Journal of Entomological Society of Iran
Year:2017 | Volume:37 | Issue:2 |Papers Count:16

Pieris brassicaeis one of the most serious pests of cultivated crucifers in the world. The present experiment is intended to determine the proteolytic digestion of fifth instar larvae and the effects of four cruciferous hosts toP. brassicae nutritional physiology. Brassica oleracea var. botrytis, Brassica oleracea var. capitata, Brassica oleracea var. italica and Brassica oleracea var. viridis were assessed under laboratory conditions at 25 ± 2°C, 60 ± 5% RH and a photoperiod of 16: 8 (L: D) h. The maximum total proteolytic activity in the midgut extract was observed at pH 11, suggesting the presence of serine protease. The lowest rate of tryptic activity and both the highest general proteolytic (0.11 ± 0.01 Umg-1) and chymotryptic activities (0.45 ± 0.002 Umg-1) were observed in B. oleracea var. viridis. The proteolytic activity of P. brassicae on this host plant indicates that B. oleracea var. viridisis not a suitable host for the pest likely due to the presence of some secondary chemicals or proteinaceous protease inhibitors.

The efficacy of milk thistle, Silybum marianum methanolic extract was investigated on the third instar larvae of cotton bollworm, Helicoverpa armigera (Hübner). The experiments were done at 25 ± 1 °C, 65 ± 5 RH and photoperiod of 16: 8 (L: D) h. The LC50 and LC20 values were estimated 10449 and 5654 ppm, respectively. One hundred microliters of the plant extract at 5654 ppm was added to 0.9 grs of artificial diet. Nutritional indices, crustacean cardioactive peptide (CCAP) content and digestive enzymatic (a-amylase and protease) activities were measured after 72 h. Plant extract decreased nutritional indices including approximate digestibility (AD), relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of ingested food (ECI) and efficiency of digested food (ECD). Methanolic extract of S. marianum decreased á-amylase and protease activities in the midgut ofH. armigera. The activity of a-amylase from 194 mU in control decreased to 86.8 mU in treatment. It also decreased protease activity from 108.2 mU in control to 60.6 mU in treatment. Incubation of dissected midgut with CCAP increasedá-amylase and protease activities in H. armigerawhereas the buffer alone had no effect. Feeding on artificial diet containing methanolic extract of S. marianum caused CCAP level in the midgut of the insect to decrease. Feeding on artificial diet containing methanolic extract of S. marianum inhibits release of CCAP in the midgut and leads to reduction ofá-amylase and protease activities.

The fall webworm, Hyphantria cunea Drury (Lep.: Arctiidae), is an important pest of forest and cultivated plants in Guilan Province, Iran. The reproductive performance of Chouioia cunea Yang (Hym.: Eulophidae), a gregarious pupal parasitoid of H. cunea was studied at 24 ± 1°C, 70 ± 5% (RH), and a photoperiod of 14: 10 (L: D) hours. The pupal hosts were exposed to 1, 2, 4, 8, 12, 16 newly emerged adult parasitoids. The parasitoids remained in contact with host pupae for 24 hours in Petridishes (10x1 cm) until the death of all parasitoids. The results showed that parasitoid density influenced offspring production, as the higher parasitoid densities resulted in the lowest mean number of offspring per female (179.06 ± 6.29). The sex ratio was not influenced by parasitoid density, but the age of parasitoid affected sex ratio as a higher sex ratio (0.92 ± 0.001♀) was observed in the progeny produced by younger parents. Rate of parasitism was higher at density of 4 wasps (33.33%). The mean percent parasitism by 1, 2 and 3 day-old female parasitoids were 21, 13 and 9, respectively (P<0.05). Maximum number of offspring produced per female was obtained at host/parasitoid ratio of 15 to 4. The female parasitoids survived 1-3 days after oviposition. The searching efficiency of the parasitoid decreased from 0.18 to 0.009h-1 with increasing its density. The survival rate for C. cunea was not significantly different at all densities of male or females, but a statistical difference was observed with increasing parasitoid age. It was concluded that the performance of C. cunea was mainly affected by its density and age.

