Applied Entomology and Phytopathology
Year:2013 | Volume:81 | Issue:1 (96)|Papers Count:11

Microcerotermes diversus Silvestri (Isoptera: Termitidae) is the most economically destructive termite in buildings in Khuzestan province (Iran) that is fed by anything containing cellulose. Considering the importance of using environmentally friendly chemicals with applicable potential in integrated pest management programs such as essential oils and plant extracts, this study evaluated the contact and fumigation toxicity effects of Eucalyptus essential oil using tunneling and fumigation tests on M. diversus.Concentrations of the essential oil were 0.3 to 1.6% (g/ml) and 0.7 to 1.6% in tunneling method and fumigation methodes respectively. The results of tunneling method showed that essential oil could act as a repellent at given concentrations. It also increased the mortality of termites at concentrations higher than 0.7%. Concentrations used in fumigation tests resulted in mortality of termites, and a direct regression was found between concentration and mortality. The results suggest that the Eucalyptus oil might be an effective compound for inducing mortality against subterranean termites.

Bethylidae are cosmopolitan wasps, with about 100 valid genera and about 2,400 valid species around the World that poorly studied in Iran. Within this family the genus Epyris Westwood (Hym.: Bethylidae, Epyrinae) is reviewed in Azarbaijan Sharghi Province of Iran. Eight species were collected and identified from northwestern Iran. All of them are recorded for the first time from Iran. The studied species in this research are as follow: Epyris bilineatus Thomson, Epyris macrocerus Kieffer, Epyris macromma Kieffer, Epyris marshalli Kieffer, Epyris minor Kieffer, Epyris niger Westwood, Epyris transversus Kieffer and Epyris quinquecarinatus Kieffer.

Biology of apterous morph of rose grain aphid, Metopolophium dirhodum, one of the most abundant wheat aphids, was studied in a laboratory condition with temperature of 25±1oC, 50-60% relative humidity, and a photoperiod of 16:8 (L:D) hours. The experiment was carried out by rearing 50 first instar aphid nymphs in leaf cages on wheat (Triticum aestivum cv. Mahdavi). Biological characteristics of aphid were recorded daily and used for estimating population increase parameters according to Carey (1993). Mean nymphal development time of rose grain aphid was obtained 10.72±0.37 days. Pre oviposition period was 1.17±0.09 days and mean generation time of rose grain aphid (from nymph to next generation nymph) was obtained 11.89±0.37 days. Mean longevity was 42.66±1.87 days. Adult longevity was high (33±2.28 days) and they reproduced during most of their lifespan (17.65±1.37 days). Survival curve of M. dirhodum on wheat was determined as Type І. Regarding to the age specific survival of aphid, nymphs and young adults didn't suffer any mortality. Like to the development of herbivorous insects on susceptible host plants, there was even no mortality until age 27 (day). Study on stable population parameters revealed that each female produced 33.84 female in next generation (R0). Intrinsic rate of increase (rm) was 0.194 female per female per day. Estimating the finite rate of increase (l) was also indicated 21.4% increment in aphid population per day. Estimation of doubling time (DT) (3.57 days) and mean generation time (T) (18.18 days) was also showed considerable population increase potential of rose grain aphid on Mahdavi wheat cultivar.

Verticillium wilt caused by Verticillium dahliae is an important disease of cucumber grown in greenhouses. In this study, the inhibitory effects of volatile and non-volatile metabolites of wood vinegar (Pyrolignious acid) on the mycelial growth of V. dahliae as well as the combined effects of wood vinegar and vermicompost on the control of associated disease were studied in vitro and in situ conditions. To study the effect of non-volatile and volatile metabolites, 0, 0.025%, 0.05%, 0.125%, 0.25%, 0.37%, 0.5% and 0.75% of wood vinegar were tested. Four replicates were considered for each concentration. The mycelial growth of the fungus was measured daily up to 10 days. Both volatile and non-volatile metabolites inhibited significantly the fungal growth in vitro conditions at 0.05 probability level. Three concentrations of wood vinegar 0.125%, 0.25%, 0.5% were drenched into the soil one and 14 days post transplanting. The effect of treatments was assessed through measurement of disease severity index, wet and dry weight of roots and shoots, as well as root length and shoot height. Disease severity was significantly reduced in all concentrations used (a= 0.05). The combination of vermicompost and vinegar reduced the pathogenicity of the pathogen and increased the weight of roots and shoots.

