Effect of temperature on the biological parameters of pink bollworm, Pectinophora gossypiella Saunders (Lepidoptera: Gelechiidae).

Pink bollworm (PBW) Pectinophora gossypiella is an important pest cotton worldwide. There are multiple factors which determines the occurrence and distribution of P. gossypiella across different cotton growing regions of the world, and one such key factor is 'temperature'. The aim was to analyze the life history traits of PBW across varying temperature conditions. We systematically explored the biological and demographic parameters of P. gossypiella at five distinct temperatures; 20, 25, 30, 35 and 40 ± 1 °C maintaining a photoperiod of LD 16:8 h. The results revealed that the total developmental period of PBW shortens with rising temperatures, and the highest larval survival rates were observed between 30 °C and 35 °C, reaching 86.66% and 80.67%, respectively. Moreover, significant impacts were observed as the pupal weight, percent mating success, and fecundity exhibited higher values at 30 °C and 35 °C. Conversely, percent egg hatching, larval survival, and adult emergence were notably lower at 20 °C and 40 °C, respectively. Adult longevity decreased with rising temperatures, with females outliving males across all treatments. Notably, thermal stress had a persistent effect on the F1 generation, significantly affecting immature stages (egg and larvae), while its impact on reproductive potential was minimal. These findings offer valuable insights for predicting the population dynamics of P. gossypiella at the field level and developing climate-resilient management strategies in cotton.

Genome-Wide Gene Birth-Death Dynamics Are Associated with Diet Breadth Variation in Lepidoptera.

Comparative analyses of gene birth-death dynamics have the potential to reveal gene families that played an important role in the evolution of morphological, behavioral, or physiological variation. Here, we used whole genomes of 30 species of butterflies and moths to identify gene birth-death dynamics among the Lepidoptera that are associated with specialist or generalist feeding strategies. Our work advances this field using a uniform set of annotated proteins for all genomes, investigating associations while correcting for phylogeny, and assessing all gene families rather than a priori subsets. We discovered that the sizes of several important gene families (e.g. those associated with pesticide resistance, xenobiotic detoxification, and/or protein digestion) are significantly correlated with diet breadth. We also found 22 gene families showing significant shifts in gene birth-death dynamics at the butterfly (Papilionoidea) crown node, the most notable of which was a family of pheromone receptors that underwent a contraction potentially linked with a shift to visual-based mate recognition. Our findings highlight the importance of uniform annotations, phylogenetic corrections, and unbiased gene family analyses in generating a list of candidate genes that warrant further exploration.

Temperatures above 37°C increase virulence of a convergent Klebsiella pneumoniae sequence type 307 strain.

Background: Convergence of Klebsiella pneumoniae (KP) pathotypes has been increasingly reported in recent years. These pathogens combine features of both multidrug-resistant and hypervirulent KP. However, clinically used indicators for hypervirulent KP identification, such as hypermucoviscosity, appear to be differentially expressed in convergent KP, potential outbreak clones are difficult to identify. We aimed to fill such knowledge gaps by investigating the temperature dependence of hypermucoviscosity and virulence in a convergent KP strain isolated during a clonal outbreak and belonging to the high-risk sequence type (ST)307. Methods: Hypermucoviscosity, biofilm formation, and mortality rates in Galleria mellonella larvae were examined at different temperatures (room temperature, 28°C, 37°C, 40°C and 42°C) and with various phenotypic experiments including electron microscopy. The underlying mechanisms of the phenotypic changes were explored via qPCR analysis to evaluate plasmid copy numbers, and transcriptomics. Results: Our results show a temperature-dependent switch above 37°C towards a hypermucoviscous phenotype, consistent with increased biofilm formation and in vivo mortality, possibly reflecting a bacterial response to fever-like conditions. Furthermore, we observed an increase in plasmid copy number for a hybrid plasmid harboring carbapenemase and rmpA genes. However, transcriptomic analysis revealed no changes in rmpA expression at higher temperatures, suggesting alternative regulatory pathways. Conclusion: This study not only elucidates the impact of elevated temperatures on hypermucoviscosity and virulence in convergent KP but also sheds light on previously unrecognized aspects of its adaptive behavior, underscoring its resilience to changing environments.

