الفهرس 
Medical importance of mosquitoes in KSAOnly 14 pages are availabe for public view
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Abstract
The present study was undertaken during the period from February 2009 to September 2010 to survey
the different species of mosquitoes in Jazan region, study the distribution, prevalence as well as
abundance of that mosquito species. Also study the climatic factors governing the distribution of
mosquitoes. The prevalent mosquito was chosen to treat with some natural products to
evaluate the biological aspects of these products on it.
Our work revealed that the presence of 7 genera and 16 species of mosquitoes in Jazan region; these
were Aedes caspius Pallas, Aedimorphus vexans arabiensis Patton, Anopheles (An.) d’thali Patton,
An. pretoriensis Theobald, An. arabiensis Patton, An. turkhudi Liston, Culex (Cx.) sitiens Wiedmann
Cx. decens Theobald, Cx. bitaeniorhynchus Giles, Cx. pipiens Linnaeus, Cx. quinquefasciatus Say,
Cx. sinaiticus Kirkpatrick, Cx. tritaeniorhynchus Giles, Culliseta longiareolata Macquart, Lutzia
(Metalutzia) tigripes de Grandpre & de charmoy, Stegomyia aegypti Linnaeus.
6.1. Distribution of mosquitoes in Jazan region
A total of 29414 larval and 738 adult mosquitoes specimens were collected from 41
collection sites represented in frequently visited sites (Gizan, Arda, Baish and Ahad El
Masarha) and occasionally visited sites (Samta, Wadi Gizan,
Haroob, El Darb, Bany Malek and Farasan).
6.1.1. Distribution of Culicine larvae in Jazan region
During our study a total 11063 larval Culicine were collected from all collection sites, Gizan,
Arda, Baish, Ahad El Masarha, Wadi Gizan, El Darb, Samta, Haroob, Bany Malek and Farasan during
this study. Cx. pipiens larvae were the most abundant in the region, comprising about 4463 (40.3%)
of total collected Culicine larvae (T C C L). It was encountered in Gizan, Arda, Baish, Ahad El
Masarha, Samta, El Darb, Bany Malek and Farasan. The relatively abundant Culicine species in Jazan
region is Cx. tritaeniorhynchus. It was comprised by 38.3 % (4239) T C C L. It was collected from 8
collection sites, Gizan, Arda, Baish, Ahad El Masarha, Samta, El Darb, Haroob and Bany Malek. Cx.
sitiens larvae recorded 17.3 % (1911) T C C L and were encountered in Gizan, Arda, Baish, Ahad El
Masarha and Wadi Gizan. from Gizan, Arda, Baish and Farasan Cx. quinquefascitus larvae were
collected and resembled by 2 % (226) T C C L. Cx. sinaiticus were encountered as larvae in Gizan
and Arda acting as
1.7 % (191) T C C L. Cx. decens and Cx.bitaeniorhynchus were recorded from only one collection
site , Arda and Haroob resembling 0.2 % (22) and 0.1 % (11) T C C L respectively6.1.2. Distribution of Anopheline larvae in Jazan region
According to this work, 423 larval Anopheline mosquitoes were collected from Jazan region. An.
Arabinesis larvae were the most abundant Anopheline mosquitoes in the region, comprising about 300
(70.9%) of total collected Anopheline larvae (T. An. L.). They were encountered in 5 collection
sites, Gizan, Arda, Baish, Samta and Haroob. The frequency varied across localities but it was the
most prevalent Anopheline species in Jazan region. An. d’thuli was comprised by 23.6 % (100) of T.
An. L. It was collected from 3 collection sites, Arda, Ahad El Masarha and Haroob. An. pretariensis
and An. turkdi were reported from only one collection site, Ahad El Masarha and Samta by 5 and 18
larvae samples respectively. An. pretariensis and An. turkdi were resembled by 1.2 % (5) and 4.3 %
(18) of T. An. L.
