Moth Larvae Research Articles

Light conditions have a greater impact on leaf quality as food for emperor moth (Saturnia japonica) larvae than tree size

ABSTRACT Emperor moth (Saturnia japonica) outbreaks in Hokkaido’s deciduous forests have been happening since 2006. The susceptibility of monarch birch (Betula maximowicziana) leaves differs, with the specific mechanisms affecting their defensibility at the ontogenetic level remaining unknown. In this study, the first instar emperor moth larvae were fed monarch birch leaves from 32 individual trees (saplings to mature trees), and their body weights were compared. Various leaf characteristics (water content, toughness, leaf mass per area, total phenolics, condensed tannin, nitrogen content, carbon content, and carbon to nitrogen [C/N] ratio) were measured concurrently to identify the factors affecting larval growth. Structural equation model analysis indicated that the C/N ratio was the most important factor affecting larval weight and that light conditions have a greater effect on the C/N ratio. In conclusion, light conditions had a strong effect on the foliar C/N ratio which in turn had a significant impact on the weight of emperor moth larvae. This study provides insights into monarch birch management and proposes that maintaining a lighter canopy is important to reduce herbivore damage.

Acquired blaCfxA-3 carried by a conjugative transposon or duplicated intrinsic blaCME-3 mediates cefiderocol resistance in Elizabethkingia anophelis clinical isolates

ObjectivesElizabethkingia spp. are resistant to multiple antibiotics. This study aimed to determine in vitro and in vivo activities of cefiderocol against Elizabethkingia spp. and to investigate resistance mechanisms. MethodsBloodstream isolates were collected from four hospitals. In vitro and in vivo activities were determined using broth microdilution and the wax moth model, respectively. Genome comparison and gene editing were used to confirm the contribution of target genes. Conjugation experiments and serial passage were used to determine transferability and stability, respectively. A MIC of ≤ 4 mg/L was designated as the susceptibility breakpoint. ResultsAmong 228 non-duplicated isolates, 226 exhibited a MIC of ≤ 4 mg/L with MIC50/90 of 1/2 mg/L. Two isolates had a MIC of 128 mg/L; both source patients had multiple comorbidities, were ventilator-dependent, and had not received cefiderocol previously. Resistance was attributable to acquisition of blaCfxA-3, carried by a conjugative transposon from Prevotella jejuni, and duplication of intrinsic blaCME-3, which led to its overexpression. tetQ coexisted with blaCfxA-3 in this conjugative transposon and minocycline facilitated its transfer among E. anophelis. Antibiotics prescribed for source patients did not induce blaCME-3 duplication. The stabilities of blaCfxA-3 and double blaCME-3 were 100% and > 90%, respectively, after 10-day serial passage. Cefiderocol failed to rescue moth larvae infected with resistant strains, but removal of resistance mechanisms restored in vivo efficacy. ConclusionsCefiderocol was in vitro and in vivo active against Elizabethkingia spp. but resistance may emerge due to the availability, transferability, and/or stability of resistance mechanisms.

Rising temperatures may increase fungal epizootics in northern populations of the invasive spongy moth in North America

Insect pest species are generally expected to become more destructive with climate change because of factors such as weakened host tree defences during droughts and increased voltinism under rising temperatures; however, responses will vary by species due to a variety of factors, including altered interactions with their natural enemies. Entomopathogens are a substantial source of mortality in insects, but the likelihood of epizootics can depend strongly on climatic conditions. Previous research indicates that rates of infection of the spongy moth (Lymantria dispar) by its host-specific fungal pathogen, Entomophaga maimaiga, increase with environmental moisture and decrease as temperatures rise. High temperatures may have direct and indirect (due to the associated drying) effects on the fungus, but the interactive effects between temperature and moisture level on larval infection are unclear. Here, we test the hypothesis that warmer, drier conditions will decrease rates of infection of spongy moth larvae by E. maimaiga. We evaluated the effects of precipitation and temperature on larval mortality caused by E. maimaiga with a manipulative field experiment, conducted in one of the northernmost and coldest parts of the spongy moth’s non-native range in North America. We caged laboratory-reared spongy moth larvae in experimentally warmed open-air forest plots, exposing the larvae to soil inoculated with E. maimaiga resting spores during two consecutive trials. Caged larvae were exposed to three temperature treatments — ambient, 1.7 °C above ambient and 3.4 °C above ambient — and either supplemental precipitation (+173 mm per trial) or ambient precipitation. Opposite to our hypothesis, there was no significant effect of supplemental precipitation, nor an interaction between precipitation and temperature. There was, however, a significant positive effect of increasing temperature on the number of larvae infected. On average, in each respective trial, larval infection increased by 44% and 50% under the elevated temperature treatments compared to ambient temperature. Experimental warming may have increased infections because ambient temperatures at the field site were suboptimal for fungal germination. The results from this experiment suggest that, in colder portions of the spongy moth’s invasive range, increasing temperatures due to climate change may enhance the ability of E. maimaiga to help control populations of the spongy moth.

