Search Results (15)

Vitellogenin (Vg) and the vitellogenin receptor (VgR) play essential roles in insect reproductive development. However, the functions of Vg and VgR genes in Lasioderma serricorne, an important insect pest of stored products, are unknown. We identified and characterized these two genes, designated LsVg and LsVgR, in L. serricorne. The open reading frames of LsVg and LsVgR were 5232 and 5529 bp, encoding 1743 and 1842 amino acid residues, respectively. Both LsVg and LsVgR were predominantly expressed in female adults and exhibited the highest expression in ovaries. The RNAi-mediated silencing of LsVg or LsVgR significantly decreased the average length of ovarian tubes and oocytes and severely affected ovarian development. The Knockdown of LsVg or LsVgR significantly reduced the oviposition period, the number of eggs laid, and the egg hatching rate. Females injected with dsLsVg and dsLsVg + VgR were found to had decreased vitellogenin content. The co-silencing of LsVg and LsVgR had a more pronounced effect on reducing the oviposition period and female fecundity in L. serricorne. This study revealed the importance of LsVg and LsVgR in regulating female reproduction and shows their potential as targets for RNAi-based control of L. serricorne. Full article

Food storage has been important since the dawn of agriculture and human settlement. Insect pests cause major losses to food grains during storage and production. Essential oils are good alternatives for chemical insecticides for the management of storage pests. Red bottlebrush, Callistemon lanceolatus, is a flowering plant of the Myrtaceae family. This research work aimed to extract the oil from bottlebrush leaves, and chemically characterize and assess their repellent and insecticidal properties against the cowpea seed beetle, Callasobruchus maculatus (F.) (Coleoptera: Chrysomelidae), cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Ptinidae), and red flour beetle, Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae), for the first time. The essential oil yielded by hydro-distillation of bottlebrush leaves was 1.02 ± 0.01%. GC-MS analysis determined the chemical composition of the volatile oil comprised 1,8-cineole (19.17%), α-terpineol (11.51%), α-pinene (10.28%), and α-Phellandrene (9.55%). The C. lanceolatus leaf oil showed potent repellence, contact toxicity, and fumigation toxic effects. In the contact toxicity assay, at 24 h, the LC₅₀ values were 1.35, 0.52, and 0.58 mg/cm² for the red flour beetle, cigarette beetle, and cowpea seed beetle, respectively. Likewise, in the fumigation assay observed after 24 h, LC₅₀ values of 22.60, 5.48, and 1.43 µL/L air were demonstrated for the red flour beetle, cigarette beetle, and cowpea seed beetle, respectively. Additionally, there was no significance found by a phytotoxicity assay when the paddy seeds were exposed to C. lanceolatus oil. The results show that the volatile oils from red bottlebrush leaves have the potential to be applied as a biopesticide. Therefore, C. lanceolatus leaf oil can be utilized as a bio-insecticide to control stored product insects. Full article

In this study, a basic insect detection system consisting of a manual-focus camera, a Jetson Nano—a low-cost, low-power single-board computer, and a trained deep learning model was developed. The model was validated through a live visual feed. Detecting, classifying, and monitoring insect pests in a grain storage or food facility in real time is vital to making insect control decisions. The camera captures the image of the insect and passes it to a Jetson Nano for processing. The Jetson Nano runs a trained deep-learning model to detect the presence and species of insects. With three different lighting situations: white LED light, yellow LED light, and no lighting condition, the detection results are displayed on a monitor. Validating using F1 scores and comparing the accuracy based on light sources, the system was tested with a variety of stored grain insect pests and was able to detect and classify adult cigarette beetles and warehouse beetles with acceptable accuracy. The results demonstrate that the system is an effective and affordable automated solution to insect detection. Such an automated insect detection system can help reduce pest control costs and save producers time and energy while safeguarding the quality of stored products. Full article