Chromosome-level Genome Assembly of Theretra japonica (Lepidoptera: Sphingidae).

Theretra japonica is an important pollinator and agricultural pest in the family Sphingidae with a wide range of host plants. High-quality genomic resources facilitate investigations into behavioral ecology, morphological and physiological adaptations, and the evolution of genomic architecture. However, chromosome-level genome of T. japonica is still lacking. Here we sequenced and assembled the high-quality genome of T. japonica by combining PacBio long reads, Illumina short reads, and Hi-C data. The genome was contained in 95 scaffolds with an accumulated length of 409.55 Mb (BUSCO calculated a genome completeness of 99.2%). The 29 pseudochromosomes had a combined length of 403.77 Mb, with a mapping rate of 98.59%. The genomic characterisation of T. japonica will contribute to further studies for Sphingidae and Lepidoptera.

Mating behavior and oviposition of Palpita forficifera (Lepidoptera: Crambidae).

Palpita forficifera Munroe, 1959 (Lepidoptera: Crambidae) is considered the main pest of the olive tree (Olea europaea L., Oleaceae) in Brazil and Uruguay. The aim of this work was to study the mating and oviposition behavior of P. forficifera in the field and laboratory. In the field, the sex emitting the mating pheromone was determined and in the laboratory, the rate of emergence of males and females; the age, time and duration of mating; number of copulations and oviposition time of P. forficifera were recorded. The field results showed that it was possible to capture up to five males per trap in just one night in traps with the presence of female P. forficifera. Copulation occurs between the seventh and twenty-third day of life and is most frequent during the third and sixth hours of scotophase. The average duration of the first copulation was 174 min, with 35% of couples recopulating, and there were cases of up to five copulations. Oviposition times were concentrated between 20:00 and 02:00. The results obtained provide insight into the reproductive behavior of P. forficifera and are useful for future studies aimed at identifying the sex pheromone to improve monitoring of the pest in olive orchards.

Enhanced Recombinant Protein Expression in Insect Cells by Natural and Recombinant Components of Lepidoptera Hemolymph.

Prior research has established the anti-apoptotic effects in insect cell cultures of Bombyx mori (B. mori) hemolymph, as well as the heightened production yields of recombinant proteins facilitated by baculovirus vectors in insect cells cultivated in media supplemented with this hemolymph. In this study, we investigated the hemolymph of another Lepidoptera species, Trichoplusia ni (T. ni), and observed similar beneficial effects in insect cells cultivated in media supplemented with this natural substance. We observed enhancements in both production yield (approximately 1.5 times higher) and late-stage cell viabilities post-infection (30-40% higher). Storage-protein 2 from B. mori (SP2Bm) has previously been identified as one of the abundant hemolymph proteins potentially responsible for the beneficial effects observed after the use of B. mori hemolymph-supplemented cell culture media. By employing a dual baculovirus vector that co-expresses the SP2Bm protein alongside the GFP protein, we achieved a threefold increase in reporter protein production compared to a baculovirus vector expressing GFP alone. This study underscores the potential of hemolymph proteins sourced from various Lepidoptera species as biotechnological tools to augment baculovirus vector productivities, whether utilized as natural supplements in cell culture media or as hemolymph-derived recombinant proteins co-expressed by baculovirus vectors.

A new species of Diolcogaster (Hymenoptera: Braconidae) from Brazil of potential use in the biological control of the pest Hypercompe brasiliensis (Stoll) (Lepidoptera: Erebidae).

