Laboratory and field evaluation of two formulations of Bacillus thuringiensis M-H-14 against mosquito larvae in the Islamic Republic of Iran, 2012.

Due to low efficacy in the field of a local commercial product of Bacillus thuringiensis M-H-14 (Bioflash(®)), a study was designed to assess its efficacy in laboratory, glass standard aquarium, semi-field and field conditions at both target and higher dosages against immature stages of Anopheles spp. and Culex spp. In laboratory conditions, the LC50 values of wettable powder and granule formulations were 227 and 1031 ppm respectively against a susceptible strain of An. stephensi. Following application of wettable powder and granules at 56.1 mg/aquarium, the survival rates of the exposed larvae to the granule formulation were 65.6% and 54.2% on days 6 and 8 respectively. In the artificial ponds, the larval density was reduced to 38.9%, 39.3% and 65.1% at dosages of 2, 4 and 8 g/m(2) respectively. In rice fields, at a dosage of 2 kg/ha, the density of immature larvae were reduced to 33.1% and 28.6% 7-days post-treatment. Further investigations are needed for the reasons for the low efficacy of this larvicide.

Interleukin 4 (IL-4) gene promoter polymorphisms in Rhombomys opimus, the main reservoir of zoonotic cutaneous leishmaniasis.

Great gerbils (Rhombomys opimus) are the most common gerbils in center to northeast of Iran as well as central Asia and serve as reservoirs for the zoonotic agents, including Leishmania major, the principal etiologic agent of zoonotic cutaneous leishmaniasis (ZCL). The outcome of L. major infection in gerbils is not uniform. Among several immune-related factors including cytokine genes, the polymorphism in interleukin 4 (IL-4) promoter gene showed a great impact on outcome and pathological symptoms of L. major infection at least in mouse model. In this study gerbils' IL-4 promoter gene polymorphism is assessed. Specific primers were designed to develop a PCR-based assay to amplify IL-4 promoter gene to possibly define IL-4 promoter gene polymorphism in great gerbil populations with a range of Leishmania infection and symptoms collected from different foci of the central, north and northeast regions of Iran. The results showed that the designed primers amplify 689bp of the promoter gene. Sequence analysis of the promoter gene revealed five polymorphic sites assembly six haplotypes among the gerbil populations. Further studies are needed to assess whether or not the five polymorphisms cause different outcome phenotypes following infection with L. major in great gerbils. The data might be used to characterize the immune responses of R. opimus against L. major infection.

Laboratory and field evaluation of two formulations of Bacillus thuringiensis M-H-14 against mosquito larvae in the Islamic Republic of Iran, 2012

Due to low efficacy in the field of a local commercial product of Bacillus thuringiensis M-H-14 [Bioflash[registered sign], a study was designed to assess its efficacy in laboratory, glass standard aquarium, semi-field and field conditions at both target and higher dosages against immature stages of Anopheles spp.and Culex spp.In laboratory conditions, the LC[50]values of wettable powder and granule formulations were 227 and 1031 ppm respectively against a susceptible strain of An.stephensi.Following application of wettable powder and granules at 56.1 mg/aquarium, the survival rates of the exposed larvae to the granule formulation were 65.6% and 54.2% on days 6 and 8 respectively.In the artificial ponds, the larval density was reduced to 38.9%, 39.3% and 65.1% at dosages of 2, 4 and 8 g/m[2]respectively.In rice fields, at a dosage of 2 kg/ha, the density of immature larvae were reduced to 33.1% and 28.6% 7-days post-treatment.Further investigations are needed for the reasons for the low efficacy of this larvicide

