Journal of Entomological Society of Iran
Year:2006 | Volume:26 | Issue:1 (37)|Papers Count:14

The mealybug fauna of southern Iran (Systan & Baluchestan, Hormozgan, Bushehr, Kbuzeztan and Fars provinces) is unknown to many coccidologists. In this paper, 17 mealybug species from the south of Iran with their host plants are reported.Maconellicoccus hirsutus (Green), Nipaecoccus viridis (Newstead) and Planococcus ficus (Signoret) are the important pests and Ferrisia virgata (Cockerell), Dysmicoccus brevipes (Cockerell) and Planococcus vovae (Nasonov) are regarded as potential pests. Antonina graminis (Maskell), Brevennia rehi (Lindinger), Dysmicoccus boninsis (Kuwana), Peliococcopsis priesneri (Laing), Peliococcus kimmericus (Kiritshenko), Phenacoccus solani Ferris, Formicococcus robustus (Ezzat & McConnell), Planococcus citri (Risso), Pseudococcus viburni (Signoret), Trabutina serpentina (Green) and Trionymus multivorus (Kiritchenko) are regarded as pests but no records of damage have been reported from the south of Iran.

Integrated pest management as a way in reduction of pesticide application, environmental pollution and protection of natural enemies of pests, is very important. A 3-year investigation was conducted in 1999-2001 in the Grizeh Agricultural Research Station in Sanandaj to study the effect of microbial pesticides (including Novodor and Bt-Col) and traded pesticides of neem, comparing with Ekamet, using of fire (in the beginning and end of winter and early April) and grazing of farm by sheep, and reciprocal effects of these treatments on population reduction and yield increases were evaluated. The experiment was conducted in the form of factorial with completely randomized design in 4 replicates. The results indicated that grazing of farm caused significant reduction in larvae population but the wet and dry yield had no significant difference with the control. Also, differences were significant (P = 0.01) between levels of the factor B (burning treatment), and field burning in late winter was the best. Differences between the applied insecticides were significant: Novodor and Bt-Col (based on Bt), and Neem plus and Neem azal-F (based on neem) had no significant differences with the control, but Ekamet reduced the pest population and increased the yield significantly.

The effect of poplar stand density on the spatial distribution pattern of an aphid species, Chaitophorus leucomelas Koch, adult and larvae of poplar flat-headed borer, Melanophila picta Pall., cicadellid leafhoppers, Rhytidodus spp., a cixiid planthopper, Hyalesthes mlokosiewiczi Signoret, predacious ladybirds (Coccinellidae), common lacewing, Chrysoperla carnea (Stephens), aphid flies, Leucopis spp., a parasitoid wasp, Adialytus salicaphis (Fitch) and spiders (Araneae) was investigated in Alborz Research Complex of Karaj during 2002-2003. Experimental treatments included four stand densities (333, 417, 498 and 833 trees/ha) of poplar-alfalfa agroforestry and poplar monoculture (833 trees/ha). Variance to mean ratio and Taylor's power law were used for determining the spatial distribution patterns of the mentioned arthropods. The results revealed that poplar stand density had different influence on the spatial distribution pattern, index of dispersion (I) and the slope of regression (b) of arthropods, resulting from their biological and ecological traits. Likewise, the spatial distribution of the natural enemies differed from their hosts, which probably resulted from their low population density, slow growth rate and the high searching behavior of natural enemies compared to the pests.

The mealybug fauna of southern Iran (Systan & Baluchestan, Hormozgan, Bushehr, Kbuzeztan and Fars provinces) is unknown to many coccidologists. In this paper, 17 mealybug species from the south of Iran with their host plants are reported.Maconellicoccus hirsutus (Green), Nipaecoccus viridis (Newstead) and Planococcus ficus (Signoret) are the important pests and Ferrisia virgata (Cockerell), Dysmicoccus brevipes (Cockerell) and Planococcus vovae (Nasonov) are regarded as potential pests. Antonina graminis (Maskell), Brevennia rehi (Lindinger), Dysmicoccus boninsis (Kuwana), Peliococcopsis priesneri (Laing), Peliococcus kimmericus (Kiritshenko), Phenacoccus solani Ferris, Formicococcus robustus (Ezzat & McConnell), Planococcus citri (Risso), Pseudococcus viburni (Signoret), Trabutina serpentina (Green) and Trionymus multivorus (Kiritchenko) are regarded as pests but no records of damage have been reported from the south of Iran.

The American white webworm, Hyphantria cunea Drury, was reported from the Guitan province in 2002. Due to its economic importance in the north of Iran, its biology, population fluctuation, host plants and other life characteristics were studied in Rezvanshahr (Guilan) in 2003 and 2004. The larvae feed on a wide range of forest trees, orchards, crops and weeds. The pest had two generations per year and over wintered as pupae in cocoons mostly under tree barks, fences and a few in the soil. The adults were appeared in mid spring and mated 2-3 days after emergence. Females laid their eggs in a cluster underside of host leaves. The maximum number of eggs laid in laboratory and field conditions was 1053 (490.4±86.47) and 1500 (758.85±79.10) per cluster respectively. In optimum conditions (23±1°C and 60-70 % RH and 16L: 8D), the eggs hatched within 7-9 days (7.29±0.22). The first and second larval instars fed gregariously in their nested webs on the leaves where the eggs were deposited. The pest had five larval instars and each larval instar lasted 4-6 days (4.26±0.31). The third and fourth instars left their nests and made webs on other leaves. The pupal stage lasted 10 days in first generation and 9 months in second generation as over wintering pupae.

