فصلنامه تحقیقات حشره شناسی
سال پنجم شماره 4 (پیاپی 20، زمستان 1392)

The cowpea weevil, Callosobruchus maculatus F. (Col.; Bruchidae) is one of the most important stored product of the pests that damages the seeds. In order to find biorational insecticides, fumigant effects of the essential oil of two plant, Artemisia dracunculus L. and Eucalyptus camaldulensis Dehnh. were assessed on adults of C. maculatus. Acute toxicity bioassay was carried out for calculating LC50. The LC50 value was compared in 3 different temperatures and relative humidities and finally the LT50 was tested. The LC50 values were 26 and 24.5 μl/lit air in 24 h for E. camaldulensis and A. dracunculus, respectively. The temperatures (20, 26, 32 ) affected the toxicity of the essential oils significantly but humidity did not. LT50 values for E. camaldulensis and A. dracunculus were 6.3 and 8.9 hours, respectively. The results showed that the effects of the essential oils were increased by increasing temperature. Our results showed that the applied essential oils were effective against the pest and could be used in IPM programs.

The dwarf honey bee, Apis florea F. is one of the two species of honey bees in Iran which is found in southern, southeastern and western provinces. In present study, some morphological characters of dwarf honey bee and effects of geographic and climatic conditions on morphological changes were studied. For this purpose, 600 worker bees were collected from 30 colonies in Sistan-Baluchestan, Hormozgan, Kerman, Fars, Bushehr, Khuzestan and Kohkiluyeh-Boyer Ahmad during year 2010. Then, 17 morphological characteristics were measured and 10200 data were obtained. To determine geographical and climatic variables, average values collected by meteorological stations were used. Analysis of variance of morphometric characters showed that characteristic of hind metatarsus width had the lowest diversity. However, length of half loop over the third and fourth dorsal abdominal segments, length of hind leg and tongue had the highest diversity as the most distinctive morphological characteristics throughout the Iranian dwarf honey bee. The number of right wing hooks were more than left wing hooks. So, it is suggested to count just the number of right hooks. The bees from Kohkiluyeh and Boyer Ahmad were significantly larger than the other bees in length of thethird and fourth dorsal abdominal segments as well as length and width of the front wings and hind leg, while, bees from Hormozgan and Bushehr were the smallest throughout the studied regions. There was a significant positive correlation between the width of the third and fourth dorsal abdominal segments, length and width of the front wing and length of hind leg. There was also a significant negative correlation between the length of tongue and length of fore wing and cubital index. Besides, there was a significant positive correlation within specification of the third and fourth dorsal abdominal segments, length and width of the front wings, and length of legs in dwarf bees with latitude, elevation and annual rainfall. Results indicated that bees from highlands are larger and also confirmed that wing of honey bees in elevated and high rainfall areas has less hook numbers.

Due to healthy and environmental hazards of chemical pesticides, it is important to change the methods in durable and Organic agriculture by using bio pesticides and essential oils. The effects of essential oils of three aromatic plants, Mentha spicata, Cuminum cyminum and Citrus aurantifolia was studied on mycelial growth, germination and conidial production rate of three entomopathogenic fungi Lecanicillium longisporum, Beauveria bassiana and Metarhizium anisopliae. This study was done in a completely randomized design with five treatments (five concentrations of essential oils) and three replicates on SDA medium in 27±1°C. Results showed that L. longisporum and B. bassianawere the most susceptible with 41.06% colony growth prevention and M. anisopliae was the most resistant to the essential oils. Also the essential oil of C. cyminum with 41.06% had the most effect and C. aurantifolia with 20.44% had the least effect on mycelial growth. In concentration of 20 μl, the essential oils of C. cyminum and C. aurantifolia showed the most and the least preventive effect in conidial germination, respectively.

Functional response of Stethorus gilvifrons Mulsant on different densities of adult female mite Oligonychus sacchari McGregor on tree commercial cultivars of sugar cane (CP 48-103
CP 57-614 and CP 69-1062) was studied under laboratory conditions. Results of logistic regression revealed a type III functional response for all cultivars. According to the results searching efficiency of S. gilvifrons on CP 48-103, CP 57-614 and CP 69-1062 varying from 0.012- 0.60, 0.014- 0.70 and 0.014- 0.70 per h and the handling time was 0.366, 0.307 and 0.350 h, respectively.

