نشریه نامه انجمن حشره شناسی ایران
سال سی و سوم شماره 3 (پیاپی 54، پاییز 1392)

The green lacewing، Chrysoperla carnea (Stephens)، is a common natural enemy of various agricultural pestsand widely used as a biocontrol agent in integrated pest management (IPM) programs. The lethal and sublethal effects of the insecticides dinotefuran and thiamethoxam on the first instar larvae of C. carnea was assessed in the laboratory conditions at 25 ± 1°C، 60 ± 5% RH and a photoperiod of 16:8 (L: D). The LC50 values for dinotefuran and thiamethoxam were 19. 382 and 9. 880 mg ai/l، respectively، that showed the high toxicity of thiamethoxam on the first instar larvae of C. carnea. To assess the sublethal effects، the first instar larvae were treated with the LC30 for dinotefuran and thiamethoxam at 3. 532 and 1. 692 mg ai/l، respectively. The estimated rm values in the control، dinotefuran and thiamethoxam were 0. 185، 0. 186 and 0. 143 day-1، respectively. Finite rate of increase (λ) in the control، dinotefuran and thiamethoxam were 1. 204، 1. 204 and 1. 154 day-1. Generation time and doubling time values in the control، dinotefuran and thiamethoxam were 30. 77، 30. 46 and 35. 14 as well as 3. 73، 3. 72 and 4. 82 days، respectively. The gross and net reproductive rates in the control، dinotefuran and thiamethoxam were 459. 89، 439. 08 and 309. 42، and also 298. 01، 278. 45 and 155. 03 (female/female/generation)، respectively. Dinotefuran caused no significant adverse effects on the population growth parameters of C. carnea. If similar results are obtained for dinotefuran in the field، it might be an insecticide with low toxicity to C. carnea by using the reduced doses of the insecticide in IPM context. Studies under the laboratory conditions can help us to select some insecticides for additional studies under more natural conditions and for application of suitable insecticides along with natural enemies in pest management.

The common reed، Phragmites australis (Cav.) Trin. ex Steudel (Poaceae)، is a perennial rhizomatous grass that occurs all over the world and grows in a wide range of habitats. The chloropid Lipara lucens Meigen is a monophagous gall inducer at the apical part of common reed stems in Urmia region، Azarbaijan-e Gharbi province. A recent study on the biology of this species during the years 2011 and 2012 indicated that L. lucens completes a single generation annually and overwinters as mature larvae inside the gall where all of its developmental stages occur. The adults appear during the late April and early June. The females lay their eggs separately on the surface of leaves and stems of common reed. Female''s potential fecundity was calculated 87. 4 ± 19. 8 (range: 59-121). In natural conditions، the incubation period takes 10. 5 ± 1. 8 (range: 8-13) days. Upon hatching، the young larvae migrate to the top and enter the bud and gnaw their ways to the growing point. There are three larval stages that take more than 10 months to complete inside the gall. The mature larvae stay in the gall until mid-May of the following year. The pupal stage begins in early April and depending on environmental conditions lasts 19. 7 ± 5. 3 (range: 15-26) days. The new generation of adults appears in late April. The larvae of L. lucens were parasitized by Polemochartus liparae (Giraud) (Hym.: Braconidae) and Tetrastichus legionarius Giraud (Hym.: Eulophidae) in Urmia region. The species P. liparae was responsible for up to 48% of parasitism. Both species are newly recorded from Iran. The specimens of Cryptonevra flavitarsis Meigen (Dip.: Chloropidae) were found in L. lucens galls as well.

Thrips tabaci Lindeman، is one of the most important pests of vegetables and ornamental plants across the world. The functional response of Orius albidipennis Reuter was studied in relation to different densities of second instar larvae of T. tabaci. Laboratory experiments were conducted to evaluate the effect of two different host plants (cucumber and bean plantlets) on the functional response and its parameters (attack rate and handling time) using different densities of 2، 5، 10، 20، 30 and 40 thrips. The cucumber and bean plantlets، in relatively small pots with a diameter of 4 cm and 7 cm high were supplied to the predators to feed on the thrips in a 24-hour-period. Each density was repeated 10 times. The experiment was carried out at 25-29°C، 60 ± 5% R. H. and photoperiod of 16:8 L: D hours. The logistic regression suggested a type II functional response on two host plants. The Roger’s random predator equation was compatible with the results. The type of functional response was not affected by the host plants. Attack rate (a)، handling time (Th) and maximum predation of O. albidipennis were 0. 073 ± 0. 013، 1. 67 ± 0. 12 and 14. 37 on the cucumber and 0. 095 ± 0. 02، 1. 51 ± 0. 11 and 15. 89 on the bean plantlets، respectively. There was no significant difference among estimated parameters in both plantlets.

Termites play a major role in reducing and decomposing woody materials within terrestrial ecosystems by degrading lingo-cellulosic materials with the help of the microbial community of their guts. We isolated the lignin-degrading bacteria from Anacanthotermes vagans (Hagen) using liquid and solid media containing wheat straw and lignin hydrochloric acid. Cellulose-degrading bacteria were also isolated using liquid medium containing filter paper، agar-cellulose and Congo red agar-cellulose. By conducting various experiments، 16 bacterial species were isolated and subjected to different biochemical tests for comparing their growth rates. The genera Enterobacter and Klebsiella showed the highest growth rate among the rest species of isolated lignin-degrading bacteria. The species Staphylococcus lentus and Bacillus subtilis were isolated from the media containing cellulose.