في ضوء تضاؤل الكفاءة للمنتج التجاري المحلي المستحضر من العصية الثورنجية صمم الباحثون دراسة لتقييم كفاءته في المختبر ضمن حوض مائي زجاجي معياري، وفي ظرف ميدانية وشبه ميدانية لكل من الجرعات المستهدفة والجرعات الأعلى ضد المراحل غير الناضجة من أنواع الأنوفيلات وأنواع الباعضات. وفي الظروف المختبرية، كانت قيم الجرعة القاتلة للنصف من مستحضرات المسحوق المرطب جزءا بالمليون ومن الحبيبات جزءا بالمليون، ضد الذراري المستجيبة من الأنوفيلة الأسطفانية. وبعد تطبيق المسحوق المرطب والحبيبات على حوض مائي بمقدار 65.1 مغ/حوض وجد الباحثون أن معدل بقاء اليرقات على قيد الحياة بعد تعرضهن لمستحضر الحبيبات كان 65.6 % في اليوم 6، و 54.2 % في اليوم 8. أما في الأحواض الاصطناعية فإن كثافة اليرقات انخفضت إلى 38.9 % بجرعة 2 غرام/متر مربع، وإلى 39.3 بجرعة 4 ميلي غرام، وإلى 65 % بجرعة 8 غرام/متر مربع. وفي حقول زراعة الأرز فقد أدت جرعة مقدارها 2 كيلو غرام/هيكتار إلى انخفاض كثافة اليرقات غير الناضجة إلى 33.1 % و 28.6 % بعد مرور 7 أيام على المعالجة. وهناك حاجة لمزيد من الدراسات حول أسباب انخفاض كفاءة مبيدات اليرقات

En raison de la faible efficacité sur le terrain d'un produit commercial local de Bacillus thuringiensis M-H-14 [Bioflash[R], une étude a été élaborée pour évaluer son efficacité en laboratoire, en aquarium de verre standard ainsi que dans des conditions déterraient de semi-terrain à des doses cibles mais aussi à des doses supérieures contre des Anopheles spp.et des Culex spp.à des stades immatures.Aux conditions de laboratoire, les valeurs de la CL[50]pour la poudre mouillable et les formulations en granulés étaient de 227 et 1031 ppm respectivement sur une souche sensible d'An.stephensi.Après application de poudre mouillable et de granules à 56, 1 mg/aquarium, les taux de survie des larves exposées à la formulation en granules étaient de 65, 6 % et 54, 2 % aux jours 6 et 8 respectivement.Dans les plans d'eau artificiels, la densité larvaire a été réduite, passant à 38, 9 %, 39, 3 % et 65, 1 % à des doses de 2 g/m[2], 4 g/m[2]et 8 g/m[2]respectivement.Dans les rizières, à une dose de 2 kg/ha, la densité des larves immatures a été réduite, passant à 33, 1 % et 28, 6 %, sept jours après le traitement.Des recherches supplémentaires sont nécessaires pour expliquer la faible efficacité de ce larvicide

Molecular detection of Leishmania infection in sand flies in border line of Iran-Turkmenistan: restricted and permissive vectors.

A molecular study was carried out to incriminate sand fly vectors of cutaneous leishmaniasis (CL) in rural areas of Sarakhs district, Khorassane-Razavi Province, northeastern Iran, in 2011. Sand flies of Sergentomyia with three species and Phlebotomus with six species respectively comprised 73.3% and 26.7% of the specimens. Phlebotomus papatasi was the most common Phlebotomine species in outdoor and indoor resting places. Leishmania infection was found at least in 17 (22%) specimens including Ph. papatasi (n=9 pool samples), Phlebotomus caucasicus (n=6), Phlebotomus alexandri (n=1), and Sergentomyia sintoni (n=1). The parasites were found comprised Leishmania major (n=5), Leishmania turanica (n=10), and Leishmania gerbilli (n=4). Infection of Ph. papatasi with both L. major and L. turanica supporting the new suggestion indicating that it is not restricted only with L. major. Circulation of L. major by Ph. alexandri, and both L. gerbilli and L. turanica by Ph. caucasicus, in addition to previous data indicating the ability of Ph. alexandri to circulate Leishmania infantum and Leishmania donovani, and Ph. caucasicus to circulate L. major, suggests that these two species can be permissive vectors. The results suggest that Ph. papatasi and Ph. alexandri are the primary and secondary vectors of CL where circulating L. major between human and reservoirs, whereas Ph. caucasicus is circulating L. turanica and L. gerbilli between the rodents in the region.

Identification of chemical constituents and larvicidal activity of Kelussia odoratissima Mozaffarian essential oil against two mosquito vectors Anopheles stephensi and Culex pipiens (Diptera: Culicidae).

