فصلنامه تحقیقات حشره شناسی
پیاپی 4 (زمستان 1388)

Oligonychus afrasiaticus (McGregor)is an important date palm pest orchard in Iran and other date growing in the world. Direct mite incidence along feeding on date fruit caused 100% losses on commercial date varieties. Chemical date palm spider mite (DPSM) control initiated in 1960 in southwestern part of Iran through Tetradifen application and today extended in large date orchards in the country. Water spray application on DPSM under taken through block randomized designed with four replications during period of 2000-2001 on date varieties i.e. Mordarsangh, Kabkab, Berhi, Mazafati, Halileh in Hormozghan, Bushehr, Khuzestan, Kerman and Sistan and Baluchestan provinces of Iran respectively. Amount of 8 to 10 little water spray with help of concern instrument during late morning hours. The mobile mite mortality% was evaluated through Henderson–Tilton method by collecting 20 date fruits which two date clusters selected randomly from each replication and counted with help of stereo-microscope. Mite sampling followed at interval of one day before, 3, 7, 14 and 25 days after treatments. Light copious webbing around date clusters observed in late April in Kuzestan province and this type of injuries recorded after three months interval (July) on date palm's of Sistan and Baluchestan provinces in south eastern part of country. Mean date palm infested by DPSM was found higher in year of 2001 in comparison of the first year study. Max & min mean of mite's densities on a date fruit recorded 14.9 and 2.08 mites on Kabkab and Berhi var. in Bushehr and Kuzestan respectively while Halileh var. in Sistan and Baluchestan province possess higher number of mite during two years of investigation. Mean of mite mortality% statistically observed significant at level of 5% during sampling period with maximum control of mite at seven days interval whereas longer effects of water spray recorded up to 25 days in Kerman province. Two years mite mortalities% analysis result over 90% mite control in date orchards of Khuzestan, Hormozgan and Kerman provinces during first and second year respectively. Max water spray effect can expected when mean of mite on a date fruit was recorded below three mites with three consequent spray at 7 to 10 days interval which make possible organic date production in Iran with regard further mite resistance and hazardous of pesticides to the environment.

The Indian meal moth, Plodia interpunctella (Hübner) (Lep., Pyralidae) is one of the serious pests of stored date in Iran and many parts of the world. Biology of this pest on three cultivars of date was studied. The experiments were conducted in laboratory conditions at temperature of 27±2 ºC, 45±5% relative humidity and a photoperiod of 16L:8D hours. Mean incubation period were estimated 3.10, 3.27 and 2.67 days respectively and mean larval developmental time were estimated 37.85, 43.01 and 48.0 days on Zahedi, Shahabi and Kabkab cultivars respectively. There was significant difference between mean larval developmental time and incubation period on different cultivars. Mean period of pupa on Zahedi, Shahabi and Kabkab cultivars were estimated 7.47, 8.01 and 7.19 days respectively. No significant difference was observed between mean period of pupa moths developed in Zahedi and Kabkab cultivars but pupal period was significantly different on Shahabi cultivars. Mean adult longevity on Zahedi, Shahabi and Kabkab cultivars were estimated 8.04, 8.37 and 7.72 days respectively. There was no significant difference between mean adult longevity on different cultivars of date.

The effect of different temperatures, 20, 25 and 30Cº on each stage duration of the coccinellids Hippodamia variegate Goeze was studied under laboratory conditions, feeding on A. fabae. The threshold temperatures and constant degree day requirement for each stage were also calculated using linear regression. The development periods from egg to adult were 27.75, 21.3 and 15.4 days in 20, 25 and 30Cº. The threshold temperatures ranged from 2.47 for the first instar larvae to 14.63 for the pupae. However, the threshold temperatures and thermal constant for whole generation from egg to adult were 7.93 with ±1 range feeding on A. fabae Scopoli, 65±5 RH and 16:8 (L:D) photoperiod. Under laboratory conditions at 20±1, 25±1 and 30±1Cº developmental period from egg to adult lasted 27.75, 21.35 and 15.40 days respectively. The minimum thermal developmental threshold ranged from 2.47 and 14.63 for 1st larval instar and pupa, respectively. However, the minimum temperature growth threshold from egg to adult stage was 7.93 Cº and 346.4 DD.

