Applied Entomology and Phytopathology
Year:2013 | Volume:80 | Issue:2 (95)|Papers Count:17

Digestive proteolytic and amylolytic activities and feeding responses of fifth instar Helicoverpa armigera on different maize hybrids (DC370, SC704, SC700, SC500 and SC260) incorporated into artificial diets were investigated under controlled conditions (25±1oC, 65±5% R.H. and a photoperiod of 16:8 (L:D) h). The highest total proteolytic activity was in the larvae reared on DC370 (7.954±0.543 U mg-1) and SC500 (7.965±0.171 U mg-1), whereas the lowest one was in the larvae fed on SC704 (5.878±0.160 U mg-1). The highest amylolytic activity was detected on DC370 (0.055±0.001 mU mg-1) and SC500 (0.047±0.007 mU mg-1) and the lowest activity was on SC704 (0.012±0.001 mU mg-1). Larval weight of fifth instar H. armigera demonstrated significant difference, being heaviest on SC704 (45.77±6.16 mg) and lightest on DC370 (18.14±1.61 mg). The highest and lowest values of food consumption were on SC500 (219.56±11.4 mg/larva) and DC370 (155.05±10.3 mg/larva), respectively. The feces weight of H. armigera was the highest on SC704 (50.74±8.2 mg/larva) and lowest on SC500 (27.51±4.21 mg/larva). According to the results, hybrid DC370 is unfavorable host for feeding fifth instar larvae of H. armigera.

In this study, the nutritional indices of Helicoverpa. armigera larvae on five different host plants including cowpea, chickpea, soybean, navy bean and corn were determined in the laboratory. The lowest relative consumption rate (RCR) of the third instar larvae was on cowpea (3.21±0.512). The efficiency of conversion of ingested food (ECI) and the relative growth rate (RGR) were the highest on cowpea (6.8±0.004 and 0.243±0.007, respectively). The lowest values of efficiency of conversion of ingested food (ECI) and Efficiency of conversion of digested food (ECD) (2.4±0.002 and 6.9±0.005, respectively) of the fourth instar larvae were observed on corn.The highest ECI and ECD of the fifth instar larvae (23.2±0.010 and 84.5±0.10, respectively) and the sixth instar larvae (26.7±0.017 and 40.5±0.011, respectively) were obtained on cowpea. The Approximate digestibility (AD) of whole larval instars (the third to sixth instars) on different host plants ranged from 28.9±0.024 to 55±0.015, which was the lowest on corn and highest on cowpea. The larvae fed on cowpea showed the highest values of ECI and ECD (20.1±0.002 and 83.4±0.080, respectively) and RGR (7.59±0.15).

In this survey, the genus Orthocentrus Gravenhorst, 1829 (Hymenoptera: Ichneumonidae, Orthocentrinae) was studied in Tehran and Gilan provinces of Iran. A total of 154 specimens of the genus were collected using Malaise traps during 2010. The genus Orthocentrus and its seven species and one subspecies are new records for the fauna of Iran: O. asper (Gravenhorst, 1829), O. castellanus Ceballos, 1963, O. hirsutor Aubert, 1969, O. protervus Holmgren, 1858, O. sannio Holmgren, 1858, O. strigatus Holmgren, 1858, O. winnertzii Forster, 1850 and O. winnertzii planator Aubert, 1978. Seasonal abundance, emergence period, distribution and altitudinal changes in Orthocentrus fauna on two slopes of the Alborz Mountains are provided. Keys for identification of Orthocentrus species found in Gilan and Tehran provinces are presented based on males and females.

