Insecticidal and Genotoxic effects of some indigenous plant extracts in Culex quinquefasciatus Say Mosquitoes.

Five different weed plants viz. Convulvulus arvensis, Chenopodium murale, Tribulus terrestris, Trianthema portulacastrum, and Achyranthes aspera were investigated for their entomocidal and genotoxic effects against Culex quinquefasciatus mosquitoes. High mortality was observed at 72 hours in a dose dependent manner. Among all the tested plants, A. aspera was found highly significant which showed 100% mortality at 250 ppm after 72 hours with LC50 of 87.46, 39.08 and 9.22 ppm at 24, 48, respectively. In combination with Bacillus thuringiensis israelensis (Bti); A. aspera also caused 100% mortality at 250 ppm concentration after 72 hours (LC50 8.29 ppm). Phytochemical analysis of all the tested weed plants showed the presence of flavonoids, saponins, tannins, steroids, cardiac glycosides, alkaloids, anthrequinones and terpenoids. Random Amplification of Polymorphic DNA-Polymerase chain reaction (RAPD-PCR) and comet assay were performed to assess the genotoxic effect of A. aspera but no change in DNA profile was observed. Furthermore, FTIR showed the presence of phenolic compounds in A. aspera extract. It is suggested that certain phenolic compounds such as flavonoids modulate the enzymatic activity and, hence, cause the death of larvae of Cx. quinquefasciatus. Altogether, current study would serve as an initial step towards replacement of synthetic insecticides to plant-microbe based biopesticide against Culex mosquitoes in future.

Insecticidal, biological and biochemical response of Musca domestica (Diptera: Muscidae) to some indigenous weed plant extracts.

In the current study; insecticidal, growth regulation, oviposition deterrence and repellency of petroleum ether extracts of Azadirachta indica, Penganum harmala, Datura stramonium, Tribulus terrestris and Chenopodium murale against 2nd instar larvae of housefly was investigated. Five different concentrations (5%, 10%, 15%, 20% and 25%) were used through larval feeding and the mortality data was recorded after 24, 48 and 72 hrs. Highest mortality was induced by P. harmala (63.87%) followed by D. stramonium (62.78%), A. indica (53.84%), T. terrestris (41.86%) and C. murale (4.09%) after 72 h at 25% concentration, respectively. Increased mortality was observed with increased time duration and concentration. Longest larval duration (9.33 ±â€¯0.33 days) and pupal duration (7.33 ±â€¯0.33 days) days) was recorded in larvae treated with 25% concentration of P. harmala which also caused a decrease in the activity of AChE, ACP, AKP, α-Carboxyl, and ß-Carboxyl enzymes. However, at 25% concentration, C. murale showed highest oviposition deterrence activity (81.88%) followed by D. stramonium (79.58%). In comet assay test, at highest concentration (25%) the mean comet tail lengths represented by Penganum harmala, Datura stramonium and Azadirachta indica (Reference plant) were 10.20 ±â€¯0.49, 9.20 ±â€¯0.37 and 7.80 ±â€¯0.49 µm while percent DNA damage was 10.56 ±â€¯0.77, 10.67 ±â€¯1.62 and 8.11 ±â€¯0.85% respectively compared to controls cells. Phytochemical analysis indicated the presence of flavonoids, steroids, saponins, cardiac glycosides, tannins, alkaloids, terpenoids and anthraquinones. Fourier Transform Infrared spectroscopy (FTIR) analysis revealed the presence of phenolic flavonoids, saponins, tannins as major functional groups. Further studies are needed to explore and thus, to incorporate weed plant extracts for the management of house flies.

Toxicity, Phytochemical Composition, and Enzyme Inhibitory Activities of Some Indigenous Weed Plant Extracts in Fruit Fly, Drosophila melanogaster.

Drosophila melanogaster being used as model organism is considered as pest of homes, restaurants, and fruit markets. The damaged fruits are also reported to serve as a carrier for various diseases. The current study was designed to evaluate the toxicity of petroleum extract of some weed plants, namely, Euphorbia prostrata, Parthenium hysterophorus, Fumaria indica, Chenopodium murale, and Azadirachta indica, against D. melanogaster. Mortality at 10, 20, and 30% concentrations after 24 and 48 hours was found comparatively low. E. prostrata caused high mortality (51.64%) at 30% concentration and was found more toxic (LC50 27.76; P value 0.00) after 72 hours. A. indica showed high LC50 value (P value 0.15) compared to other weed plants. The combination of E. prostrata and Bti showed highest mortality (100%; LC50 12.49; P value 0.00) after 72 hours. Similarly, the same combination caused maximum reduction in the activity of AChE, AcP, AkP, α-Carboxyl, and ß-Carboxyl enzymes. Phytochemical analysis showed the presence of flavonoids, saponins, tannins, steroids, cardiac glycosides, alkaloids, anthraquinones, and terpenoids. FTIR analysis of E. prostrata showed the presence of phenolic compounds. It is suggested that further studies are needed in order to incorporate weed plant extracts in combination with Bti for the management of fruit flies.

Genetic Analysis of Aedes aegypti Using Random Amplified Polymorphic DNA (RAPD) Markers from Dengue Outbreaks in Pakistan.

BACKGROUND: Keeping in view the havoc situation of dengue fever in Pakistan, the current study was designed to demonstrate the genetic variations, gene flow and rate of migration from Lahore and Faisalabad. METHODS: The larvae were collected from both natural and artificial breeding places from each collection site. The adult mosquitoes were collected by means of sweep net and battery-operated aspirator. DNA extraction was performed using TNE buffer method. Ten GeneLink-A series RAPD primers were used for PCR amplification and the data was analyzed through POPGENE. RESULTS: The number of amplification products produced per primer varied from 8-12, ranging from 200 to 2000 bp with an average of 10.0 bands per primer. The percentage of polymorphic loci amplified by each primer varied from 22.5 to 51%. The UPGMA dendrogram demonstrates two distinct groups from Faisalabad and Lahore populations. The genetic diversity ranged from 0.260 in Faisalabad to 0.294 in Lahore with a total heterozygosity of 0.379. The GST value for nine populations within Lahore was 0.131 (Nm= 3.317), whereas for nine populations in Faisalabad GST value was 0.117 (Nm= 3.773). The overall genetic variation among eighteen populations showed GST= 0.341 and Nm= 1.966. CONCLUSION: The genetic relatedness and Nm value show that Ae. aegypti populations exhibit intra-population gene flow both in Faisalabad and Lahore. Although, both cities show a distinct pattern of genetic structure; however, few areas from both the cities show genetic similarity. The gene flow and the genetic relatedness in few populations of Lahore and Faisalabad cities need further investigation.