Journal of Entomological Society of Iran
Year:2009 | Volume:29 | Issue:1 (44)|Papers Count:15

Adult individuals of the ladybird, Coccinella septempunctata L., and also the melon aphid, Aphis gossypii Glover, were collected ITom cucumber fields in Rasht area, north of Iran. They were reared in a growth chamber at 26±2oC, R.H. of 65±5% and a photoperiod of 16L: 8D. Ten mated pairs of two-day- old predators were separately transferred in to a plastic container (8 x 10 x 12 cm) that were covered with an organdy net. A demographic life table was constructed based on the daily fertility results. The intrinsic rate of increase (rm) and also the net reproductive rate (R.J) of C. septempunctata were 0.159 and 373.916, respectively. The mean generation time (T) of ladybird was 37.25 days and the population was doubled (DT) in 4.35 days. The population of C. septempunctata was able to multiply 3.45 times per week (rw). In order to determine rm and R0 of the melon aphid, twenty wingless adults were put separately into a leaf cage (10 x 60 mm) on cucumber leaves. The R.J and rm values of the aphid were 49.256 and 0.471, respectively. The Twas 8.27 days and the population of the aphid was doubled within 1.47 days. Female aphids were able to multiply 27.03 times per week. Adult longevity was 13.8±1.09 days and mean number of offspring produced per female was 49.05±2.32 and mean number of females per female per day (mx) was 3.22±0.59.

Field experiment was conducted to determine the economic threshold for spraying of flubendiamide against the brinjal shoot and fruit borer. Flubendiamide was applied based on 10 thresholds including 2% shoot infestation, 5% shoot infestation, first fruit set + 2% fruit infestation, first fruit set + 5% fruit infestation, 2% fruit infestation, 5% fruit infestation, 2% shoot + 2% fruit infestation, 5% shoot + 2% fruit infestation, 5% shoot + 5% fruit infestation and schedule spray at 7 days interval. Flubendiamide applied at 2% shoot + 2% fruit infestation reduced the highest percent of shoot (87.46%) and fruit (81.43%) infestation over control and also produced the highest healthy (13.26 t/ha) and total fruit yield (13.77 t/ha) of brinjal and similar results were obtained for 5%. fruit infestation. The highest benefit-cost ratio (BCR) was obtained (7.45) by application flubendiamide at 5% fruit infestation with 8 applications and that was the lowest (1.84) for schedule spray at weekly intervals with 16 sprays. Flubendiamide applied at 2% shoot +2% fruit infestation had the BCR of 2.92 with the highest number of spray (19). Considering number of sprays, marketable yield of brinjal and also BCR, 5% fruit infestation was considered as economic threshold of flubendiamide spraying for the management of brinjal shoot and fruit borer.

An investigation was carried out to study the developmental time, reproduction and life table of three populations of the onion thrips, Thrips tabaci Lindeman, on onion (Khorasan and Golestan populations) and also on tobacco (Mazandaran population) in the laboratory at 25oC, 50% RH and 16: 8 h L: D. The total life cycle from egg to adult of Khorasan, Golestan and Mazandaran populations were gauged as 15.22, 14.66 and 17.82 days, respectively. However, theses populations showed 30%, 38% and 58% immature mortality, respectively. The females of T. tabaci laid 29.5, 27.7 and 26.3 eggs averagely, and had a mean longevity of 18.0,17.78 and 19.07 days in Khorasan Razavi, Golestan and Mazandaran populations, respectively. The net reproductive rate (R0) was 19.75, 18.48 and 10.84, and the intrinsic rate of increase (rm) was 0.143, 0.141 and 0.096 in Khorasan Razavi, Golestan and Mazandaran populations, respectively. Khorasan Razavi and Golestan populations (both reared on onion) had similar developmental time, mortality and life table parameters, while Mazandaran population (on tobacco) yielded significantly different values. Based on the differences of development, fecundity and life table parameters, there might be two distinct populations exploiting onion and tobacco in Iran.

