نشریه نامه انجمن حشره شناسی ایران
سال سی و چهارم شماره 1 (پیاپی 56، بهار 1393)

Beet armyworm، Spodoptera exigua (Hübner) is an important pest of field crops with a wide range of host plants. Using safer insecticides with different modes of action and lower possibility of development of resistance such as insect growth regulators (IGRs) would be useful for effective control of this pest. In this study، effects of three IGRs namely methoxyfenozide، lufenuron and flufenoxuron were assessed on 1st instar larvae of S. exigua. To investigate the effect of insecticides، bioassays were performed using diet incorporation and leaf dipping methods. Mortalities were recorded 144 h after treatment. The LC50 values obtained for methoxyfenozide، flufenoxuron and lufenuron were 0. 154، 0. 254 and 2. 398 mg ai/l، in diet incorporation method; and 1. 302، 0. 427and 3. 510 mg ai/l in leaf dipping method، respectively. Comparison of the LC50 values for the insecticides revealed that the LC50 values for the treated insecticides were significantly different in both bioassay methods. The results indicated that in both bioassay methods، lufenuron had the lowest toxicity against the 1st instars of beet armyworm. It was revealed that all insecticides tested were effective against 1st instars of beet armyworm at low concentrations. If similar results are obtained in field conditions، due to fewer unwanted effects of these insecticides، they can be considered in beet armyworm control programs.

The sweetpotato whitefly، Bemisia tabaci Genn. (Hemoptera: Aleyrodidae) is a worldwide economic pest both in the field and in the greenhouse. In this study، the efficiency of plant extracts of Fumaria parviflora (Lam.) (Fumariaceae) and Teucrium polium (L.) (Lamiaceae) and release of green lacewing Chrysoperla carnea (Steph.) eggs were compared with pymetrozin pesticide to control this pest in semi-field conditions. LC50 of plant extracts and pesticide for sweet potato whitefly were calculated by bioassay test. In the original experiment، plant extracts and pesticides were sprayed on tomato plants in cages that were covered with mesh fabric. Cardboard chamber containing lacewing eggs was hanged to plant tomatoes. Various days after applying control methods، sweetpotato whitefly populations were counted. The experiments were carried out at 25 ±5 °C، 50±5 RH and photoperiodism of 16:8 h (L: D). T. polium and F. parviflora extracts and pymtrozin LC50 was respectively 82. 629، 23. 002 and 0. 118 mg/ml. Comparison of different control methods efficacy indicated efficacy of F. parviflora and T. polium extracts، pymetrozin and green lacewing was respectively 86. 91، 83. 51، 84. 29 and 54. 26 percent to control egg stage، 81. 39، 79. 68، 78. 05 and 52. 40 percent in controlling nymphal stage، 82. 76، 77. 31، 78. 12 and 44. 99 percent to control total immature stages and 83. 01، 81. 07، 79. 00 and 64. 20 in controlling of total nymphal stages. Results of efficacy experiments could be an introduction for further studies to replace the herbal extract rather than chemical pesticides in natural conditions.

The Sunn pest، Eurygaster integriceps Puton، is a univoltine insect and considered as one of the most important pests of wheat and barley. The adults of E. integriceps migrate to higher altitude in mountains for about nine months to complete their aestivation and hibernation period. To measure the cryoprotectants compounds، the insects were collected monthly between August 2009 and May 2010 in an altitude of 2000 meters and from wheat fields on the outskirts of Kabudarahang in the province of Hamadan. The level of cryoprotectants was determined using high performance liquid chromatography (HPLC). The identified compounds were trehalose، glycerol، glucose، myo-inositol، ribitol and sorbitol. It appears that trehalose and glycerol are the major cryoprotectants. The amount of trehalose significantly increased from 1. 36 µmol/g fresh weight (f. w.) in September to 8. 26 µmol/g f. w. in December. The amount of glycerol (22. 36 µmol/g f. w.) and glucose (8. 97 µmol/g f. w.) were at their highest levels in February and December، respectively. The amount of total cryoprotectants significantly increased from 12. 28 µmol/g f. w. in September to 44. 07 µmol/g f. w. in February. Results show that the Sunn pest has a great capacity to synthesize various cryoprotectants.

In the course of the study of the tribe Leucostomatini (Dip.: Tachinidae: Phasiinae) in Iran، 11 species were collected and identified. The four genera Dionaea Robineau-Desvoidy، Eulabidogaster Belanovsky، Labigastera Macquart and Weberia Robineau-Desvoidy، as well as the eight species Dionaea aurifrons (Meigen)، Eulabidogaster setifacies (Rondani)، Labigastera pauciseta (Rondani)، Leucostoma abbreviatum Herting، Leucostoma anthracinum (Meigen)، Leucostoma simplex (Fallén)، Leucostoma turonicum Dupuis and Weberia digramma (Meigen) are newly recorded from Iran. An identification key to the genera and species of Leucostomatini of Iran in addition to illustrations of the male and female postabdomens are given.

