Periplaneta americana is a cosmopolitan pest cockroach endemic to tropical and subtropical climates. It occurs frequently in urban sewer and wastewater system and transit in human proximities, spreading pathogens that causes serious public health concerns such as asthma, allergies, and others. By using the Next-generation Sequencing (NGS) known as Illumina NovaSeq 6000, this article documents for the draft genome data set of P. americana collected in Penang Island, Malaysia. This article displays the pair-end 150 bp genome dataset and results on the sequence quality. This genome dataset presents the information for further understanding of P. americana populations at molecular level and the opportunity to develop effective control and management strategies for the species. This dataset is available under Sequence Read Archive (SRA) databases with the SRR23867103.
The subterranean termite Globitermus sulphureus is an important Southeast Asian pest with limited genomic resources that causes damages to agriculture crops and building structures. Therefore, the main goal of this study was to survey the G. sulphureus transcriptome composition. Here, we performed de novo transcriptome for G. sulphureus workers' heads using Illumina HiSeq paired-end sequencing technology. A total of 88, 639, 408 clean reads were collected and assembled into 243, 057 transcripts and 193, 344 putative genes. The transcripts were annotated with the Trinotate pipeline. In total, 27, 061 transcripts were successfully annotated using BLASTX against the SwissProt database and 17, 816 genes were assigned to 47, 598 GO terms. We classified 14, 223 transcripts into COG classification, resulting in 25 groups of functional annotations. Next, a total of 12, 194 genes were matched in the KEGG pathway and 392 metabolic pathways were predicted based on the annotation. Moreover, we detected two endogenous cellulases in the sequences. The RT-qPCR analysis showed that there were significant differences in the expression levels of two genes β-glucosidase and endo-β-1,4-glucanase between worker and soldier heads of G. sulphureus. This is the first study to characterize the complete head transcriptome of a higher termite G. sulphureus using a high-throughput sequencing. Our study may provide an overview and comprehensive molecular resource for comparative studies of the transcriptomics and genomics of termites.
The surge in tropical bed bug Cimex hemipterus (Fabricius) (Hemiptera: Cimicidae) infestations has led to an increase in genomic studies. In this study, the population genetics and breeding patterns of 22 Malaysian populations were analyzed, including genetic differentiation and genetic distance. For seven microsatellite loci, the number of alleles varied from 6 to 14. The allelels per loci contrasted sharply between the overall population and within the populations. The average observed and expected heterozygosity was 0.280 and 0.828 for the overall population and 0.281 and 0.657 among the populations, respectively. Based on polymorphic information criteria, the markers with a value >0.5 were highly polymorphic. In the Hardy-Weinberg equilibrium, the loci of Ch 09ttn, Ch 01dn, and Ch 13dn of the overall population showed signs of a null allele. The stutter peaks caused no scoring errors; large allele dropouts were not detected for any loci; and a correlation imbalance was not indicated. The genetic differentiation among populations was moderate, with a coefficient of genetic differentiation (FST) of 0.144. The bed bug populations showed strong inbreeding, with highly positive coefficients of inbreeding (FIS). The molecular variation attributed to inbreeding was 83% within the populations, compared with 17% among the populations. The admixture individuals in STRUCTURE and neighbor-joining phylogenetic trees also indicated weak genetic structure in the geographical populations, suggesting moderate gene flows between populations. Thus, moderately active dispersion and human-mediated transport shaped the genetic structure of C. hemipterus populations in Malaysia.
Coptotermes termites were collected from forestry habitats at University Sains Malaysia, Penang, while urban samples were collected from residentials from Penang and Kedah, Malaysia. Mitochondrial DNA markers, Cytochrome Oxidase 1 (CO1), and 16S ribosomal RNA (16S rRNA) genes were amplified and sequenced to confirm the species of the termite samples as Coptotermes gestroi. Through Blastn, all 25 CO1 and 16S rRNA sequences, respectively from urban and natural habitats were found to be 99.54-100.00 % similar to C. gestroi reference sequences from previous studies in Peninsular Malaysia. The phylogenetic trees constructed using Neighboring-joining (NJ) and Maximum Likelihood (ML) methods resulted in CO1 sequences clustering in two clades and 16S rRNA sequences clustering in a single clade. The overall mean distance was low for the C. gestroi populations from natural habitats and urban settings (FST = 0.004). Analysis of natural habitat populations using CO1 sequences revealed two haplotypes within the population, with a haplotype diversity (Hd) of 0.045 ± 0.005, while the urban population shared a common haplotype with the natural habitat populations and there was no haplotype diversity recorded between the populations. Urban and natural habitats included only one haplotype for 16S rRNA sequences, indicating a lack of nucleotide diversity. Based on the findings, a non-significant difference between the natural habitat and urban population suggests C. gestroi inhabiting both regions likely originated from a similar source and underwent population homogeneity in different settings facilitated by anthropogenic dispersal.
