A comparison of the toxicity of the botanical insecticide, Sirinol and two chemical insecticides, Mospilan and Consult, on two natural enemies of the pistachio psyllid, coccinellid predator (Oenopia conglobata)...

Full Title: A comparison of the toxicity of the botanical insecticide, Sirinol and two chemical insecticides, Mospilan and Consult, on two natural enemies of the pistachio psyllid, coccinellid predator (Oenopia conglobata) and parasitic wasp (Psyllaephagus pistaciae)The common pistachio psyllid, Agonoscena pistaciae, is one of the most important pests of pistachio tree. This pest has many natural enemies and some of the important ones are the coccinellid predator (CP) (Oenopia conglobata) and the parasitic wasp (PW) (Psyllaephagus pistaciae). In this research, the effect of three concentrations of Sirinol on the first and fourth instar larvae and the adult of O. conglobata and on the pupae and adult of P. pistaciae was tested and the toxicity of this insecticide was compared with that of two chemical insecticides, Consult and Mospilan. Topical bioassay was carried out in laboratory condition; however, to investigate the resistance stage of the parasitic wasp, a completely randomized experimental design was used in the field condition in 2010 and 2011. The results of these experiments show that the chemical pesticide, Mospilan, caused more mortality of all the stages of the two previously mentioned natural enemies than did Sirinol. The results show that Mospilan had a slightly harmful, moderately harmful, moderately harmful, and slightly harmful effect on the adult of the PW and the adult and the first and fourth instar larvae of the CP, respectively and Consult had a harmless, slightly harmful, slightly harmful, and moderately harmful effect on the named stages of the PW and CP respectively. On the other hand, Sirinol had a slightly harmful effect on the adult of PW, but a harmless effect on the other stages; consequently, it falls into the category of International Organisation for Biological Control (IOBC). The field experiments conducted in 2010 and 2011 showed that 15.79% Mospilan, 13.8% Consult, and 6.49% Sirinol caused the mortality of the larvae and pupae of the PW. This research showed that Sirinol which caused very low mortality of the natural enemies of pistachio psyllid can be used in Integrated Pest Management (IPM) program in pistachio orchards.Keywords: Oenopia conglobata, Psyllaephagus pistaciae, insecticide, Sirinol, Consult, Mospila

Reproductive biology of jinga shrimp (Metapenaeus affinis) in coastal waters of Hormozgan Province, southern Iran

The main goal of this study was to understand the reproductive biology of Jinga Shrimp (Metapenaeus affinis) that is found in coastal waters of Hormozgan Province and is relatively unknown to the scientific community. To achieve this goal, we conducted a monthly sampling over the years 2001 to 2003 sweeping a long area from Bandar Abbass to Sirik in the south of Iran.We found that the sex ratio is not 1:1 either seasonally (except in autumn 2001) or annually (p<0.05). The peak of spawning of the shrimp observed in spring and also calculated the carapace length of female shrimps at first maturity (LM50) as 27.16mm

Changes of hormones (T3, T4 and cortisol) and ions (Na+ , Cl, K+ ) during smoltification in Salmo trutta caspius Kessler 1877

Salmo trutta caspius is an important and economic fish in the Caspian Sea has several morphological and physiological changes during smoltification. In this study, Hormonal (T3, T4 & Cortisol) and ionic (Na+ , Cl & K+ ) changes in the serum were determined during the period of smoltification in 5, 10, 15 & 20g of hatchery reared salmo trutta caspius in different seasons (spring, summer, autumn & winter). Hormones were measured by Eliza and Radio Immuno Assay, Na+ and K+ using flame photometer, Cl by colorimeter. T3 and T4 were quite high in spring, especially in the juvenile of 20g. Cortisol was quite low in spring and summer in all of weight groups. Ionic changes showed no significant differences with weight, but it was significantly different among seasons. This result suggests that analyzing the plasma thyroid hormones and ionic provide useful information about the optimal time of transferring Caspian Sea trout from fresh water to sea water. It is concluded that the juvenile fish of 20g shows a better smoltification process in the spring