Was conducted weekly and the second plot was considered as the control (no pest control measures applied). The total number of mines (mean±SE) bearing live and dead larvae and parasitism percentage of leaf miner larvae/plant were 26.61±5.54, 35.32±7.42 and 39.00±7.00, respectively in release treatment of the first greenhouse. The same parameters estimated to be 95.37±12.95, 4.60±0.92 and 5.00±2.00, respectively for the control at the same greenhouse. Similarly, in the second greenhouse above mentioned parameters for release treatment (3.16±0.66, 4.69±0.92 and 40.00±7.00 respectively), was significantly different with those of the control (12.83±1.63, 1.89±0.60 and 8.00±2.00). The activity of parasitoid was increased following the increase of ambient temperature and pest population at the end of the sampling period.

Crown and root gall caused by Rhizobium vitis, is one of the most important diseases of grapevine worldwide. In Iran, the disease has been reported in different areas such as Zanjan province. Despite the importance of the disease in the orchards, there is no an effective control measure for the disease. In this study the most important soil inhabiting bacteria from vineyards in Zanjan province were isolated and were identified. Antagonistic effects of some isolates were investigated against the pathogen. For this mean, samples were collected from grapevine roots with surrounding soil in vineyards in different areas of the province. Based on morphological, physiological and biochemical characteristics, 200 isolates were selected and their inhibitory effects were investigated on the pathogen in vitro for antibiotic production. Fifty isolates with the most inhibitory-effect in the tests were identified to genus and species levels. Some isolates identified as Pseudomonas spp. were further studied for the hcnABC gene. Biochemical tests identified representatives as Pseudomonas fluorescens biovare I, III and V, P. putida, Basillus subtilis, Pseudomonas sp., and Bacillus sp. Identified Pseudomonads showed significant inhibitory effect on R. vitis on King-B medium also via HCN production. In the PCR, hcnABC gene was amplified from five Pseudomonas strains. Indeed, seven strains with the most inhibitory-effect in vitro were selected across identified Pseudomonas and Bacillus strains and their antagonistic effect on the pathogen population was studied in the soil environment. Based on the results, all tested bacteria showed significant inhibitory effect on the pathogen population. However, Pseudomonas fluorescens bv. V, III and Bacillus subtilis were more effective.

In order to study the Dorylaimid nematode 150 soil samples were collected from different localities in Chaharmahal va Bakhtiari province, during 2009 to 2011. Nematodes were extracted by combined sieving and centrifugal flotation technique and processed to be transferred in glycerin by De Grisse (1969) method. After preparing microscopic slides, the morphological and morphometrical features were studied using the light microscope equipped with drawing tube. In this study five species including M. vulneratus, M. graciosus, M. pseudobastiani, M. ibericus and M. litoralis belonging to Mesodorylaimus were identified, that the first four species are new for the nematode fauna of Iran. Vulva has a transverse slit in three first species in spite of longitudinal slit in the two latter. Lip region was observed offset in M. vulneratus while continuous with body in M. ibericus and M. graciosus. Odontostyle in M. ibericus was shorter than M. graciosus. M. pseudobastiani and M. litoralis can be distinguished by different number of supplements in males.

In this research, adult lacewings were reared in the greenhouse on an artificial diet. The larvae were fed by the eggs of Mediterranean flour moth. Sub lethal effects of endosulfan, imidacloprid and indoxacarb were assessed using demographic toxicology method on adult lacewings at concentrations of 317, 46 and 9 mg AI/lit (as LC25), respectively. Most of the biological parameters of the lacewing, except mean age of fecundity and gross hatch rate, were significantly affected by the insecticides. The gross fecundity rate in control, imidacloprid, endosulfan and indoxacarb treated insects were 618, 492, 313 and 279 eggs per female; indicated that the parameter was reduced significantly by imidacloprid and endosulfan treatments compared to the control. The stable population parameters were affected by the treatments. The intrinsic rates of increase (rm) values were 0.179, 0.161, 0.157 and 0.136 female offspring per female per day in control, imidacloprid, endosulfan and indoxacarb treated cohorts, respectively. In general, the sublethal toxicity ranking of the treatments was as follows: imidacloprid<endosulfan<indoxacarb. We concluded that the adult lacewing was sensitive to endosulfan and indoxacarb.