Improving biocontrol of black vine weevil (<Emphasis Type="Italic">Otiorhynchus sulcatus</Emphasis>) with entomopathogenic fungi in growing media by incorporating spent mushroom compost

Amending a peat-based growing medium with 10% v/v spent mushroom compost, a source of fungal chitin and other nutrients, prolonged the persistence of entomopathogenic fungi (Metarhizium brunneum Petsch and Beauveria bassiana (Balsamo) Vuillemin; Hypocreales: Clavicipitaceae). This resulted in improved efficacy of M. brunneum against black vine weevil, Otiorhynchus sulcatus F. (Coleoptera: Curculionidae) larvae compared with using inoculum without spent mushroom compost. B. bassiana only controlled larvae when used in combination with spent mushroom compost (75?±?7% reduction in live larvae). Mixing entomopathogenic fungal inoculum with spent mushroom compost and growing medium was as effective in controlling black vine weevil larvae as using spent mushroom compost colonised with M. brunneum or B. bassiana in the growing medium (80?±?12% reduction in live larvae). The former method is preferable since it does not require production and storage of colonised spent mushroom compost, or registration of new substrate formulations of M. brunneum or B. bassiana.     

Evaluation of <Emphasis Type="Italic">Nastus fausti</Emphasis> Reitter (Coleoptera: Curculionidae: Entiminae: Nastini) for biological control of invasive giant hogweeds (<Emphasis Type="Italic">Heracleum</Emphasis> spp.)

The weevil Nastus fausti Reitter (Coleoptera, Curculionidae) was evaluated for its potential in the biological control of invasive giant hogweeds (Heracleum spp.). Quantitative sampling suggested that at a high population density (more that 3–4 mature larvae per plant) damage by N. fausti larvae could have some negative impact on the above-ground part of the plant. However, no-choice laboratory tests showed that N. fausti females were able to feed on a number of Apiaceae genera, including such important cultivated crops as carrot, parsnip, and celeriac. Feeding on these plants did not cause any significant decrease in female survival or fecundity. Moreover, at least part of N. fausti larvae may feed and develop on roots of these plants, and the rate of their growth and development does not differ significantly from that in larvae fed on roots of H. mantegazzianum. N. fausti adult and larval feeding on Angelica purpurascens, representative of related genus of the same tribe, was recorded under natural conditions, too. In combination, these data suggest that N. fausti is an oligophagous species connected with plants from at least several genera of Apiaceae and thus it cannot be considered a potential agent for biological control of invasive Heracleum species.     

Regulatory activity of heterologous gene-activator <Emphasis Type="Italic">xlnR</Emphasis> of <Emphasis Type="Italic">Aspergillus niger</Emphasis> in <Emphasis Type="Italic">Penicillium canescens</Emphasis>

The gene encoding the xlnR xylanolytic activator of the heterologous fungus Aspergillus niger was incorporated into the Penicillium canescens genome. Integration of the xlnR gene resulted in the increase in a number of activities, i.e. endoxylanase, β-xylosidase, α-L-arabinofuranosidase, α-galactosidase, and feruloyl esterase, compared to the host P. canescens PCA 10 strain, while β-galactosidase, β-glucosidase, endoglucanase, and CMCase activities remained constant. Two different expression constructs were developed. The first consisted of the nucleotide sequence containing the mature P. canescens phytase gene under control of the axhA promoter region gene encoding A. niger (1,4)-β-D-arabinoxylan-arabinofuranohydrolase. The second construct combined the P. canescens phytase gene and the bgaS promoter region encoding homologous β-galactosidase. Both expression cassettes were transformed into P. canescens host strain containing xlnR. Phytase synthesis was observed only for strains with the bgaS promoter on arabinose-containing culture media. In conclusion, the bgaS and axhA promoters were regulated by different inducers and activators in the P. canescens strain containing a structural tandem of the axhA promoter and the gene of the xlnR xylanolytic activator.     

Effect of excretory-secretory products of some fouling organisms on settling and metamorphosis of the larvae of <Emphasis Type="Italic">Styela rustica</Emphasis> (Ascidiae)

The effect of the excretory-secretory products of some fouling animals on the settling and metamorphosis of larvae of the solitary ascidian Styela rustica was assessed. The substances secreted by the sponge Halichondria panicea stimulated settling of larvae, but concurrently blocked their metamorphosis. The excretory-secretory products of the mussel Mytilus edulis and the ascidian Molgula citrine did not affect settling of the S. rustica larvae but impeded their subsequent development. Water conditioned by the bivalve Hiatella arctica, stimulated settling and, apparently, metamorphosis of the larvae of S. rustica. The chemical substances produced by adult individuals of S. rustica facilitated settling of conspecific larvae but slightly delayed their metamorphosis.     