Nectar is the staple diet of adult mosquitoes in the wild, but its availability is inconsistent and can be affected by rainfall. In urban centers, Aedes vectors commonly use man-made containers as their major habitat; however, they can colonize any items replenished by rainfall. Garbage output has increased significantly in recent years, at a time when collection frequency is reducing. Such garbage usually includes organic components, some of which are sweet and can be fed upon by other animals or become can containers for rainwater. Despite evidence that Aedes larvae can thrive in containers comprised of organic waste material, which can be produced by rodents gnawing on fruits or vegetables, and that adults can survive on sweet waste fluids, the capacity of organic waste materials to accumulate rainwater and act as egg deposition sites has not been examined. It is also unknown for how long sweet extracts can sustain the life of adult vectors. Here, we investigated the abundance of sweet leftovers at garbage sites and the rainwater retention capacity of some organic materials through a field survey and laboratory bioassays. We also examined whether sweet waste fluids impact egg hatching success and longevity of Aedes aegypti. The results of this study indicated that sweet products with leftovers are highly prevalent in garbage. When exposed to rain, food items (BAFrc, banana fruit resembling container; and BSPrc, boiled sweet potato resembling container) and the packaging of sweet foods (SMIc, sweetened condensed milk can) retained water. When provided an opportunity to oviposit in cups containing BAF extract (BAFex), BSP extract (BSPex), and SMI extract (SMIex), eggs were deposited in all media. Egg maturation in the BAFex environment resulted in similar larval eclosion success to that resulting from embryo development in a water milieu. Adults maintained on sweet waste extracts had long lifespans, although shorter than that of their sugar solution (SUS)-fed counterparts. Taken together, these results indicated that sweet waste materials are useful to dengue mosquitoes, acting both as oviposition sites and energy sources.
In this paper, we present the metagenomic dataset of gut microbial DNA of the lower group of subterranean termites, i.e. Coptotermes gestroi, and the higher groups, i.e. Globitermes sulphureus and Macrotermes gilvus, in Penang, Malaysia. Two replicates of each species were sequenced using Next-Generation Sequencing (Illumina MiSeq) and analysed via QIIME2. The results returned with 210,248 sequences in C. gestroi, 224,972 in G. sulphureus, and 249,549 in M. gilvus. The sequence data were deposited in the NCBI Sequence Read Archive (SRA) under BioProject number of PRJNA896747. The community analysis showed that Bacteroidota is the most abundant phylum in C. gestroi and M. gilvus, while Spirochaetota is prevalent in G. sulphureus.
The metagenomic datasets of the microbial DNA from tropical bed bugs (Cimex hemipterus) after feeding on human blood were presented. Next-generation sequencing of the community DNA was carried out on an Illumina Miseq platform and the raw fastq files were analyzed using QIIME (version 1.9.1). The metagenome of three samples comprised of 108,198 sequences representing 44,646,263 bps with a mean length of 412.63 bps. The sequence data is accessible at the NCBI SRA under the bioproject number PRJNA600667. Community analysis showed Proteobacteria was the most abundance (more than 99%) microbial community that present in the guts of fully fed tropical bed bugs.
The metagenomics dataset presented here is based on bacterial 16S rDNA gene amplicons of DNA extracted from tropical bed bugs (Cimex hemipterus). Amplicon-based sequencing was performed using the Illumina MiSeq platform, and the raw sequence data were analyzed using QIIME (version 2022.8.3). The metagenome sequence comprised ten samples that include C1 (133 511bps), C2 (108 920bps), CH1 (106 562bps), CH2 (101 778bps), P1 (103 618bps), P2 (133 258bps), T1 (113 558bps), T2 (133 952bps), TM1 (125 335bps), and TM2 (118 345bps). The sequence data is readily accessible at the NCBI SRA under bio project PRJNA918835. The most abundant microbial community present in the C. hemipterus is the Proteobacteria, with more than 99% of the abundance.
