Search Results (21)

This study aims to characterize for the first time the insect assemblage associated with sown, introduced guayule (Parthenium argentatum A. Gray, Asteraceae) in Castilla-La Mancha, Spain, and identify potential relationships with the crop. Insect sampling was conducted using nets and pan traps during spring and early summer, coinciding with the flowering period of the plant. A total of 352 insect species/morphospecies across 12 orders were identified. Diptera, Coleoptera, Hemiptera, and Hymenoptera were the most species-rich and abundant orders. Within these orders, Muscidae, Syrphidae, Tenebrionidae, Dermestidae, Miridae, Halictidae, and Apidae were the most numerous families. Guayule flowering intensity increased gradually until mid-June, aligning with the peak activity of pollinating Diptera. The majority of the identified insects (74.4%) were potential pollinators, while nearly 50% were detritivores and approximately 30% were herbivorous. The similarity in insect families and functional roles observed in this study to previous studies in the USA and Mexico suggest that guayule may serve as a similar trophic resource for insects in Spain, despite being a non-native species. Full article

Representatives of Dermestidae (skin, larder, and carpet beetles) play a crucial role as decomposers in global ecosystems, facilitating the recycling of animal and plant biomass to sustain nutrient cycling. Despite their widespread ecological presence and functional importance, the fossil record of their larval stages has remained sparse, with previous documentation limited to occasional discoveries. This study significantly expands the larval fossil record by identifying 36 amber-preserved specimens from the Cretaceous, Eocene, and Miocene time slices, obtained from deposits distributed globally. By challenging the historical view of larval fossil rarity, we reveal morphological changes in defensive setae over geological time, demonstrating that Cretaceous and later fossil larvae possess significantly longer absolute and relative setal lengths compared to their extant counterparts. These findings, bolstered by quantitative comparisons of setal and body dimensions across fossil and extant representatives, indicate evolutionary adaptations in defensive structures dating back at least 100 million years. Our results offer new insights into the paleobiology of the group Dermestidae, highlighting how the morphology of larvae potentially reflects historical ecological pressures and resources availability. This study emphasizes the importance of integrating fossil evidence with comparative morphology to elucidate the evolutionary trajectories and functional roles of larvae in ancient terrestrial ecosystems. Full article

Background:Envenomation by poisonous creatures is a major global cause of mortality. Its concomitant impact on the postmortem corpse decomposition and associated insect succession pattern is still poorly understood. Purpose of the study: This study comparatively investigates the impact of envenomization with the venoms of the snake Walterinnesia aegyptia L. versus the scorpion, Androctonus crassicauda L., on rabbit corpse decomposition and beetle succession. Methods: Three groups of rabbits (five animals each) were injected with the snake venom, the scorpion venom, or 0.9% saline (control) prior to euthanasia with CO₂. The corpse decomposition stages and beetle succession were monitored over 11 days. Results: Four stages of decomposition with venom-dependent duration variation were observed. The scorpion-envenomized corpses showed a longer decay stage and a delayed dry stage. A total of 1094 beetles belonging to 27 species of 14 families were reported. Histeridae, Dermestidae, Scarabaeidae, and Tenebrionidae were the most diversified and prevalent families. Chrysomelidae, Elateridae, Hybosoridae, and Ptinidae were incidentally attracted to control corpses, while Nitidulidae and Zopheridae were only found on control and snake-envenomized ones. Four species belonging to the families Anthicidae, Histeridae, Scarabaeidae, and Tenebrionidae were predominant on all corpses. Four species belonging to the families Chrysomelidae, Curculionidae, Elateridae, and Hybosoridae were distinctively associated with the control corpses. Conclusions: These findings provided evidence that envenomation impacted the decomposition process and beetle succession in a venom-dependent manner, which could be significant for forensic investigations. Full article