Rapid evasive behaviors of diamondback moth larvae against ants

Abstract Larvae of the diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) wriggle vigorously backward when physically stimulated. To explore whether this behavior is effective against ant attacks on their host plants with three-dimensional structures, we experimentally observed DBM larval movements and consequences thereof when attacked by Formica japonica (Hymenoptera: Formicidae) ants on the upper and lower surfaces of host plant leaves. On the upper surfaces of leaves, DBM larvae wriggled backward in response to ant attacks, and most larvae hung from leaf edges by spinning silk threads. On the lower surfaces of leaves, DBM larvae did not wriggle backward but immediately hung from the lower surface in response to attacks. No ants were able to pursue hanging larvae. We conclude that wriggling backward by DBM larvae belongs to a sequence of evasive movements against ant attacks on upper leaf surfaces. To our knowledge, this is the first report of combined wriggling and hanging behaviors by Lepidopteran larvae that are effective against ants in three-dimensional habitats.

Galleria mellonella as an Antimicrobial Screening Model.

To combat the rising global issue of antibiotic resistance, the accelerated development of novel antibiotics is essential. Current preclinical antimicrobial development yields a significant number of leads that prove unsuitable either prior to or during clinical trials. To increase the efficiency of preclinical development, relevant, standardized, accessible, and cost-effective models must be developed. Galleria mellonella (greater wax moth) larvae are widely used as an infection model to assess microbial virulence, conduct drug toxicity testing, and serve as a preliminary means of evaluating the in vivo efficacy of novel antimicrobial compounds. These infection models have greater biological relevance than many in vitro screens of comparable throughput and decrease reliance on mammalian models when used as a pre-screen for antimicrobial testing. This protocol describes a standardized methodology for the optimization of G. mellonella infection models, which can be applied to bacterial species and antimicrobial therapeutics of choice. Using the WHO priority pathogen Pseudomonas aeruginosa as an exemplar, we outline steps that can be undertaken to develop a reproducible model of infection and therapeutic testing. This includes recommendations on experimental setup, sample preparation, and infection and treatment protocols. Integration of this model within preclinical antimicrobial development pipelines would decrease reliance on mammalian models, reduce the number of ineffective compounds reaching clinical trials, and ultimately increase the efficiency of preclinical antimicrobial development.

Toxicity and Physiological Effect of Lemongrass Essential Oil Nano-capsules on the Greater Wax Moth Larvae Galleria mellonella L. (Lepidoptera: Pyralidae)

Toxicity and Physiological Effect of Lemongrass Essential Oil Nano-capsules on the Greater Wax Moth Larvae Galleria mellonella L. (Lepidoptera: Pyralidae)

Reassessing the Diversity of the Arthropod-Pathogenic Genus Pandora Batko (Entomophthoromycotina; Erynioideae)

The fungal order Entomophthorales occurs worldwide, with most species infecting arthropods as pathogens. Species in this order can cause epizootics and change the behavior of infected hosts. Molecular data are available only for 20% of the known species, and distributions of species are seldom summarized. Significant diversity of hosts, poor molecular data availability, and poor resolution of the phylogenetic relationships within this fungal order suggest that the diversity of these fungi is not sufficiently described. The subfamily Erynioideae includes 111 arthropod pathogens, divided among six genera, with the genus Pandora being one of the most diverse genera. Sequences of 18S, 28S, and ITS for two species are used to place these Pandora species in a phylogenic tree of the subfamily; this tree also supports our synonymy of the genus Furia with Pandora. Among the two species specifically covered in this paper, Pandora gloeospora was observed during epizootics occurring in mushroom flies (Diptera: Sciaridae) on Agaricus bisporus cultures in Pennsylvania, Delaware, and Maryland (US) mushroom farms and also in Florida on Pleurotus sp. Outside the US, P. gloeospora was found infecting several Nematocera (Diptera) in Europe (France) and Asia (China). Pandora sylvestris n. sp. was collected during epizootics occurring in larvae of hickory tussock moths, Lophocampa caryae (Lepidoptera: Erebidae), in hardwood forests in Michigan and Vermont.