The German cockroach, Blattella germanica (L.), a prominent pest that requires management due to its detrimental economic and medical consequences. Several research discovered that German cockroaches were insecticide resistant, mainly commercial pesticides. One-week-old nymphs from two strains in Penang, Malaysia (Georgetown strain: EL and Greenlane strain: IC strain) were tested in the laboratory against two commercial insecticides, Cislin® 25 (deltamethrin) and Sumithion 50 (fenitrothion). The concentration of solutions used in the residual test based on the manufacturer labeling. Cislin® was tested at 1.90 ppm, 1.60 ppm, 1.30 ppm, and 1.0 ppm; Sumithion 50 was tested at 25 and 27.00 ppm, 23.00 ppm, 18.00 ppm, 14.00 ppm using the residual method. Probit analysis and one-way analysis of variance (ANOVA) were used to compare the data. Cislin® 25 and Sumithion 50 were more effective and high toxicity against the IC strain compared with the EL strain. Sumithion 50 demonstrated a fast knockdown time on cockroaches, but Cislin® 25 showed no knockdown time. Sumithion 50 showed a significant mortality rate in cockroaches within a short period of time compared to Cislin® 25. Both insecticides were found to be effective against both strains, but Sumithion 50 is more effective at controlling cockroaches than Cislin® 25.
The ability to isolate and generate a DNA profile from human DNA recovered from tropical bed bugs (Cimex hemipterus) for identifying individuals can be useful for public health, forensic, and medical entomology. In this study, genomic DNA was recovered from both male and female bed bugs at every time interval tested (0, 1, 3, 5, 7, 14, 30, and 45 days post blood meal). The total DNA concentrations recovered from male bed bugs ranged from 12.93 to 65.97 ng/µL, while the total DNA concentrations from female bed bugs ranged from 8.93 to 44.53 ng/µL. However, based on the results from the BLAST search and PCR products, human DNA could be detected from female bed bugs at 0, 3, 5, 14, and 30 days post blood meal using the D18S51 marker. Concentrations of PCR products of the D18S51 locus from male bed bugs ranged from 4.20 to 35.50 ng/µL, whereas, for female bed bugs, concentrations ranged from 4.31 to 22.47 ng/µL. These were generally higher compared to the PCR products of the first hypervariable part (HVR1) marker. The results indicate the HVR1 locus was less sensitive than the D18S51 locus.
Due to the growing public health and tourism awareness, Cimex hemipterus Fabricius (Hemiptera: Cimicidae) has gained a great interest in increasing reported infestation cases in tropical regions of the world, including Malaysia. Since the information on the molecular ecology and population biology of this species are tremendously lacking, the isolation and development of molecular markers can be used to determine its genetic structure. In this study, novel microsatellite primers isolated from enriched genomic libraries of C. hemipterus were developed using 454 Roche shotgun sequencing. Seven validated polymorphic microsatellite primers were consistently amplified and characterized from 70 tropical bed bugs collected from seven locations throughout Malaysia. The number of alleles per locus identified ranged from 6 to 14. Comparison of loci for overall and between population were done with mean observed and expected heterozygosity were determined at 0.320 and 0.814, 0.320 and 0.727, respectively. Polymorphic information criteria (PIC) valued the markers as highly informative as PIC >0.5. Overall population, they are possibly in Hardy-Weinberg equilibrium with loci Ch_09ttn, Ch_01dn, and Ch_13dn showing signs of a null allele. There were no scoring errors caused by stutter peaks, no large allele dropout was detected for all loci and showed no evidence of linkage disequilibrium. In conclusion, all seven molecular microsatellite markers identified can be beneficially used to gain more information on the population genetic structure and breeding patterns of C. hemipterus as well as the relationship of dispersal and infestation.
The potential of integrating the mycoinsecticide, Metarhizium anisopliae (Met.), into house fly control programs is tremendous. However, the interaction between the fungus and insecticide, when applied at poultry farms, remains poorly understood. This study investigated the interaction between M. anisopliae and two selected insecticides, cyromazine and ChCy (a mixture of chlorpyrifos and cypemethrin), with three objectives: to assess the compatibility of M. anisopliae and the insecticides by measuring fungal vegetative growth and conidia production in the presence of insecticides; to evaluate the effect of M. anisopliae on these insecticides by analyzing insecticidal residue using ultra performance liquid chromatography; and to study the synergistic effects of M. anisopliae and the insecticides by applying sublethal concentrations of insecticides with M. anisopliae to house fly larvae. Metarhizium anisopliae was more tolerant to ChCy than to cyromazine, as M. anisopliae showed significantly more growth when grown with this insecticide. The M. anisopliae + ChCy combination resulted in significantly less chlorpyrifos residues compared to the ChCy plate, and 62-72% house fly larva mortality occurred when M. anisopliae and sublethal concentrations of ChCy were combined, implicating synergistic effects of the fungus with low concentrations of ChCy. Integrating M. anisopliae with compatible chemical at right concentration is crucial for poultry farm house fly control programs.