Knowledge about population diversity of broomrape in response to herbicides can help to better management this parasite. This experiment was carried out in a factorial with randomized complete block design with 3 replications under natural condition. First factor was broomrape populations and second factor was included active ingredient (a.i) of glyphosate (41%EC) at 21 & 41 ml ha-1 and sulfosulfuron (75%WG) at 27 & 50 g a.i ha-1, and 15, 20 and 30 ppm banzotiadiazol (BTH) sprayed 30, 40 & 50 days after transplanting or DAT. Density and dry weight reduction percentages of broomerape and yield loss of tomato were estimated. In all population except Oromieh 50 g a.i ha-1 sulfosulfuron was the best treatment (80% control). But only Behshahr broomrape population was completely controlled. Oromieh broomrape population was controlled 80%with 41 ml a.i ha-1 glyphosate. All dosages of banzotiadiazol except 30 ppm a. i. ha-1, couldn’t control broomrape populations.

The main potato growing areas in Hamadan province including Bahar, Razan and Kabodar-Ahang were surveyed during 2010 and 2011 to find distribution of Potato virus X. A total of 426 leaf samples (132 and 324 symptomatic and random, respectively) were collected from 9 potato fields. Totally 42 random samples were showed positive reaction with PVX specific antibodies in ELISA assay. The highest virus incidence was recorded in Bahar (18.3%), followed by Razan (12.5%) and Kabodar Ahang (9.2%). Coat protein gene (CP) of two Iran-HB1 and Iran-HK2 PVX isolates from Bahar and Kabodar-Ahang districts, respectively, were amplified (size about 750 bp) by reverse transcriptase polymerase chain reaction (RT-PCR) using specific primers. Evolutionary relationship demonstrated that Iranian isolates fell into Eurasia group. These two isolates with other Iranian PVX isolate from Pisum sativum are closely related together with high bootstrap support. The complete CP nucleotide sequences of Iranian potato isolates were 714 nucleotides long, encoding an ORF with 237 amino acids as previously reported for isolates belong to Eurasia group. The lowest (%78.7) and highest (%99.2) identities were found with Netherland (group II) and Iranian (group I) isolates with accession numbers X88785 and FJ461343, respectively, whereas for two Iranian isolates the identities were 100%. Although Iranian isolates were found in the Eurasia population we do not know yet whether these are dominant isolates in this region or not. However, evolutionary comparisons of a large number of isolates from Asia Minor and mid-Eurasia with representative worldwide isolates are necessary to determine this. The present study to our knowledge shows for the first time, the evolutionary relationships of PVX from potato collected in the mid-Eurasian region of Iran.

During 2007-2010, diseased samples of sugar beet were collected from fields in major sugar beet production areas of Iran in different growth stages. From 71 diseased samples, 23 isolates of Pythium aphanidermatum were isolated. On the basis of pathogenic variability in seed, seedling and mature stages of sugar beet, the results showed that P. aphanidermaum isolates have significant differences in their pathogenicity. All of the tested isolates were classified in 3 groups with high, moderate and low pathogenicity. 8P isolate from West Azarbaijan province had the highest pathogenicity among investigated isolates in each 3 stages. PCR fingerprinting was used to confirm identification of P. aphanidermatum isolates. The results showed an individual band approximately 2000 bp using OPA-15 and two bands (1000 and 1850 bp) using OPB-08 decamer primers. The bands were observed through all P. aphanidermatum isolates. The banding patterns of P. aphanidermatum was not similar to other species including P. ultimum, P. oligandrum, P. deliense, Phytophthora drechsleri, Fusarium solani and Rhizoctonia solani. It seems that OPA-15 and OPB-08 primers are capable to identify P. aphanidermatum from other root rot agents of sugar beet as well as other pythium species.

For managing the winter wild oat in wheat fields, four field experiments were conducted in four regions of Iran: Zanjan, Karaj, Varamin and Amol during 2006 and 2007. The predictive weed management maps were produced for Mazandaran province using Geographic Information System (GIS). The results showed that despite high variation in phenological stages during growing season at different sites of experiments, these stages were relatively similar when evaluated based on degree days. The starting and terminating time for application of post emergence herbicides for control of winter wild oat in wheat fields were determined 400 and 1000 GDD, respectively. Using prediction map that produced by GIS, the suitable time for starting and terminating post emergence chemical control (post emergence) and the suitable time for nitrogen fertilizer application in order to reduce competitive ability of winter wild oat against wheat in different regions of Mazandaran province could be determined.

