Journal of Entomological Society of Iran
Year:2003 | Volume:23 | Issue:1|Papers Count:7

In this study the specimens belonging to the genus Euchromius held in Hayk Mirzayans Insect Museum (HMIM) of Plant Pests and Diseases Research Institute (PPDRI), examined and revised. Identification keys for the Iranian species, their diagnostic characters, differences with the original descriptions and the distribution of the species are provided. The mentioned species are listed as follow: Euchromius bellus (Hubner), E. rayatellus (Amsel), E. keredjellus (Arosel), E. ramburiellus (Duponchel), E. jaxartellus (Erschoff), E. cambridgei (Zeller), E. vinculellus (Zeller), E. ocelleus (Haworth), E. viettei (Bleszynski). E. rayatellus (Amsel, 1949) collected in 1971 in Mashhad as well as 1974 in Kuhrang and E. viettei Bleszynski, 1961 collected in 2000 in Farm Island (Persian Gulf) are new records for fauna ofIran.    

The life table parameters of populations of cotton whitefly, Bemisia tabaci (Genn.) (Hom.: Aleyrodidae) as an important pest of cotton fields were studied during 2002. The infested leaves containing nymphs and pupae were collected from Darab, College of Agriculture (Tehran) Qom, Saveh, Gonbad, Gorgan, Varamin, Garmsar, Orsoiieh (Kerman) and Shooshtar cotton fields. Experiments were carried out in a growth chamber under 24±2°C, 55:±3%RH and 16:8 (L:D) photoperiod on cotton, Gossypium hirsutum L. (Varamin 76 variety). The newly emerged adults from each location were released into a large cage (40×50×70 cm) set on cotton plants separately. Using mean data obtained on 15 adult whiteflies from each population from 10 local populations, life table parameters were calculated. The most basic life table parameters were age x, surviving from birth to exact ages x (Lx) using this factors for calculation of life table parameters such as number of survivors for successive x and x+1 dx , survival period Px age specific mortality qx, and life  expectancy ex and the curves were prepared. The results revealed that proportion of a cohort surviving  from birth to exact ages x (Lx) began at 24th day and reached to zero at 48th day, also age specific mortality (qx) began at 22nd day and reached highest at 49th day. Life expectancy (ex) was 26.9 at the initiation of development which reduced to zero at 28th days. Surviving from birth to exact ages x (Lx) were highest at the College of Agriculture (23) and lowest at Gonbad (8) populations. Also life expectancy (ex) was highest (29.72) in College of Agriculture and lowest (24.95) in Varamin population. The results revealed that there were differences between parameters of life table in diverse populations    

According to the studies carried out from July to December 2000, the species Lycoriella auripila (Winnertz) and Coboldia fuscipes (Meigen) are known as important pests of button mushroom, Agaricus bisporus (Lange), in Karadj mushroom houses. These species are the most important pests of button mushroom in the most regions of the world. The biology of these pests was studied in laboratory conditions (20±1ºC, R.H. > 80% and 16L: 8D photoperiod). The results indicated that developmental time in males and females were 29.85±0.146 and 29.08±0.153 days in L. auripila and 30.24±0.14 and 29.10±0.14days in C.fuscipes, respectively. The incubation larval and pupal periods were determined as 4. 18±0.031, 17.57±0.128 and 4.82±0.051 days for L. auripila and 2.6±0.0 1, 20.88±0.13 and 4.57±0.03 days for C.fuscipes, respectively. The adult longevity of males and females in natural condition of mushroom cultivation were obtained 4.06±0.115 and 3.31±0.102 days in L. auripila and 3.19±0.12 and 2.95±0.12 days in C.fuscipes, respectively. The juvenile mortality in L. auripila and C.fuscipes were 61.9±2.76 and 77.15±5.32 percent, respectively. Sex ratio in artificial feeding condition (Malt, Yeast, and Agar) were 1.15:1 male to female in L. auripila and 1.09:1 in C. fuscipes and in natural cultivation condition of mushroom were 1.09:I male to female in L. auripila and 1.11:.1in C.fuscipes. Net reproductive rate and intrinsic rate of increase were calculated as 9.3 and 0.07 in L. auripila and 28.4 and 0.107 in C.fuscipes, respectively.    