Hormone receptor 3 (HR3), an early-late gene of the 20-hydroxyecdysone (20E) signaling pathway, plays a critical role in insect metamorphosis and development. In this study, we identified and characterized an HR3 gene (LsHR3) from the cigarette beetle, Lasioderma serricorne. The open reading frame of LsHR3 is 1581 bp encoding a 527 amino acid protein that contains a conserved DNA binding domain and a ligand binding domain. LsHR3 was mainly expressed in the fourth-instar larvae, prepupae, and pupae and showed high expression in the fat body. The expression of LsHR3 was induced by 20E, while it was significantly suppressed by silencing of six 20E synthesis and signaling pathway genes. RNA interference (RNAi)-aided knockdown of LsHR3 in the fourth-instar larvae disrupted the larval–pupal molting and caused 100% mortality. The 20E titer of LsHR3-depletion larvae was decreased, and expressions of five 20E synthesis genes were dramatically decreased. Silencing LsHR3 reduced chitin content and downregulated the expression of genes involved in chitin synthesis and degradation. Hematoxylin and eosin staining of abdominal cuticle showed that no apolysis occurred after silencing LsHR3. These results suggest that LsHR3-mediated 20E signaling is involved in the regulation of chitin metabolism during the molting process of L. serricorne, and targeting this gene by RNAi has potential in controlling this pest. Full article

The cigarette beetle Lasioderma serricorne (Fabricius) is a major pest of stored products worldwide, especially tobacco and foods, causing huge economic losses. This study aimed to experimentally investigate the population dynamics of this pest at different temperatures and provide theoretical input for its control. Populations of L. serricorne were established under laboratory conditions at five temperatures (21 °C, 24 °C, 27 °C, 30 °C, and 33 °C). Results showed that an increasing temperature significantly affected the developmental time, longevity, oviposition period, and fecundity of L. serricorne. Both the longevity and fecundity of adult beetles were significantly reduced as the temperature increased. High temperatures significantly reduced the total duration of the preoviposition period but prolonged the oviposition period of L. serricorne. Increasing the temperatures from 21 °C to 33 °C significantly influenced the life table parameters of L. serricorne. The intrinsic increase rate (r), finite increase rate (λ), and gross reproductive rate (GRR) all increased with a greater rearing temperature, but mean generation time (T) was significantly shortened. To our best knowledge, this is the first report to detail the entire life history of the cigarette beetle in response to different temperatures when reared on tobacco dry leaves. This finding may provide basic information on the occurrence of L. serricorne in a warehouse setting and its mass rearing. Full article

The cigarette beetle, Lasioderma serricorne F. (Coleoptera: Anobiidae) is an important food storage pest affecting the tobacco industry and is increasingly impacting museums and herbaria. Monitoring methods make use of pheromone traps which can be implemented using chili fruit powder. The objective of this study was to assess the response of L. serricorne to the volatile organic compounds (VOCs) from different chili powders in order to identify the main semiochemicals involved in this attraction. Volatiles emitted by Capsicum annuum, C. frutescens, and C. chinense dried fruit powders were tested in an olfactometer and collected and analyzed using SPME and GC-MS. Results indicated that C. annuum and C. frutescens VOCs elicit attraction toward L. serricorne adults in olfactometer, while C. chinense VOCs elicit no attraction. Chemicals analysis showed a higher presence of polar compounds in the VOCs of C. annuum and C. frutescens compared to C. chinense, with α-ionone and β-ionone being more abundant in the attractive species. Further olfactometer bioassays indicated that both α-ionone and β-ionone elicit attraction, suggesting that these compounds are candidates as synergistic attractants in pheromone monitoring traps for L. serricorne. Full article