Species of Diolcogaster parasitize Lepidoptera pests of commercial plants. The diversity of this genus is high, but few species of Diolcogaster have been described. The description of a new Diolcogaster species provides information for the biological control using this insect. This study presents the description and key notes on the biology of a new Diolcogaster parasitoid wasp. This species was reared from a caterpillar of Hypercompe brasiliensis collected after feeding on a Gloxinia perennis plant important to floriculture. Two complementary identification analyzes were performed on Diolcogaster adult bodies. The first was the analyses of its external morphology and the second its molecular analysis (mitochondrial DNA). The morphological analysis defined the insect as a new species of Diolcogaster, named Diolcogaster joanesi sp. nov. A maximum-likelihood (ML) analysis partially confirmed the morphological analysis, placing D. joanesi within a cluster including a previously identified species (Diolcogaster choi) and seven other morphospecies. The proximity of D. joanesi to D. choi is discussed and an updated key for all New World species of the xanthaspis group is provided. Twenty-eight adult wasps were obtained (22 females and six males) out of 50 cocoons which larvae emerged from the caterpillar host. The findings contribute to the broader understanding of Diolcogaster in the Neotropics and its potential for the biological control of lepidopteran defoliators.

Minimally destructive hDNA extraction method for retrospective genetics of pinned historical Lepidoptera specimens.

The millions of specimens stored in entomological collections provide a unique opportunity to study historical insect diversity. Current technologies allow to sequence entire genomes of historical specimens and estimate past genetic diversity of present-day endangered species, advancing our understanding of anthropogenic impact on genetic diversity and enabling the implementation of conservation strategies. A limiting challenge is the extraction of historical DNA (hDNA) of adequate quality for sequencing platforms. We tested four hDNA extraction protocols on five body parts of pinned false heath fritillary butterflies, Melitaea diamina, aiming to minimise specimen damage, preserve their scientific value to the collections, and maximise DNA quality and yield for whole-genome re-sequencing. We developed a very effective approach that successfully recovers hDNA appropriate for short-read sequencing from a single leg of pinned specimens using silica-based DNA extraction columns and an extraction buffer that includes SDS, Tris, Proteinase K, EDTA, NaCl, PTB, and DTT. We observed substantial variation in the ratio of nuclear to mitochondrial DNA in extractions from different tissues, indicating that optimal tissue choice depends on project aims and anticipated downstream analyses. We found that sufficient DNA for whole genome re-sequencing can reliably be extracted from a single leg, opening the possibility to monitor changes in genetic diversity maintaining the scientific value of specimens while supporting current and future conservation strategies.

Effects of the insecticide flupyradifurone on Anticarsia gemmatalis caterpillar and its predator Podisus nigrispinus.

The caterpillar Anticarsia gemmatalis (Lepidoptera: Noctuidae) is a prevalent pest in soybean plantations, managed using both natural and synthetic chemical products. However, the emergence of resistance in some populations emphasizes the need to explore alternative insecticides. Flupyradifurone, a neurotoxic insecticide, has not been previously used for controlling A. gemmatalis. This study evaluated the potential of flupyradifurone in the management of A. gemmatalis. Initially, the toxicity and anti-feeding effects, as well as histopathological and cytotoxic impacts, of flupyradifurone on A. gemmatalis were evaluated. Subsequently, the indirect effects of flupyradifurone on the midgut and fat body of the predator Podisus nigrispinus (Hemiptera: Pentatomidae) were verified. The results indicate the susceptibility of caterpillars to flupyradifurone, with an LC50 of 5.10 g L-1. Furthermore, the insecticide adversely affects survival, induces an anti-feeding response, and inflicts damage on the midgut of the caterpillars. However, flupyradifurone also leads to side effects in the predator P. nigrispinus through indirect intoxication of the caterpillars, including midgut and fat body damage. While flupyradifurone demonstrates toxicity to A. gemmatalis, suggesting its potential for the chemical control of this pest, the indirect negative effects on the predator indicate the need for its controlled use in integrated pest management programs with the insecticide and the predator.

Selection of host plants for production of Clanis bilineata (Lepidoptera: Sphingidae).