Citrus psorosis virus (CPV) is causal agent of one of the important citrus diseases in the world. A disorder was observed on Thomson Navel orange trees on sour orange or citrange rootstocks, with ring spot symptoms on mature fruits, especially around the stylar end. It had often caused expanded yellow ring lesions on mature leaves. Severe fruit abscission was occurred in the infected trees. Leaf samples were collected from spring flashes of the infected trees and tested by TAS-ELISA, using Citrus psorosis virus (CPV) 13C5 monoclonal antibody and CPV infections were confirmed. RT-PCR was done with four pair primers closely related to ICRSV, CRSV-4, CPV-RNA2 and CPV-CPG on leaves of thirty infected Thomson Navel orange trees. The samples only amplified by CRSV-4 primers and produced a fragment about 218bp. This fragment length size was similar to the fragment obtained from CPV ring spot isolates from Florida and Argentina. Seven isolates were selected for biological indexing and based on the indicator plants divided into two groups. Based on the serological, molecular and biological results, the isolates can be settled into Citrus psorosis virus, B type group, without bark scaling symptoms.

Sunburn of pomegranate fruits, is one of the most important agent causing losses in Iran and other pomegranate producing countries which reduce the quantity and quality of the product. Application of the kaolin particle film might be an alternative for control of the pomegranate fruit sunburn. To assess the impact of kaolin, trials were conducted in the fields on Malas and Galoobarik varieties of pomegranate during 2009 in Saveh and Garmsar regions (central part of Iran). Two concentrations of kaolin clay (SepidanÒ WP) (3 and 5%) were sprayed over the whole canopy and fruits, four times at 4–5-week intervals from early May to early September. Based on the field studies, the rates of fruits sunburn were 4.15 and 1.77 for control and kaolin (5%) treatmentrespectively. Also, the high sunburn of pomegranate fruits were recorded 44.7 and 4.2% for control and kaolin (5%) treatment respectively. The fruit cracking was reduced 64% and fruit weight mean were increased 9% in kaolin treatments in comparison with the control treatment. Spray of kaolin 5% on pomegranate trees was no evil-effect on leaves chlorophyll and photosynthesis.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is one of the most important pests of citrus in Iran, through transmitting Candidatus Liberibacter asiaticus the bacterial pathogenic agent of important and destructive disease known as huanglongbing (HLB) or greening. Several samplings were carried out in infected orchards of sweet lemon trees Citrus limetta (Rutaceae) in May 2011 and 2012 at Koshkmor, Jiroft region of Kerman province (N= 28o 19’ 54.32”, E= 58o 14’ 46.17”, 549 m a.s.l.) to collect and identify the dominant parasitoid species for subsequent ethological studies. The reared parasitoid specimens were identified by the fourth author (HL) as Psyllaephagus procerus Mercet, 1921 (Hym.: Encyrtidae), that is a new report from Iran (1, 2). This species is a synonym of Metaprionomitus procerus Mercet, 1921 (3). So far species P. pistaciae Ferriere, P. stenopsyllae (Tachikawa) and P. zdeneki Noyes & Fallahzadeh, have been reported from Iran (1).Body length in females 1.3 mm and in males 1.1 mm; scape 4 to 5 times as long as funicle segments combined; 1st-4th funicular segments longer than broad, 4th and 5th funicular segments quadrate.Legs at least in part darkened (at least coxae of one pair of legs or hind femur are darkened); mid and hind tibiae darkened; marginal vein punctiform or little longer than broad and not less than 2.5 times shorter than stigmal vein; scutellum green or blue-green; gaster not longer or only slightly longer than thorax (4).Fraxinus sp. (Planta: Oleaceae) and Pyrus communis (Planta: Rosaceae) have been reported as host plant for this encyrtid (3). This study let us to add Citrus limetta (Rutaceae) as a new associated host plant for P. procerus.This species is a nymphal parasitoid of Hemiptera. Hosts reported include: Eulecanium ciliatum (Hem.: Coccidae) and Cacopsylla sp., Cacopsylla pyri and Psyllopsis fraxini (Hem.: Psyllidae) (3).This parasitoid has been reported from Armenia, Azerbaijan, Georgia, Hungary, Italy, Moldova, Mongolia, Poland, Russia, Spain, Turkey and Ukraine (3).The specimens were deposited in the collection of Department of Entomology, Vali-e-Asr University of Rafsanjan and East-Azarbaijan Research Center for Agriculture and Natural Resources.