In this study, bifenthrin (Maxxthor SC, Ensystex Australasia Pty Ltd), imidacloprid (Prothor SC, Ensystex Australasia Pty Ltd) and fipronil (Regent(®)50SC, Bayer) were applied on the natural infest manures according to the manufacturer rate during a broiler breeding cycle. Solvent direct-immersion extraction (SDIE) was used in detecting the target compound and later, quantification of the insecticide residues in field condition was investigated. The samples were prior cleaned up by solid-phase extraction (SPE) and analysed by Ultra-Performance Liquid Chromatography (UPLC) - photodiode array (PDA) system. In the field trial, three insecticides were showed accumulation during the broiler breeding period and it is suggested that they acted as adulticides when applied on the poultry manures, this is supported by the significant correlation between the increment of insecticide residues to the reduction percentage of adult flies (<0.05). Fipronil showed significantly greater reduction on the adult fly compared to the other insecticides, in which the reduction rate compared to control population at the end of the broiler breeding period; fipronil, imidaclopril and bifenthrin reduced 51.51%, 28.30% and 30.84% of adult flies, respectively.
Despite major insecticide-based vector control programs, dengue continues to be a major threat to public health in urban areas. The reasons for this failure include the emergence of insecticide resistance and the narrowing of the spectrum of efficient products. Cigarette butts (CBs), the most commonly discarded piece of waste, also represent a major health hazard to human and animal life. CBs are impregnated with thousands of chemical compounds, many of which are highly toxic and none of which has history of resistance in mosquitoes. This study was performed to examine whether exposure to CB alters various biological parameters of parents and their progeny. We examined whether the mosquito changes its ovipositional behaviors, egg hatching, reproductive capacity, longevity and fecundity in response to CB exposure at three different concentrations. Females tended to prefer microcosms containing CBs for egg deposition than those with water only. There were equivalent rates of eclosion success among larvae from eggs that matured in CB and water environments. We also observed decreased life span among adults that survived CB exposure. Extracts of CB waste have detrimental effects on the fecundity and longevity of its offspring, while being attractive to its gravid females. These results altogether indicate that CB waste indirectly affect key adult life traits of Aedes aegypti and could conceivably be developed as a novel dengue vector control strategy, referring to previously documented direct toxicity on the larval stage. But this will require further research on CB waste effects on non-target organisms including humans.
Tropical bed bugs, Cimex hemipterus, which commonly feeds on human blood, may be useful in forensic applications. However, unlike the common bed bug, Cimex lectularius, there is no information regarding tropical bed bug, C. hemipterus, being studied for its applications in forensics. Thus, in this study, lab-reared post-feeding tropical bed bugs were subjected to Short Tandem Repeat (STR) and Single Nucleotide Polymorphism (SNP) analyses to establish the usage of tropical bed bugs in forensics. Several post-feeding times (0, 5, 14, 30, and 45 days) were tested to determine when a complete human DNA profile could still be obtained after the bugs had taken the blood meal. The results showed that complete STR and SNP profiles could only be obtained from the D0 sample. The profile completeness decreased over time, and partial STR and SNP profiles could be obtained up to 45 days post-blood meal. The generated SNP profiles, complete or partial, were also viable for HIrisPlex-S phenotype prediction. In addition, field-collected bed bugs were also used to examine the viability of the tested STR markers, and the STR markers detected mixed profiles. The findings of this study established that the post-blood meal of tropical bed bugs is a suitable source of human DNA for forensic STR and SNP profiling. Human DNA recovered from bed bugs can be used to identify spatial and temporal relations of events.