The red flour beetle, Tribolium castaneum Hbst., is an important pest of food processing facilities world wide. The use of elevated temperatures or heat treatments is a very effective method for managing of stored pests. In this study, the mortality of pest in 5 constant temperatures, including 35, 45, 50, 55 and 60°C at times 5, 10, 15, 20 and 30 minutes on different growth stages (5-days larvae, 15-days larvae, pupae and adult of T. castaneum) were determined. Insects after heating, at temperatures of 28±1°C and relative humidity 65±5% were maintained. The results showed that, the most sensitive and resistant stages were 15-days larvae and pupal stages, respectively. It also revealed that the minimum temperature controller for 5-days larvae, 15-days larvae, pupal and adults stages were 55, 50, 55 and 50°C, respectively. Therefore, considering the possible all growth stages in an infected mass, 15°C temperature in 55 minutes, can be effective for control of all pest growth stages.

The pod borer, Heliothis viriplaca Hufn., is one of the most serious pests of chickpea in the Middle East countries. For the life cycle studies, determination of different larval stages and other behavioral activity, the pupae were collected from cultivated fields and reared under laboratory conditions (25±2°C, %70±5 RH and 14/10 L:D). The laboratory test showed that this pest has one generation per year with obligate diapause. By measuring of head capsule width determined five larvae instars for the pest, with the ranges of 0.423, 0.699, 1.29, 1.84 and 2.64 mm respectively. It has been also indicated that larvae have high cannibalistic tendency under unsuitable conditions so that the larger larvae feed on other small larvae and prepupation stage. In addition the laboratory trials revealed that although all pupae held in 2±1°C condition for 30 days emerged, average oviposition of females decreased and most of the eggs did not hatch.

The encyrtid parasitoids (Hym., Encyrtidae) of scale insects (Hem., Coccoidea) were investigated during 2008 in some parts of Lorestan and Markazi provinces. A total of eleven species were collected and identified. According to the available literature, two species which marked with an asterisk are reported for the first time from Iran: Blastothrix sericea (Dalman, 1820) Discodes coccophagus (Ratzeburg, 1848) Encyrtus aurantii (Geoffory, 1785) Microterys cuprinus (Nikolskaya, 1952)* Microterys hortulanus Erdos, 1956 Cheiloneurus claviger Thomson, 1876 Habrolepis dalamanii (Westwood, 1837) Zaomma lambinus (Walker, 1837) Metaphycus lounsburyi (Howard, 1898) Metaphycus chermis (Fonscolombe, 1832)* Metaphycus sp. Morphological characters, host range and geographical distribution of the two new species from Iran have been presented and discussed.

In this study the biological parameters (life table, reproduction, population growth rate) of the predatory bug Orius albidipennis Rueter (Hem., Anthocoridae) were studied on Tetranychus urticae Koch reared on three cultivars of soybean. The experiments conducts in laboratory conditions at 25 ± 1oC, % 65 ± 5 relative humidity and a photoperiod of 16:8 hours (L:D). There were no significant differences between mean incubation period and mean preimaginal developmental times on three cultivars of soybean. On three soybean cultivars, the females develpopmental time were higher than males. Net reproducation rate (R0), the intrinsic rate of increase (Rm), finite rate of increase (λ), mean generation time (T) and dubling time (DT) for O. albidipennis calculated were on Gorgan3, 7.14, 0.08, 1.09, 22.44 and 7.89 respectively and on DPX 9.68, 0.09, 1.10, 22.87 and 6.96 respectively and on Williams 3.65, 0.05, 1.05, 22.30 and 11.88 respectively.

The paper deals with the some of the more important parasitic mites associated with honeybees. Varroa destructor Anderson and Trueman is worldwide and the most familiar and destructive of the bee mites, causing death and damage to large numbers of honeybees. Known from Asia, the tropical bee mites Tropilaelaps clareae Delfinado and Baker and T. koenigerum Delfinado Baker and Baker, are spreading and are a potential threat to bee keepers in many parts of the world. Two new species of Tropilaelaps have recently been described. Acarapis woodi Rennie, known as the honeybee tracheal mite (H.B.T.M.) reduces the resistance of bees to other parasites and diseases, shortens the life cycle and in heavy infestations can block the tracheae of bees.