Evaluating the effect of some botanical insecticides on the citrus mealybug Planococcus citri (Risso) (Hemiptera: Pseudococcidae)

Planococcus citri (Risso) (Homoptera: Pseudococcidae), is one of the key pests of citrus. The use of chemical pesticides for a long time can cause many problems such as pesticide resistance, as well as having an adverse effect on the environment. The use of chemical pesticides needs to be replaced with non-chemical control methods. The effects of tondexir (pepper extract) and palizin (eucalyptus extract) using five doses (500, 1000, 1500, 2000 and 3000 ppm) and sirinol (garlic extract) with five doses (1000, 1500, 2000, 2500 and 3500 ppm) on citrus mealybug was investigated. The effect of barter (a botanical synergist) using a single dose (1000 ppm) being added to tondexir and palizin at three doses (500, 1000 and 1500 ppm) and barter (1000 ppm) added to sirinol at four doses (1000, 1500, 2000 and 2500) on citrus mealybug was examined. Mortality was recorded after 24, 48, 72 and 96 h post-treatments. Analysis of variance showed that the highest mortality with 3000 ppm doses of tondexir and palizin was 90/60 ± 2/93 and 89/16 ± 1/92% with sirinol (3500 ppm) with 87.11 ± 1.11% mortality, respectively. However, the highest mortality by using barter plus tondexir and palizin (1500 ppm) was 94.44 ± 2.59 and 86.66 ± 3.6% and barter plus sirinol (2500 ppm) was 83.33 ± 3.6% mortality, respectively. There were significant differences between the two experiments (p &lt; 1%).Keywords: Palizin, sirinol, tondexir, bartar synergist, Planococcus citr

Comparative study on gonad development in rainbow trout (Oncorhynchus mykiss) reared in fresh and brackish water in the Yazd Province

Rainbow trout (Oncorhylichus mikiss) weidting 200±5 grams were used in this study to compare their gonad development in fresh and brackish water in Yazd Province. The culture period lasted 140 days from October to March 2003 during which time the temperature 03.8+0.6), pH (8.18±0.12) and dissolved oxygen (6.2+0.11) of fresh and brackish water were kept nearly constant. The salinity of fresh and brackish water was 0.4 -0.5 and 14.3-14.7ppt respectively. The fish were fed common commercial trout food (Chineh GFT2) based on temperature and biomass. Histological studies indicated that the gonad development is accelerated in brackish water where the males mature two month eal her than those reared in freshwater. The gonadosomatic index (G51) also affirmed the gonad development (P<0.05)

Sperm fertilization capacity of Caspian salmon, Salmo trutta caspius under ultraviolet irradiation

The optimum dose of ultraviolet (UV) irradiation to produce gynogenetic Caspian salmon, Salmo trutta caspius, with emphasis on the "Hertwig effect" and photoreactivation (PR) were investigated. The sperm of Caspian salmon was irradiated with UV at 2010 ± 200 µw.cm-2 in different times including 0, 1, 3, 5, 8, 10, 15, 20, 25, 35 and 45 min and was allowed to fertilize normal ova; the fertilization, eyed and hatching rates were calculated to assess the performance. Using the irradiated sperm decreased the fertilization, eyed as well as hatching rates and the so-called "Hertwig effect" was observed, with the time-dependent decrease in the hatching rates at 0+ to 3 min irradiation, but better hatching rates were observed at more prolonged irradiation times. The best hatching rate was achieved at 25 min of UV irradiation; after that the survival rates rapidly declined to near zero. For PR studies, the semen was irradiated with UV (5, 30 and 120s) and untreated semen (0s) was used as control. Irradiated semen and/or fertilized eggs by treated semen were exposed to visible light (60 W) at a distance of 30 cm for 10 min; the eyed and hatching rates were measured. UV irradiation as low dose as 5s, significantly decreased the hatching rate (P 0.05). So, based on the results of this study, it was impossible to detect any PR mechanism in Caspian salmon

Optimization of UV irradiation for production of gynogenetic rainbow trout, Oncorhynchus mykiss: emphasising Hertwig effect and photoreactivation