In order to determine the effect of the type of host species on searching efficiency, handling time and functional response of Trichogramma embryophagum, it was reared on Ephestia kuehniella and Sitotroga cerealella eggs for 15 generations. Different levels of hosts egg densities as: 2,4, 6, 8, 14, 20, 30,40 and 50 were used. Each density was placed in a test tube (l6×100mm) and then exposed to a 24 h mated female. The experiments were carried out at 25±1°C, 50 ±5%RH and 16:8 (L:D) photoperiod. In both experiments functional response was a type III and Holling disc equation was used to estimate the parameters. Searching efficiency, handling time and estimated maximum percent of parasitism for parasitoids reared on S. cerealella were 0.13, 1.64 and 75.73, and for those reared on E. kuehniella were 0.11, 1.65and 68.78, respectively. There was no significant difference between estimated parameters in both experiments. The results revealed that the type of laboratory host has no important effect on functional response of T. embryophagum.    

Twelve Iranian isolates of B. thuringiensis were evaluated for β-exotoxin using combination of bioassay and HPLC methods. Bioassay results on 4 days old larvae of Helicoverpa armigera showed the existence of a mortality factor, which can be β -exotoxin, in some autoclaved supernatant of isolates (with no spores and crystals). To verify these results, the β -exotoxin was measured in each isolate using HPLC method. The results indicated that the concentrated supernatant of isolates Krm23, Kn4, 3R and 4t contained β -exotoxin. Isolates Krm23 and 3R had the lowest (7.37 µg/ml) and highest (294.5 µg/ml) amounts of β -exotoxin, respectively. Comparison of bioassay results with β-exotoxin analyzed by HPLC showed that measured quantities of β –exotoxin were confirmed by the mortality percentage of Helicoverpa armigera.  

An experiment was carried out to evaluate the alcoholic extracts of leaf and flowers (red and white) of Nerium oleander, leaf of Lavandula officinalis and gum of Ferula assafoetida on Tribolium castaneum. Nutritional indexes, namely relative growth rate (RGR), relative consumption rate (RCR), efficacy of coversion of ingested food (ECI) and feeding deterrent index (FDI) were measured. Treatments were evaluated by the method of flour disk bioassay, under controlled condition, at 28±1ºC and 70-80% RH. and l6:8h (L:D) photoperiod. Of each extract several concentrations (30, 60, 90, 120, 150 µl/disk)with control were prepared. Thereafter; ten seven -day adults were introduced to each disk. Then, nutritional indices were measured three days later. Results showed that gum extract of F. assafoetida was the most effective, and significantly decreased the RGR and RCR. These rates, at the concentration of 150 µl/disk was decreased to 0.005 and 0.032 mg/day respectively. However, at the same concentration, there were not any significant differences among remaining extracts. Moreover, the gum extract, in higher concentration (150 µl/disk), decreased the ECI significantly as compared with other extracts. The efficiency (ECI) was decreased to 13.33. While, the ECI at 150 µl/disk did not significantly differed among the other extracts. The gum extract of F. assafoetida had the most effective on FDI and increased it up to 87.33%.    

During 2002-2003 a research was carried out on species abundance of edaphic Uropodoidea mites and spatial distribution of Nenteria stylifera (Beriese, 1904) in Tehran area. For this purpose, soil samples were taken from humus rich areas of orchards, parks and lawns of the region. Mites were extracted from the soils using Berlese-Tullgreen apparatus. In this study 10 species of three families were collected and identified. Five species are considered to be new records in Iran and one is probably new species, which are marked by one and two asterisks respectively. Mite species are listed according to their families as follows: Family: Trematuridae 1- Nenteria sp.** 2- Nenteria breviunguiculata * Willmann, 1904 3- Nenteria stylifera (Berlese, 1904) 4- Trichouropoda sp. 5- Trichouropoda elegans* Kramer, 1882 Family: Urodinychidae 1- Uroobovella fimicola Beriese, 1903 2- U. marginata (Koch, 1839) 3- U. obovata* Can and Berlese, 1834 4- U. pulchella* (Berlese, 1904) Family: Uropodidae l-Uropoda orbicularis Muller, 1776 Scientific names of the species which were new records for Iranian fauna were confirmed by international acarologists. Moreover, relative abundance of different species was also determined.In this study, N. stylifera was collected in almost all soil samples, thus it was considered a dominant species of the region. Spatial distribution of N. stylifera was also determined as aggregate distribution using variance mean index and Taylor regression methods.