Clanis bilineata Walker (Lepidoptera: Sphingidae), a burgeoning edible insect, is experiencing rising demand in China and other regions. Despite this interest, larval production is currently constrained by the limitations of artificial production technologies, particularly the selection of optimal host plants. This study rigorously evaluated the performance of C. bilineatha larvae on four main host plants: round-leaf soybean, pointed-leaf soybean, black locust, and kudzu. Preference tests demonstrated that the larvae were most attracted to black locust (34.76 ± 4.65%), with subsequent preferences for kudzu (25.00 ± 6.12%), round-leaf soybean (23.17 ± 2.79%), and pointed-leaf soybean (14.02 ± 4.74%). No significant preference differences were noted between round-leaf soybean and either black locust or kudzu. In feeding assays, the larvae exhibited a marked preference for round-leaf soybean (37.36 ± 0.81 g, total feeding amount for larvae), followed by kudzu (37.26 ± 0.82 g), pointed-leaf soybean (35.38 ± 1.31 g), and black locust (28.53 ± 0.81 g). When the larvae were fed on round-leaf soybean, they exhibited significantly higher survival rate (39.33 ± 0.90%), body weight (9.75 ± 0.07 g), total biomass (383.43 ± 7.35 g), pupation rate (87.78 ± 1.73%), and egg production (189.80 ± 1.06 eggs/female) compared to other hosts. These findings uncovered that round-leaf soybean significantly enhances larval performance, suggesting its potential for improving C. bilineata larval production and sustainability in cultivation systems.

Lipopolysaccharide with long O-antigen is crucial for Salmonella Enteritidis to evade complement activity and to facilitate bacterial survival in vivo in the Galleria mellonella infection model.

Bacterial resistance to serum is a key virulence factor for the development of systemic infections. The amount of lipopolysaccharide (LPS) and the O-antigen chain length distribution on the outer membrane, predispose Salmonella to escape complement-mediated killing. In Salmonella enterica serovar Enteritidis (S. Enteritidis) a modal distribution of the LPS O-antigen length can be observed. It is characterized by the presence of distinct fractions: low molecular weight LPS, long LPS and very long LPS. In the present work, we investigated the effect of the O-antigen modal length composition of LPS molecules on the surface of S. Enteritidis cells on its ability to evade host complement responses. Therefore, we examined systematically, by using specific deletion mutants, roles of different O-antigen fractions in complement evasion. We developed a method to analyze the average LPS lengths and investigated the interaction of the bacteria and isolated LPS molecules with complement components. Additionally, we assessed the aspect of LPS O-antigen chain length distribution in S. Enteritidis virulence in vivo in the Galleria mellonella infection model. The obtained results of the measurements of the average LPS length confirmed that the method is suitable for measuring the average LPS length in bacterial cells as well as isolated LPS molecules and allows the comparison between strains. In contrast to earlier studies we have used much more precise methodology to assess the LPS molecules average length and modal distribution, also conducted more subtle analysis of complement system activation by lipopolysaccharides of various molecular mass. Data obtained in the complement activation assays clearly demonstrated that S. Enteritidis bacteria require LPS with long O-antigen to resist the complement system and to survive in the G. mellonella infection model.

Bacteriophage cocktail shows no toxicity and improves the survival of Galleria mellonella infected with Klebsiella spp.

