Digestive enzyme as benchmark for insecticide resistance development in culex pipiens larvae to chemical and bacteriologic insecticides

This work monitored changes in some digestive enzymes [trypsin and aminopeptidase] associated with the building up of resistance in Cx. pipiens larvae to two chemical insecticides [methomyl and/or malathion] and one biological insecticide [Bacillus thuringiensis-H14 or B.t HI4]. The LC[50] value of methomyl for both field and the 12[th] generation [F12] of the selected strain was 1.789 ppm and 8.925 ppm respectively. The LC[50] value of malathion for both field and the F12 of the selected strain was 0.082 ppm and 0.156 ppm respectively, and those of B.t H14 of field strain and the F12 was 2.550ppm and 2.395ppm respectively. The specific activity of trypsin enzyme in control susceptible colony was 20.806 +/- 0.452[micromol/min/mg protein; but at F4 and F8 for malathion and methomyl treated larvae were 10.810 +/- 0.860 and 15.616 +/- 0.408 [micromol/min/mg protein, respectively. Trypsin activity of F12 in treated larvae with B.t.H14 was 2.097 +/- 0.587micromol/min/mg protein. Aminopeptidase specific activity for susceptible control larvae was 173.05 +/- 1.3111micromol/min/mg protein. This activity decreased to 145.15 +/- 4.12, 152.497 +/- 6.775 and 102.04 +/- 3.58 [a]micromol/min/mg protein after larval [F12] treatment with methomyl, malathion and B.t H14 respectively

Monthly abundance of rodent and their ectoparasites in newly settled areas, east of lakes, Ismailia governorate, Egypt

Rodents and their ectoparasites were studied inside and outside houses in the newly settled areas, east of lakes, Ismailia Governorate, Egypt. Forty traps per month in each of the two sides were used for collecting rodent during 2009. From 221 rodent were collected from inside houses; Mus musculus N=115 [52.04%], Rattus rattus. frugivorous N=54 [24.43%], R. r. alexandrinus N=40 [18.10%] and R. norvegicus N=12 [5.43%]. From 177 rodent were collected from outside houses; M musculus N=4 [2.3%], R. r. frugivorous N=29 [16.43%], R r. alexandrinus N=37 [20.9%], R. norvegicus N=36 [20.3%], Gerbillus pyramiduin N=67 [37.9%] and Jaculus jaculus N=4 [2.3%]. Total ectoparasites per rat inside houses were 765 [3.46 E/Rat] which were classified as fleas, N=464 [2.11 F/R]; lice N=150 [0.68 L/R] and mites N=151 [O.68 M/R]. From outside house, total ectoparasites per rat were 984 [5.5 E/R] which were classified as fleas, N=410[2.31 F/R]; lice N=100 [0.56 L/R], mites N=400 [2.23 M/R] and ticks, N=74 [0.42 T/R]. From indoors two fleas species were recorded [Xenopsylla cheopis and Ctenopsyllus segnis]; one species of lice [Polyplax spinulosa] and four species of mites [Laelaps nuttall, Ornithonyssus bacoti, Dermanyssus gallinae and Eulaelaps stabularis]. The outdoors ectoparasites were; six fleas species [X cheopis, X ramesis, Pulex irritans, C. segnis, Stenoponia tripectinata and Nosopsylla sinaiensis]; one lice species [P. spinulosa]; Six mites species [L. nuttalli O. bacoti, D. gallinae, E. stabularis, Haemogamasus pontiger and Hirstionyssus isabellinus] and immature stages of two ticks species [Rhipicephalus sp. and Hyalomma sp.]. Most of these ectoparasites were recorded infesting G. pyramidum

Zoonotic helminthes of commensal rodents in Talkha center, Dakahlia governorate

Commensal rodents were trapped alive from different areas near garbage, canal edges, farm animals and the likes in Talkha Center over one year. A total of 135 rodents were collected, their species and index were Rattus norvegicus [0.11], R. r. frugivorous [0.13], R. r. al-exandrinus [0.16] and Mus musculus [0.5]. The zoonotic helminthes were trematodes [10 species], cestodes [4 species], and nematodes [10 species]. The results were discussed on light of other works

