants and interact with GF14C to activate plant immunity.

Salivary-secreted vitellogenin suppresses H2O2 burst of plants facilitating Recilia dorsalis leafhopper feeding.

Vitellogenin (Vg), known as the yolk protein precursor for oocyte development in female insects, can be secreted to plant host from salivary glands of hemipterans, including rice leafhopper Recilia dorsalis. The aim of this study was to investigate the function of salivary-secreted Vg of R. dorsalis (RdVg) in rice host. We propose that RdVg possibly regulates the rice defense against insects, benefiting R. dorsalis feeding. RdVg was released into rice phloem along with saliva during R. dorsalis feeding. Knocking down RdVg increased the level of H2O2 and improved H2O2 metabolism in rice plants, making it difficult for R. dorsalis to feed. The transient expression or overexpression of the lipoprotein N-terminal domain of RdVg (RdVg2) significantly reduced hydrogen peroxide (H2O2) metabolism in plants. This suggests that salivary-secreted RdVg acts as an effector suppressing the H2O2 burst in rice plants, and RdVg2 is the key domain. RdVg2 could interact with rice sulfite oxidase (OsSO), which catalyzes the oxidation of SO3 2- and produces H2O2. Exposure of rice plants to R. dorsalis, overexpression of RdVg2 or knocking out OsSO reduced OsSO accumulation and SO3 2- oxidation, benefiting R. dorsalis feeding. However overexpression of OsSO increased SO3 2- oxidation and H2O2 metabolism, inhibiting R. dorsalis feeding. RdVg inhibits H2O2 generation via suppressing OsSO accumulation, ultimately benefiting R. dorsalis feeding. These findings identify RdVg as an effector that suppresses plant defense to insects, and provide insights into the function of salivary-secreted Vg in other Hemiptera insects. © 2024 Society of Chemical Industry.

Evolution of Einkorn wheat centromeres is driven by the mutualistic interplay of two LTR retrotransposons

BackgroundCentromere function is highly conserved across eukaryotes, but the underlying centromeric DNA sequences vary dramatically between species. Centromeres often contain a high proportion of repetitive DNA, such as tandem repeats and/or transposable elements (TEs). Einkorn wheat centromeres lack tandem repeat arrays and are instead composed mostly of the two long terminal repeat (LTR) retrotransposon families RLG_Cereba and RLG_Quinta which specifically insert in centromeres. However, it is poorly understood how these two TE families relate to each other and if and how they contribute to centromere function and evolution.ResultsBased on conservation of diagnostic motifs (LTRs, integrase and primer binding site and polypurine-tract), we propose that RLG_Cereba and RLG_Quinta are a pair of autonomous and non-autonomous partners, in which the autonomous RLG_Cereba contributes all the proteins required for transposition, while the non-autonomous RLG_Quinta contributes GAG protein. Phylogenetic analysis of predicted GAG proteins showed that the RLG_Cereba lineage was present for at least 100 million years in monocotyledon plants. In contrast, RLG_Quinta evolved from RLG_Cereba between 28 and 35 million years ago in the common ancestor of oat and wheat. Interestingly, the integrase of RLG_Cereba is fused to a so-called CR-domain, which is hypothesized to guide the integrase to the functional centromere. Indeed, ChIP-seq data and TE population analysis show only the youngest subfamilies of RLG_Cereba and RLG_Quinta are found in the active centromeres. Importantly, the LTRs of RLG_Quinta and RLG_Cereba are strongly associated with the presence of the centromere-specific CENH3 histone variant. We hypothesize that the LTRs of RLG_Cereba and RLG_Quinta contribute to wheat centromere integrity by phasing and/or placing CENH3 nucleosomes, thus favoring their persistence in the competitive centromere-niche.ConclusionOur data show that RLG_Cereba cross-mobilizes the non-autonomous RLG_Quinta retrotransposons. New copies of both families are specifically integrated into functional centromeres presumably through direct binding of the integrase CR domain to CENH3 histone variants. The LTRs of newly inserted RLG_Cereba and RLG_Quinta elements, in turn, recruit and/or phase new CENH3 deposition. This mutualistic interplay between the two TE families and the plant host dynamically maintains wheat centromeres.

Species-specific microsymbiont discrimination mediated by a Medicago receptor kinase.