While the majority of symbiosis research is focused on bacteria, microbial eukaryotes play important roles in the microbiota and as pathogens, especially the incredibly diverse Fungi kingdom. The recent emergence of widespread pathogens in wildlife (bats, amphibians, snakes) and multidrug-resistant opportunists in human populations (Candida auris) has highlighted the importance of better understanding animal–fungus interactions. Regardless of their prominence there are few animal–fungus symbiosis models, but modern technological advances are allowing researchers to utilize novel organisms and systems. Here, I review a forgotten system of animal–fungus interactions: the beetle–fungus symbioses of Drugstore and Cigarette beetles with their symbiont Symbiotaphrina. As pioneering systems for the study of mutualistic symbioses, they were heavily researched between 1920 and 1970, but have received only sporadic attention in the past 40 years. Several features make them unique research organisms, including (1) the symbiont is both extracellular and intracellular during the life cycle of the host, and (2) both beetle and fungus can be cultured in isolation. Specifically, fungal symbionts intracellularly infect cells in the larval and adult beetle gut, while accessory glands in adult females harbor extracellular fungi. In this way, research on the microbiota, pathogenesis/infection, and mutualism can be performed. Furthermore, these beetles are economically important stored-product pests found worldwide. In addition to providing a historical perspective of the research undertaken and an overview of beetle biology and their symbiosis with Symbiotaphrina, I performed two analyses on publicly available genomic data. First, in a preliminary comparative genomic analysis of the fungal symbionts, I found striking differences in the pathways for the biosynthesis of two B vitamins important for the host beetle, thiamine and biotin. Second, I estimated the most recent common ancestor for Drugstore and Cigarette beetles at 8.8–13.5 Mya using sequence divergence (CO1 gene). Together, these analyses demonstrate that modern methods and data (genomics, transcriptomes, etc.) have great potential to transform these beetle–fungus systems into model systems again. Full article

The susceptibility of Lasioderma serricorne to phosphine (PH₃), ethyl formate (EF) and their combination (PH₃ + EF) was evaluated in this study. Eggs, larvae, pupae and adults were subjected to treatment with fumigants to determine the 90% lethal concentration time (LCt₉₀) values. Treatment with PH₃ for 20 h resulted in LCt₉₀ values of 1.15, 1.39, 14.97 and 1.78 mg h/L while treatment with EF resulted in values of 157.96, 187.75, 126.06 and 83.10 mg h/L, respectively. By contrast, the combination of PH₃ + EF resulted in LCt₉₀ values of 36.05, 44.41, 187.17 and 35.12 mg h/L after 4 h. These results show that, through treatment with PH₃ + EF, control can be achieved at lower concentrations than for treatment with EF alone and at lower exposure times than for treatment with PH₃ alone. The sorption rates of the fumigants on cured tobacco leaves were determined for filling ratios of 2.5%, 5.0% and 10.0% (w/v). Cured tobacco leaves were treated with either 2 mg/L PH₃, 114 mg/L EF or 0.5 mg/L PH₃ + 109 mg/L EF. Treatment with PH₃ showed sorption rates of 0.0%, 7.1% and 14.3%. EF, however, showed higher sorption rates of 64.9%, 68.5% and 75.5%, respectively, for the indicated filling ratios. When PH₃ and EF were combined, the sorption rate of PH₃ was 0.0%, while the sorption rates of EF were lower (9.1%, 12.0% and 23.2%) than treatment with only EF. EF required a ventilation time of longer than 22 h to desorb from cured tobacco leaves. Therefore, PH₃ + EF can effectively control L. serricorne in cured tobacco leaves, with sufficient ventilation time required after treatment for the safety of workers. Full article

Chitin deacetylases (CDAs) are chitin-modifying enzymes known to play vital roles in insect metamorphosis and development. In this study, we identified and characterized a chitin deacetylase 1 gene (LsCDA1) from the cigarette beetle Lasioderma serricorne. LsCDA1 contains a 1614 bp open reading frame encoding a protein of 537 amino acids that includes domain structures typical of CDAs. LsCDA1 was mainly expressed in the late larval and late pupal stages. In larval tissues, the highest level of LsCDA1 was detected in the integument. The expression of LsCDA1 was induced by 20-hydroxyecdysone (20E) in vivo, and it was significantly suppressed by knocking down the expression of ecdysteroidogenesis genes and 20E signaling genes. RNA interference (RNAi)-aided silencing of LsCDA1 in fifth-instar larvae prevented the larval–pupal molt and caused 75% larval mortality. In the late pupal stage, depletion of LsCDA1 resulted in the inhibition of pupal growth and wing abnormalities, and the expression levels of four wing development-related genes (LsDY, LsWG, LsVG, and LsAP) were dramatically decreased. Meanwhile, the chitin contents of LsCDA1 RNAi beetles were significantly reduced, and expressions of three chitin synthesis pathway genes (LsTRE1, LsUAP1, and LsCHS1) were greatly decreased. The results suggest that LsCDA1 is indispensable for larval–pupal and pupal–adult molts, and that it is a potential target for the RNAi-based control of L. serricorne. Full article

