نشریه نامه انجمن حشره شناسی ایران
سال سی و ششم شماره 3 (پیاپی 66، پاییز 1395)

Citrus red mite, Panonychus citri McGregor is one of the most important pests of citrus orchards in the world. Due to excessive use of chemical pesticides and development of resistance plus their increasing environmental hazards, the use of essential oils has been highly studied. But the low solubility of essential oils in water, oxidation, in addition to their instability in presence of light, humidity and high temperature has diminished their application. Formulation technology is one of the main strategies that can modify the physical properties and the viability of the essential oils in agricultural pest management programs. In this research, the essential oil of Cuminum cyminum L. was encapsulated by in situ polymerization of oil/water emulsion in nano scale and then the effects of nanoencapsulated essential oil (NEO) were analyzed against P. citri. The results showed that LC50 of NEO's contact toxicity was 743.17 ppm over 24 hours. NEO also affected mortality and decreased oviposition rate in P. citri. NEO had deterrence capacity at 300, 500 and 700 ppm. Moreover, NOE had oviposition deterrence, lowering the number of eggs per female compared to the control. Our finding suggests that high-tech formulations including nanoencapsulation technology can be used as botanical pesticides and as alternatives to chemical pesticides.

The predatory mite, Amblyseius swirskii (Athias-Henriot) is an efficient predator of some insect pests particularly thrips and whiteflies. To evaluate the optimum temperature for A.swirskii, a life table study, based on the age-stage, two-sex life table theory, was conducted using the stored product mite, Carpoglyphus lactis L. as the food diet. Experiments were performed at temperatures of 22, 25, 30 and 32° C, %70 ± 5 relative humidity and 16: 8 (L: D) photoperiod. Developmental time of eggs at 30° C was significantly shorter comparing to the temperatures 22 and 32° C. Developmental time of the mobile pre-adult stages, male and female, were significantly shorter at 32° C, comparing to 25° C. The highest fecundity of the predator was observed at 25° C (72.34 eggs / female). The intrinsic rate of increase (r), finite rate of population increase (λ), net reproductive rate (R0), at temperature of 22° C were 0/226 day-1, 1/25 day-1, 25/53 offspring/individual; at 25° C were 0/304 day-1, 1.35 day-1, 33/82 offspring/ individual; at 30° C were 0/097 day-1, 1/102 day-1, 2/42 offspring/ individual; at a temperature of 32° C were 0/128 day-1, 1/137 day-1, 2/67 offspring/ individual. The population parameters of A. swirskii, except mean generation times (T), at 25° C and 32° C were significantly higher than those at 30° C, and the average generation time (T), at temperature of 22° C, was found to be the highest. The total population projection demonstrated that the highest population growth of predatory mite, A. swirskii occurred at 25° C.

Mites are one of the largest and most diverse subclasses of Arachnida with a worldwide distribution. The order includes 456 families and more than 56,000 species.
In this study, mesostigmatic soil mite fauna was studied as indicators of biodiversity in the 52-hectare Police park of the city of Tehran, Iran. The area of the park was divided into 7 sections in terms of their vegetational and geographical properties. Soil samplings were conducted through theyear and a total of 6167 mite specimens of 80 species were collected. Species diversity was calculated using Simpsons index of diversity and Shannon-Wiener index. Species richness was estimated using Menhinicks index and Margalefs diversity index and species evenness calculation was based on Peet and Hill.
Cheiroseius sp., Halolaelaps sp., Oplitis sp., Asca sp., Androlaelaps aegypticus, Pergamasus falculiger, Gamasiphis pulchellus, Cosmolaelaps lutegiensis, Macrocheles insignitus, Euandrolaelaps karawaiewi, Lasioseius youcefi, Proctolaelaps pygmaeus, Macrocheles peniculatus, Iphidozercon gibbus, Antennoseius masoviae, Pergamasus crassipes and Neogamasus cervicornis are reported here from Tehran for the first time. Uroseius (Apinoseius) sp. is new to Iran.

In this research, a Learning Vector Quantization (LVQ) neural network model was developed to predict the spatial distribution of Tuta absoluta in tomato fields of the city of Ramhormoz, Iran. Pest density was assessed through 10 m × 10 m grid pattern on the field with a total of 100 sampling units. Some statistical tests, such as means comparison, variance and statistical distribution were performed between the sampling point data and the estimated pest values in order to evaluate the performance of prediction of pest distribution. In training and test phase, there was no significant difference in average, variance, statistical distribution and coefficient of determination at 95% confidence level. The results suggest that LVQ neural network can learn pest density model precisely and trained LVQ neural network high capability (88%) of predicting pest density for non-sampled points. The LVQNN successfully predicted and mapped the spatial distribution of Tuta absoluta whose aggregation distribution implied the possibility of using site-specific pest control in the field.

Intraguild predation is defined as killing and eating another predator species as potential competitors that depends upon the same or limited resources. In this study, intraguild predation between the ladybird Hippodamia variegata Goeze and the parasitoid wasp Lysiphlebus fabarum (Marshall) was investigated in association with cotton aphid, Aphis gossypii, on cucumber plants. Host preference for healthy or previously parasitized aphids in third instar larvae and adult females of H. variegata was studied in a choice access situation as well as in a Y-tube olfactometer bioassay. We cut an antenna of each experimental aphid to reliably distinguish the parasitized aphids from healthy ones. All experiments were performed at 22±1°C, 60%–70% RH, and a 16:8 (L:D) photoperiod. Based on the pre-test results, cutting the antenna of aphids, did not significantly affect the host preference of adults or third instar larvae of ladybirds. In a choice access test, female ladybirds significantly preferred healthy aphids to previously parasitized ones (24 and 72 hours: t =2.15, df =1,18, P =0.04 and t =6.35, df =1,18, P

Onion thrips, Thrips tabaci Lindeman, is one of the most common and important pests of agricultural products including eggplant. In present study, we investigated the mechanism of antixenosis, trichomes density and chlorophyll content of 10 eggplant genotypes (Black beauty, Blacky, Yalda, Lady, Linda, Lyma, Kyme, Borazjan, Siah-Mashhad and Mahali-Zabol) to the thrips in festationin a selection test . Experiments were performed in a greenhouse at 25 ±1°C, 65 ± 5 RH and 16L: 8D photoperiod. Total protein of the cultivars was isolated and electrophoresed using SDS-PAGE to determine the protein-electrophoresis pattern and its relation to the quantity of attracted thrips. Protein-electrophoresis showed differences in the number and type of the protein bands which are related to the variation among the cultivars in which the thrips-resistant cultivars can be used in the inbreeding programs. The genotypes were significantly different in terms of trichome densities and chlorophyll content as well as thrips-mediated damage percentage. There was no significant correlation between morphological attributions and molecular data. We believe that Lima and Linda genotypes, with highest genetic distance (0.454), can be successfully used in cross breeding programs, although complementary tests are required to improve the efficiency of the programs.

During the faunistic survey of aphid species associated with ornamental shrubs in the urban green spaces of Mashhad, the capital city of Khorasan-Razavi province of Iran, in 2015, specimens of the species Appendiseta robiniae (Gillette, 1907) were collected from a colony on Vitex agnus-castus. This aphid species is reported here for the first time from Iran.

During the course of our study on the paper wasp fauna of the Iranian province of Kerman, between 2015 and 2016, we collected 11 vespid species of which Polistes rothneyi Cameron (Hymenoptera: Vespidae: Polistinae) found to be a new record for the Iranian fauna. The specimen is deposited at the insect collection of the University of Shahid Bahonar, Kerman, Iran. Geographical distribution and diagnostic characters of this species is provided.