RESUMEN

Background: The Bostrichidae is a small family of Coleoptera, with up to 600 described species all over the world. Almost 90 species of the family have been recorded in China at present and several new species of powder-post beetles have been described in recent years. Since the 1940s, the family Bostrichidae has become a neglected group in the taxonomy research of the Chinese mainland compared with its extensive territorial and super complex ecological diversity. Thus, there is need for more field specimen collection and in-depth taxonomic study. New information: In this study, two powder-post beetles species Trogoxylonspinifrons (Lesne, 1910) and Mintheabivestita Lesne, 1937, are recorded for the first time from China. New provincial distribution records of another 18 Bostrichidae also listed.

RESUMEN

Background: In the last decades, climate change and globalisation have been exacerbating the introduction of non-native beetles worldwide. Due toits peculiar territory, climate and geographical position in the middle of the Mediterranean Basin, Italy is one of the European countries with the highest number of intercepted, adventive and established non-native beetles, some of which are invasive. In this perspective, producing new faunistic records and continuously updating reliable and easily accessible distributional data is a fundamental step in investigating and potentially preventing further species introduction. New information: The aim of this contribution is to report and discuss new faunistic records of non-native Coleoptera in Italy. For some species, new records enlarge the previously-known distribution (e.g. the ambrosia beetles Anisandrusmaiche (Kurentzov, 1941) and Cnestusmutilatus (Blandford, 1894) or the click beetle Monocrepidiusposticus (Eschscholtz, 1829)), while for others (e.g. the scarab beetle Archophileurusspinosus Dechambre, 2006), data confirm their establishment and highlight a possible expansion phase. The false powderpost beetles Ptilineurusmarmoratus (Reitter, 1877) and the longhorn beetle Xylotrechuschinensis (Chevrolat, 1852) are two new additions to the Italian fauna, while the establishment of the monotomid beetle Monotomaamericana Aubé 1837 is confirmed.

RESUMEN

The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), is a major global pest of cereal grains. Infestations are difficult to control as larvae feed inside grain kernels, and many populations are resistant to both contact insecticides and fumigants. We sequenced the genome of R. dominica to identify genes responsible for important biological functions and develop more targeted and efficacious management strategies. The genome was assembled from long read sequencing and long-range scaffolding technologies. The genome assembly is 479.1 Mb, close to the predicted genome size of 480.4 Mb by flow cytometry. This assembly is among the most contiguous beetle assemblies published to date, with 139 scaffolds, an N50 of 53.6 Mb, and L50 of 4, indicating chromosome-scale scaffolds. Predicted genes from biologically relevant groups were manually annotated using transcriptome data from adults and different larval tissues to guide annotation. The expansion of carbohydrase and serine peptidase genes suggest that they combine to enable efficient digestion of cereal proteins. A reduction in the copy number of several detoxification gene families relative to other coleopterans may reflect the low selective pressure on these genes in an insect that spends most of its life feeding internally. Chemoreceptor genes contain elevated numbers of pseudogenes for odorant receptors that also may be related to the recent ontogenetic shift of R. dominica to a diet consisting primarily of stored grains. Analysis of repetitive sequences will further define the evolution of bostrichid beetles compared to other species. The data overall contribute significantly to coleopteran genetic research.

Asunto(s)

RESUMEN

Insect-fungus mutualism is one of the better-studied symbiotic interactions in nature. Ambrosia fungi are an ecological assemblage of unrelated fungi that are cultivated by ambrosia beetles in their galleries as obligate food for larvae. Despite recently increased research interest, it remains unclear which ecological factors facilitated the origin of fungus farming, and how it transformed into a symbiotic relationship with obligate dependency. It is clear from phylogenetic analyses that this symbiosis evolved independently many times in several beetle and fungus lineages. However, there is a mismatch between palaeontological and phylogenetic data. Herein we review, for the first time, the ambrosia system from a palaeontological perspective. Although largely ignored, families such as Lymexylidae and Bostrichidae should be included in the list of ambrosia beetles because some of their species cultivate ambrosia fungi. The estimated origin for some groups of ambrosia fungi during the Cretaceous concurs with a known high diversity of Lymexylidae and Bostrichidae at that time. Although potentially older, the greatest radiation of various ambrosia beetle lineages occurred in the weevil subfamilies Scolytinae and Platypodinae during the Eocene. In this review we explore the evolutionary relationship between ambrosia beetles, fungi and their host trees, which is likely to have persisted for longer than previously supposed.