Background: Ptinidae, within the infraorder Bostrichiformia, are a cosmopolitan, ecologically diverse but poorly known group. The phylogeny within Bostrichiformia and the monophyly of Ptinidae and its phylogenetic placement in Bostrichiformia remain contentious. Methods: In this research, we determined the entire mitochondrial genome (mitogenome) of Gibbium aequinoctiale, the first representative mitogenome of the subfamily Ptininae, and reconstructed the phylogenetic relationships for Bostrichiformia based on four mitochondrial datasets using maximum likelihood (ML) and Bayesian inference (BI) methods. Results: The mitogenome of G. aequinoctiale is a circular molecule spanning 17,020 bp and harbors 37 mitochondrial genes and a presumed control region (CR). The mitogenome exhibited a marked preference for the utilization of A and T bases, which was also observed in three kinds of genes and CR. AAT was inferred as the putative candidate initiation codon for cytochrome oxidase subunits 1 (COI). The control region contains three tandem repeats (TDRs) and one poly-thymine stretch (Poly-T) in both coding strands. The phylogenetic results appeared to support the monophyly of four families, Nosodendridae, Derodontidae, Dermestidae, and Bostrichidae, and the basal position of the latter two families within Bostrichiformia. However, the family Ptinidae was not verified as monophyly because of one species diverging from the main lineage. Three families, Dermestidae, Bostrichidae, and Ptinidae, clustered as the major clade in Bostrichiformia, among which Bostrichidae and Ptinidae grouped together as sister groups. Conclusions: The present study provides valuable mitochondrial information for Ptinidae and provides novel perspectives on the inner phylogeny within the infraorder Bostrichiformia. Full article

The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and khapra beetle, Trogoderma granarium E. (Coleoptera: Dermestidae) are primary stored-grain insect pests. Differences in certain biological and physical parameters of both pest species and wheat genotypes were investigated under laboratory conditions. Zinc (Zn)-biofortified (Zincol-2016 and Akbar-2019) and conventional (Arooj-2022, Nawab-2021, Dilkash-2021, Bhakkar Star-2019) wheat genotypes were used in this study. Zn-biofortified genotypes outperformed the conventional ones, with significant differences observed in fecundity, percent adult emergence, total developmental duration, percent grain damage, and weight loss of both insect species. The results further revealed that the fecundity of R. dominica and T. granarium were lowest on Akbar-2019 in both the free-choice test (42.50 and 33.17) and no-choice test (35.50 and 32.50), respectively. Similarly, percent adult emergence of both insect species was also lowest on Akbar-2019 in both the free-choice test (69.78 and 70.28%) and no-choice test (67.38 and 70.71%). The total developmental period also showed significant variation among the tested genotypes. The longest developmental period was recorded in Akbar-2019, i.e., 44.33 and 58.83 days, for R. dominica and T. granarium, respectively. Similarly, percent grain damage (13.23 and 10.33%) and weight loss (3.62 and 2.12%) were found to be minimum in Akbar-2019 for both pest species, respectively. Additionally, a positive correlation was observed between grain moisture content and damage parameters, suggesting that the higher moisture content may aggravate the percent grain damage and weight loss. These findings indicate that the nutritional qualities of Zn-biofortified wheat genotypes negatively affected the development of both insect species; thus, it can be an efficacious approach not only for ensuring food security but also for protecting grains against storage pests. Full article

Background: Coleoptera is the second-most significant insect group associated with decomposing carcasses, yet its role in the decomposition process and postmortem colonization following envenomation is poorly understood. Purpose of the Study: This study aimed to investigate the effects of the venoms from Cerastes cerastes and Naja haje on the decomposition of rabbit carcasses while evaluating the main beetle taxa attracted to these decaying remains. Methods: Three groups of rabbits, each with five individuals, were utilized. The first group was injected with the venom of Cerastes cerastes, the second with Naja haje venom, and the control group received 0.85% physiological saline before euthanasia with CO₂. Results: Four decomposition stages (fresh, bloating, decay, and dry) with durations varying based on venom type and carcass condition were observed. A total of 647 individual beetles of six species (Necrobia rufipes, Attagenus sp., Dermestes frischii, D. maculatus, Bledius sp., and Apentanodes sp.) belonging to four families (Cleridae, Dermestidae, Staphylinidae, and Tenebrionidae) were collected and identified. D. maculatus was the most abundant species. Fewer beetles were attracted to carcasses envenomed with N. haje compared to the other groups. Conclusions: Envenomation by snake venom influences the attraction and succession rate of necrophilous coleopterans to carcasses, which is important for forensic investigations. Full article

