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 ± 0.33 days) and pupal duration (7.33 ± 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 β-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 ± 0.49, 9.20 ± 0.37 and 7.80 ± 0.49 μm while percent DNA damage was 10.56 ± 0.77, 10.67 ± 1.62 and 8.11 ± 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.

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 LC 50 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 (LC 50 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.Mosquitoes are reported to cause nuisance to humans and transmit several viral and protozoan diseases of public health concern worldwide. These are female mosquitoes which make a bite during their search for blood meal before oviposition which thus, increases their tendency to transmit several diseases including malaria, filariasis, dengue fever, japanese encephalitis, chikungunya, zika virus and yellow fever. These diseases make life at risk of millions of people particularly in subtropical/tropical world 1,2 . Of various mosquito species, Cx. quinquefasciatus transmits various diseases i.e., West Nile virus, Japanese encephalitis, filariasis, bancroftian filariasis (Wuchereria bancrofti), St. Louis encephalitis, and avian malaria 3 . In southern United States, St. Louis virus and West Nile virus (WNV) were transmitted by Cx. quinquefasciatus 4,5 . Almost 120 million people are affected annually only by lymphatic filariasis, whereas 1.3 billion are at risk resulting in nearly $1.3 billion loss of productivity per year 6 . Similarly, three billion individuals are at risk of being infected by Japanese encephalitis with 30,000-50,000 reported cases every year in disease endemic areas 7 . Besides disease transmission in humans; Cx. quinquefasciatus is also responsible for transmitting several diseases to livestock and companion animals viz. Rift Valley fever, canine dirofilariasis (dog heartworm), avian malaria, avian pox, and West Nile encephalitis which lead to high mortalities or decreased productivity 8 . open Scientific RepoRtS | (2020) 10:6826 | https://doi.org/10.1038/s41598-020-6381...

Housefly, Musca domestica, is considered responsible for transmitting a wide variety of human and veterinary diseases. Mostly, insecticides are being used for their control and more commonly, pyrethroid insecticides worldwide. However, resistance has been reported against various pyrethroid insecticides. Houseflies become resistant by two major mechanisms, i.e., target site insensitivity through knockdown resistance gene mutation (kdr) and enzyme detoxification. Thus, the current study was designed to monitor the frequency of pyrethroid resistance gene kdr in housefly populations of District Jhang. The flies were collected from seven sampling sites and then reared in the lab for molecular and biochemical assays. The amplification of template DNA was performed for knockdown resistance gene through the outer primers kdr1 and kdr4, and the inner primers kdr1 and kdr2 using PASA (PCR Amplification of Specific Alleles) method which specifically amplify the domain-II of kdr gene. Three populations were found homozygous susceptible (+/+; 42.85%), whereas two populations were found genetically homozygous resistant (−/−; 28.57%) which are insensitive to pyrethroid insecticides. Similarly, two populations were found heterozygous (+/−; 28.57%) for kdr suggesting thereby that at least 1/4th homozygous-resistant (−/−) housefly populations with insensitivity to pyrethroids would be produced in the future keeping in view the Mendelian ratio. Biochemical assay showed that homozygous-resistant populations had increased activity of Acetylcholinesterase (AChE), α-Carboxylesterases (α-Carboxyl), β-Carboxylesterase (β-Carboxyl), Alkaline Phosphatase (AkP), and Acidic Phosphatase (AcP) enzymes. In addition, heterozygous populations also showed increased activities of these enzymes. The current results would not only help avoid the indiscriminate load of insecticides onto the environment but also serve as a hallmark for the management of housefly populations in target areas in the future.

Resistance development against some frequently used insecticides, i.e., deltamethrin (1.5% EC), cypermethrin (10% SC), permethrin (0.5% WP) and DDVP (50% EC) was evaluated against Musca domestica L. Insecticide bioassays were carried out against susceptible and resistant strains at 2.5, 5, 10, 20 and 40 µg/µl concentrations. Mortality data was recorded after 24, 48 and 72 hours. Resistance was monitored up to three generations and the flies with higher LD 50 values than the F1 generation were considered resistant. LD 50 values for Permethrin increased from 58.258 µg/µl to 85.1375 µg/µl with highest resistance ratio (RR) in F1 to F3. The lowest resistance ratio was observed with DDVP. Maximum inhibition in adult emergence was observed against DDVP. The inhibitory activity of Esterases; Acetylcholine and Phosphatases; ACP, AKP was recorded. Deltamethrin inhibited the maximum activity of AChE (50%), whereas, DDVP caused maximum inhibition of acid phosphatases. The results suggested that house fly populations are more resistant to pyrethroids compared to organophosphate insecticides.

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