The larvicidal activity of essential oil extracted from an indigenous plant, Kelussia odoratissima Mozaffarian was evaluated against two mosquito species, Anopheles stephensi and Culex pipiens. The chemical composition of the essential oil obtained by hydrodistillation from branch tips and leaf of this plant was determined by GC and GC/MS analysis. Forty-nine constituents were identified in the oil. The main constituents of the oil were Z-ligustilide (77.73%), 2-octen-1-ol acetate (6.27%), E-ligustilide (2.27%) and butylidene phthalide (1.97%). Five different logarithmic concentrations of essential oil were evaluated against the 4th instar larvae of An. Stephensi and Cx. pipiens. The LC(50) and LC(90) values against An. stephensi larvae were 4.88 and 9.60 ppm and for Cx. pipiens were 2.69 and 7.90 ppm, respectively. These properties suggest that K. odoratissima oil has potential source of valuable larvicidal compounds for mosquito larval control. This plant which causes high mortality at lower dose could be considered as a highly active plant. In this paper a guideline suggested for larvicidal activity of plant essential oils.

First detection of Leishmania infantum in Phlebotomus kandelakii using molecular methods in north-eastern Islamic Republic of Iran.

Shirvan district in north-eastern Islamic Republic of Iran is a new focus of visceral leishmaniasis. This study aimed to identify the vector(s), the parasite and the species composition of sand flies in the district during July-September 2009 using polymerase chain reaction techniques. In all, 2088 sand flies were collected from 3 villages. Nine sand fly species were identified: Phlebotomus kandelakii (Shchurenkova), P. major (Annandale), P. halepensis (Theodor), P. papatasi (Scopoli), P. sergenti (Parrot), P. longidactus (Parrot), P. caucasicus (Marzinovsky), Sergentomyia sintoni (Pringle) and S. sumbarica (Perfil'ev). P. sergenti and P. kandelakii were the most prevalent Phlebotomus species at 31.3% and 10.0% respectively. Of 59 female P. kandelakii, 2(3.4%) were naturally infected with L. infantum. This is the first finding of natural infection of P. kandelakii by L. infantum in this region suggesting P. kandelakii may be the vector of L. infantum in the area although it is the second most prevalent phlebotomine species.

First detection of Leishmania infantum in Phlebotomus kandelakii using molecular methods in North-Eastern Islamic Republic of Iran

Shirvan district in north-eastern Islamic Republic of Iran is a new focus of visceral leishmaniasis. This study aimed to identify the vector [s], the parasite and the species composition of sand flies in the district during July-September 2009 using polymerase chain reaction techniques. In all, 2088 sand flies were collected from 3 villages. Nine sand fly species were identified: Phlebotomus kandeiakii [Shchurenkova], P. major [Annandale], P. halepensis [Theodor], P. popatasi [Scopoli], P. sergentl [Parrot], P. longidoctus [Parrot], P. caucasicus [Marzinovsky], Sergentomyia sintoni [Pringle] and S. sumbarica [Perfii'ev]. P. sergentl and P. kandetakii were the most prevalent Phlebotomus species at 31.3% and 10.0% respectively. Of 59 female P. kandelokll, 2 [3.4%] were naturally infected with L infantum. This is the first finding of natural infection of P. kandelakii by L infantum in this region suggesting P. kandelakii may be the vector of L infantum in the area although it is the second most prevalent phlebotomine species

Ecology of malaria vector Anopheles culicifacies in a malarious area of Sistan va Baluchestan province, south-east Islamic Republic of Iran.

A study was done of the bionomics, insecticide susceptibility and irritability status of Anopheles culicifacies in Sistan va Baluchestan province. Sampling was performed to determine the following parameters: species identification, seasonal activity, adult and larval susceptibility tests, irritability tests, anthropophily index and sporozoite rate. An. culicfacies adults were susceptible to all tested pyrethroid insecticides. An. culicfacies started to appear indoors in late May, showing 2 peaks in June and September. Fenitrothion, cyfluthrin and permethrin had the least irritancy effect and DDT the highest. Only 2/860 females tested were infected with Plasmodium spp. (sporozoite rate: 0.25%). ELISA testing of 250 blood meals derived from night-biting collections of female mosquitoes from humans and cows revealed that only 12.5% were human-fed.

Anopheline species composition in borderline of Iran-Azerbaijan.