Klebsiella spp. are causative agents of healthcare-associated infections in patients who are immunocompromised and use medical devices. The antibiotic resistance crisis has led to an increase in infections caused by these bacteria, which can develop into potentially life-threatening illnesses if not treated swiftly and effectively. Thus, new treatment options for Klebsiella are urgently required. Phage therapy can offer an alternative to ineffective antibiotic treatments for antibiotic-resistant bacteria infections. The aim of the present study was to produce a safe and effective phage cocktail treatment against Klebsiella pneumoniae and Klebsiella oxytoca, both in liquid in vitro culture and an in vivo Galleria mellonella infection model. The phage cocktail was significantly more effective at killing K. pneumoniae and K. oxytoca strains compared with monophage treatments. Preliminary phage cocktail safety was demonstrated through application in the in vivo G. mellonella model: where the phage cocktail induced no toxic side effects in G. mellonella. In addition, the phage cocktail significantly improved the survival of G. mellonella when administered as a prophylactic treatment, compared with controls. In conclusion, our phage cocktail was demonstrated to be safe and effective against Klebsiella spp. in the G. mellonella infection model. This provides a strong case for future treatment for Klebsiella infections, either as an alternative or adjunct to antibiotics.IMPORTANCEKlebsiella infections are a concern in individuals who are immunocompromised and are becoming increasingly difficult to treat with antibiotics due to their drug-resistant properties. Bacteriophage is one potential alternative therapy that could be used to tackle these infections. The present study describes the design of a non-toxic phage cocktail that improved the survival of Galleria mellonella infected with Klebsiella. This phage cocktail demonstrates potential for the safe and effective treatment of Klebsiella infections, as an adjunct or alternative to antibiotics.

The BTB-ZF gene Bm-mamo regulates pigmentation in silkworm caterpillars.

The color pattern of insects is one of the most diverse adaptive evolutionary phenotypes. However, the molecular regulation of this color pattern is not fully understood. In this study, we found that the transcription factor Bm-mamo is responsible for black dilute (bd) allele mutations in the silkworm. Bm-mamo belongs to the BTB zinc finger family and is orthologous to mamo in Drosophila melanogaster. This gene has a conserved function in gamete production in Drosophila and silkworms and has evolved a pleiotropic function in the regulation of color patterns in caterpillars. Using RNAi and clustered regularly interspaced short palindromic repeats (CRISPR) technology, we showed that Bm-mamo is a repressor of dark melanin patterns in the larval epidermis. Using in vitro binding assays and gene expression profiling in wild-type and mutant larvae, we also showed that Bm-mamo likely regulates the expression of related pigment synthesis and cuticular protein genes in a coordinated manner to mediate its role in color pattern formation. This mechanism is consistent with the dual role of this transcription factor in regulating both the structure and shape of the cuticle and the pigments that are embedded within it. This study provides new insight into the regulation of color patterns as well as into the construction of more complex epidermal features in some insects.

The good, the bad and the boa: An unexpected new species of a true boa revealed by morphological and molecular evidence.

Snakes of the genus Boa are outstanding elements of the New World biota with a broad sociological influence on pop culture. Historically, several taxa have been recognized in the past 300 years, being mostly described in the early days of binomial nomenclature. As a rule, these taxa were recognized based on a suite of phenotypic characters mainly those from the external morphology. However, there is a huge disagreement with respect to the current taxonomy and available molecular phylogenies. In order to reconcile both lines of evidence, we investigate the phylogenetic reconstruction (using mitochondrial and nuclear genes) of the genus in parallel to the detailed study of some phenotypic systems from a geographically representative sample of the cis-Andean mainland Boa constrictor. We used cyt-b only (744bp) from 73 samples, and cyt-b, ND4, NTF3, and ODC partial sequences (in a total of 2305 bp) from 35 samples, comprising nine currently recognized taxa (species or subspecies), to infer phylogenetic relationships of boas. Topologies recovered along all the analyses and genetic distances obtained allied to a unique combination of morphological traits (colouration, pholidosis, meristic, morphometric, and male genitalia features) allowed us to recognize B. constrictor lato sensu, B. nebulosa, B. occidentalis, B. orophias and a distinct lineage from the eastern coast of Brazil, which we describe here as a new species, diagnosing it from the previously recognized taxa. Finally, we discuss the minimally necessary changes in the taxonomy of Boa constrictor complex; the value of some usually disregarded phenotypic character system; and we highlight the urgency of continuing environmental policy to preserve one of the most impacted Brazilian hotspots, the Atlantic Forest, which represents an ecoregion full of endemism.

Development and characterization of microsatellite markers for population genetics of the cocoa pod borer Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillaridae).