Infestations of stored-product pests cause significant losses of agricultural produce every year. Despite various environmental and health risks, chemical insecticides are now a ready-to-use solution for pest control. Against this background and in the context of Integrated Pest Management research, the present study focuses on the potential insecticidal effect of caffeic acid at five different concentrations (250, 500, 750, 1500 and 3000 ppm), and their combination with Cydia pomonella Granulovirus (CpGV), Bacillus thuringiensis subsp. tenebrionis and Beauveria bassiana strain GHA on three major insect stored-product beetle species, Tribolium confusum (Coleoptera: Tenebrionidae), Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) and Trogoderma granarium Everts (Coleoptera: Dermestidae). Treatment efficacy was expressed as mortality in relation to exposure time and adult species number. Compared to the control, the results showed a clear dose-dependent pesticidal activity, expressed as significant adult mortality at a high-dose application, although some of the combinations of caffeic acid concentrations with the other substances acted positively (synergistically and additively) and some negatively. Based on our results, bioinsecticides can be combined with plant compounds such as caffeic acid and be integrated with other modern IPM tools in storage facilities. Full article

Beetles of the family Dermestidae, especially of the genus Dermestes Linnaeus, 1758, are often identified on corpses in late stages of decomposition. They usually feed on remains devoid of organs and soft tissues or when the corpses undergo mummification. In Europe, eight species from two subgenera Dermestes and Dermestinus Zhantiev, 1967, have so far been identified on human corpses. Despite the relatively frequent presence of Dermestes sp. in experimental studies conducted in Poland, no reports concerning Dermestes directly collected from human corpses have been published to date. This article again describes observations of Dermestidae collected from human corpses found in indoor conditions in Wrocław, the capital of the Dolnośląskie Voivodeship. For the second time, there is evidence of the presence of Dermestes (s.str.) haemorrhoidalis on human corpses—a species considered to be relatively rare, as evidenced by faunistic data published from Poland, as well as the results of ongoing experiments of forensic interest. Full article

Stored-product commodities are attacked by numerous insect species. The adulticidal effects of entomopathogenic nematodes (EPNs) on grains remain uninvestigated. Thus, in the current study, seven doses of the EPNs Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae), and Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) were inoculated on wheat kernels against adults of Trogoderma granarium Everts (Coleoptera: Dermestidae), Tenebrio molitor L. (Coleoptera: Tenebrionidae), and Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae). Complete mortality (100.0%) of T. granarium was recorded after exposure for eight days to the highest dose of 50,000 Infective Juveniles/mL (IJs/mL) of all tested EPN species. At the same exposure interval, 62.2%, 85.6%, and 76.7% of T. molitor were killed by 50,000 IJs/mL of H. bacteriophora, S. carpocapsae, and S. feltiae, respectively. The highest mortality of A. diaperinus (11.1%) was documented eight days post-exposure to 50,000 IJs/mL of H. bacteriophora. In general, T. granarium was highly susceptible, followed by T. molitor and A. diaperinus. Concerning EPN species, S. carpocapsae exhibited the highest insecticidal capacity, followed by S. feltiae and H. bacteriophora. Trogoderma granarium and T. molitor can be sufficiently managed by the highest dose of 50,000 IJs/mL of all three EPNs and by S. carpocapsae, respectively. However, A. diaperinus was not affected by any EPNs. Full article