The Oriental Fruit Moth (Grapholitha Molesta Busck.) and its Natural Enemies in the Absheron Peninsula

Abstract Garden plants, trees and bushes suffer damages caused by lots of pests by 30-50 % every year, and sometimes by 80-90 % during the period when they grow massively. For this purpose, scientific bases for the use of perspective entomophages in the biological fight against harsh pests by studying the species composition, bioecological features of 6 species of insects, which damage garden and forest plants, and entomophages (parasites and predators), which regulate their number, have been developed in Azerbaijan. The research paper established that the oriental fruit moth infests fruit crops by 50-60 %. It was found that 22 types of parasites play a role in the regulation of abundance. Among them, macrocentrus infests oriental fruit moth larva up to 80 %, scambus up to 60 %, apanteles up to 40-50 %. The scoliidae parasite is of economic importance and can be used for biological control against the oriental fruit moth. Considering the prospects of some parasites, the bioecological features on the Absheron Peninsula have been studied.

Accidents with Lepidoptera (Insecta): Biology, Poisonous, Clinical Manifestations, Treatment, Prevention, and Therapeutic Possibilities

Accidents triggered by contact with winged adult forms of moths and accidents caused by contact with larvae. These accidents are caused by contact with the bristles on the abdomen of females of certain species, belonging to the genus Hylesia Hübner, 1820 (Family: Hemileucidae). Therefore, the simple fact of penetration of the bristles seems to be capable of causing intense inflammatory, popular, and pruritic reactions. Pararama (pararamose) is the common name for a stinging caterpillar found in the artificial rubber plantations of Pará, Brazil, the larval stage of the moth Premolis semirufa (Walker, 1856) (Famíly: Erebidae). Therefore, accidental contact with the small bristles of the caterpillars or with those of the cocoons causes a chronic inflammatory reaction in the interphalangeal joints that leads to ankylosis. The morbid condition mainly affects rubber tappers and is classified as an occupational disease. Eruca=larva; erucism is poisoning caused by a moth larva. The main families of Lepidoptera fireworms that cause erucism accidents are Megalopygidae, Saturniidae, and Arctiidae. The caterpillars of the Megalopygidae family have a body covered with long, harmless bristles that cover the smaller, sharp spines that carry poison glands this manuscript aims to report the biological characteristics of venomous Lepidoptera (Insecta) and their biological, clinical manifestations, treatment, prevention, and therapeutic possibilities. That paper is a narrative review of the literature, which is designed to explain and discuss a certain subject from a theoretical or contextual perspective, to allow the reader to acquire or update knowledge on a specific topic. The scientific articles that made up this review were searched on Google Scholar, Biological Abstract, HAL, Qeios, ResearchGate, Scielo, and SSRN. The following descriptors in Health Sciences (DeCS) were used: biological therapy, larva, wound, debridement, and healing. The following inclusion criteria were considered: original articles and reviews, published nationally and internationally in full, available electronically, and published in Portuguese, English, and Spanish. The exclusion criteria were dissertations, theses, monographs, and conclusion work, duplicates, and those that required payment to access the content in full.

Development of Galleria mellonella (wax moth) larvae as a model for snakebite envenoming

Development of Galleria mellonella (wax moth) larvae as a model for snakebite envenoming

The venom of Habrobracon hebetor induces alterations in host metabolism.

The ability of parasitic wasps to manipulate a host's metabolism is under active investigation. Components of venom play a major role in this process. In the present work, we studied the effect of the venom of the ectoparasitic wasp Habrobracon hebetor on the metabolism of the greater wax moth host (Galleria mellonella). We identified and quantified 45 metabolites in the lymph (cell-free hemolymph) of wax moth larvae on the second day after H. hebetor venom injection, using NMR spectroscopy and liquid chromatography coupled with mass spectrometry. These metabolites included 22 amino acids, nine products of lipid metabolism (sugars, amines and alcohols) and four metabolic intermediates related to nitrogenous bases, nucleotides and nucleosides. An analysis of the larvae metabolome suggested that the venom causes suppression of the tricarboxylic acid cycle, an increase in the number of free amino acids in the lymph, an increase in the concentration of trehalose in the lymph simultaneously with a decrease in the amount of glucose, and destructive processes in the fat body tissue. Thus, this parasitoid venom not only immobilizes the prey but also modulates its metabolism, thereby providing optimal conditions for the development of larvae.

Altered Heat-Avoidance Behavior Following Damage to the Extended Architecture of Mexican Jumping Bean Moth Larvae (Cydia saltitans)

Altered Heat-Avoidance Behavior Following Damage to the Extended Architecture of Mexican Jumping Bean Moth Larvae (Cydia saltitans)

Study of Altenia wagneriella (rebel) as a predator associated with Forda marginata from Iran.

