JOURNAL OF ENTOMOLOGICAL RESEARCH
Year:2010 | Volume:2 | Issue:1 (5)|Papers Count:8

The family Aphelinidae belongs to the superfamily Chalcidoidea of Hymenoptera. Various species of theses wasps are parasitoids of different stages of Hemiptera especially Coccoidea and Aleyrodoidea. These parasitoid wasp emerged from soft scales (Eulecanium tiliae, Sphaerolecanium prunastri and Didesmococcus unifasciatus), armored scales (Childaspis asiatica and Lepidosaphes ulmi) on fruit trees of Markazi and Lorestan provinces, Iran and two whiteflies (Trialeurodes vaporariorum and Aleyrodes singularis) on the grasses and ornamental plants in Markazi province in laboratory conditions. A total of five parasitic wasps were collected and identified:Coccophagus lycimnia Walker, 1939Aphytis mytilaspidis (Le Baron, 1870)Encarsia inaron Walker, 1839E. formosa Gahan, 1924According to the available literature, Coccobius varicornis (Howard, 1881) is recorded from Iran for the first time.Morphological characters of the new record species, parasitism rate, similarity index and Simpson’s index for different regions were calculated and discussed.

We aim to assess the in vitro genetic and oxidative effects of different Callimenus latipes Stal, 1875 (Orthoptera: Tettigoniidae: Bradyporinae) extracts (acetone, ethanol and diethyl ether) on human lymphocytes. We used the micronucleus (MN) test to monitor genetic damage. In addition total antioxidant capacity (TAC) of blood was measured to evaluate the oxidative status. For these aims, heparinized blood samples were obtained from two, non-smoking healthy men, with no history of exposure to any genotoxic agent. The extracts containing all body parts were sterilized and added to the cultures at different concentrations (1 to 160 ppm). Our results showed that the application of insect extracts at different concentrations did not elevate (p<0.05) the number of MN formations. However, the extracts (except for ethanol) decreased TAC level at higher concentrations (80 and 160 ppm). Thus, these results suggest that C. latipes can be consumed safely, but it is necessary to take into consideration the cytotoxicity at increasing doses.

The Ichneumonid fauna (Hym., Ichneumonidae) was investigated in different regions of Yazd and vicinity during 2006 -2008. A total of nine species were collected and identified. According to the available literatures, the two asterisked species are reported for the first time from Iran.1. Diplazon laetatorius (Fabricius, 1781)2. Ophion ventricosus Gravenhorst, 18293. Ophion luteus (Linnaeus, 1758)*4. Ophion obscurus Fabricius, 1804*5. Ichneumon caloscelis Wesmael, 18456. Netelia arimeniaca Tolkanitz, 19717. Meringopus calescens (Gravenhorst, 1829)8. Cryptus spinosus Gravenhorst, 1829Some information relating to the morphological characters, host range and geographical distribution of two new species records were presented and discussed.

The common cutworm (Agrotis segetum Schiff.), is one of the most important pests of sugar beet (Beta vulgaris L.), in Iran. Among the alternatives to control this pest, use of B.T.-transgenic sugar beet expressing cry1Ab gene has gained attention due to its efficiency. In the present study, larval mortality, larval weight loss and damage level of this pest on 18 treatments (16 T1 transgenic and 2 non-transgenic sugar beet lines) were evaluated in 3 CRD experiments with 4 replications.Therefore, 40 larvae of the common cutworm in 4 replications (10 larvae/replication) were fed on leaves of the treatment lines in glass Petri dishes. The mortality, weight of larvae and weight loss of leaves were recorded at the third and the sixth days after infestation (DAI). ANOVA results confirmed the significantly differences at %1 probability level among treatments in all of the evaluated factors (except larval mortality at 3 DAI). Finally, mean comparisons were carried out using Duncan’s multiple range tests at %5 probability levels. Based on the results, all of the examined transgenic lines were more effective than non-transgenic lines against A. segetum. The results confirmed that the transgenic line S36-13 (7.5-20% larval mortality, 1.57-10.76 mg LaWL and 39.3-53.64% Leaf Weight Loss at 3 and 6 DAI) was the most effective among evaluated transgenic and non-transgenic lines.