Asunto(s)

RESUMEN

Ambrosia beetles are small wood inhabiting members of the Curculionidae that have evolved obligate symbioses with fungi. The fungal symbionts concentrate nutrients from within infested trees into a usable form for their beetle partners, which then utilize the fungi as their primary source of nutrition. Ambrosia beetle species associate with one or more primary symbiotic fungal species, but they also vector auxiliary symbionts, which may provide the beetle with developmental or ecological advantages. In this study we isolated and identified ophiostomatalean fungi associated with ambrosia beetles occurring in a native forest area in South Africa. Using a modified Bambara beetle trap, living ambrosia beetle specimens were collected and their fungal symbionts isolated. Four beetle species, three Scolytinae and one Bostrichidae, were collected. Five species of ophiostomatalean fungi were isolated from the beetles and were identified using both morphological characters and DNA sequence data. One of these species, Raffaelea sulphurea, was recorded from South Africa for the first time and two novel species were described as Ceratocystiopsis lunata sp. nov. and Raffaelea promiscua sp. nov.

Asunto(s)

RESUMEN

Bark and ambrosia beetles, mainly the ones belonging to groups Scolytinae, Bostrichidae and Platypodinae, can kill trees from reforestation areas or native forests and damage the wood. Population monitoring and the identification of quarantine species are carried out by assembling ethanol-baited traps. The aims of the current study are to evaluate the influence of the color of ethanol-baited traps on the efficient capture of these insects, as well as to measure changes in colorimetric variables based on trap exposure in the field and to investigate whether these changes affect capture efficiency. Eight ethanolic traps (red, yellow, black and transparent traps - two of each color) were installed in a forest fragment in the first experimental stage ­ samples were collected on a weekly basis, for 11 months. New and used transparent traps were installed in the field in the second experimental stage - samples were collected for additional 11 months. A portable spectrophotometer was used to measure the colorimetric variables in these traps. The mean number of Scolytinae individuals (± SD) captured in transparent traps (48±50) was significantly higher than that of individuals captured in black (24±25), yellow (23±21) and red (22±21) traps. However, transparent traps subjected to field conditions were colonized by such as fungi, bacteria and mosses, which changed the transparent state of the traps into a darkened color and significantly affected their capture efficiency. The total number of 6,268 Scolytinae individuals were collected at this experimental stage: 4,977 of them were captured in new traps, whereas 1,291 were captured in the old ones. Based on the herein measured colorimetric variables, such color change got significantly intensified as transparent traps remained under field conditions. In conclusion, transparent traps were more efficient in capturing Scolytinae individuals than the black, yellow and red traps. In addition, the exposure to field conditions has progressively changed equipment color and decreased its capture efficiency.

Asunto(s)

RESUMEN

Primary pests such as Rhyzoperta dominica may increase the contents of dockage, dust, and frass in grain mass. Although it has been suggested that frass can affect the population growth of stored product pests and ecological interactions among primary and secondary pests in stored grain, this has not been validated experimentally. Therefore, this work experimentally tested the hypothesis that R. dominica wheat frass may support population increases in secondary pests such as Tribolium confusum, T. castaneum, and Oryzaephilus surinamensis for the first time. The effect of frass on secondary pest performance was compared with the effects of various physical qualities of wheat grain (i.e., intact grain kernels, grain fragments, flour, grain + frass) and an artificially enriched control diet (milled wheat kernels, oat flakes, and yeast). The results showed that the clean intact grain kernels did not support the population growth of any tested species, and the nutrient-rich control diet provided the best support. Frass was a significantly better food medium for O. surinamensis and T. castaneum than flour or cracked grain, while T. confusum performed equally well on flour and frass. Our results showed that in terms of food quality and suitability for the tested species, frass occupied an intermediate position between the optimized breeding diet and simple uniform cereal diets such as cracked grain or flour. The results suggest that (i) the wheat frass of primary pest R. dominica is a riskier food source for the development of the tested secondary pests than intact or cracked wheat grain or flour; (ii) frass has the potential to positively influence interspecific interactions between R. dominica and the tested secondary pests; and (iii) wheat grain should be cleaned if increases in R. dominica populations and/or accumulated frass are detected.