The poplar leaf-miner moth, Phyllonorycter populifoliella (Treitschke) (Lep.: Gracillariidae) is one of the important pests of Populus spp. This pest is widely distributed in Iran with a high economic importance. Larvae of this pest penetrate the leaf and cause different shapes of mines. It is one of the important pests of populus plantations in West-Azarbaijan province and has many natural enemies that vigorously control the pest.In order to study of its parasitoids in Mahmod-Abad (N 36˚ 43’ 08”, E 46˚ 30’ 55”) of Shahindezh area (south of the West-Azarbaijan province), during 2010, the leaves infected by leaf-miner moths were collected and reared in laboratory condition. Emerged parasitoids were separated and transferred into vials containing alcohol 75%. Identification was made by second author. Parasitoid wasp was identified under the name of Halticoptera polita (Walker) (Hym.: Pteromalidae), which is reared for the first time on P. populifoliella.The most important morphological characteristics of this species are as follow: Antennal scape as long as the length of compound eyes, scape larger than other segments and located far from the eyes, funicular segments nearly quadrate, male with two terminal segments of maxillary palpi very inflated and subglobose; marginal vein in forewings longer than postmarginal vein and 1.5- 3.5 times the length of stigmal vein; pygostylar bristles subequal in length (3).This species has been reported from northwest of Europe, UK, Sweden and former Czechoslovakia, Romania, Germany, Hungary, New Zealand, China, Sudan, Turkey, United Kingdom, Northern Ireland and England (2, 4), but has not been reported from Iran. It is reported as parasitoid of several families of Diptera, Hymenoptera and Lepidoptera (4).

The cosmopolitan mites of the family Parasitidae, including more than 400 identified species, are free-living predators that feed on eggs and immature stages of the other soil inhabiting microarthropodes and nematodes (1). The family includes two subfamilies: Pergamasinae and Parasitinae; Pergamasinae often prefers stable habitats such as forests and grasslands litter, moss and rotting seaweed and so far no phoretic association has been reported between them. Members of the subfamily Parasitinae live in temporal habitats such as dung, compost and nests of small mammals and insects which often disperse during deutonymphal stage usually associated with insects (4). The genus Saprogamasus Willmann, 1949 was established by description of S. ambulacralis Willmann, 1949 as its type species and separated from the genus Trachygamasus Berlese, 1905 by presence of two small, sclerotized jugular platelets, sternal shield with posterior transverse margin, distinct metasternal shields and the fairly sclerotized body and this was followed by few authors, but the former genus has been considered as junior synonym of the latter by most authors and we follow it (1). Among species of 11 genera of the family Parasitidae reported from Iran, only one species of the genus Trachygamasus as T. gracilis Karg, 1971 has been recorded from rat carcass (2, 3).During a survey on edaphic Mesostigmata in North Western Kerman Province and also mesostigmatic mites associated with Coleoptera in Bam region, T. ambulacralis was collected and identified in soil and litter in Mani region (5 May 2012) and associated with Oryctes elegans Prell in Sekahour region (26 May 2012).This species is similar to T. gracilis and can be distinguished from it by larger body size (700-900 mm), bearing 15-18 pairs of opisthonotal setae, six pairs of pre-anal setae on ventral shield and jugular platelets small and trapezoidal while T. gracilis has smaller body size (400-475 mm), 14-15 pairs of opisthonotal setae, seven pairs of pre-anal setae present on ventral shield and jugular platelets bigger and semicircular.Iranian specimens of T. ambulacralis differ from T. gracilis by presence of two small and trapezoidal jugular platelets, 18 pairs of opisthonotal satae, six pairs of pre-anal setae and the idiosomal length 688-713 mm.