Host range specificity is a prominent feature of the legume-rhizobial symbiosis. Sinorhizobium meliloti and Sinorhizobium medicae are two closely related species that engage in root nodule symbiosis with legume plants of the Medicago genus, but certain Medicago species exhibit selectivity in their interactions with the two rhizobial species. We have identified a Medicago receptor-like kinase, which can discriminate between the two bacterial species, acting as a genetic barrier against infection by most S. medicae strains. Activation of this receptor-mediated nodulation restriction requires a bacterial gene that encodes a glycine-rich octapeptide repeat protein with distinct variants capable of distinguishing S. medicae from S. meliloti. This study sheds light on the coevolution of host plants and rhizobia, shaping symbiotic selectivity in their respective ecological niches.

Harmfulness and biological characters of a leaf beetle Gastrolina depressa (Coleoptera: Chrysomelidae) to its host plant Pterocarya stenoptera (Fagales: Juglandaceae)

Harmfulness and biological characters of a leaf beetle Gastrolina depressa (Coleoptera: Chrysomelidae) to its host plant Pterocarya stenoptera (Fagales: Juglandaceae)

Risk assessment of the laboratory host range and a molecular characterization determining the field host range of Lixus aemulus, for the biological control of Chromolaena odorata in South Africa

Chromolaena odorata (Asteraceae: Eupatorieae) is a sprawling shrub native to the Americas, and a destructive invader of much of the humid tropics and subtropics of the Old World. Opportunistic native-range exploration in 1995 identified a stem-boring weevil, Lixus aemulus, as a promising biological control candidate agent. Host-specificity testing was conducted on L. aemulus in South Africa using laboratory no-choice and paired-choice tests. Three invasive alien plants closely related to C. odorata may be utilized by L. aemulus but no indigenous, ornamental or crop species in South Africa will be attacked by the weevil. A native-range field survey was conducted in Brazil to determine the exact identity of the host plant L. aemulus had been collected in 1995, and to identify additional host-plant species. Genetic assessments of the Lixus sp.(p.). adults collected on the three host plants (C. odorata, Chromolaena laevigata and Heterocondylus vitalbae) reveal these individuals are L. aemulus and the weevil can be classed as an oligophage in its native range. Over 5,500 adults were released in South Africa, but establishment has been poor. A climate mismatch between the region of South Africa invaded by C. odorata and Rio Branco, Acre state, Brazil, seems the most likely explanation, but the extent of the native range of L. aemulus is unknown. Thus, it is uncertain whether L. aemulus can be collected from a population in an area with a more similar climate to South Africa.

Densovirus infection facilitates plant-virus transmission by an aphid.

The interactions among plant viruses, insect vectors, and host plants have been well studied; however, the roles of insect viruses in this system have largely been neglected. We investigated the effects of MpnDV infection on aphid and PVY transmission using bioassays, RNA interference (RNAi), and GC-MS methods and green peach aphid (Myzus persicae (Sulzer)), potato virus Y (PVY), and densovirus (Myzus persicae nicotianae densovirus, MpnDV) as model systems. MpnDV increased the activities of its host, promoting population dispersal and leading to significant proliferation in tobacco plants by significantly enhancing the titer of the sesquiterpene (E)-β-farnesene (EβF) via up-regulation of expression levels of the MpFPPS1 gene. The proliferation and dispersal of MpnDV-positive individuals were faster than that of MpnDV-negative individuals in PVY-infected tobacco plants, which promoted the transmission of PVY. These results combined showed that an insect virus may facilitate the transmission of a plant virus by enhancing the locomotor activity and population proliferation of insect vectors. These findings provide novel opportunities for controlling insect vectors and plant viruses, which can be used in the development of novel management strategies.

Plant growth promoting activities of endophytic bacteria from Melia azedarach (Meliaceae) and their influence on plant growth under gnotobiotic conditions

Bacteria that live asymptomatically within plant tissues are known as endophytes. Because of the close relation with the plant host, they have been a matter of interest for application as plant growth promoters. Melia azedarach is a widely distributed medicinal tree with proven insecticidal, antimicrobial, and antiviral activity. The aim of this study was to isolate and characterize endophytic bacteria from M. azedarach and analyze their plant growth promoting activities for the potential application as biological products. Bacteria were isolated from roots and leaves of trees growing in two locations of Northeastern Argentina. The isolates were characterized by repetitive extragenic palindromic sequence PCR and 16S rDNA sequence analysis. The plant growth-promoting activities were assayed in vitro, improvement of plant growth of selected isolates was tested on M. azedarach plantlets, and the effect of selected ACC deaminase producing isolates was tested on tomato seedlings under salt-stress conditions. The highest endophytic bacterial abundance and diversity were obtained from the roots. All isolates had at least one of the assayed plant growth-promoting activities and 80 % of them had antagonistic activity. The most efficient bacteria were Pseudomonas monteilii, Pseudomonas farsensis, Burkholderia sp. and Cupriavidus sp. for phosphate solubilization (2064 μg P ml−1), IAA production (94.7 μg ml−1), siderophore production index (5.5) and ACC deaminase activity (1294 nmol α-ketobutyrate mg−1 h−1). M. azedarach inoculation assays revealed the bacterial growth promotion potential, with Pseudomonas monteilii, Pseudomonas farsensis and Cupriavidus sp. standing out for their effect on leaf area, leaf dry weight, specific leaf area, and total Chl, Mg and N content, with increases of up to 149 %, 58 %, 65 %, 178 %, 76 % and 97.7 %, respectively, compared to NI plants. Efficient ACC deaminase-producing isolates increased stress tolerance of tomato plants under saline condition. Overall, these findings indicate the potential of the endophytic isolates as biostimulant and biocontrol agents.