Odors play an important role in the seeking behavior of wasp parasitoids and enhances their performance in biological control programs. This study was intended to determine the olfactory response of Tamarixia radiata (Waterston) to chemical cues that emanates from various stages of Asian citrus psyllid، Diaphorina citri Kuwayama، in Y-tube olfactometer in laboratory conditions (27 ± 1°C، 60 ± 10% RH، 1600 lux light intensity and constant airflow of 300 ml/min). The effect of green leaf volatiles (GLVs) and herbivore-induced plant volatiles (HIPVs) of four varieties of the rutaceous plants، Mexican lime، Citrus aurantifolia، Campbell Valencia orange، C. sinensis، Marsh grapefruit، C. Paradisi، and sour orange، C. aurantium، were also evaluated based on separately release of 30 females and 30 males of T. radiata. The results indicated that the females were significantly attracted to the volatiles emanating from D. citri nymphs and HIPVs resulted from the feeding of nymphs and adults of D. citri. The males were not responsive to the odors emanating from various stages of D. citri، GLVs or HIPVs. It is found that the female parasitoid wasps use chemical cues emanating from the nymphs of Asian citrus psyllids and HIPVs for host seeking. Using the synthetic volatile compounds could increase the viability of the biological control agents in integrated pest management programs.

The responses of digestive enzymes of the midgut of Andrallus spinidens Fabricius nymphs، toward feeding on Chilo suppressalis Walker، Galleria melonella (L.)، Plodia interpunctella (Hübner) and Ephestia kuehniella Zeller were analyzed to find the most satisfactory species for a mass rearing program. The nymphs were fed from 2nd instar until 24 hours after the emergence of the 5th instar. The highest weight gain was recorded in the nymphs that fed on C. suppressalis and G. melonella، and the highest amount of total protein found in the nymphs feeding on G. mellonella. Carbohydrase activities including α-amylase، α- and β-glucosidase were the highest in the nymphs that were fed on C. suppressalis and E. kuhniella. The highest TAG-lipase activity occurred in the nymphs feeding on G. mellonella and the related gel electrophoresis showed distinctive zones in comparison with the rest. General proteolytic was performed at two pH values and the highest activity recorded in G. melonella (pH 8) and E. kuehniella (pH 6). The highest activities of serine proteinases، cysteine proteinases and two exopeptidases were found in the nymphs fed on G. mellonella and E. kuehniella. Correlation between digestive enzyme activities in A. spinidens and nutritional composition of their feeds may reflect the adaptive nature of the enzymatic profile. These findings can efficiently help to find the most suitable species for an efficient control program and successful mass rearing of the biocontrol agent.

Alfalfa weevil، Hypera postica Gyllenhal، is a key pest of alfalfa and widely distributed in alfalfa fields of Iran. In early autumn، the first adults of H. postica arrive in the fields where they steadily increase their populations during autumn and following winter. To evaluate the impact environmental factors including temperature on the survival of the weevils، this study was conducted to measure the levels of variability in supercooling point and cold hardiness in the weevils. Overwintering adults were collected monthly from alfalfa fields on the outskirts of Karaj during the autumn 2011and winter 2012. The supercooling points and survivorship were studied at sub-zero temperatures from -5 to -13 ºC for 210 minutes. The average supercooling point ranged from -14. 4 ± 0. 68 in October to -8. 8 ± 0. 80 in March. Mean supercooling points for H. postica adults were significantly lower in autumn (-13. 4 ºC) comparing winter (-8. 6 ºC). Insects survived after being exposed to -5 ºC in all months. The mortality of the adults increased with cold intensity. The percent mortality for adults treated at -11 ºC was approximately 89% in November and December and reached 100% in January and February. The range of LT50 values varied from -5. 7 ºC (highest) to -8. 6 ºC (lowest). Results showed that adults could not withstand the temperatures below the supercooling point. It is found that the cold intensity around supercooling point could cause 80% mortality. It can be concluded that as the ambient temperature in the field approaches the supercooling point، it tends to be detrimental on H. postica population.

In the course of a faunistic survey، between 2008 and 2009، on the oribatid mites of Shendabad region in the Iranian province of East Azerbaijan، the species Eulohmannia ribagai (Berlese) was collected and identified. The species and its associated family Eulohmanniidae are newly recorded from Iran.

In the course of a faunistic survey on the Iranian oribatid mites (Acari: Oribatida) in the southeastern province of Sistan and Balouchestan، the species Bicyrthermannia duodentata Hammer، 1979 of the family Nanhermanniidae was identified. This species is a new record for the Palaearctic region.

An investigation on the fauna of Myrmeleontidae (Neuroptera) was carried out in Markazi Province in August 2009. Identification and taxonomy was studied via examining morphological characteristics and their internal male genitalia. As a result، Distoleon nuristanus Hölzel، 1972 is presently reporting as new for Iran fauna

Metaphycus bogdanovikatkovi Myartseva is recorded here for the first time from Iran. This species is reared on Rhizopulvinaria sp. (Hem.: Coccidae) on wild almond shrubs in Darab region، Fars province of Iran.

Following the appearance of a quarantine pest، tomato leaf miner، Tuta absoluta (Povolny)، in Europe، monitoring of this species in Iran was started by the cooperation of the Plant Protection Organization of Iran and the Iranian Research Institute of Plant Protection. According to the surveys، the first emergence of this pest was detected in October 2010 in Azerbaijan-e-Gharbi province.