The present study was conducted to establish an electrostatic-based experimental system to enable new investigations of insect behavior. The instrument consists of an insulated conducting copper ring (ICR) linked to a direct current voltage generator to supply a negative charge to an ICR and a grounded aluminum pole (AP) passed vertically through the center of the horizontal ICR. An electric field was formed between the ICR and the AP. Rice weevil (Sitophilus oryzae) was selected as a model insect due to its habit of climbing erect poles. The electric field produced a force that could be imposed on the insect. In fact, the negative electricity (free electrons) was forced out of the insect to polarize its body positively. Eventually, the insect was attracted to the oppositely charged ICR. The force became weaker on the lower regions of the pole; the insects sensed the weaker force with their antennae, quickly stopped climbing, and retraced their steps. These behaviors led to a pole-ascending–descending action by the insect, which was highly reproducible and precisely corresponded to the changed expansion of the electric field. Other pole-climbing insects including the cigarette beetle (Lasioderma serricorne), which was shown to adopt the same behavior. Full article

β-N-acetylglucosaminidases (NAGs) are carbohydrate enzymes that degrade chitin oligosaccharides into N-acetylglucosamine monomers. This process is important for chitin degradation during insect development and metamorphosis. We identified and evaluated a β-N-acetylglucosaminidase 2 gene (LsNAG2) from the cigarette beetle, Lasioderma serricorne (Fabricius). The full-length open reading frame of LsNAG2 was 1776 bp and encoded a 591 amino acid protein. The glycoside hydrolase family 20 (GH20) catalytic domain and an additional GH20b domain of the LsNAG2 protein were highly conserved. Phylogenetic analysis revealed that LsNAG2 clustered with the group II NAGs. Quantitative real-time PCR analyses showed that LsNAG2 was expressed in all developmental stages and was most highly expressed in the late larval and late pupal stages. In the larval stage, LsNAG2 was predominantly expressed in the integument. Knockdown of LsNAG2 in fifth instar larvae disrupted larval–pupal molting and reduced the expression of four chitin synthesis genes (trehalase 1 (LsTRE1), UDP-N-acetylglucosamine pyrophosphorylase 1 and 2 (LsUAP1 and LsUAP2), and chitin synthase 1 (LsCHS1)). In late pupae, LsNAG2 depletion resulted in abnormal adult eclosion and wing deformities. The expression of five wing development-related genes (teashirt (LsTSH), vestigial (LsVG), wingless (LsWG), ventral veins lacking (LsVVL), and distal-less (LsDLL)) significantly declined in the LsNAG2-depleted beetles. These findings suggest that LsNAG2 is important for successful molting and wing development of L. serricorne. Full article

Small heat shock proteins (sHsps) are molecular chaperones that play crucial roles in the stress adaption of insects. In this study, we identified and characterized four sHsp genes (LsHsp19.4, 20.2, 20.3, and 22.2) from the cigarette beetle, Lasioderma serricorne (Fabricius). The four cDNAs encoded proteins of 169, 180, 181, and 194 amino acids with molecular weights of 19.4, 20.2, 20.3, and 22.2 kDa, respectively. The four LsHsp sequences possessed a typical sHsp domain structure. Quantitative real-time PCR analyses revealed that LsHsp19.4 and 20.3 transcripts were most abundant in pupae, whereas the transcript levels of LsHsp20.2 and 22.2 were highest in adults. Transcripts of three LsHsp genes were highly expressed in the larval fat body, whereas LsHsp20.2 displayed an extremely high expression level in the gut. Expression of the four LsHsp genes was dramatically upregulated in larvae exposed to 20-hydroxyecdysone. The majority of the LsHsp genes were significantly upregulated in response to heat and cold treatments, while LsHsp19.4 was insensitive to cold stress. The four genes were upregulated when challenged by immune triggers (peptidoglycan isolated from Staphylococcus aureus and from Escherichia coli 0111:B4). Exposure to CO₂ increased LsHsp20.2 and 20.3 transcript levels, but the LsHsp19.4 transcript level declined. The results suggest that different LsHsp genes play important and distinct regulatory roles in L. serricorne development and in response to diverse stresses. Full article