The larvae of Altenia spp. and gall aphids are known to feed on plants related to Anacardiaceae. This study documents the aphidophagous habit of Altenia wagneriella, which was verified by molecular techniques, subsequently by the gut dissection test, and direct observation. To identify the moth larvae and adult aphids, two mitochondrial genes, cytochrome c oxidase I (COI) and cytochrome b (Cytb), were amplified by polymerase chain reaction (PCR). Nested PCR with the aphid-specific primer pairs AphidF and AphidR was used to detect aphids in the body of moth larvae. The specificity of the primers was verified by PCR analysis of DNA from moth larvae and adult aphids. The method detected aphids in moth larvae, and a band of approximately 200bp was amplified from moth larvae feeding on aphids. No cross reactions with moth larvae were observed. In the laboratory, all moth larvae feeding on aphids (Forda marginata) were also PCR positive for aphids. Gall-inducing insects are microhabitat engineers that manipulate their host to obtain a better nutrient supply, as well as protection from natural enemies and abiotic factors. This is the first recorded instance worldwide of the carnivorous larva of the moth A. wagneriella acting as an aphid predator, as well as the first record of a host insect for this species. Additionally, it is the first effort to molecularly analyze the predator-prey relationship between the moth larvae and the aphids inside the wild pistachio gall.

Consumption and Digestion of Plastics by Greater Hive Moth Larvae.

The accumulation and unsustainable management of plastic waste generate environmental pollution that affects ecosystems, wildlife, and human health. We studied the possibility of using the consumption and digestion of oxo-biodegradable, compostable plastics and polypropylene from face masks by the fifth-instar larvae of G. mellonella as a strategy for the sustainable management of plastic waste. We used Fourier transform infrared spectrophotometry (FTIR) to determine the percentage of consumption and presence of microplastics in the digestive tract and excreta for 10 treatments evaluated for 135 h. The effects of plastics on the continuity of the life cycle of the greater hive moth were also determined. We established that the larvae fragmented and consumed 35.2 ± 23% of the plastics evaluated, with significant differences between treatments. Larvae were able to consume more of the intermediate layers of masks (86.31%) than the other plastics. However, none of the plastics were digested. Instead, microplastics accumulated in the excreta, resulting in nutritional deficits that affected the continuity of the life cycle, including the induction of the early formation of pupae after 24 h and a reduction in the number of eggs laid by the females.

Influence of the parasitoid Cotesia vestalis on the distribution of diamondback moth larvae on cabbage plants

Influence of the parasitoid Cotesia vestalis on the distribution of diamondback moth larvae on cabbage plants

Neurotransmitter acetylcholine mediates the mummification of Ophiocordyceps sinensis-infected Thitarodes xiaojinensis larvae.

Parasites can manipulate host behavior to facilitate parasite transmission. One such host-pathogen interaction occurs between the fungus Ophiocordyceps sinensis and the ghost moth Thitarodes xiaojinensis. O. sinensis is involved in the mummification process of infected host larvae. However, the underlying molecular and chemical mechanism for this phenomenon is unknown. We characterized the small molecules regulating host behaviors and the altered metabolites in infected and mummified host larvae. Lipid-related metabolites, such as phosphatidylcholine, were identified in infected and mummified larvae. Decreased levels of the neurotransmitter acetylcholine (ACh) and elevated choline levels were observed in the brains of both the infected and mummified larvae. The aberrant activity of acetylcholinesterase (AChE) and relative mRNA expression of ACE2 (acetylcholinesterase) may mediate the altered transformation between ACh and choline, leading to the brain dysfunction of mummified larvae. Caspofungin treatment inhibited the mummification of infected larvae and the activity of AChE. These findings indicate the importance of ACh in the mummification of host larvae after O. sinensis infection.IMPORTANCEOphiocordyceps sinensis-infected ghost moth larvae are manipulated to move to the soil surface with their heads up in death. A fruiting body then grows from the caterpillar's head, eventually producing conidia for dispersal. However, the underlying molecular and chemical mechanism has not been characterized. In this study, we describe the metabolic profile of Thitarodes xiaojinensis host larvae after O. sinensis infection. Altered metabolites, particularly lipid-related metabolites, were identified in infected and mummified larvae, suggesting that lipids are important in O. sinensis-mediated behavioral manipulation of host larvae. Decreased levels of the neurotransmitter acetylcholine were observed in both infected and mummified larvae brains. This suggests that altered or reduced acetylcholine can mediate brain dysfunction and lead to aberrant behavior. These results reveal the critical role of acetylcholine in the mummification process of infected host larvae.