Resistance of different almond cultivars/genotypes including: ‘Sefid‘, ’Mamaei’, ‘Rabie’,‘Shokofeh’, ‘Azar’, ‘Non pariel’, ‘Shahrood 6’, ‘Shahrood 7, ‘Shahrood 12‘, ’Shahrood 13’ and ‘Shahrood 21’ were studied to two-spotted spider mite (TSSM, (Tetranychus urticae Koch. All cultivars/genotypes were grafted on ‘Gf677’ rootstock in 4 replications. Study was done in the laboratory and greenhouse conditions. Leaf discs (2.5×1.2 cm) were prepared from leaves and placed on wet cotton in a plastic petri dish and infested with 5 adult female mites (3-5 days in age). Leaf discs were kept in an incubator at 25±1  C, RH= 55 ±5% and a photoperiod of 14:10 (L:D). After 72 h, mite oviposition and mortality were measured. Based on the results, the highest and lowest oviposition were observed on ‘Mamaei’ and‘ Shahrood 21’ cultivars. The highest mite mortality was observed on ‘Shahrood 13’. Biological characteristics study of TSSM on different cultivars in the laboratory showed that cultivars significantly affected survival, immature period, mature period and mite oviposition. The highest survival percentage was recorded on‘ Azar’ (88%) and the lowest on ‘Shokoofe’ (47%) and ‘Shahrood. (%) ’ The longest (5.27 days) immature period was observed on‘ shahrood 21’. The shortest mature period was observed on‘ Shahrood 21’ (5.15 days) and ‘Shokoofe’ (5.2 days); whereas, the longest (10.45 days) was observed on ‘Mamaei’. The highest ovipositional rate (57.6 eggs/female) was observed on ‘Mamaei; ’whereas, the lowest was recorded on ‘Shokoofe’ (15.1eggs/female (and ‘Shahrood 21’ (31eggs/female). Greenhouse study showed that the highest density of mite population was supported on ‘Non pareil’ and ‘Shahrood 6’ cultivars while the lowest one was reared on ‘Shokofeh’ and ‘Shahrood 21’. Results indicated that ‘Shokofeh’, ‘Shahrood 21’ and ‘Shahrood 13’variety/genotypes were the most resistant, whereas‘, Mamaei ’and ‘Non pariel ’were the most susceptible varieties to two-spotted spider mite.

The study were done during 2010-2011 to investigate the integrated effects of different doses of gamma radiation and diatomaceous earth (INSECTO®) on Red Flour Beetle Tribolium castaneum (Herbst) in laboratory conditions (27±1°C, 60±5% humidity, dark room). In this study, adults of red flour beetle were grown on mashed corn (50 gram) and then treated with different doses of Gamma ray (100, 500 and 1000 Gray) and three doses of diatomaceous earth (0.5, 1 and 1.5 g kg-1). Percentage of mortality were recorded after 1, 2, 7, 14, 21, 28, 35 and 42 days and compared with control. Results showed significant differences among various doses of diatomaceous earth (DE) and Gamma ray and their interactions in most days after treatment. In comparing the means mortality in different doses of diatomaceous earth (DE) and various doses of Gamma ray, most mortality were recorded after 35 days in 1.5 gr/kg diatomaceous earth and 1000 Gray Gamma ray separately. In combination of Gamma ray and diatomaceous earth, most mortalities were recorded after 35 days for 1 and 1.5 g kg-1 (DE) combined with 500 and 1000 gray Gamma ray. It is concluded that 1 gkg-1 (DE) combined with 500 gray gamma ray is the best combination of the lreatmants.

Porthesia melania Stgr. (Lep., Lymantriidae) is the most important pest of oak trees inKermanshah province iran and its larvae feed on upper surface of oak leaves. The population fluctuations of larvae were investigated weekly in the region, from March 2008 until April 2009. The highest and lowest densities of larvae were observed in the late March and mid May, respectively. During summer and winter, no larvae were observed on oak leaves. The third larval stage which lasted eight months from the late July until mid March in diapauses form, was the longest life stage of the oak moth. The pupae were formed in the soil. The adults emerged gradually during 37 days in the nature. The peak of adult emergence was on 23 May. The egg hatch was started from 5 May. Female moths lay 60-140 eggs on the oak leaves. The latest eggs hatched in mid June. Investigation on biology of oak moth revealed that this pest had one generation in a year in Miandar region and overwintered as the third instar larvae.

Family of Isotomidae is the second largest family in the order of Collembola. These springtails are elongate and lack scales on the upper surface of the body. In contrary of Entomobyridae family, the abdominal segments are all of similar length. They live in soil, leaf litter in terrestrial ecosystem or in associated with freshwater in aquatic ecosystem. In a faunistic study of Isotomidae family, several soil and leaf litter samples were collected from different location of Sari regions during 2010-2011. The specimens were extracted by heat in Berlese funnel and mounted on microscopic slides using Hoyer’s medium. Totally, eight species of seven genuses from this family were identified as follows: Isotomiella minor, Folsomia candida, Isotoma viridis, Folsomides parvulus, Proisotoma minima*, Isotomurus cf. italicus*, Isotomurus sp.* (aff. palustris-unifasciatus), Cryptopygus* cf. ponticus. The marked species by * are considered as new records for Collembola fauna of Iran.

Water mites as a dominant animal fauna of freshwater resources are a bioindicator factorof freshwater and also as an important biocontrol agent for aquatic insect pests. The research was carried out during 2008-2009 to study the aquatic mites fauna of Khorramabad district. In this research 12 mite species belonging to six genera and five mite families were collected and identified and Hygrobates calliger Piersig,1896 was the most predominant species with 30% of collected species.The identified mites are as fallowing:1) Family Hygrobatidae Koch, 18241-1) Hygrobates fluviatilis (Strom, 1768)1-2) Hygrobates longiporus Thor, 18981-3) Hygrobates calliger Piersig, 18961-4) Hygrobates bucharicus Sokolow, 19281-5) Hygrobates sp.1-6) Atractides acutirostris Motas & Angelier, 19271-7) Atractides mirkopesici Pesic, 2004Family Sperchontidae Thor, 1900 2)2-1) Sperchon sp.3) Family Lebertiidae Thor, 19003-1) Lebertia sp.4) Family Torrenticolidae Piersig, 19024-1) Torrenticola brevirostris (Halbert, 1911)4-2) Montractides aberratus (Lundblad, 1941)5) Family Mideopsidae Koenike, 19105-1) Mideopsis roztoczensis Biesiadka & Kowalik, 1987