53 research outputs found
Studies On Foraging And Evaluations Of Imidacloprid Treatments For Controlling Subterranean Termites In Selected Premises (Isoptera:Rhinotermitidae) [QL529. H139 2007 f rb].
A survey was conducted in Penang to determine the main termite infestation in buildings.
Satu tinjauan telah dijalankan di negeri Pulau Pinang untuk menentukan spesies anai-anai perosak utama bangunan
The Breeding Pattern and Population Genetic Structure of Coptotermes gestroi (Blattodea: Rhinotermitidae) Population in Natural Woodland Habitats
Microsatellite markers are suitable tools for assessing the population structure of eusocial species, especially those with a dynamic breeding system, such as the Asian subterranean termite Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae). Therefore, this study applied seven microsatellite markers to infer the breeding pattern and population genetic structure of C. gestroi found in natural woodland habitats at Universiti Sains Malaysia, Penang, Malaysia. The natural woodland habitat C. gestroi colonies show significant deviation from HWE (all p < 0.05). The uncovered genetic pattern suggested that the C. gestroi colonies presented a combined breeding pattern of mixed- and extended-family colonies with moderate genetic differentiation and elevated inbreeding. In particular, the breeding pattern of C. gestroi colonies was inferred to vary depending on the demographic variation and the age of the colony. Nevertheless, the results revealed comprehensive information on the C. gestroi population structure, habitat-specific to natural woodlands. Furthermore, future studies with exclusive datasets on the population structure of C. gestroi on marginal demography are necessary to enhance the management strategies of this pest species.
Define colony number of subterranean termites coptotermes gstroi (Isoptera: Rhinotermitidae) in selected infested structures
Termites are one of the social insects living in large colonies that can cause economic loss. The objective of this study was to estimate foraging territory of infested subterranean termites on building structure. A mark-recapture study was conducted on eight Coptotermes gestroi colonies located at selected infested building structures in Penang, Malaysia. From the foraging study, the population of C. gestroi was estimated to be within the range of 106,592±6,968 to 4,185,000±2,127,328. Additionally, the foraging territory was from 13 to 300 m2 of the infested building structures. Meanwhile the maximum foraging distance was from 4 to 30 m of the infested structures. The results indicated that each of the building structures was infested by a single colony. This study also showed that the triple mark recapture technique used to estimate the population size of the termite colony was capable of providing rough estimates of foraging population of C. gestroi
Genetic diversity and phylogenetic relationship of higher termite Globitermes sulphureus (Haviland)(Blattodea:Termitidae)
The subterranean higher termite Globitermes sulphureus (Blattodea: Termitidae), is a peridomestic forager and regarded as a significant pest in Southeast Asia. In this study, the populations of G. sulphureus from the USM main campus area were investigated based on partial sequences of the mitochondrial COII gene. The genetic diversity was determined using DnaSP v5 software while the phylogenetic relationship was defined using Neighbor-joining (NJ) and maximum likelihood (ML) methods using Molecular Evolutionary Genetics Analysis (MEGA 7) software. A total of 2 haplotypes were detected among the 5 sample sequences that differed by two variable sites. In addition, both phylogenetic trees gave similar topology and supporting the results from haplotype diversity. Based on the haplotype diversity and molecular phylogeny, it is proposed that geographic isolation and lack of human activities have contributed to the neutral genetic diversity of G. sulphureus.
Population Genetic Structure and Breeding Pattern of Higher Group Termite Globitermes sulphureus (Haviland) (Blattodea:Termitidae)
The subterranean termite Globitermes sulphureus (Blattodea: Termitidae) can be found in tropical regions. We chose seven novel species-specific microsatellite markers to infer the breeding pattern of G. sulphureus based on its colony and population genetic structure in eight selected populations (natural-n = 4 and metropolitan-n = 4) in Kedah and Penang, Malaysia. A strong correlation with their geographical location is shown by the acquired genetic gap for all studied populations from this study. The breeding pattern of family structure and comparisons of estimated F-statistics among G. sulphureus workers suggests 60% of all colonies are mixed families, whereas the remaining are simple families. Average relatedness values within simple and mixed family colonies are similar (r = 0.121). Positive fixation index FST values (FST = 0.086) indicate all eight populations (>500 m apart) have a significantly moderate genetic differentiation and low levels of inbreeding based on the low overall inbreeding coefficient FIT value of 0.391. Furthermore, four populations; Palapes USM (PU), Tmn Astana (TA), Kg Teluk (KT), and Penang National Park (NP), deviate from Hardy–Weinberg equilibrium (HWE, all p = 0.000) and five studied polymorphic loci (GS1, GS10, GS15, GS27 and GS29) are possibly under selection. The findings also reveal signs of a bottleneck effect in two populations: Tikam Batu (TB) and Penang National Park (NP), indicating genetic drift
Effects of different coffee extracts on the egg fertility and lifespan of dengue vectors (Aedes albopictus and Aedes aegypti) (diptera: culicidae)
This study was conducted to examine the impacts of various
extracts of coffee on the egg production aedes fertility and adult
lifespan in two dengue vectors. Coffee is known for its chemical
richness that is so far no resistance in insects was documented.