Carbohydrate Specificity of Antibodies against Phytopathogenic Fungi of the <Emphasis Type="Italic">Aspergillus</Emphasis> Genus

Brush rabbits were immunized with injections prepared from the fungi Aspergillus fumigatus, Aspergillus niger, and Aspergillus repens. A library of synthetic biotinylated oligosaccharides containing the key fragments of antigenic polysaccharides of the fungal cell wall—galctomannan, α- and β-glucans, mannan, and chitin—was used to analyze carbohydrate specificity. The anticarbohydrate antibodies obtained from animals immunized with preparations from A. fumigatus and A. repens predominantly recognized epitopes containing galactofuranoside residues, while the majority of the antibodies against A. niger bound the chitooligosaccharide ligand. These results are the basis for the identification of specific markers required for the development of immunoenzyme test systems.     

VeA of <Emphasis Type="Italic">Aspergillus niger</Emphasis> increases spore dispersing capacity by impacting conidiophore architecture

Aspergillus species are highly abundant fungi worldwide. Their conidia are among the most dominant fungal spores in the air. Conidia are formed in chains on the vesicle of the asexual reproductive structure called the conidiophore. Here, it is shown that the velvet protein VeA of Aspergillus niger maximizes the diameter of the vesicle and the spore chain length. The length and width of the conidiophore stalk and vesicle were reduced nearly twofold in a ΔveA strain. The latter implies a fourfold reduced surface area to develop chains of spores. Over and above this, the conidial chain length was approximately fivefold reduced. The calculated 20-fold reduction in formation of conidia by ΔveA fits the 8- to 17-fold decrease in counted spore numbers. Notably, morphology of the ΔveA conidiophores of A. niger was very similar to that of wild-type Aspergillus sydowii. This suggests that VeA is key in conidiophore architecture diversity in the fungal kingdom. The finding that biomass formation of the A. niger ΔveA strain was reduced twofold shows that VeA not only impacts dispersion capacity but also colonization capacity of A. niger.     

Identification and genomic analysis of antifungal property of a tomato root endophyte <Emphasis Type="Italic">Pseudomonas</Emphasis> sp. p21

Pseudomonas sp., which occupy a variety of ecological niches, have been widely studied for their versatile metabolic capacity to promote plant growth, suppress microbial pathogens, and induce systemic resistance in plants. In this study, a Pseudomonas sp. strain p21, which was isolated from tomato root endophytes, was identified as having antagonism against Aspergillus niger. Further analysis showed that this strain had the ability to biosynthesise siderophores and was less effective in inhibiting the growth of A. niger with the supplementation of Fe³⁺ in the agar medium. Genomic sequencing and the secondary metabolite cluster analysis demonstrated that Pseudomonas sp. p21 harboured 2 pyoverdine biosynthetic gene clusters, which encode compounds with predicted core structures and two variable tetra-peptide or eleven-peptide chains. The results indicated that siderophore-mediated competition for iron might be an important mechanism in Pseudomonas suppression of the fungal pathogen A. niger and in microbe-pathogen-plant interactions.     

Host Foraging Behavior of <Emphasis Type="Italic">Dastarcus helophoroides</Emphasis> (Coleoptera: Bothrideridae) Adults,a Coleopteran Parasitoid of <Emphasis Type="Italic">Monochamus alternatus</Emphasis> (Coleoptera: Cerambycidae)

Dastarcus helophoroides adults, a coleopteran parasitoid of Monochamus alternatus, were reared in the laboratory. The objectives of this paper are to investigate the host foraging behavior of D. helophoroides, and the evidence for learning in such behaviors. Choice and no-choice experiments were carried out. The choice experiments show that the number of D. helophoroides adults choosing the Pinus massoniana log infested with M. alternatus larvae was significantly higher than that choosing the blank (a flavorless simulative log made of brown kraftpaper), and the number of D. helophoroides adults choosing the uninfested P. massoniana log was also significantly higher than that choosing the blank. The no-choice experiment shows no significant difference between the number of D. helophoroides adults that chose the infested log and that chose the uninfested log, despite previous experience with uninfested log, infested log, or neither of them. No evidence of learning in host foraging behavior in D. helophoroides adults was found. The results indicate that the volatile chemicals emitted by uninfested P. massoniana logs and infested logs with M. alternatus larvae are equally attractive to D. helophoroides.     

