No abstract

The red palm weevil (RPW) Rhynchophorus fcrrugincus Oliver is an economically important pest of palm in Al-Hassa (Eastern Province of Saudi Arabia). The RPW was noted associated with mites during May--June 2009. Three mite species were found. One of which Aegyptus alhassa n. sp. (Gamasida, Trachyuropodidae) as a parasite collected from eggs, larvae, pupae cocoons and under the elytron of insect adult was described. The second mite species Sejus sp. may feed on fungi or organic debris, while the acarid hypopial stage may feed on dead insects.

Red palm weevil (RPW) is the most aggressive date palm parasite in the Middle East, and especially in the Gulf region. Originated in Southeast Asia, this pest has been detected in the entire Arabian Peninsula, North Africa, Italy, Latin America, and other territories. It is important to local from obtrusive species, which help augmenting the pest control strategies. In the present study we collected 21 RPW samples from 21 different locations in the Eastern Province, Saudi Arabia to genetically characterize them using RAPD- and ISSR-based clustering. Unweighted pair group method with arithmetic mean (UPGMA) for RAPD data categorized the 21 accessions into seven distinct groups, with Al-Oyonn and Juaymah each categorized in solitary group, meanwhile, UPGMA for ISSR indicated six different groups, with Battaliyah, Al-Oyoon, and Juaymah each assigned to a separate group. Combining RAPD and ISSR data revealed two accession; Al-Oyoon and Juaymah that might be considered obtrusive species. Based on distance calculations, we proposed that the potential origins of RPW collected from these locations are Iran and the United Arab Emirates. However, this assumption needs further studies for confirmation.

All tested bacteria and plant extracts proved larvicidal activity against third instar larvae of both mosquitoes Culex pipiens and Aedes caspius .Bacillus sphaericus, indigenous strain (dammam) showed higher activity against Cx. pipiens larvae, with LC50 = 0.35x10-7 ppm. Than to Ae. caspius (LC50= 4.5x10-7 ppm) .Bacillus thuringiensis H-14 (Bactimos) has higher toxicity against Ae. caspius, followed by Cx. pipiens (LC50=8.0x10-7 and 1.4x10-6 ppm respectively. Both mosquito larvae were susceptible to all tested native plant extracts,