The hard scale, Lepidosaphes malicola Borckh (Hem.: Diaspididae) is one of serious pests of orchards in Iran. This pest sucking tree’s sap causes physiological problem of trees and finally cause it’s die.In the study of parasitic wasps of this pest in the northern parts of East-Azarbaijan province in 2010 (May-June), some infested scale insects on apple trees were collected from Komarsofla of Jolfa (y=4291738, x=38s586294). Rearing of parasitoids were made in laboratory condition. Emerged parasitoids were transferred to vials contained ethanol and were identified by second author (HL).It was identified as Thysanus ater Walker, 1840 (Hym.: Chalcidoidea, Signiphoridae). This species has reported from Europe, Turkey and India (2) but is new for Iranian fauna. Its important morphological characters are as follow:length 0.75mm, body generally dark brown, fore wing in about basal half infuscated, rest hyaline, head 1.3X as broad as frontovertex width, frontovertex width 0.63X of length of antennal clava, antennal pedicel 0.7X of scape length, F1-3 and annelliform, F4 quadrate, clava 2.29X of scape length, fore wing about 3X as long as broad, with marginal fringe about as long as wing width, hind wing about 8X as long as broad, with marginal fringe about 2.5X as long as wing width, ovipositor 3.27X as long as mid tibia, 1.98X longer than hind tibia (1).These specimens were deposited in Insect collection of Department of Plant Protection, Agricultural and Natural Resources Research of East-Azarbaijan, Tabriz, Iran.

The free-living predatory ascid mites of the genus Antennoseius Berlese, 1916 includes about 60 described species worldwide and divided into two subgenera Antennoseius (without ambulacra and claws on leg I) and Vitzthumia Thor, 1930 (with ambulacra and claws on leg I) (1, 4). So far, five species of the genus have been reported from Iran, two of them belong to the subgenus Antennoseius and three of them to Vitzthumia, of which A. (Vitzthumia) kamalii Moraza & Kazemi, 2009 had been new to science (3, 4). During an investigation on edaphic mites of the genus Antennoseius in Tehran and Fars Provinces, three species of the subgenus Antennoseius were collected from soil and litter and identified. Adult female and male specimens of A. (Antennoseius) hispaniensis Bernhard, 1963 were collected in agricultural fields of Faculty of Agriculture, Tarbiat Modares University in Tehran (19 December 2006) by senior author, and adult female specimens of A. (Antennoseius) bacatus Athias-Henriot, 1961 and A. (Antennoseius) maltzevi Eidelberg, 1994 were collected in oak forests in Koohmare-Sorkhi region, Fars Province (5 March 2010) by junior author. Antennoseius (Antennoseius) hispaniensis has been collected in soil and litter and reported before from Spain, former USSR and Japan and A. (Antennoseius) maltzevi associated with carabid beetles from Italy and Ukraine. These species are considered here as new records for Iran mite fauna (1, 2).Differential diagnosis of adult female of A. (Antennoseius) hispaniensis: Dorsal shields together 640-650 mm long, reticulate-granulate. Podonotal and opisthonotal shields with 20 and 15 pairs of setae, respectively, without unpaired setae on opisthonotal shield, dorsal setae slightly widened and dentate, setae j1 wider (31-35 mm), setae z1 shortest (19–22 mm) and Z5 longest (45 mm), other setae sub-equal (30–35 mm) (Fig. 3). Sternal shield with two pairs of setae (st2-st3) and three pairs of lyrifisures, st1 inserted in soft cuticle anterior to shield. Epigynal shield slightly widened, posteriorly convex. Ventrianal shield bearing two pairs of pre-anal setae and three circum-anal setae. Peritrematal-exopodal shields widened and slightly continued around posterior edge of coxae IV. Tectum finely convex, with small denticles (Fig. 1). Movable digit of chelicerae bidentate, fixed digit with about 15 minute denticles, and a small sub-apical tooth. Most of leg setae, especially dorsal setae, barbed; without thick and modified setae on leg segments.Differential diagnosis of adult female of A. (Antennoseius) maltzevi: Dorsal shields together 600-610 mm long, reticulate-lineate. Podonotal shield with 20 and opisthonotal shield with 15 pairs of setae, unpaired setae on opisthonotal shield absent, eight pairs of podonotal setae (j2-j5, z2-z4, s4) thick, short and blunt, ca. 10 mm long, setae j1 short (13-15 mm) and spine-like, z1 short (10-15 mm) and setiform, other setae needle-like, sub-equal in length, except Z5 as longest setae (ca. 60 mm), Z5 (Fig. 4), S5 and some posterior opisthonotal setae barbed in distal half. Sternal shield bearing two pairs of setae (st1-st2) and three pairs of lyrifissures, posterior margin of shield irregularly concave, setae st3 and st4 inserted on soft cuticle. Epigynal shield narrow, nearly long and rounded posteriorly. Anal shield with three circum-anal setae. Peritrematal-exopodal shields nearly wide, not continued to posterior area of coxae IV. Tectum slightly convex, with minute denticles (Fig. 2). Movable cheliceral digit bidentate, fixed digit with several minute denticles. Most of leg setae smooth, some dorsal setae on trochanter, femur, genu and tibia I thickened.