6.1.3. Distribution of Stegomya, Aedomorphus, Lutzia
and Aedes larvae in Jazan region
Stegomya, Aedomorphus, Lutzia and Aedes larvae were only represented by one species St.
aegypti, Am. Vexans, L. tigripis and A. caspius respectively. St. aegypti larvae were collected
from 3 collection sites Gizan, Arda and Haroob. It resembled by 2.3 % (665) of the total collected
mosquito larvae in Jazan region. Am. Vexans acted as the most abundant species in Jazan region
recording 58.2 % (17121) of the total collected
mosquito larvae in Jazan region. It was collected from 2
collection sites, Arda and Ahad El Masarha. L. tigripis larvae were comprised by 0.2 % (68) of the
total collected mosquitoes larvae in Jazan region. It was collected from 5 collection sites, Arda,
Ahad El Masarha, El Darb, Haroob and Farasan. A. caspius was recorded from only one collection
site, Ahad El Masarha, recording 74 collected larvae that resemble 0.3 % of total
collected mosquitoes in Jazan region.
6.1.4. Distribution of adult mosquitoes in Jazan region
A total of 738 adult mosquitoes specimens were collected from both frequently and occasionally
visited sites. In general, the number of mosquito specimens collected was rather low over the
period of study. This is due to the effective regular and extensive larvicide operations that take
place in the region. In addition, occasional use of space and residual sprays assists in reducing
the density of flying mosquitoes in the areas well as low rain fall rate during the study period.
Also the low number of collected adults when compared with the number of collected larvae may be
because of traps efficiency as well as traps distribution that may confuse some of Jazan people to
put them in their houses.
An. Arabinesis adults were collected from 3 collection sites, Gizan, Samta and Bany Malek,
recording 1.9 % (8) of total collected mosquito adults (of T C M A) in Jazan region. An.
d’thuli was collected from only one site as an adult, Arda,
resembling 0.3 % of T C M A in the study area. from 4 collection sites, Gizan, Baish,
Ahad El Massarha and Bany Malek St. aegypti adults recorded 15.6 % of T C M A in Jazan region. L.
tigripis adults were recorded in Arda, Ahad El Massarha and Haroob by 2.4 % of T C M A in Jazan
region. Am. vexance adults were only recorded from Arda by 3.9 % of T C M A in Jazan region. Cx.
pipiens adults were encountered in 6 collection sites, Gizan, Arad, Baish, Ahad El Massarha, El
Darb, Haroob and Farasan, by 14.9 % of T C M A in Jazan region. Mosquito adults that comprised 34 %
of T C M A in Jazan region were related to Cx. tritaeniorhynchus which encountered in Gizan, Arda
, Baish, Samta and Haroob. Cx. sitiens was collected as adults from Gizan and Arda was comprised
1.8 % of T C M A in the study area. Cx. quenqifaciatus adults were recorded from 3 collection
sites , Arda, Baish and Ahad El Massarha by 14.4 % of T C M A in the study area. from Haroob Cx.
bitaeniorynchus adults were collected by the percent of 8.3 % of T C M A in Jazan region. Cs.
Longiareolata was only recorded from Arda as an adult recording
2.6 % of T C M A, in Jazan region.
6.2. Prevalence of mosquitoes in Jazan region
Cx. pipiens is the most prevalent species in Jazan region. It was encountered in 9 collection sites
(90%), Gizan, Arda, Baish,
Ahad El Masarha, samta, Haroob, El Darb, Bany Malek and Farasan,. Cx. tritaeniorhynchus is less
prevalent than the previous species and encounted in 8 collection sites (80%), Gizan, Arda, Baish,
Ahad El Masarha, samta, Haroob, El Darb and Bany Malek,. An. Arabinesis was encountered in 6
collection sites (60%), Gizan, Arda, Baish, samta, Haroob, Bany Malek,. L. tigripis was collected
from 5 collection sites (50%), Arda, Ahad El Masarha, El Darb, Haroob, Farasan and so Cx. sitiens
was collected from 5 collection sites, Gizan, Arda, Bais, Ahad El Masarha and Wadi Gizan. Cx.
quinquefascitus also recorded in different 5 collection sites, Gizan, Arda, Baish, Ahad El Masarha
and Farasan. St. aegypti was collected from (40%) Gizan, Arda, Haroob and Bany Malek. An. d’thuli
was collected from 3 collection sites (30%), Arda, Ahad El Masarha and Haroob. Am. vexans was
collected from 2 collection sites (20%) Gizan and Ahad El Masarha. And so Cx. sinaiticus was
collected from 2 collection sites Gizan and Arda. An. pretariensis, An. turkdi, A.. caspius, Cx.