Malaria is still one of the most important health-problems in the world and is endemic in Iran. Since 1994, after collapse of former Soviet Union, a new threat of malaria importation emerged from those countries into the northern Iran. This work was carried out to provide further evidence on the status of anopheline species composition, the malaria parasite species, and natural infectivity of mosquitoes distributed in Pars-Abad district, on the borderline of Azerbaijan in northwestern Iran. Mosquitoes were collected from May to December 2008 in anopheline seasonal activity and were identified at the species level. The genus- and species-specific primers against Plasmodium ssrDNA gene were used for specific amplification on female mosquito head+thorax. Members of the Anoheles maculipennis complex were identified by sequence analysis of the ribosomal internal transcribed spacer II (ITS2-rDNA). Morphological character-based identification showed that out of 1455 anopheline female specimens, 1121 (77%) were of A. maculipennis s.l. and 334 (23%) were of Anoheles hyrcanus. Molecular analysis of the species complex indicated the presence of Anoheles sacharovi 984 (67.6%) and A. maculipennis 137 (9.4%) in the region. None of themosquito's head-thorax was found to be naturally infected by malaria parasite. Results of this study, particularly high dominance of A. sacharovi, suggest a potential risk of malaria epidemic in the region, and the need for a continuous epidemiological surveillance.

First report on Anopheles fluviatilis U in southeastern Iran.

Anopheles fluviatilis James, one of the malaria vectors in Iran, is a complex of at least three cryptic species provisionally designated as species S, T and U. These species are morphologically indistinguishable at any stage of their life cycle and can be identified only by the examination of species-specific fixed inversions in the polytene chromosomes. Recently, sequence analysis of 28S D3 and second internal transcribed spacer (ITS2) regions of ribosomal DNA has revealed 7 haplotypes of S, U, T1, T2, Y, X and V within the complex. Identification of the cryptic species of the complex is of paramount importance in a disease control program due to contrasting differences in their vectorial efficiency, preference for feeding on humans and resting behavior. In this study we analyzed the sequence of 28S D3- and ITS2-rDNA loci to identify the species composition of the An. fluviatilis complex in Jiroft and Chabahar districts, two of the most important endemic malaria foci in southeastern corner of Iran. The ITS2 sequence analysis revealed that all of the An. fluviatilis specimens were identical to the Y/T2 haplotype of An. fluviatilis T, whereas D3 sequence analysis revealed presence of species T in Jiroft and species U in Chabahar district. It is the first report of species U in Iran.

Ecology of malaria vector Anopheles culicifacies in a malarious area of Sistan va Baluchestan province, south-east Islamic Republic of Iran

A study was done of the bionomics, insecticide susceptibility and irritability status of Anopheles culicifacies in Sistan va Baluchestan province. Sampling was performed to determine the following parameters: species identification, seasonal activity, adult and larval susceptibility tests, irritability tests, anthropophily index and sporozoite rate. An. culicifacies adults were susceptible to all tested pyrethroid insecticides. An. culicifacies started to appear indoors in late May, showing 2 peaks in June and September. Fenitrothion, cyfluthrin and permethrin had the least irritancy effect and DDT the highest. Only 2/860 females tested were infected with Plasmodium spp. [sporozoite rate: 0.25%]. EL1SA testing of 250 blood meals derived from night-biting collections of female mosquitoes from humans and cows revealed that only 12.5% were human-fed

Designing of a laboratory model for evaluation of the residual effects of deltamethrin (K-othrine WP 5%) on different surfaces against malaria vector, Anopheles stephensi (diptera: culicidae).

BACKGROUND & OBJECTIVES: Deltamethrin plays an important role in controlling malaria vectors, and is used in indoor residual spraying and manufacture of long-lasting insecticidal mosquito nets. The residual activity of deltamethrin (K-othrine WP 5%) @ 25 mg/m(2) was studied in laboratory conditions on different surfaces. METHODS: The surfaces were made artificially with different building materials such as mud, plaster, cement and wood in the laboratory. The surfaces were mounted inside petri-dishes (diam: 20 cm) and wood surface was prepared separately. The prepared surfaces were attached to the walls and deltamethrin was applied using standard Hudson pump sprayer with a discharge rate of 757 ml/ min or 0.2 gal/min. The spraying was conducted at standard rhythm as recommended by WHO. After application all the sprayed surfaces were transferred into the special wooden boxes designed for this purpose. The surfaces were maintained at laboratory conditions. The WHO's recommended bioassay kit and method was used during this study. RESULTS: Bioassays on Anopheles stephensi Liston showed that the persistence of deltamethrin on different surfaces (>70% mortality) was around 4 months on plaster (Mortality = 77+/-6.2%), 2 months on mud (76.9+/-6.8%), 4.5 months on cement (79+/-3.2%), 4 months on wood (71.7+/-6.8%) and 4 months on filter papers (82.3+/-5.4%). INTERPRETATION & CONCLUSION: The results of this study on residual effects of deltamethrin WP 5% (25 mg/m(2)) are highly concordant with two field bioassays carried out in a malarious area at south-eastern Iran. This method can be replaced by the field bioassay tests which are time consuming and costlier.

