Search

[Display omitted] • Proteobacteria and Firmicutes were the most predominant phyla identified from Pheidole rugaticeps. • Acinetobacter and Enterococcus might be vital parts of the microbiota of Pheidole rugaticeps. • These findings provided insight on the bacterial communities associated with Pheidole rugaticeps. Insect microbiota are receiving increasing attention from researchers, particularly with the continued advances in next generation sequencing (NGS) techniques. However, there is a paucity of data on the microbiota of ants that scavenge around human settlements. In this study, we characterized the bacterial communities of Pheidole rugaticeps Emery that were collected scavenging on other household insects using Illumina MiSeq high-throughput sequencing of the bacterial 16S ribosomal DNA gene. P. rugaticeps DNA was extracted from the insect samples using a HiYield™ Genomic DNA isolation kit according to the manufacturer's protocols and amplified using polymerase chain reaction (PCR). The PCR products were sequenced with the Illumina MiSeq platform according to the standard protocols to amplify the V3–V4 of the 16S rDNA gene. The results for the 16S rDNA genes were analysed using QIIME 2 Core − 2020.6, and a 16S rDNA metabarcoding dataset was presented. A total of 46,651 reads were obtained from three genomic samples. A total of 368 amplicon sequence variants (ASV) comprising 165 genera were revealed and classified into 17 phyla. Proteobacteria (57.47%) and Firmicutes (33.14%) were the most abundant taxa, while Acinetobacter (37.10%) was the most abundant genus in all three sampling groups. Pathogenic bacteria species, such as Acinetobacter baumannii (15%) and Pseudomonas aeruginosa (2.92%), were identified from P. rugaticeps samples collected from a hospital environment. However, this study recommends more studies on the microbiota of Pheidole ants with different feeding habits and habitats to establish their core microbiome. [ABSTRACT FROM AUTHOR]

Abstract Globitermes sulphureus is a major pest in coconut plantations and also a secondary pest in the urban, suburban and rural areas of building structures, as well as in tropical agriculture areas. Although the literature revealed microbiome in termite guts, the bacterial community in G. sulphureus intestinal tracts remain largely unidentified. Here, we aimed to characterize the bacterial community associated with the worker and soldier castes of G. sulphureus using 16S metagenomic. The Illumina HiSeq 2500 sequencing machine was used to amplify the V3 and V4 regions of the 16S rRNA gene. The sequencing output was analyzed using Qiime pipeline v1.9.1. The result of the analysis showed that Spirochaetes, Fibrobacteres, Firmicutes, Proteobacteria, and Bacteroidetes were the dominant phyla that reside in the guts of the worker and soldier castes. We found that the worker and soldier castes shared similar bacterial phyla in their guts but different bacterial genera. Our findings provided a baseline information on microbial community inhabiting G. sulphureus guts up to the genus level for some phyla. Graphical abstract Unlabelled Image Highlights • Worker and soldier castes of G. sulphureus shared similar symbiotic bacterial phyla. • Spirochaetes, Fibrobacteres, and Firmicutes were the dominant bacterial phyla. • Spirochaetes and Fibrobacteres were prevalent in wood-feeding higher termites. • Treponema and Fibrobacteres-2 were the dominant bacterial genera. [ABSTRACT FROM AUTHOR]

Abstract Host-plant preferences of Tetraponera rufonigra Jerdon (Hymenoptera: Formicidae) were assessed by field measurement in relation to the types of trash found in the surrounding tree perimeters. The correlations between the density of T. rufonigra and the plants (types of trash and levels of infestation) were determined based on the data gathered at 34 study sites in the Eastern part of the Penang Island to clarify the density differences of T. rufonigra among the sites. A simple linear regression analysis was also employed to assess the effects of environmental parameters i.e. UV light, temperature and humidity on the density of T. rufonigra. No significant difference was found between the infestation level at each site and the types of trash. Six species were identified as host-plant preferences of T. rufonigra i.e. Cassia fistula L., Azadirachta indica A. Juss., Mimusops elengi L., Delonix regia (Hook) , Cerberra odollam Gaertn and Tabebuia rosea (Bertol.). These tree species were recorded for the first time as the most preferred host trees by T. rufonigra in Malaysia. The results also identified that T. rufonigra preferred the trees with high humidity level, suitable surrounding temperature and UV light as their habitats. Graphical abstract Unlabelled Image Highlights • Host-plant preferences were assessed by field measurement of Tetraponera rufonigra density in relation to types of trashes. • T. rufonigra showed specific plant preferences. • Humidity, temperature and UV light density influence T. rufonigra distribution. [ABSTRACT FROM AUTHOR]