The optimum dose of UV irradiation to produce gynogenesis rainbow trout, Oncorhynchus mykiss with emphasis of Hertwig effect and photoreactivation (PR) was investigated. For this purpose, the sperm of rainbow trout were irradiated with UV at 2010±200 µw.cm-2intensity in different alternatives of 0, 1, 3, 5, 8, 10, 15, 20, 25, 35 and 45 minutes and allowed to fertilize normal ova; the fertilization, eyed and hatching rate were calculated to assess the performance. Using the irradiated sperm decreased the fertilization, eyed as well as hatching rates and the so-called "Hertwig effect" was observed, with the time-dependent decrease in hatching rate at 0+to 10 min of irradiation, but a better hatching rate at greater time of irradiation was observed. The highest hatching rate was observed in 20 min of UV irradiation; after that the survival rate decreased rapidly. Interestingly, irradiation even up to 45 min could not eradicate sperm fertility and a hatching rate above zero was observed at this treatment. For PR studies the semen was irradiated with UV for 5, 30 and 120 seconds and untreated semen (Os) was used as control. Irradiated semen and/or fertilized eggs by treated semen were exposed to visible light (60 W) at a distance of 30 cm for 10 min; the eyed and hatching rates were measured. The results showed that UV irradiation in as low as 5s could cause deleterious effect on semen chromatin and decrease the eyed and hatching rates (p<0.05). Illumination of semen and\or eggs with visible light resulted in PR in rainbow trout when sperm was irradiated by UV at 120s. We could conclude that the best UV irradiation time for production of gynogenesis rainbow trout was 20 min and UV irradiation, fertilization and egg hardening must be done far from visible light to eliminate the PR mechanism

Genetic difference and resemblance between Acipenser persicus and Acipenser gueldenstaedtii by means of RAPD Technique

We studied genetic difference and resemblance between Acipenser persicus and Acipenser guldenstaediii using Random Amplified Polymorphic DNA (RAPD) technique. The DNA of tail fin tissue of three A. persicus and A. gueldenstaedtii were extracted using phenol-chloroform method. After electrophoresis of the samples by agarose gel, their concentrations were regulated and Polymerise Chain Reaction (PCR) was conducted by 53 primers. PCR products were electrophoresed on polyacrylamide gel and silver staining was done to reveal the DNA bands of the samples. Among 53 primers, 17 had no site on genomic DNA of A. persicus and A. gueldenstaedtii and did not produce any bands while the remaining 36 primers showed band pattern. Analyzing the PCR products data using RAPD PLOT program showed that the maximum and minimum genetic distance between species were 73% and 65% respectively. Also, the mean difference between the species was 70% and the maximum and minimum genetic resemblance between the two species were 35% and 27% respectively. Based on the results, we conclude that A. persicus is an independent species from A. gueticienstaeditii

Effects of letrozole, non-steroidal aromatase inhibitor, on serum sex steroid levels, oocyte diameter and gonadosomatic index (GSI) in rainbow trout (Oncorhynchus mykiss)

The objective of this study was to contribute to investigate the efficacy of letrozole, a potent non-steroidal aromatase inhibitor, on serum sex steroid levels and oocyte growth in rainbow trout females. Serum steroid levels were measured using an indirect enzyme-linked immunosorbent assay (ELISA) before and 22 days after an initial injection with 1, 2.5 mg kg^-1 and subsequent weekly injection with 2.5 mg kg^-1 letrozole. After the last blood collection, gonad tissues were removed and oocyte diameter and GSI were determined. In all groups treated with letrozole, serum 17β-esteradiol levels (E2) decreased significantly and inversely serum 17α-20ß dihydroxy-4 pregnen-3-one (17α-20ß-P), testosterone (T) levels increased significantly from 6 to 96 h after injection (p<0.05). The lowest E2 levels, oocyte diameter and GSI were measured in the group treated weekly with 2.5 mg kg^-1 letrozole (p<0.05). This study demonstrates that letrozole has the potential to interfere in the synthesis of endogenous estrogens from androgens and delay gonadal development