For this purpose, two types of extracts (crude and used) from
two types of coffee (fresh and roasted) of Coffea canephora
(Robusta coffee) were used. We compared the effects of the
extracts on the egg hatching responses and the longevity of
dengue vectors; Aedes albopictus and Aedes aegypti. Overall,
the roasted coffee extracts tend to have more negative impact
than the fresh coffee extracts in reducing the hatching success.
Crude extracts of both fresh/green and roasted coffee seems to exerts more chemicals and appears to be more acidic than the
used extracts in which resulted in reduced rate of larval
eclosion. Longevity statistically has no difference among coffee
extracts However, based on the overall observation on the
longevity of the adult and the difference in the longevity
suggested that the exposure of the coffee to the dengue vectors
during the embryogenesis does reduces the longevity of the
survived adult by few days difference
Laboratory efficacy of insect growth regulators on the mortality rate of tropical bed bugs, Cimex hemipterus (F.)
Cimicidae are blood feed ectoparasites of mammals and birds. The Cimex hemipterus has
been pestering humans since before globalisation and urbanisation. Till today, this pest has
shown resilience and resurgence in infestation cases as documented in North and South
America, Africa, Asia, and Europe. Hence, research on the efficacy of insect growth regulators
was conducted using surface contact bioassay on a plastic surface using six insecticides at four
concentrations (100ppm, 500ppm, 1000ppm, and 10 000ppm). Bioassay was performed in
triplicates comprising of five-bed bugs (an adult male, two adult females, and two nymphs) per
replicate. Six exposure times were designed; 1hr, 2hr, 3hr, 24hr, 48hr, 72hr and continuous
exposure until mortality was achieved. The mean mortality of bed bugs within the first week
of exposure demonstrated significant difference (P=0.004) while when evaluated for
continuous exposure of 13 weeks tropical bed bugs showed no significant interaction
(P=0.126) with zero knockdown rate. Treated bed bugs indicate significant difference between
the mean egg deposited and hatched (P<0.001). During the exposure, chlorfluazuron resulted
in the fastest mortality rate, followed by beta-cyfluthrin+imidacloprid, tebufenozide,
methoprene, chlorfluazuron, and pyriproxyfen. Better killing efficacy was observed in
insecticide at high concentrations, followed by lower concentrations with a slightly slower
mortality assessment interval. The mortality of bed bugs proves that insect growth regulators
do work on bed bugs. Further studies should be done before better control measures could be
proposed to curb the infestation of bed bug populations
Morpho-molecular characterization and phylogenetic relationship of Tapinoma indicum forel from metropolitan area
Tapinoma indicum Forel is one of the most abundant nuisance pests found in Penang Island, Malaysia. However, limited research has been done on T. indicum, especially in the molecular genetic field. This paper aims to collect T. indicum from three districts in Penang Island, Malaysia including George Town, Gelugor, Balik Pulau, characterize T. indicum based on morphological measurements and molecular characterization of T. indicum using mitochondrial cytochrome c oxidase subunits 1 (CO1) sequences and 16S ribosomal DNA (16S rDNA) sequences. The morphological measurements resulting in HL = 4.31 ± 0.12 mm, HW = 3.87 ± 0.06 mm, EL = 0.89 ± 0.05 mm, EW = 0.58 ± 0.01 mm, SL = 3.56 ± 0.08 mm, ML= 1.11 ± 0.12 mm, CI = 89.83 ± 1.17, EI = 20.59 ± 0.88 and SI = 82.95 ± 2.34. The CO1 sequences and 16S rDNA sequences of T. indicum from each population are deposited and accessible via Genbank (NCBI) database. The phylogenetic trees result in two clades with three haplotypes, but the genetic structure is not well revealed
Genetic variation, diversity and molecular phylogenetic of higher group termite Macrotermes carbonarious Hagen (Blattodea: Termitidae)
Limited studies pertaining to evolutionary history and intraspecific diversity of Macrotermes genus have been carried out by
researchers. Such studies are vital as from phylogeny we can understand the origin of species in a particular region. Thus, in
this study, we investigated the phylogenetic relationships and genetic diversity among the population of Macrotermes
carbonarius around USM campus. Seventeen Macrotermes carbonarius colonies were used to conduct a molecular genotyping
study and the mitochondrial (COII) gene was used as marker. The data obtained were analyzed using T-Coffee, Clustal X,
Mega 7.0 and DnaSP software programs. Our results show one main monophyletic clade that consists of two groups: HP1
and HP2. The samples from Stadium Hoki were classified in HP2, differing from the other populations studies by one
singleton base. Our HP2 shows some similarity with some sequence from Pasoh Forest Reserved Malaysia, suggesting a
state diversity connection. The disparity index suggests that all the samples are homogeneous populations, supported by the
low value of mean pairwise distance between the samples. This study will serve as a platform for scientific community to
enhance the knowledge on the phylogeny and genetic diversity of Macrotermes genus in South East Asia region
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