Phenotypic and phylogenetic characterization of actinomycetes isolated from <Emphasis Type="Italic">Lasius niger</Emphasis> and <Emphasis Type="Italic">Formica cunicularia</Emphasis> ants

Multiple actinomycete strains were isolated from two ant species, Lasius niger and Formica cunicularia, and their phenotypic properties and phylogenetic position were studied. Partial sequencing of 16S rRNA assigned the greater part of them to the genus Streptomyces, but only one belonged to Nocardia. However, some isolates had significant color and morphological differences from their closest phylogenetic relatives. The abundance and biodiversity of actinomycete communities isolated from L. niger ants greatly exceeded those found for F. cunicularia. All of the actinomycetes associated with F. cunicularia ants demonstrated cellulolytic activity, but only one had such ability among the strains associated with black ants.     

Effect of <Emphasis Type="Italic">BBX-B8</Emphasis> overexpression on development,body weight,silk protein synthesis and egg diapause of <Emphasis Type="Italic">Bombyx mori</Emphasis>

Bombyxin (BBX) is an insulin-like peptide exists in the silkworm Bombyx mori. Our previous studies on the effects of inhibiting BBX-B8 expression found that BBX-B8 is important for the development of organ, reproduction and trehalose metabolism in the silkworms. In this paper, we investigated the expression profile of the BBX-B8 gene and effect of BBX-B8 overexpression on the development, body weight, silk protein synthesis and egg diapause of B. mori to further understand BBX-B8 functions. BBX-B8 gene expression could be detected in the brains, midguts, anterior silkglands, ovaries, testes, fat bodies, hemolymph, malpighian tubules and embryos by RT-PCR, however it was mainly expressed in the brain. Western blots showed that the change in BBX-B8 expression was not obvious in the brain of 1- to 4-day-old larvae of fifth instar silkworms, but expression increased substantially at 5- to 6-day-old larvae of fifth instar silkworms. Transgenic silkworms overexpressing BBX-B8 were obtained by introducing non-transposon transgenic vector pIZT-B8 containing a BBX-B8 gene driven by Orgyia pseudotsugata nucleopolyhedrovirus IE2 promoter into the genome. Development duration of the transgenic silkworms was delayed by 2.5–3.5 days. Cocoon shell weight of transgenic silkworms was reduced by 4.79 % in females and 7.44 % in males, pupal weight of transgenic silkworms was reduced 6.75 % in females and 13.83 % in males compared to non-transgenic silkworms, and 5.56–14.29 % of transgenic moths laid nondiapausing eggs. All results indicated that BBX-B8 plays an important role in the development, silk protein synthesis and egg diapause of silkworm.     

Histone acetyltransferase CBP-related H3K23 acetylation contributes to courtship learning in <Emphasis Type="Italic">Drosophila</Emphasis>

Background

Histone modifications are critical in regulating neuronal processes. However, the impacts of individual histone modifications on learning and memory are elusive. Here, we investigated the contributions of histone H3 lysine modifications to learning and memory in Drosophila by using histone lysine-to-alanine mutants.

Results

Behavioural analysis indicated that compared to the H3WT group, mutants overexpressing H3K23A displayed impaired courtship learning. Chromatin immunoprecipitation analysis of H3K23A mutants showed that H3K23 acetylation (H3K23ac) levels were decreased on learning-related genes. Knockdown of CREB-binding protein (CBP) decreased H3K23ac levels, attenuated the expression of learning-related genes, led to a courtship learning defect and altered development of the mushroom bodies. A decline in courtship learning ability was observed in both larvae and adult treatments with ICG-001. Furthermore, treatment of Drosophila overexpressing mutated H3K23A with a CBP inhibitor did not aggravate the learning defect.

Conclusions

H3K23ac, catalysed by the acetyltransferases dCBP, contributes to Drosophila learning, likely by controlling the expression of specific genes. This is a novel epigenetic regulatory mechanism underlying neuronal behaviours.