Ectoparasites of commensal rodents in Talkha center, Dakahlia governorate, Egypt

The ecto-parasites infesting commensally rodents were collected from the different localities in Talkha Center [Dakahlia Governorate] from April 2006 to March 2007. The seasonal abundance of rodent number and rat index was 52 [0.58] in spring, 27 [0.3] in summer, 39 [0.22] in autumn and 17 [0.05] in winter. From 135 rodent species and rat index was Rattus norvegicus N=33 [0.24], R. r. frugivorous N=39 [0.29], R. r. alexandrinus N=48 [0.36] and Mus musculus N=15 [0.11]. From 388 ecto-parasite infested rodent collected number and ecto index was fleas N= 114 [0.84 flea/rat], Lice N=93 [0.69 lice/rat], Mites N= 165 [1.2 mite/rat] and larva of ticks N=16 [0.12 tick/rat]. No doubt, rodents and their ectoparasites played a serious role in spreading and transmission of zoonotic diseases to human and animal

Spectral and landscape characterization of filarious and non-filarious villages in Egypt

Filarial disease is endemic in Egypt in some villages of Nile Delta governorates where it is transmitted by Culex pipiens female. GIS functions are used to identify environmental indicators of high-risk village as indicated by mosquito density, human infection rate, vector species composition, mean life expectancy "e0" and environmental variables [geology, hydrology, soil types, etc] as well as meteorological factors [temperature, RH and rainfall] in relation to filaria transmission risk. Remote-sensing technology was used to distinguish between the two studied villages as high and non-infected, as defined by microfilarial prevalence. The results indicate that filaria transmission risk is higher at an area characterized by highly productive aquifers, silt clay soil, receiving little amount of rain with low relative humidity [RH]. The results indicate that the most important landscape elements associated with preva1ence are Water and different vegetation. This work showed that the integration between GIS and remote sensing technologies to analyze and identify the environmental factors, associated with the disease, did not only allow mapping current spatial patterns, but also predicting its distribution under expected future developmental and environmental changes

Biochemical fingerprints of salviary gland for some ticks species in Egypt by SDS-polyacrylamide gel electrophoresis

SDS-PAGE gel electrophoresis as a sensitive method is used for simultaneously comparing the total protein extracted from salivary glands in some ticks species [Argas persicus, Hyalomma antolicum excavatum, H. an antolicum, H. dromedarii, H. impeltatum and Rhipicephalus sanguineus]. The results of A. persicus were characterized by 4 bands with molecular weights ranging from 82.76 to 16.076 KD. On the other hand, H. an. excavatum females were characterized by 6 bands with molecular weights ranging from 103.74 to 6.216 KD. H. an. antolicum males were characterized by 5 bands with molecular weights ranging from 79.183 to 2.092 KD. R. sanguineus was characterized by 4 and 8 bands with molecular weights ranging from 88.864 to 6.216 KD and 126.69 to 7.1 12 KD for male and female, respectively. Female H. impeltatum was characterized by 8 bands with a range of molecular weights from 106.96 to 7.829 KD. H. dromedarii was characterized by 4 and 7 bands with ranges of molecular weights from 88.147 to 4.602 KD and 110.20 to 2.630 KD for male and female, respectively

Outdoor resting and nectar feeding behaviour of some mosquito species in two villages in Egypt

Mosquito samples resting on different host plants were collected from 2 localities in Egypt, Kafr Tohoria Village, Qalyoubia Governorate, and El-Abttal Village, Ismailia Governorate. Collected mosquitos were identified, classified according to their feeding stage and tested for carbohydrate feeding. Results indicated that Cx. pipiens represented 96% and above of collected species in the 2 localities. The available plants and crops showed different attraction levels for resting female mosquitos. Most of the collected females were empty. Mosquitos may be attracted to certain plants due to the presence of some phagostimulant chemicals rather than the presence of the sugars

Haemoglobinometry as a method to determine the blood meal size of two argasid tick specties

A standardized clinical method for measuring hemoglobin was applied to measure the quantity of blood ingested by Argas persicus and A. hermanni feeding on chicken and pigeons, respectively. The blood fed ticks were added to a reagent that converted all hemoglobin to hemoglobincyanide [HiCN], which can be read spectrophotometrically. The validity of this method was established by comparing hemoglobin determination with the size of blood meals measured by weight. Linear relationships with high correlation coefficients were obtained for nymphs, males and females of A. persicus and A. hermanni, showing that both gravimetric [weighing] and HiCN methods gave similar estimates of ingested blood