Asunto(s)

RESUMEN

A new species and a new genus of a microsporidium Alternosema bostrichidis isolated from an adult Prostephanus truncatus in Mexico and from three species of the genus Dinoderus in Nigeria are described. The microsporidium is monomorphic, monoxenic, and develops in direct contact with host cell cytoplasm. The infection first appears with thoracic muscles, followed by a generalized invasion of the host. All developmental stages are diplokaryotic. Sporogony is disporoblastic. Mature spores are ovoid. Unfixed spores measure 3.7-4.2 × 2.0-2.6 µm, fixed and stained spores 3.5-5.0 × 2.4-2.8 µm. The polaroplast consists of dense lamellae and rare lamellae. The polar tube is slightly anisofilar, consisting of 11-17 coils, with 9-14 proximal (130 nm in diameter) and 2-3 distal coils (120 nm in diameter) arranged in one layer. Molecular phylogenetic analysis based upon a short portion of small-subunit ribosomal RNA gene (Genbank accession # KP455651) placed the new microsporidium within Liebermannia-Orthosomella lineage, which contains multiple undescribed parasites. In particular, A. bostrichidis showed maximal sequence similarity of 95% to Microsporidium sp. BBRE2 (# FJ755987) from Baikalian Diplacanthus brevispinus (Amphipoda: Acanthogammaridae) and Microsporidium sp. Comp CD Van 2 (# KC111784) from compost and soil in Canada. Frequent, devastating epizootics of laboratory cultures of A. bostrichidis support its potential as a biological control agent of grain borers.

Asunto(s)

RESUMEN

Phthalides and their precursors have demonstrated a large variety of biological activities. Eighteen phthalides were synthesized and tested on the stored grain pest Rhyzopertha dominica. In the screening bioassay, compounds rac-(2R,2aS,4R,4aS,6aR,6bS,7R)-7-bromohexahydro-2,4-methano-1,6-dioxacyclopenta[cd]pentalen-5(2H)-one (15) and rac-(3R,3aR,4R,7S,7aS)-3-(propan-2-yloxy)hexahydro-4,7-methano-2-benzofuran-1(3H)-one (17) showed mortality similar to the commercial insecticide, Bifenthrin® (≥90 %). The time (LT50 ) and dose (LD50 ) necessary to kill 50 % of the R. dominica population were determined for the most efficacious phthalides 15 and 17. Compound 15 presented the lowest LD50 (1.97 µg g-1 ), being four times more toxic than Bifenthrin® (LD50 =9.11 µg g-1 ). Both compounds presented an LT50 value equal to 24 h. When applied at a sublethal dose, both phthalides (especially compound 15), reduced the emergence of the first progeny of R. dominica. These findings highlight the potential of phthalides 15 and 17 as precursors for the development of insecticides for R. dominica control.

Asunto(s)

RESUMEN

The lesser grain borer, Rhyzopertha dominica (Fabricius) is a primary pest of starch-containing stored products worldwide. Here, we report characterization of mitogenome of R. dominica and its phylogenetic position. Rhyzopertha dominica complete mitochondrial genome (GenBank accession number MN527959) from Jingziguan town consisted of a circular DNA molecule of 15,862 bp (with 74.36% A + T content). The mitogenome comprised of 13 protein-coding genes (PCGs), and 22 tRNA and two rRNA genes. PCGs had typical ATN (Met) initiation codons and were terminated by typical TAN stop codons.

RESUMEN

Three specimens of Stephanopachys quadricollis (Marseul, 1878) were recently found in Malta in UV light traps and represent the first record of this species for this country. Although Stephanopachys quadricollis is native to the Mediterranean basin, it is not yet clear if these Maltese records are due to a natural population or to an interception. Distributional, nomenclatural and biological data on this species are summarized, and a new synonymy is established: Stephanopachys quadricollis (Marseul, 1879) = Stephanopachys quadraticollis Kocher, 1956, syn. n.