The ladybird species Oenopia conglobata contaminata (Menetries) is one of the major predators of pests in the orchards across Iran. The life history and predation rate of this predator were studied under laboratory conditions with 27. 5 ± 2oC، 55 ± 5 RH and 16:8 h (L: D) photoperiod to 6-cm petri dishes. To study the demography، a cohort containing about 100 eggs with less than 24h of age was chosen. Ladybeetle larvae were fed daily on the immature stages of pomegranate green aphids، Aphis punicae Pass. The daily fertility، immature developmental time، mortality and predation rate data were analyzed using age-stage، two-sex life table analysis - MSChart software. Means and standard errors of population growth parameters were calculated by bootstrap method. To determine the predation rate، the first-instar beetle larvae were fed on the third and forth developmental stages of A. punicae. The adult ladybirds were grouped in pairs of opposite sexes to investigate their predation rates on daily basis. The intrinsic rate of increase (rm)، finite rate of increase (λ)، mean generation time (T0) and net reproductive rate)R0 (were 0. 181 d-1، 1. 198 d-1، 30. 58 d and 251. 65 offspring per individual respectively. Predation rate of different stages of forth-instar larvae and both adult sexes were 49. 56، 95 and 125، aphids respectively، and the average predation rate (C0) was 118 aphids that shows a high rate of predation on the aphid population.

The parasitoid and hyperparasitoid chalcidoid wasps of scale insects deposited at the Hayk Mirzayans Insect Museum (affiliated to the Iranian Research Institute of Plant Protection، Tehran، Iran) were studied. The specimens had been collected from different parts of Iran and belonged to four families. The following 35 species were identified: Aphelinidae: Ablerus atomon (Walker)، Ablerus sp.، Aphytis chrysomphali (Mercet)، A. mytilaspidis (Le Baron)، A. proclia (Walker)، Coocobius testaceus (Masi)، Coccobius sp.، Coccophagus insidiator (Dalman)، C. lycimnia (Walker)، C. piceae Erdös، C. pseudococci Compere، Encarsia aurantii (Howard)، E. berlesei (Howard)، E. citrina (Craw)، E. fasciata (Malenotti)، Marietta picta (André). Encyrtidae: Anagyrus agraensis Saraswat، A. dactylopii (Howard)، A. mirzai Agarwal & Alam، A. pseudococci (Girault)، Blastothrix ilicicola Mercet، B. sericea (Dalman)، Cerapterocerus mirabilis Westwood، Comperiella bifasciata Howard، Encyrtus aurantii (Geoffroy)، Metaphycus angustifrons Compere، M. pulvinariae (Howard)، M. punctipes (Dalman)، Microterys hortulanus Erdös، M. lunatus (Dalman)، M. nietneri (Motschulsky)، Mi. nuticaudatus Xu. Pteromalidae: Moranila californica (Howard)، Pachyneuron muscarum (Linnaeus). Signiphoridae: Chartocerus sp. The two species of C. insidiator and C. piceae are found to be new records for the Iranian insect fauna.

The acaricidal activity of new formulation of Neem EC 1. 28% was compared with Neem Azal® (EC 1%) and spirodiclofen against the two-spotted spider mite، Tetranychus urticae Koch، under both laboratory and field conditions. The method of leaf dipping was used for bioassay experiments. The common bean leaves were dipped into different concentrations of treatments before exposing them to the adult mites from the same age. The mortality for mites was recorded after 24 hours. The experiment was conducted under 25 ± 2ºC، RH 60 ± 5 %، and 16:8 (L: D) h photoperiod conditions. LC50 and related parameters were calculated، using POLO-PC software. The field studies were conducted in randomized complete block design with five treatments of 1 ml/l، 2 ml/l and 3 ml/l of EC 1. 28% formulation، 0. 5 ml/l spirodiclofen and 1 ml/l of Neem Azal®. Plain water was used for the control group. The LC50 values for Neem Azal®، spirodiclofen and Neem EC 1. 28% formulation were 52. 04 mg/l، 37. 55 mg/l and 21. 06 mg/l، respectively. The results showed that mites were more susceptible to the new EC 1. 28% formulation. In the field، spirodiclofen was found to be the most effective compound after 3 and 7 days of treatment causing 89. 3 ± 1. 7% and 77. 8 ± 2. 3% mortality، while Neem Azal® was less effective with 64. 40 ± 4. 04% and 68. 7 ± 2. 9% mortality on mites. The new EC 1. 28% formulation was used at the rate of 3 ml/l، which caused 82. 8 ± 2. 4% and 70. 2 ± 3. 9% mortality، without significant difference with spirodiclofen treatment.

The species Dibrachys lignicola Graham is newly recorded from Rayen region of Kerman province، Iran. The diagnostic characters and geographical distribution of the species are briefly discussed.

During a study on the pests of button mushrooms in the city of Kermanshah، the sphaerocerid species of Pullimosina heteroneura (Haliday) was collected from mushroom culture media. This species is a new record for the Iranian insect fauna.

The carabid beetle Pterostichus (Phonias) strenuus (Panzer) is newly recorded from Iran. It was collected by hand from Ghaleroudkhan forests in the Caspian province of Guilan. This carabid beetle is widely distributed throughout the Palaearctic region including Europe، Uzbekistan، Kazakhstan and Russian Far East.

Systematic study of Ichneumonidae was carried out during 2009 to 2012 in Sari region and suburb. In this study Malaise trap، Window trap، Yellow Pan trap، Light trap and Sweeping trap were used for collecting. Stilbops vetula (Gravenhorst، 1829) from Stilbopinae subfamily is reported for the first time from Iran.