JOURNAL OF ENTOMOLOGICAL RESEARCH
Year:2010 | Volume:2 | Issue:2 (6)|Papers Count:8

A survey of aphids was carried out during 2008 to 2009 in central parts of Iran by collecting and identifying them and their host plants. Aphids were collected from 83 host plants. Seventy seven species from 37 genera, belong to 5 families include: Aphididae, Drepanosiphidae, Pemphigidae, Lachnidae, Phloeomyzidae were recorded. According to collected data, these families have the highest total identified species and distribution respectively. The greatest diversity of aphids was found on plants of the family Asteraceae. Furthermore, the family Asteraceae has the greatest host plant species for aphids. A list of aphids and their host plants is presented in this study.

Extensive uses of synthetic pesticides caused development of resistant strains of insects to pesticides and also environmental pollution. Therefore, the use of essential oils extracted from plants as pest control agents of stored product insects has been received much attention in recent years. Essential oils contain various effects such as toxicity, repellency, oviposition and feeding deterrency on different species of insects. In this research, effects of essential oil of Thymus vulgaris L. (Lamiaceae) were studied on Callosobruchus maculatus (F.) (Col., Bruchidae) at 27±1oC and 65±5 % RH in dark condition. The essential oil was obtained via hydro distillation. Ovicidal and larvicidal effects of the essential oil were investigated on C. maculatus Results showed that old eggs were more sensitive than the young ones. However old larvae were less sensitive than the young ones. The highest oviposition deterrency of C. maculates was observed at highest concentration of 1500 ppm.

The olive leaf moth, Palpita unionalis Hubner, is one of the most important pest of olive trees in Golestan province. The larva attacks young shoots and feed on leaf parenchyma. In heavy infestations larvae also attack the fruits of late ripen cultivars. Biological studies in controlled and field conditions, during 2001-2003, showed that the insect has six generations per year in Gorgan. Adults of overwintered larvae appeared by the end of winter and adults of the first generation appeared in mid-March. Insect overwintered as larva among leaves on olive trees. Eggs were laid on the lower surface of terminal rows of leaves, most of eggs were laid solitary. Results showed that, the present work, the mean number of eggs that was laid by each female, was 231. Eggs hatched after 2.5 days, the larva and pupa stage duration were 21.5 and 8.6 days, respectively. Nearly most of pupae were formed in cocoons in the soil. The average longevity of female and male adults was 14 and 13.6 days, respectively.

Eggs of grape leafhopper Arboridia kermanshah Delabola (Hem., Cicadellidae) are attacked by two parasitoid species Anagrus atomus L. (Hym., Mymariade) (species A) and Ufens sp. (Hym., Trichogramatidae) (species B) in Isfahan vineyards, Iran. For this research, 27 vineyards were selected randomly in different climatic regions of Isfahan. Ten plants were selected randomly per hectare of each vineyard and 3 leaves were sampled on each plant from lower, middle and upper strata. Then healthy and parasitized eggs were counted and the percentage of apparent parasitism was calculated in each vineyard. Three samples that each including 30 parasitized leafhoppers eggs were selected randomly from different climatic regions and the number of wasps were recorded. The percentage of marginal parasitism was calculated and compared for the two species. The average percentage of apparent parasitism in area of study was 8.33 that its range was varied at least 1.5 percent in very hot with dry desert up to 43 percent in dry temperate cold desert. The semi cold with warm and dry desert and semi-arid cold with dry desert climatic region with an average 82.8 percent had the highest percentage of marginal parasitism for species A and very hot with dry desert climate with an average 4.9 percent had the highest percentage of marginal parasitism for species B. The marginal parasitism of both species had moderate to high correlation with the percentage of apparent parasitism. The correlation coefficient of, in other words, the apparent parasitism was increased by increasing its marginal parasitism in climatic regions. While the correlation coefficient of species B was negative the apparent parasitism was decreased by increasing its marginal parasitism in climatic zones. Based on data obtained, it can be interfed that A. atomus was more efficient than Ufens sp. in different climatic regions of Isfahan province.

Confused flour beetle, Tribolium confusum Duval (Col., Tenebrionidae) is one of the most important stored product pests in Iran. Regarding the environmental risks of pesticides, scientists are exploring substitute compounds with less hazard to man and environment, such as RGRs. The purpose of this project is to evaluate the efficacy of three IGR insecticides, Teflubenzuron, Hexaflumuron and Pyriproxyfen on T. confusum larvae in laboratory condition. Different concentrations of the above insecticides have been used on 3-4 (young) and 17 day-old (old) larvae. Bioassay tests showed that Teflubenzuron (LC50=116.47) and Hexaflumuron (LC50=307.04) had the most and the least efficacy on young larvae, respectively. The most and the least efficacy, on old larvae have been induced by Teflubenzuron (LC50=135.51) and Pyriproxyfen (LC50=1513.95), respectively. Results showed that, mortality was directly correlated with the IGRs concentrations, and so young larvae of T. confusum were the most susceptible to IGR insecticides. These results revealed that, Teflubenzuron, chitin biosynthesis inhibitor, were the most effective and can be used safely for controling pest.