Odor sensation is a sensory modality of considerable significance in the foraging behavior and interactional organization of ants. In the food bait technology, smell is the basis of attraction, which, in turn, is the line of bait use and a key parameter for judging efficacy. Yet, the currently available baits possess low attractiveness to many ant pests. Hence, strategies to produce ant bait with increased attractiveness are needed. Despite evidence that coffee has a diverse aroma complex that affects the behavior of honey bees and ants, its attraction to house-invading ants has yet to be investigated. In a series of Y-tube olfactometer bioassays, we examined the behavioral responses of Tapinoma indicum (TI), Monomorium pharaonis (MP) and Solenopsis geminata (SG) to various coffee-induced odor stimuli, comprised of extracts from Arabica, Robusta and Liberica. All coffee extracts showed an influence on the behavior of TI, MP and SG workers, with Arabica showed the most significant influence to the tested ants. The workers of TI, MP and SG were more attracted to the odor of 0.01% Arabica extract (ONE), in comparison with 0.05% Arabica extract (TWO) or 0.10% Arabica extract (THREE). Arabica extract mixed with sugar (S) elicited a significant attraction from workers of all three species in a balanced competition with either unsweetened Arabica extract or water. These results indicated that coffee, particularly Arabica, was attractive to the foragers of TI, MP and SG, thus, the use of coffee as a novel stimulus agent seems plausible in ant bait development. [ABSTRACT FROM AUTHOR]

Tetraponera rufonigra , commonly known as the arboreal bicolored ant has gained its notoriety as one of the medically-important pest insects in Malaysia. T . rufonigra is recognizable by its excruciating sting, causing a severe anaphylaxis especially to those with the history of allergy. In this study, genetic diversity and population structure of T . rufonigra populations were examined based on a 503 base pair fragment of the mitochondrial DNA Cytochrome Oxidase I (COI) gene. Specimens were collected from six different localities in urban areas in the eastern part of Penang Island. The six populations exhibited high pairwise genetic differentiation (F ST ), ranging from 0.42 to 1.00 and low gene flow (Nm), ranging from 0.00 to 0.69, except for populations of CSA and CH (F ST = 0.0, N m = − 1813.68). From AMOVA analysis, a high genetic variation was observed among populations i.e. 99.58% (F ST = 0.996 p = 0.000 ± 0.000). These results provided the basic information for entomologists to better understand the difference of genetic structure of T . rufonigra at a population level and can be further utilized to estimate the contributing factors in the genetic differentiation of this species in urban areas. Our results suggested that the population structure and the gene flow of T . rufonigra in some studied areas might have been affected by the dispersal ability of the insect, environmental conditions, and/or human-mediated dispersal, while, populations of other areas retained their gene flow. These findings might provide useful baseline information for the implementation of area-wide pest management as well as for further characterization of genetic variation and population structure of this medically-important pest. [ABSTRACT FROM AUTHOR]

Objective To test the effectiveness of conidial spore formulations [ Aspergillus tubingensis ( A. tubingensis ) and Trichoderma harzianum ( T. harzianum )] against tropical bed bugs, Cimex hemipterus . Methods Spore formulations were made from two fungal strains, T. harzianum and A. tubingensis . The bed bugs were exposed to the conidial spores placed soaked onto a fabric cloth for 1 h and the mortality counts were recorded daily until 14 days. Results Mean survival times based on Kaplan–Meier survival analysis showed no significant differences between all the concentrations in both the fungal isolates: T. harzianum and A. tubingensis . However, the evaluation of both the isolates in terms of virulence resulted in low lethal hours in all the concentrations except for the high concentration of A. tubingensis (LT 50 = 44.629 h) at the conidial exposure of 1 × 10 6 spores/mL. Rapid mortality of the bed bugs was observed from Day 6 to Day 12, ranging from 13% to 90% in all three concentrations of A. tubingensis . With reference to the T. harzianum exposure, the concentration of 1 × 10 4 spores/mL displayed a gradual increase in the percentage mortality of 90 on Day 14. Conclusions Approaches to the bed bugs treatment should be explored in-depth using a natural biological agent like fungus especially A. tubingensis to reduce this pest population, in order to replace chemical methods. [ABSTRACT FROM AUTHOR]