Some birds are important pests of agricultural products. Chemical control of harmful birds is not recommended because of environmental problems. To find better ways of control, digital calling songs of two cicada species, Cicada orni L. and Okanagan a rimosa (Say), were used to attract house sparrows (Passer domesticus). Data were calculated by a (3x2) factorial experimental plan in complete random design with two factors: (I) calling song type with 3 levels, ((a) C. orni, (b) O. rimosa, (c) control) and (2) distance of attracted sparrows to the sound generator source with two levels of 3 and 6 meters (with at least 3 minutes interval flying out). The sound playing occasion in this plan was 7:00 to 8:30 a.m. and the amplitude of playing sound was approximately 1 watt for 5 repeats during 15 days with the same climatic conditions. The study was carried out from April in 2005 to late August of the same year in Karaj, Iran.The results showed that calling songs of C. orni and O. rimasa were significantly affecting the attractiveness of sparrows (P<0.01). However, the calling song of C. orni with 3 meters distance was more efficient than of o. rimasa.

Canola, an oil seed with high contents of oil, is a major farming in Khuzestan province, where there is an increase over its cultivation year by year. One of the canola key pests is mustard aphid (Lipaphis erysimi Kalt.) in this province. However, there was not available information on the economic injury level (EIL) of the pest that is much vital for correct decision making on pest control. Therefore, a study on EIL was conducted through complete randomized block design with 5 replications and 11 treatments (0, 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 aphid per central stem of Hayola 401 variety of canola) inside a netted cage. This research was conducted in Behbahan Agricultural Research Station during 2004-2006. The average of seed yield and also the yeild components was analyzed with Duncan's multiple range tests.The damage of the aphid was estimated by regression equation. The injury level was estimated by Grain hreshold method. The results indicated that EIL was 7.53 and 2.49 cm aphid per central stem of canola in Behbahan region in 2004-2005 and 2005-2006, respectively. Economic threshold (ET) was 5.65 and 1.87 cm2 aphid per central stem of canola.

Influence of 13 soybean cultivars (356, M4, M7, M9, Clark, Sahar, JK, BP, Williams, L17, Zane, Gorgan3 and DPX) on the life table parameters of the cotton bollworm, Helicoverpa armiger a (Hubner) was studied at 25 :101oC, relative humidity of 65±5% and a photoperiod of 16: 8 (L: D) h. The survival rate (Ix) of individuals developed to adults from the initial cohort on the mentioned cultivars was estimated 0.87, 0.83, 0.96, 0.96, 0.77, 0.72, 0.81, 0.72, 0.85, 0.74, 0.85, 0.88 and 0.72, respectively. The longest and shortest life expectancy (ex) of the pest was 44.22 and 35.98 days on Gorgan 3 and BP, respectively at the beginning of life. The intrinsic rate of natural increase (rm) on different cultivars ranged from 0.1324 to 0.1848 (day .1), which was lowest on 356 and highest on M9. The highest net reproductive rate (R0) was on M7 (354.92 female/female/generation) and the lowest value of this parameter was on 356 (89.35). The values of finite rate of increase (l), mean generation time (T) and doubling time (DT) on different soybean cultivars were as follows: 1.14 to 1.20 female offspring per female per day for l 28.85 to 36.61 days for T and 3.75 to 5.23 days for DT. Because of the higher coefficient of determination(R2) value in compertz model, data from different cultivars had a better fit to this model compared with Weibull model. The results indicated that 356, L17, Gorgan 3, BP and Sahar cultivars were less suitable host plants, suggesting that they are more resistant to H. armigera than the other cultivars.