Geographical distribution larvae of Parasitengona mites belonging to Erythraeina and Trombidina were investigated with collection of them from different body parts of 20 insect species for the first time in Kermanshah province. Period of mite larvae sampling conducted from spring till middle of autumn seasons in two years (2007-2008). The mite larvae collected from Islamabad-Gharb, Mahidasht, Ghilan-Gharb, Sarpolehzahab, Kermanshah, Cozaran, Dalaho, Harsian, Paveh, Kangavar, Homeil, Ghasershireen, Sahneh. In this study nine species belong to 4 mite families identified so far from seven species belong to three grasshopper families Acrididae (Caliptamus tenuicercis Tarbinsky, Caliptamus sp., Tetanocera robusta Loew,), Pamphagidae (Iranotmethis persa Saussure, Nocarodes crispus Mishchenko), Tettigoniidae (Platycleis (Squamiana) squamiptera Uvarov), and Cicadidae (Cicadatia persica Kirkaldy), Buprestidae (Julodis laevicostata Gorg., J. armenica Mars), Chrysomelidae (Galeruca spectabilis Faldermann), Meloidae (Lydus sp.), Tenebrionidae (Adesmia sp., Pachyscelis sp., Tentyria sp.), Coccinellidae, Curculionidae and some other insect such as sunn pest and butterflies. Five mite larvae are new to mite fauna in species (three) and genus (two) level. Out of 7000 insects so far collected on 14 localities, more than 85 percent of them were belong to different grasshopper species which only 7.08% of them observed associated with grasshopper number of larvae (5 individual’s larvae mite) recorded on two grasshopper species (P. squamiptera, T. robusta). All insects collected in Mahidasht observed coexistence with larvae mite among surveyed localities whereas the least of larvae mite recorded only on grasshopper in Sahneh region. Maximum geographical distribution among mite species observed for E. sepasosariani in eight regions. Maximum biological activities and abundance seen during June-August for all mite species collected in all the regions. With reference to extensive Parasitengona larvae mite distribution in pastures of Kermanshah province and their feeding effects on grasshopper, It seems that they can be natural biological control agents on grasshopper population in this province.

This research was carried out to evaluate different aspects of one square meter quadrat size to estimate sunn pest over-wintered adults, Eurygaster integriceps Put. (Hem., Scutelleridae) in rainfed wheat field of Borujerd, north of Lorestan province, Iran, during 2003 and 2004. Iwao’s regression had higher determination coefficients (r2=0.93) and showed a better fit as compared to r2 values calculated by Taylor’s power law (r2=0.86). Iwao’s patchiness regression slope (b=1.07±0.05) was not significantly larger than 1.0. Consequently, random dispersion pattern was determined for over-wintered adults in rainfed wheat fields. Therefore, Kuno’s fixed precision sequential sampling scheme based on Iwao’s parameters was constructed for overwintered adults of E. integriceps. An additional nine independent data sets, was used to validate the fixed-precision sequential sampling plans with resampling software of RVSP. Sample size curves indicated that estimating over-wintered adult population in rainfed field can be accomplished with a few sampling efforts when population is>2 insects per quadrat. For example only six samples need to be taken for the over-wintered adults, on average to achieve a precision of 0.25 (Dexp=0.25) when=3 insects per quadrat. However, sample sizes increase suddenly when population density is less than 0.3 insects per quadrat. Based on these results, 1*1m quadrat is not recommended to estimate number of over-wintered adults in rainfed wheat field.

Preliminary investigation on geographical distribution of the Mediterranean fruit fly, Ceratitis capitata (Wied.) was conducted in Mazandaran province, Iran in 2006–2008. It is one of the most destructive pests of different crops, which observed after 20 years, in Noor (a city of Mazandaran) in October – November 2006. The primary studies for monitoring of the pest was carried out by direct observation of some citrus orchards encountered severe fallen of damaged fruits. Following to this issue, different types of fly traps (sticky yellow card, plastic bottle of mineral water, Jackson and McPhail) and attractant compounds (mixing of 2% protein hydrolizate with Malathion 2 lit. per 1000 lit. water, ceratrap and sex pheromone) were used in 2007-2008. The monitoring of the pest was started by setting of the traps in both infested and intact fruit orchards at the beginning of spring. The traps were checked weekly and number of flies and new infested areas in each city were recorded, separately. The infested cities recognized in 2006 were Sari, Qaem-Shar, Babol, Juibar, Mahmodabad, Babolsar and Amol. Generally, infestation was limited to urban parts and rarely observed in rural parts. Investigation in 2007 determined the presence of the pest in new areas such as Savad-kuh, Noshar and Chalous that the range of distribution reached to rural parts (7 to 10 Km. far from the infestation center). In spite of severe cold weather (-15oC) in winter 2007, adults of the pest appeared earlier in the following season compared to 2006. Constant monitoring revealed the invasion of pest to the new areas including: Behshar, Neka and Tonekabon cities. geographical position of more than 500 infested localities was determined by GPS and analyzed by GIS software on the map of Mazandaran province. The results of three-year investigation indicated that the Mediterranean fruit fly distributed its geographical dispersion from the east part of Mazandaran (Behshar) to the west part of the province (Tonekabon), except Ramsar.