The cocoa pod borer (CPB) Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillaridae) is one of the major constraints for cocoa production in South East Asia. In addition to cultural and chemical control methods, autocidal control tactics such as the Sterile Insect Technique (SIT) could be an efficient addition to the currently control strategy, however SIT implementation will depend on the population genetics of the targeted pest. The aim of the present work was to search for suitable microsatellite loci in the genome of CPB that is partially sequenced. Twelve microsatellites were initially selected and used to analyze moths collected from Indonesia, Malaysia, and the Philippines. A quality control verification process was carried out and seven microsatellites found to be suitable and efficient to distinguish differences between CPB populations from different locations. The selected microsatellites were also tested against a closely related species, i.e. the lychee fruit borer Conopomorpha sinensis (LFB) from Vietnam and eight loci were found to be suitable. The availability of these novel microsatellite loci will provide useful tools for the analysis of the population genetics and gene flow of these pests, to select suitable CPB strains to implement the SIT.

Identifying Areas of Invasion Risk and Changes in the Ecological Niche Occupied by the Coffee Leaf Miner Leucoptera coffeella (Lepidoptera: Lyonetiidae).

Insects of economic importance such as Leucoptera coffeella can cause high defoliation in plants and reduce crop yields. We aimed to identify changes in the ecological niche and potential zones of the invasion. Occurrence records were obtained from databases and bibliography. WorldClim V2.0 bioclimatic layers were used. For the modeling of the potential distribution, the kuenm R package was used by executing the Maxent algorithm. The potential distribution models suggested greatest environmental suitability extends from Europe, South Asia, and Central and South Africa, showing the "tropical and subtropical moist broadleaf forests" as the ecoregion that presents the greatest probability of the presence of L. coffeella. The potential distribution model projected in the invaded area agrees with the known distribution in the region (America), although the results show that it is occupying environmental spaces not present in the area of origin. This species presented a large proportion of the invaded niche that overlaps the native niche and is colonizing new environmental conditions in the invaded area relative to its native distribution (Africa). This information could be used in the planning of coffee crops on the American continent.

Spatio-temporal classification of land use and land cover and its changes in Kerala using remote sensing and machine learning approach.

Land use and land cover (LULC) analysis gives important information on how the region has evolved over time. Kerala, a land with an extensive and dynamic history of land-use changes, has, until now, lacked comprehensive investigations into this history. So the current study focuses on Kerala, one of the ecologically diverse states in India with complex topography, through Landsat images taken from 1990 to 2020 using two different machine learning classifications, random forest (RF) and classification and regression trees (CART) on Google Earth Engine (GEE) platform. RF and CART are versatile machine learning algorithms frequently employed for classification and regression, offering effective tools for predictive modelling across diverse domains due to their flexibility and data-handling capabilities. Normalised Difference Vegetation Index (NDVI), Normalised Differences Built-up Index (NDBI), Modified Normalised Difference Water Index (MNDWI), and Bare soil index (BSI) are integral indices utilised to enhance the precision of land use and land cover classification in satellite imagery, playing a crucial role by providing valuable insights into specific landscape attributes that may be challenging to identify using individual spectral bands alone. The results showed that the performance of RF is better than that of CART in all the years. Thus, RF algorithm outputs are used to infer the change in the LULC for three decades. The changes in the NDVI values point out the loss of vegetation for the urban area expansion during the study period. The increasing value of NDBI and BSI in the state indicates growth in high-density built-up areas and barren land. The slight reduction in the value of MNDWI indicates the shrinking water bodies in the state. The results of LULC showed the urban expansion (158.2%) and loss of agricultural area (15.52%) in the region during the study period. It was noted the area of the barren class, as well as the water class, decreased steadily from 1990 to 2020. The results of the current study will provide insight into the land-use planners, government, and non-governmental organizations (NGOs) for the necessary sustainable land-use practices.

Biochemistry and transcriptomic analyses of Phthorimaea absoluta (Lepidoptera: Gelechiidae) response to insecticides.