Insects can increase their survival at subzero temperatures, prior to long or short term exposure, to non-lethal cold temperatures by cold acclimation (ACC) or rapid cold hardiness (RCH). In this research, the effect of rapid or gradual decrease in temperature on cold tolerance of adults of the greenbug, Schizaphis graminum (Rondani) was investigated. LT50 (lower lethal temperature for 50% mortality) of aphids acclimated at 10°C for one week showed no significant differences with control (aphids reared at 20°C). In addition to the cold acclimation, adults of S. graminum showed RCH response too. When the rearing aphids at 20°C were transferred directly to a range of sub-zero temperatures for 2 h, LT80 (lower lethal temperature for 80% mortality) was -11.6 °C, but acclimation at 0°C for 5 h before transfer to -11.6 °C, induced maximum RCH, led to increase of survival to 73%. RCH was induced by cooling of the insects at 0°C for different rates. Maximum survival (66%) was achieved by cooling at 0.05°C/min. Accumulation of sugars and polyols is one of the major mechanisms underlying ACC and RCH. In this study, trehalose and glucose increased considerably through ACC and RCH treatments, suggesting the role of these compounds in increasing cold tolerance of S. graminum.

The new armored scale speciesAcanthomytilus cupressicola Moghaddam sp. n. is described and illustrated from specimens collected on Cypress trees in Iran. Although most species of Acanthomytilusare known to occur on Poaceae, this is the second species of the genus, except A. kurdicus Bodenheimer, that is here recorded from woody plants.

A survey on the morphology and biology of the elm leaf-mining moth Bucculatrix ulmifoliae was conducted under natural conditions. The developmental periods of 1th+2th, 3th, 4th and 5th larval instars as well as pupa were calculated as 6.40 ± 0.67, 1.76 ± 0.12, 1.92 ± 0.20, 3.51 ± 0.37, 9.61 ± 0.77 days, in a cage at field; and 6.40 ± 0.66, 1.50 ± 0.27, 1.78 ± 0.47, 2.71 ± 0.48, 7.64 ± 0.33 days at the laboratory (25 ± 2°C, RH 65 ± 5 and 16L: 8D hours) respectively. The average life span of the moth was obtained as 23.04 ± 1.02 days at the laboratory and 25.84 ± 0.91 days at the field. Adults of the first generation appeared in early April. The fertile females laid their eggs underside of leaves near the midribs. Upon hatching, the first instar larva penetrates directly via base of the egg into the leaf tissue and creates the mine. B. ulmifoliae had three generations of which the second generation showed its tendency for oviposition. Third generation was observed from the first half of August, and overwintering started at the first half of September. The first and second instars mined the leaf and fed inside, while the other instars fed externally on the underside. Bucculatrix ulmifoliae has three generations a year and overwintering as a pupa in a cocoon in the crevices of barks and fallen leaves on the ground.

Citrus leafminer, Phyllocnistis citrella Stainton, recently has become a serious pest in Iran, especially in citrus nurseries. This study was aimed to assess the effect of temperature on the biological parameters of theP. citrella at three constant temperatures: 20, 27 and 35°C, 70 ± 10% RH, photoperiod of 14: 10 (L: D) and on seedlings of Citrus sinensis cultivar Valencia as host. Results showed significant reduction in incubation period from 6.22 at 20°C to 2.18 days at 35°C and adversely mortality increase from 7 to 21% at 20 and 35°C, respectively. Larval period was 8.06, 5.26 and 4.14 days and pupal period was 11.18, 6.86 and 5.03 days at 20, 27 and 35°C, respectively. The highest mortality in both larval and pupal periods was observed at 35°C (11.4 and 15.8%, respectively). Both females and males lived longer at 20°C (9.31 and 7.38 days) and shorter at 35°C (5.38 and 4.21 days, respectively). Moth emergence rate was the highest at 27°C (female: 82.2% and male: 84.5%). The sex ratio for the offspring was 1: 1.2, 1: 1.4 and 1: 1.3 male: female at 20, 27 and 35 °C, respectively.