The Use of Some Herbal Essential Oils Against Galleria mellonella Larvae and Testing of Bacillus thuringiensis Bacterium Isolated from Galleria mellonella Under Laboratory Conditions

Larvae of wax moths cause great damage in honey bee hives and especially in stored honeycombs. Biological control methods are especially important in the control of wax moth in warehouses, as they do not harm the bee, the product and the environment. This study was carried out to determine the effect of 5%, 10%, 25%, 45% and 55% of peppermint, thyme, nettle seed, and walnut herbal oils and GB1 Bacillus sp. (OR227363) against wax moth larvae (Galleria mellonella) (L1-L3) under laboratory conditions. For each group of fifteen larvae, four herbal oil and one bacterial trials were conducted and two control groups were formed. The trials were conducted in glass jars and the larvae were kept in an oven at 25°C temperature/75% relative humidity. Each jar was checked every day for two weeks and dead/viable larvae were recorded and the dead ones were removed from the jar. As a result of the dose trials, it was determined that the best dose was 2.835x109 cfu/mL for bacteria and 5% concentration of thyme and walnut oil for herbal oil. According to the data obtained, it is thought that GB1 Bacillus sp. isolate can be used as an alternative control method against wax moth larvae.

Reinforced colour preference of parasitoid wasps in the presence of floral scent: a case study of a cross-modal effect

We examined the possibility of a cross-modal effect in naïve Cotesia vestalis, a parasitoid wasp of diamondback moth larvae, by using artificial flower models of four colours (blue, green, yellow, and red) in the absence or presence of floral scent collected from Brassica rapa inflorescences. In a four-choice test, regardless of the floral scent, non-starved female wasps visited green and yellow models significantly more often than blue and red ones, although no significant difference was observed between visits to the green and yellow models. They seldom visited blue and red models. When starved, the wasps became even more particular, visiting yellow significantly more frequently than green models, irrespective of the presence of the floral scent, indicating that they preferred to use yellow visual cues in their food search. Furthermore, a factorial analysis of variance revealed a significant effect of the interaction between model colour and floral scent on the wasps’ visits to flower models. The floral scent induced starved and non-starved wasps to visit yellow and green models about twice as often as without the scent. A cross-modal effect of olfactory perception on the use of chromatic information by wasps may allow them to search efficiently for food sources.

Antimicrobial Evaluation of Two Polycyclic Polyprenylated Acylphloroglucinol Compounds: PPAP23 and PPAP53.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) comprise a large group of compounds of mostly plant origin. The best-known compound is hyperforin from St. John's wort with its antidepressant, antitumor and antimicrobial properties. The chemical synthesis of PPAP variants allows the generation of compounds with improved activity and compatibility. Here, we studied the antimicrobial activity of two synthetic PPAP-derivatives, the water-insoluble PPAP23 and the water-soluble sodium salt PPAP53. In vitro, both compounds exhibited good activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium. Both compounds had no adverse effects on Galleria mellonella wax moth larvae. However, they were unable to protect the larvae from infection with S. aureus because components of the larval coelom neutralized the antimicrobial activity; a similar effect was also seen with serum albumin. In silico docking studies with PPAP53 revealed that it binds to the F1 pocket of human serum albumin with a binding energy of -7.5 kcal/mol. In an infection model of septic arthritis, PPAP23 decreased the formation of abscesses and S. aureus load in kidneys; in a mouse skin abscess model, topical treatment with PPAP53 reduced S. aureus counts. Both PPAPs were active against anaerobic Gram-positive gut bacteria such as neurotransmitter-producing Clostridium, Enterococcus or Ruminococcus species. Based on these results, we foresee possible applications in the decolonization of pathogens.

Transcriptome analysis of CpGV in midguts of type II resistant codling moth larvae and identification of contaminant infections by SNP mapping of RNA-Seq data.

CpGV is a highly virulent pathogen of codling moth, and it has been developed into one of the most successful commercial baculovirus biocontrol agents for pome fruit production worldwide. The emergence of field resistance in codling moth to commercial CpGV products is a threat toward the sustainable use of CpGV. In recent years, different types of resistance (type I-III) were identified. For type II resistance, very little is known regarding the infection process. By studying the virus gene expression patterns of different CpGV isolates in midguts of type II-resistant codling moth larvae, we found that the type II resistance mechanism is most likely based on intracellular factors rather than a receptor component. By applying SNP mapping of the RNA-Seq data, we further emphasize the importance of identifying the infective agents in in vivo experiments when activation of a covert infection cannot be excluded.