Long-term strict ant-plant mutualism identity characterises growth rate and leaf shearing resistance of an Amazonian myrmecophyte

Over 125 million years of ant-plant interactions have culminated in one of the most intriguing evolutionary outcomes in life history. The myrmecophyte Duroia hirsuta (Rubiaceae) is known for its mutualistic association with the ant Myrmelachista schumanni and several other species, mainly Azteca, in the north-western Amazon. While both ants provide indirect defences to plants, only M. schumanni nests in plant domatia and has the unique behaviour of clearing the surroundings of its host tree from heterospecific plants, potentially increasing resource availability to its host. Using a 12-year survey, we asked how the continuous presence of either only M. schumanni or only Azteca spp. benefits the growth and defence traits of host trees. We found that the continuous presence of M. schumanni improved relative growth rates and leaf shearing resistance of Duroia better than trees with Azteca. However, leaf herbivory, dry matter content, trichome density, and secondary metabolite production were the same in all trees. Survival depended directly on ant association (> 94% of trees died when ants were absent). This study extends our understanding of the long-term effects of strict ant-plant mutualism on host plant traits in the field and reinforces the use of D. hirsuta–M. schumanni as a model system suitable for eco-co-evolutionary research on plant–animal interactions.

The RXLR effector PpE18 of Phytophthora parasitica is a virulence factor and suppresses peroxisome membrane-associated ascorbate peroxidase NbAPX3-1-mediated plant immunity.

Phytophthora parasitica causes diseases on a broad range of host plants. It secretes numerous effectors to suppress plant immunity. However, only a few virulence effectors in P. parasitica have been characterized. Here, we highlight that PpE18, a conserved RXLR effector in P. parasitica, was a virulence factor and suppresses Nicotiana benthamiana immunity. Utilizing luciferase complementation, co-immunoprecipitation, and GST pull-down assays, we determined that PpE18 targeted NbAPX3-1, a peroxisome membrane-associated ascorbate peroxidase with reactive oxygen species (ROS)-scavenging activity and positively regulates plant immunity in N. benthamiana. We show that the ROS-scavenging activity of NbAPX3-1 was critical for its immune function and was hindered by the binding of PpE18. The interaction between PpE18 and NbAPX3-1 resulted in an elevation of ROS levels in the peroxisome. Moreover, we discovered that the ankyrin repeat-containing protein NbANKr2 acted as a positive immune regulator, interacting with both NbAPX3-1 and PpE18. NbANKr2 was required for NbAPX3-1-mediated disease resistance. PpE18 competitively interfered with the interaction between NbAPX3-1 and NbANKr2, thereby weakening plant resistance. Our results reveal an effective counter-defense mechanism by which P. parasitica employed effector PpE18 to suppress host cellular defense, by suppressing biochemical activity and disturbing immune function of NbAPX3-1 during infection.

The value of pocket parks in preserving urban butterfly diversity

Butterflies, valued for their aesthetic and ecological value, are key subjects in urban biodiversity research. Our study focused on the often-overlooked roles of pocket parks, which are micro-greenspaces and small amusement parks open to the public. Despite their limited size, pocket parks are vital in maintaining the diversity of urban butterflies. We contrasted pocket park diversity with urban parks in Beijing, China. Next, using hierarchical clustering, we classified butterflies into exploiters, adapters, and avoiders based on how well they adapted to urban environments. Finally, we used Logistic regression and Poisson regression to build generalised linear models for all species and each of the three groups separately, allowing us to investigate the differences in the effects of variables from food resources and shelters on various butterfly groups in pocket parks. The results showed that although the primary restrictions differ depending on the group, pocket parks can serve as habitats for most species. Management intensity, pocket park area and nectar plants were significant variables for all species. The tourist intensity and host plants were variables that affected the presence of exploiters. Host plants, nectar plants, and management intensity all affected adapter diversity. Pocket parks’ area was only affected avoiders significantly. These results suggest that pocket parks have roles as source and sink habitats for exploiters and adapters and as stepping stones and corridors for most butterfly species inhabiting cities.