In this study, silica nanoparticles (SNPs) were prepared by sol-gel technique. Chlorpyrifos (40.8% EC) was loaded on the SNPs by immersion loading method. The Specific surface area (SBET) of nanosilica was characterized by BET and recorded 102.24 m2/g. Loading efficiency of chlorpyrifosloaded in silica nanoparticles (Ch-SNPs) was measured 86.79% using UV-VIS spectrophotometer. According to FT-IR results, chlorpyrifos properties remained intact after loading on nanosilica because of physical adsorption process of the insecticide in the pores. The residual toxicity of Ch-SNPs was assessed against two stored product insect species, Rhyzopertha dominica F. and Tribolium confusumJacquelin du Val. on Petri dish, galvanized steel, mosaic and concrete surfaces. Residual toxicity was evaluated7, 15, 30, 45 and 60-day post treatment. For each post treatment, the mortality was counted after 6, 24, 48 and 72 h of exposure. The mortality increased with increasing concentration of insecticide and time exposed to each concentration. According to the results, the Ch-SNP was effective against the both pest species, but the toxicity varied depending on the surface material. Ch-SNPs provided long-term protection on petri dishes against the pests, whilst concrete followed by mosaic surfaces with less protection. For instance, R. dominica mortality percentage after 24 h exposure to Petri dish, galvanized steel, mosaic and concrete treated with 0.2 mg cm-2 Ch-SNP was 100, 82.8, 40 and 1.4%, whereas the mortality was 100, 97.1, 20 and 18.5 % for T. confusum at 60-day post-treatment, respectively.

Several aphidophagous insects such as predators and parasitoids are known to respond positively to aphid infested plants. This study was intended to evaluate the effect of different densities (40, 60, 80, 100) and nymphal instars (1st, 2nd, 3rd, 4th) of the cotton aphid Aphis gossypii Glover (Hemiptera: Aphididae) as prey on developmental time and feeding rate of the larvae of the syrphid flyEpisyrphus balteatusDeGeer on cucumber leaves The experiment was conducted at the greenhouse condition (22 ± 5°C, 55 ± 10% RH and 14L: 10 D h photoperiod) with 10 replications. Our study indicated that lower density and poor quality of prey caused higher larval mortality. Feeding on 3rd and 4th nymphal instars and higher density of prey (80 and 100 prey/day) caused shorter developmental time of E.balteatus. The larvae fed on densities of 40 and 60 prey, even though fed on higher nymphal instars, failed to complete their larval development. It is concluded that higher prey densities (80 and 100 prey) were highly suitable for predator's larval development and significantly reduced the developmental period of E. balteatus. These findings provide further evidence that E. balteatus has high predation capacity on aphids, and therefore can be used as a successful biocontrol agent against A. gossypii.

Apisspecies that engage in symbiotic association with Lactic Acid Bacteria (LAB), have diverse functions on their hosts. This study was intended to isolate and identifyaeoccus bacteria living in the gastrointestinal tract of Asian dwarf honey bee, Apis florea, in Iran. One hundred isolates were Gram stained and tested for catalase reaction. By using bacterial universal primers, the 16S rDNA gene of bacterial colonies was amplified.16S rDNA genes from thirty bacteria were sequenced. Phylogenetic analysis showed that Enterococcus flora in the gastrointestinal tract of A. florea, contained five phenotypes which classified in the species E. faecium, E. faecalis and E. hirae. Based on the specific association between bacteria and A. florea, we divided the Asian dwarf honey bee populations into four categories.

The authors express their sincere thanks to Matthias Borer (Naturhistorisches Museum, Basel), Bernd Jager (Museum fur Naturkunde, Berlin) and Jioi Hájek (National Museum Prague, Czech Republic) for providing the material. Danny Boomsma and Godard Tweehuysen (Naturalis library) are also thanked for making the book by Klug available. Ron Felix kindly improved the English of the manuscript. ...

During our research on the Iranian Carabidae, we studied the type material of several species of which we found four new synonymies in the generaCymindis and Brachinus. ....

During a study on the diversity and biology of fruit flies (Diptera: Tephritidae), attacking Asteraceae capitulum in the northwest of Iran (Pourhajiet al., 2016), the species Chromoplex picticollis (Thomson, 1887) (Hym.: Ichneumonidae, Campopleginae) was identified by M. Riedel. The specimen of C. picticollis is deposited in the private collection of M. Riedel, Zoologische Staatssammlung München, Münchhausenstr.21, 81247 Munich, Germany.

The Banchinae Wesmael, 1845 (Hymenoptera: Ichneumonidae) is a large and species rich ichneumonid subfamily with about 1758 species (Yuet al., 2012). All members of this subfamily are koinobiont endoparasitoids of Lepidoptera (Quicke, 2014). ...

White mulberry, Morus alba L., is a fast-growing, moderate-sized and deciduous plant belonging to the family Moraceae. It is native to Asia or of Asian origin but currently cultivated in most countries around the world (Deviet al., 2013; Flaczyk et al., 2013). ...