In this study, an experiment was conducted to investigate the toxicity of three spices powders species, cinnamon (Cinnamomum aromaticum Ness.), turmeric (Curcuma longa L.) and red pepper (Capsicum annuum L.) on adults of lesser grain borer (Rhyzopertha dominica F.). Experiments were done at five different rates 0.5, 0.85, 1.5, 3 and 5 % (wt/wt) with four replications under laboratory conditions (28±1oC, 70±5 % Rh). Twenty adult insects (1-4 day olds) were released in each treatment. The mortality was noted 1, 3, 5, 7 and 14 days after exposure. All insects were removed from all replications after 14 days and the experiments were monitored for the extra 36 days in order to count the number of adult offsprings. The results revealed that the powders had significant insecticidal effects on adults of this insect compare to the control. The toxicities of these powders increased with increase in dosage as well as increase in the period of exposure to the plant materials. Highest mortalities were recorded at the highest dosages and exposure times with turmeric, red pepper and cinnamon, respectively. LD50 values (after 14 days) for turmeric, red pepper and cinnamon were 1.49, 2.10 and 3% of adult weights respectively. All tested materials at the highest dosages reduced significantly F1 progeny emergence of R. dominica. However cinnamon powder at 5 % (wt/wt) prevented reproduction completely (100%). This investigation showed that all three powders spices are suitable in protecting wheat grains against the lesser grain borer.

Cabbage aphid, Brevicoryne brassicae L. is one of the most important insect pests of canola crop causing qualitative and quantitive damage by sucking plant sap. Field studies during 2001- 2003 revealed that pest starts attacking the canola fields in different times of the season over the cultivation areas of the country. Under Tehran province (Varamin region) conditions initial infestation and the establishment of colonies of aphid were observed on young seedling of canola (winter crops) during November and subsequent spread of infestation occurred after cold period of winter in February and March. Maximum population of B. brassicae L. was recorded during April- May. The multiplication of the aphid is governed by day time abiotic factors like temperature, humidity, and sunshine. Path coefficient analysis of the impact of the abiotic factors showed that minimum temperature, minimum relative humidity and sunshine imposed direct positive effect on the pest.

Life table, reproduction and population growth parameters of Trichogramma brassicae Bezdenko were studied on eggs of two laboratory hosts, Ephestia kuehniella Zeller and Sitotroga cerealella Oliver and one natural host species eggs, Helicoverpa armigera Hubner. The experiments were carried out in a growth chamber with temperature of 25±1oC, 50±5 % relative humidity and a photoperiod of 14L: 10D hours. Adult life expectancy were 5.65, 9.45 and 4.95 days on eggs of H. armigera, E.kuehniella and S. cerealella, respectively. Gross fecundity rate of T. brassicae on eggs of E. kuehniella was higher than eggs of two other hosts. Net reproductive rate were 41.98, 55.65 and 42.17 females/female on H. armigera, E. kuehniella and S. cerealella, respectively. Intrinsic rate of increase of T. brassicae on eggs of H. armigera, E. kuehniella and S. cerealella were 0.298, 0.309 and 0.301 females/female/day, respectively. Mean generation time of T. brassicae was longer then on eggs of E.kuehniella.

Survival of the fungus Beauveria bassiana Vuillemin as a pathogen of saw-toothed beetle on the date cultivars including Sayer, Zahedi, and Deiri was investigated. Parameters including hazard rates of germination and median of survival hopes for fungal germination were estimated for each cultivar. The results showed that germination percentages decreased from the beginning to the end of storage period with different slopes in three Date cultivars. The trend of decreasing in germination of cultivars Zahedi and Sayer was more similar than Deiri. The median of spore life expectancy of Zahedi and Sayer had a slight variation until the fourth month of storage and then decreased gradually. However, in Deiri the spore life expectancy had a uniform variation until the sixth month of storage. There was a significant correlation between the acidity and water content of fruit and persistence of spore germination of B. bassiana during 6 months of storage. The effectiveness of acidity and water content of Deiri duration of spore germination in Deiri was stronger than Zahedi and Sayer. Therefore, the percentage of germination decreased steeper than the other two cultivars. These results indicated that the type of cultivar affects the survival of the pathogen, It is concluded that in using B. bassiana to control the sow-toothed beetle on date, the cultivar and storage conditions should be taken in to consideration.