Botrytis cinerea combines four molecular strategies to tolerate membrane-permeating plant compounds and to increase virulence

Saponins are plant secondary metabolites comprising glycosylated triterpenoids, steroids or steroidal alkaloids with a broad spectrum of toxicity to microbial pathogens and pest organisms that contribute to basal plant defense to biotic attack. Secretion of glycosyl hydrolases that enzymatically convert saponins into less toxic products was thus far the only mechanism reported to enable fungal pathogens to colonize their saponin-containing host plant(s). We studied the mechanisms that the fungus Botrytis cinerea utilizes to be tolerant to well-characterized, structurally related saponins from tomato and Digitalis purpurea. By gene expression studies, comparative genomics, enzyme assays and testing a large panel of fungal (knockout and complemented) mutants, we unraveled four distinct cellular mechanisms that participate in the mitigation of the toxic activity of these saponins and in virulence on saponin-producing host plants. The enzymatic deglycosylation that we identified is novel and unique to this fungus-saponin combination. The other three tolerance mechanisms operate in the fungal membrane and are mediated by protein families that are widely distributed in the fungal kingdom. We present a spatial and temporal model on how these mechanisms jointly confer tolerance to saponins and discuss the repercussions of these findings for other plant pathogenic fungi, as well as human pathogens.

Ultraviolet-enhanced detoxification of chromate and protection of Brassica napus by Aspergillus sojae SH 20

The pervasive issue of heavy metal contamination in agricultural lands poses significant concerns and has wide-ranging implications for ecosystems. However, an encouraging solution lies in exploiting the potential of fungal endophytes to alleviate these detrimental effects. This study emphasized on improving the growth-promoting and chromium-alleviating capabilities of fungal endophytes, particularly Aspergillus sojae strain SH20, through ultraviolet (UV) irradiation. Following UV treatment, SH20 exhibited significantly enhanced growth-promoting and chromium-alleviating capabilities in comparison to its non-irradiated counterpart. Distinctly, the UV-treated SH20 strain demonstrated an improved ability to accumulate and reduce toxic chromate in the soil, effectively addressing the growth constraints imposed by elevated chromium levels in Brassica napus L. The UV-irradiated SH20 variant boosted shoot length up to 3 times that of the control. Similarly, this fungal strain displayed a remarkable increase in the total fresh weight of the seedlings, recording nearly 17 times greater than the control. The isolate treated with UV light reduced the absorption of chromium by about 3 times in the roots, helping the young plants to grow well even when exposed to chromate stress. A drop in root colonization by the UV-treated strain further resulted in reduced chromate absorption by the roots. Also, the strain showed great skill in boosting the host's antioxidant defenses by reducing the buildup of harmful reactive oxygen species (ROS), increasing the removal of ROS, and improving the plant's antioxidant levels, including phenols and flavonoids. When the host plants were exposed to 25 ppm of Cr stress, the UV-irradiated variant SH 20 stimulated the production of flavonoids (246 μg/ml) and phenols (952 μg/ml) in comparison to the control (with 220 μg/ml of flavonoids and 919 μg/ml of phenols). In conclusion, this report highlights how exposing the A. sojae strain SH20 to UV light has the potential to enhance its abilities to promote growth and bioremediate. This suggests a promising solution for addressing heavy metal contamination in agricultural lands.

Morphology of Neoheegeria dalmatica Schmutz, 1909 (Thysanoptera, Phlaeothripidae) larvae—their diagnostic characteristics

This paper presents morphological description and images of the larval instars of Neoheegeria dalmatica as well as observations on its life cycle and relationships with host plants in a temperate climate. It also compares characteristics of the second larval instar with those of Haplothrips verbasci, i.e. a species previously placed in the genus Neoheegeria. The main characteristic that differentiates the larvae of both species is, among others, the sculpture of their cuticle, which is smooth in H. verbasci and covered by dense microtrichia in N. dalmatica.

Further study of the genus Mycterothrips Trybom (Thysanoptera: Thripidae) in Japan, with description of a new species and a new record

Mycterothrips albiziae sp. n. is described from Albizia julibrissin in Japan. Mycterothrips auratus is newly recorded from Japan and redescribed, second instar larvae of M. fasciatus and M. japonicus are described for the first time. Host plants and character states variation of some Japanese species of Mycterothrips, an identification key to the Japanese species, and a list of world Mycterothrips species is also provided.