Boxwood (Buxus hyrcana Pojark.) is one of the protected evergreen trees species that distributed as compact colonies in the preserved forests of the Caspian Sea region of Iran. During 2012 summer, blight symptoms and severe defoliation of boxwood trees were seen in two colonies in Lirehsar and Jeesa, in the Tonekabon region (Kia-Daliri, unpublished data). The symptoms were characterized by dark spots on leaves with grayish signs of fungus on their back side, followed by rapid death and defoliation. There were also longitudinal dark streaks on different parts of dying stems of twigs. Die-back symptoms were severe in the lower parts of trees, especially in young ones that defoliated, although new leaves appeared but diseased.Diseased leaves and stems were incubated in a moist chamber at 20-22°C and Cylindrocladium sp. was isolated. For morphological characterization, single conidia isolations were made on potato dextrose agar (PDA) amended with 2% malt extract and carnation leaf agar, and incubated at 25°C (4). Colonies grew slowly. The colony reverse was brown in the center surrounded by a creamy mycelial growth. The colony surface was covered by aerial cottony mycelium Fruiting bodies of the fungus developed after seven days. Conidiophores growing on the surface of carnation leaves were examined under the light microscope. Conidia were produced on hyaline macroconidiophores with stipe (90-180×2-3 mm) terminating in a naviculate vesicle (6-11 mm) and penicillate phyalids arrangement. Conidia were cylindrical, hyaline, with 1-septum, rounded at both ends (45-65×2-3 mm). Based on these characteristics confirm the fungus identified as Cylindrocladium buxicola Henricot & Culham, 2002, syn. Cylindrocladium pseudonaviculatum Crous, Groenewald & Hill 2002; teleomorph Calonectria pseudonaviculata.Four potted Buxus hyrcana plants were sprayed with an aqueous conidial suspension (105 conidia/ml) (4)to run off and incubated in growth chamber at 80 to 90% relative humidity in the dark at 25oC for 48 h. Control plants were sprayed with sterile water and incubated in the second tier of the same growth chamber. Thereafter, the plants were transferred to greenhouse at alternating 14 h of light and 10 h of darkness at 20-22oC. A week after inoculation the first lesions symptom appeared, leaf blight developed on all inoculated plants within two weeks, but not the controls. Re-isolations yielded the original pathogen.C. buxicola first reported on boxwood in UK in the mid-1990s (2), also during recent years it was reported as the causal agent of boxwood blight from Turkey (4), and Georgia (3). Based on our knowledge this is the first report of disease in Iran that can be a disaster for the protected species.