New in Aphids from Saudi Arabia

Aphid survey has been conducted since 1988 to April, 1997. Aphids were collected from colonies and were mounted on microscopic slides for identification. The purpose of this report is to mainpulate the new in aphids recorded for the first time in the world. Arabian Peninsula and Saudi Arabia. Two new species were found in Asir region. Sitobion asirun was collected from upper leaf surface of Phragmanthera regularis and Pseudaphis arabica from Pennisetum setaceum. Aloe vera was recorded as a new host for A. gossypii and A. craccivora. Prosopis sp. was recorded as a new host for Brachyungius harmalae . P. regularis was recorded as a new host for A. gossypii. Five aphid species were recorded for the first time in the Arabian Peninsula. These aphids are: Aphis armoraciae, A. hellerislambersi, Dysaphis emicis, Hyalopterus amygdali, Paraschizaphis rozazevedoi. Fourteen aphid species were recorded for the first time in Saudi Arabia: A. solanella, A. affinis, Hyalopterus pruni, Schizaphis rotundiventris, Acyrthosiphon kondoi, Aulacorthum solani, Brachycaudus rumexicolens, Dysaphis apiifolia, D. foeniculus, Metopolophium festucae cerealium, Nasonovia ribis-nigri, Sitobion fragariae, Cinara maghrebica, Peterochloroides persicae. Oviviparous females of Lipaphis erysimi were recorded for the first time in Saudi Arabia

Efficacy of Gamma Irradiation Against Sitophilus granarius L. ( Coleoptera : Curculionidae )

The lethal and sterilizing responses to gamma irradiation of eggs, larvae, pupa, and three-day and four-week old adults of Sitophilus granarius were investigated. Doses were 0, 10, 30, 50, 70, 100, 300 and 500 Gy. Eggs and larvae were unable to develop to adults following doses of 30-500 Gy. Emergence of adults from irradiated eggs and larvae occurred at a dose of 10 Gy. Pupae developed to the adult stage following doses of 10-70 Gy. A dose of 70 Gy at the pupal and four-week old adult stages caused sterility. Three-day old adults were most tolerant of irradiation and required 100 Gy for sterility. The percentage of damage to wheat grains caused by preadult stages following various irradiation doses was determined

Use of Radiation Disinfestation in the Control of Oryzaephilus surinamenesis L. : a Pest of Stored Dry Dates

A preliminary biological study of Oryzaephilus surinamenesis was conducted to determine the duration of preadult stages. The lethal and sterilizing effects of gamma radiation on eggs, larvae, pupae, three-day and four-week old adults of O. surinamenesis were investigated. Doses were 0.0, 0.1, 0.3, 0.5, 0.7, and 1.0 kGY. Eggs and larvae were unable to develop to adults at any dose. Pupae were able to reach adult stage at doses of 0.1 – 1.0 kGy but adults emerged from irradiated pupae failed to produce progeny. Three-day old adults were most tolerant of irradiation but a complete sterility occurred at doses of 0.3 kGy and above. These results indicate that a commercial irradiation treatment at a dose of 0.3 kGy should effectively disinfest stored dates against this pest

Patterns of arthropod abundance and diversity in an Arabian desert

We captured desert arthropods from sand and gravel substrates at five coastal or inland locations in Abu Dhabi around the new moon once every 28 days for two years. Three replicated lines of 20 unbaited pitfall traps were used from two hours before dusk until two hours after dawn. We examined the data for spatial and temporal variation, especially in relation to climate. Around 53 400 arthropods were caught, 97.3% being insects and the rest arachnids. Ants were most common (75.4%), followed by the Thysanura (12%), Coleoptera (8.4%), Araneae (1.5%) and Scorpiones (1.1%). Catches differed significantly among sites, substrates and time of year. In general, the number of arthropods caught matched the annual temperature cycle. Peak catches also followed the annual rains. Summer catches were higher at coastal than inland sites. Fewer arthropods were caught at gravel sites than on sand, but the number of taxa did not differ consistently between substrates. Community composition was generally less similar among sites than between substrates although this was not always the case. Inland communities had fewer taxa and generally fewer individuals than those near the coast. Isoptera, Tettigoniidae and Carabidae occurred less frequently (if at all) inland. We suggest that the higher humidity at sites near the coast allows more taxa to occur and to remain active during the extreme heat of summer. Further into the Empty Quarter we would expect a decline in the number of taxa and in the total catch