     

New data on larvae of weevils of the genus <Emphasis Type="Italic">Lixus</Emphasis> (Coleoptera,Curculionidae) from central Asia

Larvae are described for the first time for three species of the genus Lixus (L. bifasciatus, L. rubicundus, and L. subulatus). The larvae dwell in stalks of herbaceous plants. The larvae differ in the structure of the endocarina and prelabium and the chaetotaxy of the head and epipharynx. Analysis of larvae of the new and already described species of this genus has shown that the larva of L. bifasciatus shares some characters with the larvae of L. astrachanicus, and L. rubicundus, and the larva of L. subulatus, with that of L. bescrensis.     

The influence of density-dependent factors on larval development in native and invasive populations of <Emphasis Type="Italic">Harmonia axyridis</Emphasis> (Pall.) (Coleoptera,Coccinellidae)

Effects of the number of larvae per Petri dish (1, 5, and 10) on the preimaginal development of individuals of the native (Irkutsk, southern Siberia) and invasive (Sochi, the Northern Caucasus) populations of the multicolored Asian ladybird Harmonia axyridis were investigated in the laboratory. The experiments were conducted under short (12 h) and long (18 h) day conditions; the larvae were fed on the green peach aphid Myzus persicae or on the eggs of the grain moth Sitotroga cerealella. An increase in the number of larvae developed in one Petri dish resulted in a significant decrease in the rate of development in individuals from both populations which fed on aphids. Survival decreased with an increase in the number of larvae developed in one Petri dish fed on both prey species, but only in larvae from the invasive population of H. axyridis. The weight of emerging adults decreased with the number of larvae per dish in individuals from both study populations, but only when fed on aphids. These data suggest that the influence of density-dependent factors on the development of H. axyridis depends significantly on larval prey species. In addition, larvae from the invasive population have somewhat more aggressive interactions with competitors, this possibly having been one of the prerequisites for invasion.     

Consequences of the arms race between <Emphasis Type="Italic">Maculinea teleius</Emphasis> social parasite and <Emphasis Type="Italic">Myrmica</Emphasis> host ants for myrmecophilous butterfly conservation

The arms race between Maculinea butterflies and Myrmica host ants leads to local host-parasite adaptations. In our study, we assessed whether sympatric and allopatric Myrmica scabrinodis populations exhibit behavioural differences towards Maculinea teleius larvae during the adoption-period when butterfly larvae need to be taken inside the Myrmica nest. The second aim was to assess the butterfly survival rate inside ant colonies from different populations. We used one sympatric host population and three allopatric populations: one infested by M. teleius and two uninfested populations. We found that ants from the sympatric population showed a higher number of positive behaviours toward M. teleius larvae during adoption than ants from the allopatric populations. There were no differences in the number of inspection or negative behaviour events. The survival of butterfly larvae was highest inside sympatric host colonies and differed from the survival of M. teleius reared by ants from the allopatric, uninfested populations. No difference was found for the survival rate of M. teleius raised by infested, allopatric host colonies compared to sympatric host populations. Our results suggest the lack of behavioural counter-adaptations of local hosts of M. teleius that more easily adopt and rear butterfly caterpillars compared to naive M. scabrinodis colonies. Our results may also have implications for Maculinea butterfly conservation, especially for reintroduction programmes. We suggest that the existence of behavioural host defences should be checked for the source host population, as well as for the Myrmica population from the reintroduction site. It may also be reasonable to introduce several Myrmica host colonies from the source butterfly host population.     

Larvae of three sea spider species of the genus <Emphasis Type="Italic">Nymphon</Emphasis> (Arthropoda: Pycnogonida) from the White Sea

Larvae of three Nymphon species are described. For Nymphon brevirostre Hodge, 1863 and Nymphon micronyx Sars, 1888 protonymphon larvae are examined, larvae of N. micronyx have been studied for the first time. The fine external morphology of larvae is studied in detail using SEM methods; the internal structure of N. brevirostre protonymphon is additionally described. SEM data on external morphology and fine surface structures are given for several postembryonic stages of Nymphon grossipes Fabricius, 1780. Different types of postembryonic development are revealed in examined Nymphon species. N. brevirostre and N. micronyx have a “typical protonymphon” developmental pathway. A special developmental pathway named “lecithotrophic protonymphon” is suggested for N. grossipes and other Nymphonidae having large yolky eggs.     