Distribution and ecology of mosquitoes in a focus of dirofilariasis in northwestern Iran, with the first finding of filarial larvae in naturally infected local mosquitoes.

A study of the distribution and ecology of mosquitoes (Diptera: Culicidae) in Ardebil Province of northwestern Iran, with special reference to the known dirofilariasis focus in Meshkinshahr County, was carried out in July-August 2005 and April-October 2006. In total, 17,533 adult mosquitoes and 3090 third- and fourth-instar larvae were collected on 14 occasions and identified using morphological characters and DNA sequence data. Twenty species belonging to seven genera were found: Anopheles claviger (Meigen), An. hyrcanus (Pallas), An. maculipennis Meigen, An. pseudopictus Grassi*, An. sacharovi Favre, An. superpictus Grassi, Aedes vexans (Meigen)*, Coquillettidia richiardii (Ficalbi)*, Culex hortensis Ficalbi, Cx. modestus Ficalbi, Cx. pipiens Linnaeus, Cx. theileri Theobald, Cx. torrentium Martini*, Cx. tritaeniorhynchus Giles, Culiseta longiareolata (Macquart), Cs. annulata (Schrank)*, Cs. subochrea (Edwards), Ochlerotatus caspius (Pallas) s.l.* (= Aedes caspius sensu auctorum), Oc. geniculatus (Olivier)* (= Aedes geniculatus sensu auctorum) and Uranotaenia unguiculata Edwards (asterisks indicate new occurrence records for the province). The most prevalent species in adult catches were An. maculipennis (52%), Cx. theileri (45%) and Cx. hortensis (1%); the most prevalent species caught as larvae were Cx. theileri (27%), Cx. hortensis (21%) and An. maculipennis (19%). Anopheles maculipennis, Cx. pipiens and Cx. theileri were most widely distributed in the province. The occurrence of Cx. torrentium in Iran is verified based on differential characters of fourth-instar larvae. Anopheles maculipennis and An. sacharovi of the Maculipennis Group were identified from their diagnostic ITS2 sequences. For the first time, cytochrome c oxidase I (COI) sequences were obtained from Iranian specimens of An. hyrcanus, An. pseudopictus, Cx. theileri and Oc. caspiuss.l. Culex theileri and An. maculipennis were found naturally infected with third-stage (infective) larvae of Dirofilaria immitis (Leidy) and Setaria labiatopapillosa (Alessandrini) (Spirurida: Onchocercidae), respectively, for the first time in Iran.

Effect of washing on the bioefficacy of insecticide-treated nets (ITNs) and long-lasting insecticidal nets (LLINs) against main malaria vector Anopheles stephensi by three bioassay methods.

BACKGROUND & OBJECTIVES: The use of pyrethoid impregnated bednets is one of the main malaria vector control strategies worldwide. The objective of the present study was to evaluate the bioefficacy of bednets impregnated with various pyrethroids after repeated washings. METHODS: The effectiveness of bednets impregnated with permethrin, deltamethrin, bifenthrin, etofenprox and long-lasting bednets like OlysetNet and PermaNet which were provided by WHOPES was evaluated. The tests were carried out according to the WHO-recommended methods. Malaria vector, Anopheles stephensi was exposed to impregnated bednets for 3 min and the mortality was measured after 24 h recovery period. Knockdown was measured as well. RESULTS: Results of three methods of bioassay tests showed that between two LLINs, PermaNet was more efficient than OlysetNet. Results of ITNs exhibited that deltamethrin and permethrin were more effective than etofenprox and bifenthrin as impregnants. INTERPRETATION & CONCLUSION: Findings of this study will be useful for WHO, local authorities and people who wish to use different pyrethroid-impregnated bednets for malaria vector control.

