[Comparison of PBO and DEF effects on creating bendiocarb and carbaryl insecticide resistance in German cockroach]

German cockroach [Blattella germanica, Blattodea:Blattellidae] is considered one of the common pests in hospitals, hotels, households and dormitories which can transfer different pathogenic fungi, viruses and bacteria. The aim of this study was to determine the resistance mechanisms to bendiocarb and carbaryl in German cockroache, in vivo. In this study, German cockroach strains were collected from several hospitals and dormitories in Tehran and transferred to insectarium. The strains were reared under the same laboratory conditions. At first the discriminative doses of bendiocarb and carbaryl were determined by surface contact method. Then the susceptibility level and types of resistance mechanisms to bendiocarb and carbaryl, in the strains were studied by using PBO and DEF as synergists. Simultaneous use of DEF as synergist, with bendiocarb and carbaryl led to the breakdown of resistance in all strains. But use of PBO instead of DEF did not overcome the resistance in the strains collected from Mofid, Alvand and Vali Asr hospitals and Shariati dormitory. In general, the effect of DEF in breaking the resistance was more than that of PBO. Complete breakdown of resistance after simultaneous use of DEF with bendiocarb and carbaryl insecticides, indicated the essential role of esterase enzymes in producing resistance to bendiocarb and carbaryl in the strains. But PBO did not break the resistance completely in most wild strains, which may be due to other possible mechanisms of resistance such as reduction of cuticle penetration or insensitivity to acetyl cholinesterase enzyme

Human extensive head skin myiasis

Chrysomya bezziana Villeneuve is the most important fly, which produces myiasis, exists as an obligate ectoparasite in the animals, and afflicts human. Poor hygiene and working in contaminated areas particularly during warm seasons provide a situation to infest by this parasite. Infestation in human and livestock are often observed in wounds, normal body orifices such as eyes, ears, nose, and mouth. The manifestations include pruritus, pain, inflammation, redness, eosinophilia, and secondary bacterial infections and rarely death. A 5-year-old boy with severe headache and agitation symptoms was followed up. After physical examination and endoscopy, larvae of third instar fly were obtained from his scalp. Our precise identification indicated that the flies were the C. bezziana. This is the second report of the human scalp myiasis caused by C. bezziana in Iran. This study confirmed that the old world screwworm fly was distributed in the southern of Iran and probably could be one of the most important agents of myiasis in this area

Mass rearing of anopheles stephensi on human blood by artificial feeding under laboratory conditions

In order to control the diseases that are transmitted to human and animal by arthropod vectors, it is necessary to investigate vectors and to recognize control methods as well. These studies are applicable by rearing the colonies of arthropod blood-feeders like malaria and leishmaniasis in laboratory. The purpose of this study was to produce mass production of Anopheles stephensi [Lis.] by artificial feeding with human blood in insectary. We prepared an apparatus composed of a digital thermostat with sensor, element, contractor and magnet in order to blood-feed An. Stephensi. The Para film "M" and a human whole blood unit were used as a membrane and nutrient source for artificial feeding, respectively. The blood was placed in a soft lid and its surface was covered with Para film "M". The soft drink lids with blood were placed on the cage surface and indirectly warmed by element. An. Stephensi fed from blood. Three consecutive generations were reared without blood-feeding on host alike from the egg of mother colony. Female mosquito feeding rate was 47.7% to 64%. The average females feeding and ovipositing times were 10 and 9 times, respectively. No mortality was seen among the larvae. All of the pupae emerged to the adult. The second and third generation of population ratios to first population generation was 6 and 25 folds, respectively. Our findings showed that artificial feeding by human blood, especially in the investigational projects was completely efficient and suitable for increasing mosquitoes' population in specific time

Rapid elimination of German cockroach, Blatella germanica, by Fipronil and Imidacloprid gel baits

Baits have become popular and effective formulations against urban insect pests. Compared with residual sprays toxic gel baits are used more and more frequently to control urban cockroach populations. The aim of this study was to investigate the usage of two commercially available fipronil and imidacloprid gel bait formulations against Blattella germanica field infested in Iran. The study was carried out in an urban area at Tehran from March 2004 to September 2005. The 0.05% fipronil and 2.15% imidacloprid gel baits were placed continuously in 3 residential German cockroach infested units. Pre- and post-treatment cockroach density was assessed by visual count method. Pre- and post-treatment visual count of cockroaches in treatment and control areas, and percentage reduction in cockroach density in treatment areas in comparison to control areas was showed that density reduction was increased with the 0.05% fipronil and 2.15% imidacloprid gel baits in treated areas from 1st to 9th week in comparison to control area. After 60 days, German cockroaches eliminated completely from these areas. These results show that fipronil and imidacloprid gel baits are highly effective in field German cockroach infested after insecticide spraying control failure German cockroach infested fields where spraying of pyrethroid insecticides failed to control the situation and confirm previous reports stating that avermectin and hydramethylnon are more effective than conventional insecticides in baits against cockroaches. Therefore, fipronil and imidacloprid gel baits are appropriate candidates for controlling German cockroach infested dwellings in Iran where control with other insectices failed because of resistance