To develop natural product resources to control cigarette beetles (Lasioderma serricorne), the essential oil from Artemisia lavandulaefolia (Compositae) was investigated. Oil was extracted by hydrodistillation of the above-ground portion of A. lavandulaefolia and analyzed using gas chromatography-mass spectrometer (GC-MS). Extracted essential oil and three compounds isolated from the oil were then evaluated in laboratory assays to determine the fumigant, contact, and repellent efficacy against the stored-products’ pest, L. serricorne. The bioactive constituents from the oil extracts were identified as chamazulene (40.4%), 1,8-cineole (16.0%), and β-caryophyllene (11.5%). In the insecticidal activity assay, the adults of L. serricorne were susceptible to fumigant action of the essential oil and 1,8-cineole, with LC₅₀ values of 31.81 and 5.18 mg/L air. The essential oil, 1,8-cineole, chamazulene, and β-caryophyllene exhibited contact toxicity with LD₅₀ values of 13.51, 15.58, 15.18 and 35.52 μg/adult, respectively. During the repellency test, the essential oil and chamazulene had repellency approximating the positive control. The results indicated that chamazulene was abundant in A. lavandulaefolia essential oil and was toxic to cigarette beetles. Full article

Insect pests are responsible for substantial damage to museum objects, historic books and in buildings like palaces or historic houses. Different wood boring beetles (Anobium punctatum, Hylotrupes bajulus, Lyctus sp. or introduced species), the biscuit beetle (Stegobium paniceum), the cigarette beetle (Lasioderma serricorne), different Dermestides (Attagenus sp., Anthrenus sp., Dermestes sp., Trogoderma sp.), moths like the webbing clothes moth (Tineola bisselliella), Silverfish (Lepisma saccharina) and booklice (Psocoptera) can damage materials, objects or building parts. They are the most common pests found in collections in central Europe, but most of them are distributed all over the world. In tropical countries, termites, cockroaches and other insect pests are also found and result in even higher damage of wood and paper or are a commune annoyance in buildings. In this short review, an introduction to Integrated Pest Management (IPM) in museums is given, the most valuable collections, preventive measures, monitoring in museums, staff responsible for the IPM and chemical free treatment methods are described. In the second part of the paper, the most important insect pests occurring in museums, archives, libraries and historic buildings in central Europe are discussed with a description of the materials and object types that are mostly infested and damaged. Some information on their phenology and biology are highlighted as they can be used in the IPM concept against them. Full article

This work aimed to investigate chemical composition of essential oils obtained from Zanthoxylum dissitum leaves and roots and their insecticidal activities against several stored product pests, namely the cigarette beetle (Lasioderma serricorne), red flour beetle (Tribolium castaneum) and black carpet beetle (Attagenus piceus). The analysis by GC-MS of the essential oils allowed the identification of 28 and 22 components, respectively. It was found that sesquiterpenoids comprised a fairly high portion of the two essential oils, with percentages of 74.0% and 80.9% in the leaves and roots, respectively. The main constituents identified in the essential oil of Z. dissitum leaves were δ-cadinol (12.8%), caryophyllene (12.7%), β-cubebene (7.9%), 4-terpineol (7.5%) and germacrene D-4-ol (5.7%), while humulene epoxide II (29.4%), caryophyllene oxide (24.0%), diepicedrene-1-oxide (10.7%) and Z,Z,Z-1,5,9,9-tetramethyl-1,4,7-cycloundecatriene (8.7%) were the major components in the essential oil of Z. dissitum roots. The insecticidal activity results indicated that the essential oil of Z. dissitum roots exhibited moderate contact toxicity against three species of storage pests, L. serricorne,T. castaneum and A. piceus, with LD₅₀ values of 13.8, 43.7 and 96.8 µg/adult, respectively. Full article