Aquatic larvae of chironomid midge, Chironomus riparius Meigen, are one of the richest diets in fish rearing systems. The quantity and quality of food used to rearing these larvae, affect this developmental stage. This study was conducted to determine the effect of different diets (chicken manure, rice bran and soybean meal) with different weights (1, 3 and 5 gr) on larval development, the best time of harvesting at different constant temperatures (16-20, 22±1, 24±1, 26±1, 28±1 and 30±1°C) and the yield (larval live weight (gr) m-2 per week) based on the number of reared egg masses with the favorable diet. Results indicated that the highest weight of harvested larvae obtained when they fed on 5 gr of chicken manure (3.53±0.4, P < 0.01). The last larval instars were harvested at the shortest time (on 13th days), when reared at 24±1 or 26±1°C feeding on chicken manure (compared to other temperatures). Mean yield of 131.38± 13.99 gr m-2 per week obtained, when five egg masses were reared at 26±1°C on the chicken manure.

The American white webworm, Hyphantria cunea Drury, is an important pest of the forest, orchards and crop plants in the Guilan province of Iran. Therefore in this study nutritional indices and host preference of the larvae were evaluated on Morus alba L., Juglans regia L., Armeniaca vulgaris Lam., Platanus orientalis L. and Populus euramericana Guinier at 23: 28±1°c (night: day), 65±5 % RH and photoperiod of 16L: 8D. Results indicated that the relative consumption rate (RCR), relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD) and approximate digestibility (AD) were significantly different among hosts. The RCR on P. orientalis was significantly higher than J. regia, M alba and P. euramericana. RGR was the highest on M.alba, however, it was the lowest on A. vulgaris. ECl and ECD were the highest on M.alba. In contrast, AD was the lowest on M.alba. These results indicated a higher performance of the larvae fed on M.alba. There were significant differences among the hosts and the larvae preferred M.alba significantly than other hosts.

Prey-preference of the predatory bug, Orius albidipennis Reuter, with predation rate and prey preference tests on the basis of completely randomized design (CRD) and without the replacement of consumed prey was examined under laboratory conditions (25±1°C, 65±5% RH and L16: D8 photoperiod). Results of the predation rate test indicated that the predation of the female predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 14.8±1.46 and 20±0.7 respectively, showing a significant difference (P < 0.05) between them. In the prey-preference test, the preying of the female predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 8.4±0.84 and 4.4±0.22 respectively. The Manly preference index (a) of the 2nd larvae of onion thrips (prey I) and the female two-spotted spider mite (prey II) was 0.8±0.09 and 0.2±0.03 respectively, which demonstrated that the predatory bug more preferred the 2nd larvae of onion thrips than the two-spotted spider mite. Both tests were repeated for the male predatory bug in similar conditions. In the predation rate test, the results from the preying of the male predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 11±1.58 and 12±1.22 respectively, showing no significant difference. In the prey-preference test, consumption of the male predatory bug from the 2nd larvae of onion thrips was 3.3±0.13 and from the female two-spotted spider mite was 3.2±0.17. In this experiment, the Manly preference index (a) of the 2nd larvae of onion thrips (prey I) and the female two-spotted spider mite (prey II) was 0.52±0.03 and 0.48±0.05 respectively. According to these data, the male predatory bug showed no preference for either prey species.

During the study of parasitoids of leafminer flies, some parasitoid wasps belonging to the family Eulophidae, including Cirrospilus variegatus (Masi), Diglyphus isaea (Walker) and Hemiptarsenus zilahisebessi ErdÖs were collected and identified, of which C. variegatus is a new report for Iran. The latter species was reared from Liriomyza saliva Blanchard (Diptera: Agromyzidae) on cucumber in the glasshouses of Varamin, Tehran in April 2003, as well as an unidentified leaf miner fly from the same family on Tanacetum sp. in Shiraz in June 2004.

Nephus (Bipunctatus) bipunctatus (Kugelann) is a predator of Peliococcus kimmericus (Kiritshenko) (Hem.: Pseudococcidae) on Lactuca serriola L. in different parts of the Fars province,- Iran. Some parasitized larvae of this predaceous ladybird were collected, and two parasitoid wasps, Homalotylus jlaminius (Dalman) and H sinensis Xu & He (Hym.: Encyrtidae), reared nom these larvae in the laboratory conditions. These parasitoids, which are new records for Iran, were identified by Dr Zhihong Xu. Both species are solitary endoparasitoid and the relationship between them and their host are newly reported.

The specimens of the mealybug Peliococcus kimmericus (Kiritshenko) were collected on Lactuca serriola L. from different parts of the Fars province, Iran. Four parasitoid wasps, Anagyrus orbitalis (Ruschka), Leptomastix histrio Mayr, Cheiloneurus kollari (Mayr) and C. paralia (Walker) (Hym.: Encyrtidae), were reared from this mealybug and the identifications confirmed by Dr Zhihong Xu. The relationship between these parasitoids, which are new records for Iran, and their host are newly reported.

During the faunistic survey on the mites of Sorkhe-Hesar forest park, Tehran, many specimens were collected and identified, of which Evimirus uropodinus (Berlese) is recorded for the first time from Iran. The identification was confirmed by Dr. M. L. Moraza, Navarra University, Spain.