decens, Cx. bitaeniorhynchus and Cs. Longiareolata were collected from only one collection sites
(10%), Ahad El Masarha, Ahad El Masarha, Arda, Haroob, Baish and Arda respectively.6.3. Abundance of mosquitoes in Jazan region
During our study, although it is not prevalent, Am. vexans was reported as the most abundant
mosquito species in Jazan region recording 56.9 % of the total collected mosquitoes. Cx. pipiens
and Cx. tritaeniorhynchus were less abundant recording
15.2 % and 14.9 % of the total collected mosquitoes in Jazan region. Cx. sitiens, St. aegypti,
An. Arabinesis, Cx. quinquefascitus and Cx. sinaiticus was recording 6.4 %, 2.6 %, 1
%, 1.1 % and 0.6 % respectively. The rest of collected mosquitoes were less than 0.6 % of the total
collected mosquitoes.
6.4. Effect of ecological factors on the abundance of mosquitoes in Jazan region
Effect of climatic factors on mosquitoes abundance were studied through this research reporting
that RR was the most effective, significant (P<0.01) and (r= 0.459), factor on the mosquito’s
abundance as will be seen in the following different collection sites:-
In Gizan, mosquitoes were available throughout the year, but at different densities depending
significantly on the rain fall rate. Peak of mosquito activity was attained in April 2009 when the
rain fall rate was 3.6 and the preceding reading for the rain fall rate was 5 which lead to more
breeding sites. Population density
declined as the RR decreases but in the next month although RR reaches 12.5, population decreases
to 190 because of the intensive control applied by the government. In August 2009 RR increased by
2.9 leading to the second peak during the study period then declining and so the mosquito
population decline also but the control as well as decreasing of temperature and relative humidity
decreased reaching 29.9 0C and 54.5 % respectively prevents the increase in the mosquitoes
population when RR was 9.7 during January 2010. 3rd peak was in March 2010 when RR reaches 8.1 and
the collected mosquitoes 528 then declined as the RR declined and reached to the 4th peak
in September 2010 recording
600 collected mosquitoes when RR was 8.3 mm.
In Arda, a peak of mosquito activity was attained in February 2010 although the absence of rains
during this month and the month before which meaning that not only the local rain fall rate is only
source for breeding sites but, hence border areas, also the perennial flow from the mountain
streams from Yemen as well as the presence of artificial breeding sites. In September
2010 a peak of mosquito density take place recording 1730 when the RR was 51.5.
In Baish, typical correlation between mosquitoes density and RR was taking placed in the collection
sites of Baish. First peak take placed in August 2009 when RR increased to 4.2
leading to mosquitoes density of 218. In January 2010 mosquitoes
density reached 200 when RR recording 15 and the preceding month was 14.8 which leading to more
larval breeding sites. In March 2010 another peak of mosquito population reaching 400 when RR
increased to 18. Mosquitoes density were hesitating as RR increase and decrease. Another peak was
in the September
2010 recording 200 when RR was 12.5.
In Ahad El Masarha, during April and May 2009 RR reached 88.5 and 182 respectively leading to more
breeding sites expressed into collection of 211 adult and larval mosquitoes from different species
during the late month, May 2009,. It was declined in the next month because of intensive
control of mosquitoes but the month after, July 2009 It was rebuilt giving rise 97 collected
mosquitoes when RR was 52. RR declined in the subsequent months leading to declining in the density
of mosquitoes. In March 2010 RR reaches 57 which raise the population of mosquitoes to171. In
May increased RR, 182, leaded to increased collected mosquitoes, 63,. Increase in RR in June and
August 2010 lead to more breeding sites in September
2010 and so collecting of 200 mosquito adults and larvae.
In El Darb, 1st occasionally visited site, mosquitoes activity was increased during winter than
that of summer. Mosquitoes population was 44 when RR was 13.9 in July 2009 then increased in the
next season (March 2010) by increasing the
RR reading 319 when RR was 17. In July 2010 mosquioes
declined again by declining the RR reading 14 and 215 RR and collected mosquitoes respectively.
In Haroob, 2nd occasionally visited site, mosquito
population was 165 when RR was 19 in first winter (February
2009) then declined in the next summer (July 2009) reading 25 when RR was 2.5 then increased in the
next season (March 2010) by increasing the RR reading 96 when RR increased also to 11.1. In July
2010 although it considered as summer season but when RR increased to 47.7 mosquitoes density also
increased to 115.