Phthorimaea absoluta is an invasive solanaceous plant pest with highly devastating effects on tomato plant. Heavy reliance on insecticide use to tackle the pest has been linked to insecticide resistance selection in P. absoluta populations. To underline insights on P. absoluta insecticide resistance mechanisms to diamides and avermectins, we evaluated the transcriptomic profile of parental (field-collected) and F8 (lab-reared) populations. Furthermore, to screen for the presence of organophosphate and pyrethroid resistance, we assessed the gene expression levels of acetylcholinesterase (ace1) and para-type voltage-gated sodium channel (VGSG) genes in the F1 to F8 lab-reared progeny of diamide and avermectin exposed P. absoluta field-collected populations. The VGSG gene showed up-regulation in 12.5% and down-regulation in 87.5% of the screened populations, while ace1 gene showed up-regulation in 37.5% and down-regulation in 62.5% of the screened populations. Gene ontology of the differentially expressed genes from both parental and eighth generations of diamide-sprayed P. absoluta populations revealed three genes involved in the metabolic detoxification of diamides in P. absoluta. Therefore, our study showed that the detoxification enzymes found could be responsible for P. absoluta diamide-based resistance, while behavioural resistance, which is stimulus-dependent, could be attributed to P. absoluta avermectin resistance.

Optimizing the releasing strategy used for the biological control of the sugarcane borer Diatraea saccharalis by Trichogramma galloi with computer modeling and simulation.

One of the challenges in augmentative biological control programs is the definition of releasing strategy for natural enemies, especially when macro-organisms are involved. Important information about the density of insects to be released and frequency of releases usually requires a great number of experiments, which implies time and space that are not always readily available. In order to provide science-based responses for these questions, computational models offer an in silico option to simulate different biocontrol agent releasing scenarios. This allows decision-makers to focus their efforts to more feasible options. The major insect pest in sugarcane crops is the sugarcane borer Diatraea saccharalis, which can be managed using the egg parasitoid Trichogramma galloi. The current strategy consists in releasing 50,000 insects per hectare for each release, in three weekly releases. Here, we present a simulation model to check whether this releasing strategy is optimal against the sugarcane borer. A sensitive analysis revealed that the population of the pest is more affected by the number of releases rather than by the density of parasitoids released. Only the number of releases demonstrated an ability to drive the population curve of the pest towards a negative growth. For example, releasing a total of 600,000 insects per hectare in three releases led to a lower pest control efficacy that releasing only 250,000 insects per hectare in five releases. A higher number of releases covers a wider range of time, increasing the likelihood of releasing parasitoids at the correct time given that the egg stage is short. Based on these results, it is suggested that, if modifications to the releasing strategy are desired, increasing the number of releases from 3 to 5 at weekly intervals is most likely preferable.

The complete mitochondrial genome of Chibiraga houshuaii (Lepidoptera, Limacodidae) and its phylogenetic implications.

Chibiraga is a mall East Asian genus in the family Limacodidae (slug-moths). The latter includes many agricultural pests. Mitochondrial genome analysis is an important tool for studying insect molecular identification and phylogenetics. However, there are very few mitogenome sequences available for Limacodidae species, and none for the genus Chibiraga at all. To explore the mitogenome features of Chibiraga and verify its phylogenetic position, the complete mitogenome of Chibiraga houshuaii was sequenced and annotated. The complete 15,487 bp genome encoded 37 mitochondrial genes, including 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a control region (CR). Most of the PCGs had typical ATN start codons and terminated with TAA or a single T residue. UUA (Leu2), AUU (Ile), UUU (Phe), AUA (Met) and AAU (Asn) were the five most frequently used codons. All tRNAs were folded into cloverleaf secondary structure, except for trnS1, which lacked the DHU arm. Phylogenetic analyses within the superfamily Zygaenoidea were performed based on multiple datasets from mitochondrial genes. The results showed that the families Phaudidae, Limacodidae and Zygaenidae were respectively recovered as monophyly; C. houshuaii was clustered in a clade with nettle type larvae in Limacodidae.