Laboratory and simulated-field bioassays for assessing mixed cultures of <Emphasis Type="Italic">Lysinibacillus sphaericus</Emphasis> against <Emphasis Type="Italic">Aedes aegypti</Emphasis> (Diptera: Culicidae) larvae resistant to temephos

Aedes aegypti (L.) is the main vector of tropical diseases such as dengue, chikungunya and Zika. Due to the overuse of insecticides, Ae. aegypti resistant populations have increased. Biological control with Lysinibacillus sphaericus (Ahmed) has been used against Culex sp. and Anopheles sp. Although Ae. aegypti is refractory to the binary toxin of L. sphaericus spores, vegetative cells have been shown to be effective against Ae. aegypti larvae. In this work, the effect of L. sphaericus vegetative cells on Ae. aegypti temephos-resistant larvae was assessed under lab and simulated field conditions. L. sphaericus caused about 90% mortality of insecticide-resistant Ae. aegypti larvae under simulated field conditions. Likewise, Ae. aegypti larvae were more sensitive to mixed cultures of L. sphaericus than to individual strains; then, the most effective mixed culture exhibited an LC₅₀ of 1.21 × 10⁵ CFU/mL with Rockefeller larvae and 8.04 × 10⁴ CFU/mL with field-collected larvae. Additionally, we found that mixed cultures composed of two L. sphaericus strains were more effective than a culture formed by the three strains. Our results suggest that mixed cultures comprising L. sphaericus vegetative cells could be useful for controlling temephos-resistant populations of Ae. aegypti, as evidenced by the effectiveness demonstrated under laboratory and simulated field conditions.     

Survival possibilities of the dragonfly <Emphasis Type="Italic">Aeshna viridis</Emphasis> (Insecta,Odonata) in southern Sweden predicted from dispersal possibilities

We use public records from 1980 to 2014 to analyse survival of the EU Annex IV species Aeshna viridis in Sweden, a dragonfly strongly associated with the plant Stratiotes aloides. We clustered localities with S. aloides based on assumed dispersal abilities of A. viridis, using a dispersing radius of 2–100 km, calculating the proportion of sites with S. aloides that A. viridis is able to reach. If mean dispersal capability is high (40 km or above) 92.6 % or more of the localities are connected. For a good disperser, the probability of long-time survival is good. We further analysed the species richness of other Odonata and aquatic plants at 98 localities from the dataset. A. viridis co-occurred with more Odonata in the presence of S. aloides and running water but not in lakes. S. aloides sites had a higher number of other aquatic plants. Area had no impact on the occurrence of the species. For the present situation we surveyed 32 localities with known occurrence of the species. Only half of the sites for S. aloides contained any specimens while A. viridis occurred in the same number of sites. The species co-occurred in only 8 of 32 sites. In four sites A. viridis larvae appeared among Menyanthes trifoliata, Phragmites australis, Potamogeton natans and Sphagnum spp., indicating that at high latitudes A. viridis breeds among other species. Indirect monitoring based only on S. aloides would underestimate the number of populations of the dragonfly.     

Optimization of Methodology for Rearing <Emphasis Type="Italic">Spodoptera albula</Emphasis> on Artificial Diet

Advances in techniques for rearing insects on artificial diets are fundamental to solving issues of basic and applied entomology. In this study, we evaluated the development of Spodoptera albula (Walker) (Lepidoptera: Noctuidae) on three artificial diets used for other species of Lepidoptera, at three larval densities, and two densities of adult couples housed in oviposition cages of two sizes, with the aim of optimizing methodology for rearing S. albula in the laboratory. Biological parameters were recorded from S. albula, and a fitness index was calculated based on the larval survival and duration and weight of pupae. The total and daily oviposition was recorded using 5 or 10 adult couples of S. albula housed in two cage sizes. Concentrations of total nitrogen and protein in the tested diets were determined. Development of S. albula was completed in all artificial diets; however, the diet used for rearing Anticarsia gemmatalis (Hübner) larvae was the most suitable for S. albula, yielding intermediate development time and higher survival relative to the other diets. Individualization of larvae favored S. albula development by producing overall greater weights of larvae and pupae, higher survival rates, and longer adult longevity. Cage size and number of couples per cage did not influence S. albula fecundity in the experiment conditions. Spodoptera albula can be satisfactorily reared on the artificial diet used for A. gemmatalis, using one larva per tube, and either density of adults at any cage size. Additional amendments are needed in the rearing methodology to achieve optimal conditions for larval development to adulthood.