RESUMEN

The incidence of auger beetle, Sinoxylon anale Lesne (Bostrichidae: Coleoptera), a destructive pest of cosmopolitan occurrence is reported for the first time on allspice trees, Pimenta dioica (L.) Merr. in Kerala, India. The insects bored through the basal region of fresh twigs resulting in dieback symptoms. Morphological characterization and sequencing of a partially amplified fragment of the mitochondrial CO1 gene (696bp) revealed the insect to be Sinoxylon anale. An entomopathogenic fungus was isolated from infected cadavers of S. anale that was identified as Beauveria bassiana (Bals.-Criv.) Vuill., sensu stricto (s.s.) (Ascomycota: Hypocreales) based on morphological and molecular studies. The partial sequences of the ITS, TUB, TEF and Bloc gene regions were sequenced. The fungus grew well in ambient room temperature conditions (28-32±2°C; 60-70% relative humidity) and the infection process on the insect was documented by scanning electron microscopy. Bioassay studies with the isolate indicated that the fungus was virulent against adult beetles as evidenced by the LC50 (3.6×10(6)conidia/ml) and ST50 values (6.8days at a dose of 1×10(7)conidia/ml and 5.8days at a dose of 1×10(8)conidia/ml, respectively). This is the first record of B. bassiana naturally infecting S. anale and the fungus holds promise to be developed as a mycoinsecticide.

Asunto(s)

RESUMEN

The Bostrichidae of the Maltese Islands are reviewed. Ten species are recorded with certainty from this Archipelago, of which 6 namely, Trogoxylonimpressum (Comolli, 1837), Amphicerusbimaculatus (A.G. Olivier, 1790), Heterobostrychusaequalis (Waterhouse, 1884), Sinoxylonunidentatum (Fabricius, 1801), Xyloperthellapicea (A.G. Olivier, 1790) and Apatemonachus Fabricius, 1775 are recorded for the first time. Two of the mentioned species (Heterobostrychusaequalis and Sinoxylonunidentatum) are alien and recorded only on the basis of single captures and the possible establishment of these species is discussed. Earlier records of Scobiciapustulata (Fabricius, 1801) from Malta are incorrect and should be attributed to Scobiciachevrieri (A. Villa & J.B. Villa, 1835). A zoogeographical analysis and an updated checklist of the 12 species of Bostrichidae recorded from the Maltese Islands and neigbouring Sicilian islands (Pantelleria, Linosa and Lampedusa) are also provided. Rhizoperthadominica(Fabricius, 1792)formgranulipennis Lesne in Beeson & Bhatia, 1937 from Uttarakhand (northern India) was overlooked by almost all subsequent authors. Its history is summarized and the following new synonymy is established: Rhizoperthadominica(Fabricius, 1792)formgranulipennis Lesne in Beeson & Bhatia, 1937 = Rhyzoperthadominica (Fabricius, 1792), syn. n. Finally, records of Amphicerusbimaculatus from Azerbaijan, of Bostrichuscapucinus (Linnaeus, 1758) from Jordan and Syria, of Scobiciachevrieri from Jordan and Italy, of Xyloperthellapicea from Italy, and of Apatemonachus from Corsica (France) and Italy, are also provided.

RESUMEN

We report ten new species records for the Coleoptera fauna of New Brunswick, Canada from the families Dermestidae, Endecatomidae, Bostrichidae, and Ptinidae. Anthrenus fuscus Olivier and Anthrenus museorum (Linnaeus) of the family Dermestidae are newly recorded for New Brunswick. Endecatomus rugosus (Randall) and the family Endecatomidae are recorded for the first time for New Brunswick and the Maritime provinces. Two Bostrichidae, the adventive Dinoderus minutus (Fabricius) and the native Stephanopachys substriatus (Paykull), are newly recorded for the province. Five species of Ptinidae, the adventive Anobium punctatum (DeGeer) and Microbregma emarginatum emarginatum (Duftschmid), and the native Hadrobregmus notatus (Say), Ptilinus lobatus Casey, and Ptilinus ruficornis Say are added to the faunal list of New Brunswick. Collection data, habitat data, and distribution maps are presented for all these species.