The magnitude of dengue transmission depends largely on the level of human–vector contact. Therefore, knowledge regarding the biting periodicity of mosquitoes is crucial to determine transmission periods' risk, and in planning personal protection measures. Dengue vectors are day-active and endure transitory periods of starvation overnight. However, it is unclear how their blood feeding activity pattern is related to body size when temporarily deprived of their main source of energy — sugar. We examined the changes in Aedes albopictus diurnal biting activity, taking into account larval nutritional history and adult starvation. Overall, large body size and non-starvation conditions were associated with better blood feeding success, but these parameters did not significantly modify the timing of first blood feeding attempt. Females of both sizes showed significant temporal variations in their blood feeding activities. Under conditions of starvation, blood meal uptake was much greater in large females from morning to evening. Similar variations of feeding activity were observed in small females, except in the morning. Under non-starvation conditions, the blood feeding activity of small mosquitoes tended to decrease over time, whereas blood meal uptake activity was high and remained almost constant from morning to evening for larger mosquitoes. This work emphasizes the importance of body size and hunger on the dynamics of vector–host interaction and has important implications for the development of novel strategies for the prevention of disease transmission. Knowing when dengue vectors actively bite during the day can help in timing effective personal protective measures. [ABSTRACT FROM AUTHOR]

Objective To investigate some morphological and molecular characteristics of fungal parasites isolated from wild tropical bed bug, Cimex hemipterus . Methods A series of culture methods were used to obtain fungal isolates from field-collected bed bugs. Characteristics of the isolates such as colony appearance, mycelial texture and pigmentation were studied to explore their morphology. Isolates were also subjected to a PCR-based genotyping test. Results There were noticeable differences in morphological characteristics among the four isolates. Conidial areas of one isolate were dark green, whereas those of the remaining colonies were olive-green, black or dark brown. Conidia of the dark green isolate were globose, while those of olive-green, black and dark brown isolates were globose to subglobose, globose to spherical and globose to subglobose/finely roughened, respectively. These morphological specificities and the molecular analyses showed that the fungal internal transcribed spacer ribosomal region and β-tubulin gene sequences of the isolates shared clade with Trichoderma and Aspergillus sequences. Conclusions Overall, the new discovery of common pathogens in agricultural field developed in live bed bugs storage tank may initiate the use of biological agents in later years. [ABSTRACT FROM AUTHOR]

Termiticidal activity of chitinase enzyme of Bacillus licheniformis, a symbiont isolated from the gut of Globitermes sulphureus worker. In this article, on page 5, there is a sentence that reads: "The crude chitinase was not effective against termites within 48 h when they were provided with treated filter paper as bait (Fig. This sentence should read: "For experiment 2, the crude chitinase was less effective against termites when they were exposed to the sand treated medium within 48 h (Fig. [Extracted from the article]

Chitinase is a digestive enzyme that breaks down glycosidic bonds in chitin. Chitin is a biopolymer that can be found in the exoskeleton of insects, fungi, yeast, and algae, and in the internal structures of other vertebrates. Bacillus licheniformis strain USMW10IK was isolated from the guts of Globitermes sulphureus workers. The production of chitinase was highest during the stationary phase (72–96 h of incubation) with the enzyme activity was 0.0057 U/mL – 0.0058 U/mL. The crude chitinase extracted after 72 h was used as biotermiticide against termite G. sulphureus. A pathogenic bioassay was done in four methods; no choice, treated sand medium, topical (Petri dish lined with filter paper), and topical (Petri dish lined with sterile sand). Termite mortality was observed for 24–48 h as the crude chitinase stability has decreased by 22.8% after 48 h. As a result, topical (Petri dish lined with filter paper) has caused significant termite mortality after 24 h and topical (Petri dish line with sterile sand) gave significant termite mortality after 48 h while no choice and sand treated medium gave no significant mortality. These findings suggest that chitinase is effective to be used as a biotermiticide when it directly contacts with the termite skin. [ABSTRACT FROM AUTHOR]