The medically important mosquito, Aedes albopictus is native to Asia and has become a major health concern in most Asian countries including Malaysia. Being recognized as a dengue vector, a clearer understanding of how mosquito populations are geographically connected, may therefore represent a profound yet significant understanding of control strategies. There are no documented reports on the genetic structure of Ae. albopictus populations from different developed settlements inferred from microsatellite DNA markers in Malaysia, particularly in Penang Island (Northern Peninsular Malaysia). Here, we assessed the molecular population genetics of Ae. albopictus in terms of their allelic variation, genetic diversity and population structure. A total of 42 mosquitoes were sampled from Jelutong, Batu Maung and Balik Pulau which represented urban, suburban and rural areas in Penang Island respectively and analysed for polymorphism at six microsatellite loci. All of the microsatellite markers were successfully amplified and were polymorphic, showing low genetic structure among geographic populations (FST= 0.0362). It is supported with admixture individuals observed in STRUCTURE and FCA and this suggests that high gene flow has been experienced between populations. These findings implicate passive dispersal through human-aided transportation; as a factor shaping the genetic structure of Ae. albopictus populations in Penang Island.
The tropical bed bug is scientifically recognized as a significant public health problem. While there is an increased awareness about their resurgence by medical and life science committees, efficient bed bug management still remains unresolved. The solution may soon arise, as information about bed bugs' infestation dynamics and systematics are becoming more distinguishable. Recent developments in studies about bed bugs are based on molecular intervention by determining their genetic variation and phylogeography. The aim of this study is to assess the phylogenetic relationships and genetic diversity among the populations of tropical bed bugs inhabiting Malaysia. A molecular genotyping study was conducted with 22 tropical bed bug populations composed of three individuals per population. The mitochondrial (COI) gene was used as a marker. The data obtained were analyzed using the T-Coffee, ClustalX, MEGA 6.0, and PAUP software. The results showed one main monophyletic clade that consisted of two groups: Ch01 and Ch02. Ch02 consists of samples from the Bandar Hilir population, differing from the other populations studied by one singleton base. However, as there were no changes in the amino acid, this singleton genetic variation was considered to have no effect on genetic differentiation. Ch01 shows similarity with some sequence of Cimex hemipterus (F.) from Thailand, suggesting an international diversity connection. The disparity index apparently suggests that all isolates are homogeneous populations and are supported by the low value of the mean pairwise distance between isolates. This study will increase the knowledge about phylogeographic diversity of tropical bed bug in Malaysia.
Three polymerase chain reaction (PCR) techniques were compared to analyse the genetic diversity of Clinacanthus nutans eight populations in the northern region of Peninsular Malaysia. The PCR techniques were random amplified polymorphic deoxyribonucleic acids (RAPD), inter-simple sequence repeats (ISSR) and random amplified microsatellite polymorphisms (RAMP). Leaf genomic DNA was PCR amplified using 17 RAPD, 8 ISSR and 136 RAMP primers . However, only 10 RAPD primers, 5 ISSR primers and 37 RAMP primers produced reproducible bands. The results were evaluated for polymorphic information content (PIC), marker index (MI) and resolving power (RP). The RAMP marker was the most useful marker compared to RAPD and ISSR markers because it showed the highest average value of PIC (0.25), MI (11.36) and RP (2.86). The genetic diversity showed a high percentage of polymorphism at the species level compared to the population level. Furthermore, analysis of molecular variance revealed that the genetic diversity was higher within populations, as compared to among populations of C. nutans. From the results, the RAMP technique was recommended for the analysis of genetic diversity of C. nutans.
This study examined the tunneling activity and the behaviour of two subterranean termites, Globitermes sulphurues and Coptotermes gestroi treated with four plant extracts, namely Pyllanthus niruri, Azadirachta indica, Leucaena leucocephala and Andrographis paniculata. All plants were extracted with three different solvents (methanol, hexane and water) and were diluted into three concentrations (500, 5,000 and 10,000 ppm). A group of 50 workers and 2 soldiers were tested and observed daily during the exposure in order to determine their survivorship and behaviour. Both sections were scored to determine their tunneling activities after seven days. There was a significant difference of tunneling activities of C. gestroi on sand treated with plant extracts (X2(2) = 31.790, p < 0.0001) with a mean rank of 8.50 for methanolic extracts and 32.50 for both hexane and water extracts. Meanwhile, no significant difference was observed on tunneling activity of G. sulphureus on treated sand (X2(2) = 2.200, p = 0.333) with a mean rank of 20.72 for methanolic extracts, 26.31 for water extracts and 26.47 for hexane extracts. Results showed that plants extracted with methanol demonstrated strong repellent properties with 0 tunneling activity on the treated sand and low survivorship of both termites. Moreover, both termites did not survive (0%) when they were treated with methanolic extracts at 10,000 ppm. They also displayed a different behaviour post-exposure such as avoidance, gradually losing the ability to walk and low feeding consumption. These results indicate that there is a strong termiticidal activity of plants extracted with methanol against C. gestroi and G. sulphureus.