In Samta, 3rd occasionally visited site, mosquitoes population were present all seasons because
most of breeding sites were artificial but in the same time it increased significantly by RR. In
summer 2009, RR reading 0.0 while collected mosquitoes recording 279. In March 2010 total
mosquitoes increased by increasing of RR while RR was 9.0, collected mosquitoes was 3561. Summer
2010 when RR was declined to
0.0 but mosquitoes density recorded 73 depending on artificial breeding sites.
In Dayer Bany Malek, 4th occasionally visited site, mosquitoes population was present in low
density in summer (August 2009), RR reading was 12 and collected mosquitoes was
35. In March 2010 total mosquitoes increased by increasing of
RR reaching the peak, collected mosquitoes was 5000 when RR was 20.8. In Summer 2010, when RR was
declined to 8.0, mosquitoes density reached 0.0.
In Farasan, 5th occasionally visited site, mosquitoes population was present in April 2009 when
rains was present recording 12, collected mosquitoes was 199. No collected mosquitoes in May 2010
and august 2010 when RR was 0.0.
In Wadi Gizan, 6th occasionally visited site, it was
considered as a target for more than one organization( Agriculture, Health & Rural
affairs) for the control of mosquitoes so the collected mosquitoes were low. In April 2010
Mosquitoes population was 12 when RR was 24 and in July 2010 collected mosquitoes was 0.0 while RR
was 5.
6.5. Biological effect of some natural plant products against the most prevalent mosquito in Jazan
region, Culex pipiens,.
According to our work the 3 tested plant products showed different effects on the 4th instar larva
of Culex pipiens. The toxicity values based on Lc50 values may be arranged in a descending order
as follows 13.6, 658.39 and 5991.5 ppm for rotenone, limonine and jojoba oil respectively. The
bioassay tests of them is detailed as the following:-
1- Rotenone had a high toxic effect against the 4th instar
larvae of Cx. pipiens. The larval mortality percent were
6.7, 20, 36.7, 56.7, 73.3, 96.7 and 100 % at concentrations 1, 5, 10, 15, 20, 25 and 30ppm,
respectively. Larval duration was affected by Rotenone, where the mean duration significantly
(P<0.01) increased to 9.2±3.5, 12.4±3.4, 12.6±3.6, 12.8±3.7 and
12.1±3.2 days at the concentrations 1, 5, 10, 15 and
20ppm; respectively compared to 6.9±2.7 days for the untreated larvae. Positive correlation between
the concentration of Rotenone extract and the percent of pupal mortality was observed. The pupal
mortality percent was 10.7, 29.2, 52.6, 77, 87.5 and 100 % at the concentrations 1, 5, 10, 15, 20
and 25ppm respectively, compared to 3.3% at the control. Inverse relationship between the pupation
% and the concentration was observed, where the pupation % was 0.0% at the highest concentration
(30ppm) and 93.3% at the lowest concentration (1ppm) compared to 100% for the untreated group. It
induced some malformation percent among pupae resulted from treated larvae especially at the
highest concentrations (25, 20, 15, 10 and 5ppm), where the malformation percent was 100.0, 87.5,
77,
42.1 and 16.7%; respectively compared to 0.0% for thecontrol group. Results showed that, the mean pupal
duration was insignificantly (P>0.01) affected at all concentrations used except the highest
concentration
15ppm, where the pupal duration significantly (P<0.05) increased to 3.28±0.46 days vs. 2.97±0.24
days for the untreated group. The adult emergence 0.0 % was occurred at the concentration of 25ppm,
meanwhile the percent increased to 12.5 and 23.0% at the concentrations 20 and 10ppm,
respectively and gradually increased till reaching the highest percent (89.3%) at the lowest
concentration 1ppm. The adult emergence percent for the untreated group was 96.7%. The lethal
effect was extended to the adult stage at all concentrations, the highest percent of adult
mortality (100%) was recorded at 20 ppm, the mortality percent decreased to 66.6, 44.4, 23.5 and
8.0 % at 15, 10, 5 and
1 ppm, respectively, compared to 0.0% for the untreated insects. Rotenone total inhibition on
different stages of Cx. pipiens reached 23.3, 56.7, 83.3, 96.7 and 100 % at
1, 5, 10, 15 and 20ppm, respectively, compared to 3.3 % for the untreated group. The growth index
for larvae and pupae was greatly affected by Rotenone. Growth index was negatively correlated to
the concentration, where it recorded 0.8, 1.4, 3.1, 4.6 and 7.4 reductions at 20, 15 10, 5 and 1 ppm, respectively, compared to 10.1 for the
controls.