Bag storage of wheat is common in Asian countries, and common types of such bags include jute bags, woven plastic bags, and hermetic plastic bags. In order to assess infestation by two serious pests, namely Rhyzopertha dominica (Coleoptera: Bostrichidae) and Trogoderma granarium (Coleoptera: Dermestidae) in these bags, two experiments were performed. In the first experiment, three popular wheat varieties, namely Akbar, Dilkash, and Bakhar star were filled in above-mentioned miniature-size bags which were then placed in jars with three replicates per bag type and variety. Forty insects (adults for R. dominica and larvae for T. granarium) were released in the center of the jars for a period of 30 d in two different setups for both species. Data were recorded twice: after 15 d and 30 d. Results showed insects entered the jute bags only (made invasions due to its loose fibers and openings). Inside the bags, R. dominica caused more weight loss and live insects in Dilkash and Akbar varieties, while T. granarium preferred Bakhar star and Dilkash compared with their third variety. In the second experiment, only two bags, namely woven plastic bags and hermetic plastic bags filled with one variety, were tested to check damage (penetrations because no openings are present in these bags as in jute bags) to the bags. Results showed both species created holes in woven plastic bags but not in hermetic plastic bags. These results showed hermetic plastic bags remained safe from external infestation compared with the other two bags. Sometimes if insects are already present in the grains inside the bags, fumigation is needed from outside to kill the pests inside. To evaluate this, all three bags were filled with a wheat variety and were also infested with both insect species and placed in a fumigation container with nine replicates per bag type. A phosphine tablet (3.0 g) wrapped in muslin cloth was placed in a container which was then sealed, and the fumigation-induced mortality after 24 h was recorded. Results showed mortality was >95% to 100% in woven and jute bags, respectively, while mortality in hermetic plastic bags remained very low (<3%). These results revealed the least fumigant gas permeation in hermetic plastic bags compared with jute and woven plastic bags. Results of all three experiments demand immediate alteration in creation of all three bags to curtail infestation from outside (jute and woven plastic bags) as well as to generate maximum fumigation efficacy when the source of infestation is with the grains (hermetic bags). Full article

Dermestid beetles (Coleoptera: Dermestidae) are necrophagous insects feeding on mummified carcasses. After six to seven molts, the larvae stop feeding and dig pupation chambers to hide and safely evolve into adults. Such pupation chambers have already been observed on archaeological mammals’ bones, but the attribution and interpretation of these osteological lesions lack experimental evidence in a forensic context. To observe whether dermestid larvae dig pupation chambers in human bones, 20 or 40 Dermestes maculatus (De Geer, 1774) larvae were placed in a dermestarium with different types of bones varying in species (Bos taurus or human), age (adult or immature), and preservation method (fresh or dry). Our results show that dermestid larvae caused multiple lesions, including larval mandible traces on cortical bone, cortical perforations, drilling of pupation chambers, destruction of the trabecular network, and the perforation of cartilage. Bone destruction was mainly observed on aged dry bones, while fresh bones only exhibited soft tissue and superficial cartilage lesions. According to these results, pupation chambers could indicate the simultaneous presence of several corpses at different decomposition stages, or the addition of new corpses while others were already skeletonized. These conclusions are particularly important in the case of mass graves, where chronology is sometimes difficult to establish. Full article

The foremost concern in forensic entomology is the explicit identification of the species recovered from the crime scene. From the different orders of insects, Diptera is the prime focus in this field, followed by Coleoptera, whose identification can be extremely helpful for corpses in later decomposition stages. In this study, cytochrome oxidase subunit II (COII) was used to check its adequacy as a genetic marker and to create a reference database for eleven species belonging to five families of Coleoptera, namely, Silphidae, Staphylinidae, Histeridae, Dermestidae and Scarabaeidae, from two different states in India to assist in the accurate identification of imperative beetle species in medico-legal entomology. To achieve this, standard protocols of DNA isolation, amplification and sequencing were followed. We concluded that the COII gene can be used as a molecular marker for the identification of forensically relevant species, as observed from the similarities between the phylogenetic relationship constructed by COII and morphological data. Full article

