Population fluctuations of Diaphorina citri (Hem.: Liviidae) on Persian lime tree, Citrus latifolia, in Baluchestan, Iran

The population fluctuations of the Asian citrus psyllid nymphs, Diaphorina citri Kuwayama, was studied in Persian lime orchards on the outskirts of Sarbaz, Rask and Polan towns in southeastern Iranian Baluchestan between 2007 and 2008. The species D. citri was observed feeding on its host plant throughout the year leading to overlapping generations. The highest density (126 ± 11 and 157.63 ± 68) occurred in Sarbaz in August and March. We reported the highest density for Rask and Polan in âSeptember and Marchâ and November respectively

Biology of Diaphorina citri (Hem.: Liviidae) and parasitism by Psyllaephagus stenopsyllae (Hym.: Encyrtidae) in Baluchestan, Iran

پسیل آسیایی مرکبات، Diaphorina citri Kuwayama، یکی از آفات مهم و ناقل بیماری گرینینگ مرکبات می‌باشد. در این پژوهش، ویژگی‌های زیستی این آفت در شرایط آزمایشگاهی و میزان پارازیتیسم آن توسط زنبور Psyllaephagus stenopsyllae (Tachikawa) مورد بررسی قرار گرفت. طول دوره قبل از تخم‌گذاری و دوره تخم‌گذاری به‌ترتیب 51/0 ± 9 و 23/0 ± 7/15 روز بود. میانگین تعداد تخم گذاشته‌شده توسط حشره ماده 7/50 ± 25/230 عدد و میانگین طول دوره پورگی 7/18 ± 83/14 روز بود. میانگین درصد پارازیتیسم توسط P. stenopsyllae، 6 ± 7 درصد تعیین شد

Effects of imidacloprid, dichlorvos, pymetrozine and abamectin, on life table parameters of the predatory bug, Orius albidipennis (Hemiptera: Anthocoridae)

Effects of four pesticides (imidacloprid, dichlorvos, pymetrozine and abamectin) were evaluated on life table parameters of Orius albidipennis (Reuter). Pesticides were used at the concentrations recommended by the manufacturers. The bioassays were carried out using drum-cell method, in a growth chamber at 27 ± 1ºC, R.H. of 65 ± 5% and 16 h photo phase. The net reproductive rate (R0) value for the populations treated with imidacloprid, dichlorvos, pymetrozine, abamectin and tap water as control was, 2.91 ± 0.48, 18.85 ± 2.55, 10.16 ± 1.21, 8.00 ± 1.05, 43.40 ± 7.64; the intrinsic rate of natural increase (rm) was 0.040 ± 0.005, 0.097 ± 0.018, 0.086 ± 0.012, 0.078 ± 0.010, 0.148 ± 0.006: the mean generation time (T) was 25.60 ± 1.12, 25.94 ± 1.85, 26.37 ± 0.25, 25.61 ± 0.21, 25.20 ± 1.16; the doubling time (DT) was 18.04 ± 2.76, 7.72 ± 1.60, 8.23 ± 1.11, 9.24 ± 1.37, 4.68 ± 0.18, and the finite rate of increase (λ) was 1.041 ± 0.006, 1.102 ± 0.019, 1.090 ± 0.013, 1.081 ± 0.011, 1.160 ± 0.007, respectively. Imidacloprid and dichlorvos, which revealed the most and the least effects on the life table parameters, were the most and the least harmful among the chemicals tested

Accuracy and efficiency of conventional ground sprayers in Iran

Sunn pest, Eurygaster integriceps, is a key pest of wheat and barley in Iran. At present, infested areas are treated with ground sprayers. A survey was conducted to evaluate the efficiency and calibration accuracy of ground hydraulic sprayers in Iran. The results showed that the motorized lance sprayer and manually operated sprayer were the most conventional sprayers, and fenitrothion EC 50% and deltamethrin EC 2.5% were the conventional insecticides against sunn pest in Kermanshah province. The mean efficacy percentage was 88% and 35% against nymphs and overwintered adults, respectively. In motorized lance sprayers, there were 5% and 90% overdosage of fenitrothion and deltamethrin, respectively; while, in manually carried sprayers, there were 5% and 25% overdosage of fenitrothion and deltamethrin, respectively. Applied dosages were 5-20% and 25-90% more than recommended dosages of fenitrothion and deltamethrin, respectively. Errors in effectiveness and applied dosage were higher in motorized lance sprayer than manually carried sprayers

Effects of phosalone residues on alfalfa weevil larval parasitoid, Bathyplectes curculionis (Hym.: Ichneumonidae)

A study was carried out to determine the suitable spraying time for phosalone against alfalfa weevil, Hypera postica (Gyllenhal) (Col.: Curculionidae), with the least adverse effects on its major parasitoid, Bathyplectes curculionis (Thomson) (Hym.: Ichneumonidae). Plots of 10 m2 were sprayed with phosalone (35%) at 3.0 kg/ha, using a knapsack sprayer. The residues of phosalone in parasitoid cocoon and alfalfa foliage were measured at different time intervals after treatment using high performance liquid chromatography. Residues of phosalone on B. curculionis cocoons treated by dipping method were 0.751, 0.466, 0.245, 0.115, 0.075, 0.044 and 0.019 µg/cocoon in 2 hours, 1, 3, 7, 14, 22 and 30 days after treatment, respectively. Results of this experiment revealed that there was no penetration of the insecticide into the cocoon. In fresh foliage, the residues of phosalone were 74.066 ï± 6.9, 47.319 ï± 2.1, 16.345 ï± 1.99 and 3.743 ï± 0.33 mg/kg at 2, 4, 7 and 14 days after spraying, respectively. The residue level on foliage at day 7 is critical and this must be considered as the least interval time between the application of the phosalone and the peak of parasitoid population

Laboratory Evaluation of the Toxicity of Proteus, Pymetrozine, Deltamethrin, and Pirimicarb on Lady Beetle Hippodamia Variegata (Goeze) (Col.: Coccinellidae)

The implementation of an Integrated Pest Management (IPM) program requires selecting and using chemicals which are least harmful to natural enemies. In this study, the acute toxicity of the recommended field concentration of four conventional insecticides was evaluated in reference to the different life stages (L3, L4 and adult) of the variegated lady beetle Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae). The evaluated insecticides were Proteus, pymetrozine, deltamethrin, and pirimicarb. A completely randomized design (CRD) with four replications was used as the experimental design. The means were separated by the least significant difference (LSD). The mortalities of those predators treated with the field recommended concentrations of various insecticides, were significantly different. Proteus showed strong toxicity toward the different life stages of the predator. However, pymetrozine and pirimicarb caused less than a 50% mortality. Based on the lethal concentration (LC50) values at 24 h after treatment, the adult predator was the most susceptible to proteus, followed by deltamethrin, pymetrozine, and pirimicarb values of 35.977, 358.757, 915.667, and 2616.113. Based on sublethal concentrations (LC30), these values were 22.718, 261.957, 569.879, and 1521.424. Based on International Organization of Biological Control (IOBC) classification, the insecticides pirimicarb and pymetrozine were both categorized as having a Class 1 toxicity level (harmless), deltamethrin as having a Class 2 level (slightly harmful), and Proteus, a Class 4 toxicity level (harmful)