2- Jojoba oil induced complete larval mortality percent (100%) at the highest concentration
(12000ppm). Meanwhile, the larval mortality % decreased to (26.7%) at the lowest concentration
(4000ppm) compared to
3.3% for the untreated larvae. Duration of larvae was insignificantly (P>0.01) affected at all
concentrations used as compared with the untreated group. The lethal effect of Jojoba oil was
extended to the pupal stage inducing 100, 100, 88.9 and 59.1 % pupal mortality at the
concentrations 10000, 8000, 6000 and 4000ppm. Its lethal effect was extended also to the emerged
adults inducing 100 % adult mortality at the concentrations
4000 and 6000ppm. The pupation percent of treated larvae decreased as the concentration increased
(73.3,
60.0, 33.3, and 10.0% at 4000, 6000, 8000 and
10000ppm; respectively compared to 96.7 % for the control. Pupal malformation percent was 100,
100, 88.9 and 53.8% at the concentrations 10000, 8000, 6000 and
4000ppm; respectively compared to 0.0% for the control group. The adult emergence percent was
highly affected at all concentrations: 10000, 8000, 6000 and 4000ppm, where it recorded 0.0, 0.0,
11.1 and 40.9%, respectively
compared to 0.0% for the control group. Total inhibition
percents were 100 and 100 % at 4000 and 6000 ppm, respectively, compared to 6.6 % for the control
group. A very highly retarded effect on growth index was induced by the Jojoba oil extract. At the
concentrations
6000 and 4000ppm, the growth index was 1.2 and 4.8 compared to 11.4 for the untreated group.
3- Limonine effect was as the following; larval mortality
% was found to increase as the concentration of
Limonine extract increased, where it recorded 13.3,
23.3, 46.7, 73.3 and 100.0% at 125, 250, 500, 1000 and
1500ppm; respectively compared to 6.7% for the untreated larvae. Limonine extract significantly
prolonged the larval duration at the two highest concentrations (500 and 1000ppm), where the mean
duration prolonged to 6.9±0.94 and 7.3±0.57 days; respectively compared to 6.3±1.1 days for
control group. pupation rate decreased as the concentration increased. At the highest and lowest
concentration: 1500 and 125ppm the pupation percent was 0.0 and 86.7%; respectively vs. 93.3% for
the untreated group. The highest pupal malformation percent (87.5%) was induced by the
concentration 1000ppm and the lowest
pupal malformation percent (19.2%) was occurred at the concentration 125ppm compared to 0.0% for
the control group. The highest pupal mortality percent (87.5%) was induced at the highest
concentration 1000ppm. This percent decreased to (75.0, 47.8 19.2%) at the concentrations 500, 250
and 125ppm, compared to 3.6% for the control group. Data obtained showed that the mean pupal
duration was insignificantly (P>0.01) affected at the lowest concentrations (125 and 250ppm), while
at the highest concentration (500ppm) the mean duration was significantly (P<0.05) prolonged as
compared with the control group (2.8±0.47 vs. 2.2±0.27 days). Adult emergence % decreased as
the concentration increased, where it recorded 12.5, 25,
42.2 and 81.8% at 1000, 500, 250 and 125ppm compared to the control group (96.4%).
Limonine extract had extended toxic action on the survivorship of adults at the all concentrations.
The adult mortality percent was 100.0, 75.0, 33.3 and 19.0% at 1000, 500,
250 and 125ppm compared to 0.0% of the control group. The extended toxicity of Limonene on
different mosquito stages very obvious when reading the values of the total inhibition percents
which were 43.3, 73.3,
96.7 and 100 % at 125, 250, 500 and 1000 ppm,
respectively, while untreated group inhibited by 13.4 %. Growth index for larvae and pupae was
affected especially at the highest concentrations (1000, 500 and
250ppm) where it recorded 3.4, 3.3 and 4.8 vs. 11.8 for control.