Molecular data on vectors and reservoir hosts of zoonotic cutaneous leishmaniasis in central Iran.

Due to the increasing number of positive cases of cutaneous leishmaniasis with occurrence of new foci, a study was carried out to investigate on vectors and reservoirs of the disease in the Shahrood district, central Iran during 2005-2006. Sandflies and rodents were collected using sticky papers and Sherman live traps respectively More than 1700 sandflies were collected and identified, mainly Phlebotomus papatasi species. RAPD-PCR analysis of sandflies showed that 10% of P. papatasi and 4.2% of P. caucasicus were naturally infected with Leishmania major. Two species of rodents, potential reservoirs, Rhombomys opimus (92.5%) and Nesokia indica (7.5%) were trapped in the district. Microscopy identification from rodents confirmed that 91.9% of the Rhombomys opimus were positive to amastigotes. Species identification of isolated parasites revealed Leishmania major DNA in the infected Rhombomys using RAPD-PCR technique. This epidemiological data highlight the importance of the disease in the region and could help people involved in control programs.

Comparative performance of imagicides on Anopheles stephensi, main malaria vector in a malarious area, southern Iran.

BACKGROUND & OBJECTIVES: Jiroft district has subtropical climate and prone to seasonal malaria transmission with annual parasite index (API) 4.2 per 1000 in 2006. Anopheles stephensi Liston is a dominant malaria vector. The monitoring of insecticide susceptibility and irritability was conducted using discriminative dose as described by WHO. METHODS: The IV instar larvae were collected from different larval breeding places and transported to the temporary insectary, fed with Bemax and then 2-3 days-old emerged and sugar-fed adults were used for susceptibility and irritability tests employing WHO methods and kits to organochlorine (OC) and pyrethroid (PY) insecticides. RESULTS: Mortality rates of field strain of An. stephensi were 91.3 +/- 0.14 and 90 +/- 0.47% to DDT and dieldrin, respectively at one hour exposure time but was susceptible to all pyrethroids tested. The average number of take-offs per min per adult was 2.09 +/- 0.13 for DDT, 0.581 +/- 0.05 for dieldrin, 1.85 +/- 0.08 for permethrin, 1.87 +/- 0.21 for lambda-cyhalothrin, 1.53 +/- 0.13 for cyfluthrin, and 1.23 +/- 0.1 for deltamethrin. INTERPRETATION & CONCLUSION: Currently, deltamethrin is being used for indoor residual spraying against malaria vectors in the endemic areas of Iran. The findings revealed that the main malaria species is susceptible to all pyrethroids including deltamethrin, permethrin, cyfluthrin and lambda-cyhalothrin but was tolerant to DDT and dieldrin. This report and the finding are coincided with results of previous studies carried out during 1957-61 in the same area. Irritability tests to OC and PY insecticides revealed the moderate level of irritability to DDT compared to pyrethroids and dieldrin. Monitoring for possible cross-resistance between OC and PY insecticides should come into consideration for malaria control programme.

Anopheles peditaeniatus (Leicester) new to the Iranian mosquito fauna with notes on Anopheles hyrcanus group in Iran.

Anopheles peditaeniatus is reported for the first time in Iran. Species of the Hyrcanus Group previously reported in Iran, including An. hyrcanus, An. pseudopictus, and An. nigerrimus, are reviewed.

Larval habitats of main malaria vectors in Hormozgan province and their susceptibility to different larvicides.

Hormozgan Province is located in the south of Iran bordering the Persian Gulf. In this area, malaria is still considered a major health problem. In the province, eleven species of Anopheles were identified: An. pulcherrimus, An. sergenti, An. apoci, An. multicolor, An. subpictus, An. turkhudi, An. fluviatilis, An. stephensi, An. d'thali, An. superpictus, and An. culicifacies, among which only the last five species play an important role in malaria transmission. Larval habitats of malaria vectors varied from clean to brackish water, as well as sewage water, under palm trees, marshland, pools, pounds, drainage, irrigation canals, wells, and water containers. Malathion, fenitrothion, chlorpyrifos, and temephos were tested against An. stephensi, An. fluviatilis and An. d' thali larvae at diagnostic doses recommended by WHO. The results showed susceptibility to malathion, chlorpyrifos and temephos, but fenitrothion was not able to yield 100% mortality.