Duration of fipronil and imidacloprid gel baits toxicity against Blattella germanica strains of Iran

The current study was conducted to investigate the duration of fipronil and imidacloprid gel baits toxicity against German cockroach strains in Iran during 2003-2004. In order to conduct this study, nine German cockroach strains were used. Newly emerged adult male German cockroaches starved for one scotophase [12 h], and ingested fipronil and imidacloprid gel baits for 2 h. After the given time was over, the bait was removed and replaced with mouse pellet. Mortality was recorded at 12 intervals for 144 h [6 days]. Mortality data of the replicates were pooled and was tested using probit analysis. Both gel baits were toxic to adult male German cockroaches. In the ingested bait method, the susceptible strain showed LT[50] of 47.1 and 11.3 h for fipronil and imidacloprid gel baits, respectively, and the average LT[90] was 74.2 and 19.3 h, respectively. LT[50] of the feral German cockroach strains varied 14.9 h from 30.5 to 45.4 h and 4.4 h from 12.4 to 16.8 h for fipronil and imidacloprid gel baits, respectively. All German cockroach strains showed a similar susceptibility to fipronil and imidacloprid gel baits, compared with the susceptible laboratory strain. The steep slopes of ingested bait mortality curves indicated that the feral German cockroach strains were homogenous to fipronil and imidacloprid ingested gel baits. These results suggest that fipronil and imidacloprid gel baits appear to have considerable potential as a bait for insecticide-resistant strains of German cockroach

[Induced lactation in adopted mother]

It is a fact that most of physician dont beleive that only with stimulation of the breast and encouragement, in a woman is not pregnant and has not had delivery, adequate milk production [lactation] can be induced to feed an adopted child. In this case, we have induced lactation for a 30-years old lady who could never be pregnant as an adopted child. During 2 years fallow up, we have observed that babys growth curve was quite similar to normal pattern. In this period, baby was fed by his adopted mothers milk

Comparison of Permethrin and Fipronil toxicity against German cockroach [Dictyoptera: Blattellidae] strains

Control of insect pests of agriculture, economic, and medical importance usually focuses on the use of insecticides. The susceptibility levels of eleven strains of German cockroaches, Blattella germanica [L.], were compared with a standard susceptible strain against permethrin and fipronil. The strains were collected from nine infested students' dormitories and two infested hospitals in Tehran, capital of Iran. The susceptible strain showed LD50 of 0.43 micro g and 0.96 ng for permethrin and fipronil respectively. Comparison of the resistance ratio of collected strain with susceptible strain showed resistance ratios of 8.6 to 17.7-folds for permethrin and 1.5 to 2.6-folds for fipronil, respectively. The result of this investigation indicated that the all strains were resistant to permethrin. Resistance spectrum of fipronil to permethrin showed different pattern of susceptibility to fipronil, indicating that there was no relationship between resistance to permethrin and fipronil

Effect of fipronil on permethrin sensitive and permethrin resistant strains of blattella germanica

Strategies to manage resistance to insecticides have usually been designed when resistance has already been developed. However, if the likelihood of resistance development to novel insecticides can be predicted before their use, it should be possible to establish an effective resistance management program. The current study was designed to investigate the effect of fipronil against permethrin sensitive and permethrin resistant strains of Blattella germanica [L.] for effective control of this pest in Iran in the future. In order to conduct this study eleven feral German cockroach strains were collected from infested student dormitories of Tehran University of Medical Sciences, Sanatee Sharif, Tarbiat Modares and Tehran Universities and also residential Saman Apartments, and two infested hospitals in Tehran. Their sensitivity to permethrin and fipronil were compared with that of a standard susceptible strain. Tests were conducted on newly emerged adult males [ultimately 21 years old] by topical application. LD[50]'s of permethrin and fipronil for the susceptible strain were 0.43/micro g and 0.96 ng respectively. The resistance of feral strains to permethrin was 8.6 to 17.7 times as much as that of the susceptible strain. According to this investigation all strains are resistant to permethrin, whereas resistance rates of the strains from Bustan-10, Zanjan Fatemiyeh dormitories and residential Saman Apartments were 2 to 2.6 times more than that of the susceptible strain. Other strains were completely susceptible to fipronil. According to the results of this study and considering ever-increasing infestation of human habitations by German cockroach and the resistance to insecticides; fipronil especially its toxic bait formulations can be regarded as the appropriate candidate to control this pest in Iran