Postharvest agricultural losses constitute a major food security risk. In contrast, postharvest protection is strongly linked with food safety. The present study aims to develop novel postharvest protection tools through a bioprospecting protocol utilizing edible essential oils (EOs) as grain coatings. For this purpose, six Mediterranean culinary plants were selected for evaluation. The EOs of juniper, Juniperus phoenicea L. (Pinales: Cupressaceae), marjoram, Origanum majorana L. (Lamiales: Lamiaceae), oregano, Origanum vulgare ssp. hirtum (Link) A.Terracc. (Lamiales: Lamiaceae), bay laurel, Laurus nobilis L. (Laurales: Lauraceae) and tarhan, Echinophora tenuifolia ssp. sibthorpiana (Guss.) Tutin (Apiales: Apiaceae) were retrieved through steam distillation, while lemon, Citrus limon (L.) Osbeck (Sapindales: Rutaceae) EO was retrieved through cold press extraction. All EOs were formulated to microemulsions (MEs) and applied uniformly as a coating on wheat against larvae and adults of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and Trogoderma granarium Everts (Coleoptera: Dermestidae). All EO-based MEs have been evaluated for the first time as grain coatings. They caused moderate to high mortality to T. castaneum larvae (67.8–93.3% 14 days post-exposure) and T. granarium adults (70.0–87.8% after 7 days of exposure). Citrus limon, O. majorana and E. tenuifolia ssp. sibthorpiana EO-based MEs were the most efficient against T. castaneum larvae, by exhibiting 93.3%, 91.1% and 90.0% mortality 14 days post-exposure, respectively. Origanum majorana, L. nobilis and J. phoenicea EO-based MEs were the most efficient against T. granarium adults, exhibiting 87.8%, 84.4% and 83.3% mortality after 7 days of exposure, respectively. These results indicate that EO-based ME coating is a potent tool against the tested postharvest pests. Full article

The khapra beetle, Trogoderma granarium Everts, is defined as one of the most important quarantine pests globally, and fumigation with methyl bromide, an ozone-depleting substance, is a common phytosanitary measure currently used. The modified atmosphere (MA), irradiation, and their combination treatments of T. granarium larvae and adults were performed at room temperature (24–26 ℃) to develop an ecofriendly phytosanitary disinfestation measure and to shorten the exposure time and overcome treatment disadvantages of irradiation. Late-stage larvae are determined as the most tolerant stage resulted in large LT_99.9968 values of 32.6 (29.2–37.5) and 38.0 (35.1–41.7) days treated under 1% and 2% O₂ (with N₂ balance) atmosphere, respectively. Ionizing radiation was used to enhance the effect of MA and the mortality was highly significantly affected by all the interaction effects, indicating that the synergistic effects present in all the combined treatments. The synergistic ratios, which is defined as the estimated lethal time for MA treatment (LD₉₀, LD₉₉, and LD_99.9968), divided by that of combined treatment, were between 1.47 and 2.47. In the confirmatory tests, no individuals recovered from a sum of 111,366 late-stage larvae treated under 1% O₂ atmosphere for 14- or 15-d after 200 Gy irradiation, which resulted in validating the probit estimations and achieving an efficacy of 99.9973% mortality at 95% confidence level. Therefore, these treatment schedules are recommended to disinfest T. granarium infecting commodities for phytosanitary purposes under the warehouse, MA packaging, or in combination with international transportation by train or sea container. Full article

Hastisetae are modified setae typical of Dermestidae Megatominae and are a primary defensive tool of both larvae and pupae against invertebrates and possibly vertebrates. Given their unique morphological features, hastisetae have recently been suggested as an additional character useful for larvae identification and possible source of information to clarify the systematics of Megatominae. Hastisetae are also recognized as important contaminants of stored products, work and living environment; in particular, the exposure to hastisetae seems to cause allergic reactions and the insurgence of skin rashes, asthma, conjunctivitis, and digestive system inflammation in humans. Starting from these basic concepts, the present paper provides a detailed description of the hastisetae of some Megatominae. Fine morphology of external and internal microstructures of the hastisetae is shown and compared at the genus level. The insertion on integument, the pedicel, the shaft, and the apical head are illustrated in detail, and the first observations of active defensive behavior based on hastisetae are recorded and presented. Possible implications to the systematics of skin beetles are proposed based on the results of the study. Full article