The larvae of Hyles euphorbiae (1.) are monophagous and feed on the succulent species of the genus Euphorbia. Obtaining more information on the feeding rate and preferred host plants of the larvae of H. euphorbiae could be useful in biological control programs. In this research, the larval feeding indices of this species i.e. consumption index (CI), approximate digestibility (AD), efficiency of conversion of ingested food (ECI) and efficiency of conversion of digested food (ECD) were determined on the five most prevalent species of the genus Euphorbia (E. macroclada, E. denticulata, E. seguieriana, E. heteradena and E. boissieriana) in the fields and rangelands of West Azerbaijan in laboratory at 19±1oC, 65±5% RH and a photoperiod of 14: 10 (L: D). The experiments were conducted during larval period of the moth (four larval groups and each group containing eight larvae) inside colorless plastic containers. The results indicated that the larval feeding rate on the above mentioned Euphorbia species were not significantly different (P>0.05). The maximum (24.97±0.71 g) and minimum (21.24±0.88 g) rates of larval feeding were on E. macroclada and E. boissieriana, respectively. The mean weight of feces that excreted by rearing larvae on E. boissieriana (11.20±0.73) was significantly (P<0.05) lower than that of other Euphorbia species. The comparison of the mean weight in the late larval stage on five Euphorbia species was not significantly different (P>0.05). Mean efficiency of conversion of ingested food on E. boissieriana (0.200±0.01) was more than the other Euphorbia species, though the difference was not significant. It could be concluded that the entire Euphorbia species tested are the host plant of H.euphorbiae and larvae of H. euphorbiae for reaching to normal weight increase the efficiency of conversion of ingested food and decrease the feces and its excretion. This moth is a suitable agent for using in biological control programs of the Euphorbia weeds.

Mealybug specimens collected on the root of Alhagi pseudoalhagi (Fabaceae), dated on 5.6.2007 in Bayg, Torbat Heydarieh, Razavi Khorasan province. They were identified as Polystomophora orientalis Matesova. Herewith, the genus and species are newly reported from Iran. The species has already been reported from Armenia and Kazakhstan (Miller & Ben-Dov, 2008).The Polystomophora Borchsenius has two species, P. orientalis and P. ostiaplurima (Kiritchenko). Both species occur within the Palaearctic region. The former species can be distinguished from P. ostiaplurima using the following characters: multilocular pores are present on the entire segments of the body; only one circulus and trochanter of hind leg is present lacking translucent pores (Ter-Grigorian, 1973).

The superfamily Yponomeutoidea consists of relatively primitive micro-moths and is divided into eight families. The Yponomeutidae is an heterogeneous group including both external and internal feeders, sometimes very different in morphological aspect. Following this dissimilarity, the family is divided into six subfamilies. The members of the subfamily Yponomeutinae are relatively small in size and have dull coloured wings. The number of known species exceeds 360 placed in 24 genera (Dugdale et al., 1998). The distribution is worldwide. However, most of the species inhabits Palaearctic region, except for the northern tundra and the desert. The entire species are phytophagous, trophically associated predominantly with trees and shrubs, and because of the wide variety of food plants, the local adaptation ofthese moths is rather diverse (Gershenson & Ulenberg, 1998).The Yponomeutinae of Iran has been neglected slightly and few literature records are published on them. Five species have hitherto been reported from Iran: Yponomeuta malinelIus Zeller, Y.padellus (Linnaeus), Y.rorrellus (Hubner), Zelleria impure Staudinger and Paraswammerdamia iranella Friese (Amsel, 1959; Modarres-Awal, 1997; Gershenson & Ulenberg, 1998). Nevertheless, Yponomeuta variabillis Zeller that was listed as a Yponomeutine from Iran (Modarres-Awal, 1997), is nomen nodum for Y. padellus (Gershenson & Ulenberg, 1998).

the anthomyiid fly, Pegomya bicolor (Wiedemann, 1817), is newly recorded from Iran. it was collected during surveys on biocontrol agents of Rumex spp. (polygonaceae) in Urmia region, north west of Iran. This leaf-mining fly is widely distributed in the Palaearctic region on several species of Rumex.Voucher specimens are being held at the Natural History Museum of Urmia University.

During a faunal survey on the family Tachinidae in Pars province, six tachinid parasitoids belonging to the subfamilies Tachininae and Phasiinae were collected and identified. They are reported for the first time from Iran. The species are as follows: Linnaemya neavei Curran, Microcerophina planifacies Kugler, Phasia mesnili (Draber-Monko), Catharosia flavicomis (Zetterstedt), Leucostoma engeddense Kugler and Cylindromyia rufipes (Meigen).

A study on larval parasitoids of carob moth, Eetomyelois ceratoniae Zeller, in pomegranate orchards in Ghale-Cham, Qom province and Tarom-e-sofla, Zanjan province was carried out in 2006-2007.Two species of fly parasitoids belonging to the family Tachinidae were collected and identified as Fiseheria bieolor Robineau-Desvoidy and Clausieella suturata Rondani. The latter species is newly recorded from Iran.