In this study, a preliminary virulence test on three concentrations (1 × 106, 1 × 107 and 1 × 108 conidial spore ml-1) of the aqueous conidial suspension of the four entomopathogenic fungi isolates, Beauveria bassiana IMI 382302, Beauveria bassiana IMI 386701, Trichoderma harzianum T24 and Aspergillus flavus Link was carried out against both larval and pupal stages of Spodoptera littoralis within 5 days post-treatment. T. harzianum T24 showed 80% larval mortality only when applied at its highest conidial concentration (1 × 108/ conidial spore ml-1), while A.

Great efforts are currently being done to utilize the immune system of mosquito vectors in the battle against the different mosquito-borne parasitic and viral diseases. Based on this control strategy, the current study has been conducted to induce and enhance the most effective immune responses, the humoral and melanization responses, in the dengue fever vector, Aedes aegypti against live bacteria and non-biological agents at 24h post-treatments.

Insects have developed an efficient defence system against microorganisms, which involves both humoral and cellular mechanisms. Recent studies on insect defence system are aimed at utilizing it in the battle against mosquito-borne diseases. However, mounting immune responses of insects has proved to impose fitness costs. The current study was conducted to test the costs of enhancing the immune responses of Aedes caspius by oral administration of thymoquinone, the active ingredient of the black seed oil, Nigella sativa L. (Ranunculaceae).

In Ar-Riyadh Region in the Kingdom of Saudi Arabia (KSA), the Governorates of Al-Zulfi, Al-Ghat and Al-Majmah (north zone), of Al-Hariq, Al-Aflaj and Hawtat Bani Tamim (south zone), of Hijrat Sa`ad (east zone), of Shaqra, Durma, Al-Qasab, Huraimela`a (west zone) and Riyadh City (central zone) were surveyed for the presence of Pachycondyla sennaarensis monthly during the period from December 2007 to December 2009. The ant was not detected in Al-Majmah or Al-Zulfi.

The major volatile compounds in the poison glands of two Monomorium ant species from
Saudi Arabia have been identified. Monomorium niloticum and Monomorium najrane both
contain mixtures of alkyl- and alkenyl-pyrrolidines and -pyrrolines in their venom glands
but no Dufour gland volatile compounds were detected. Monomoriummayri showed neither
Dufour gland compounds nor venom components detectable by gas chromatography.

Ant species use branching networks of pheromone trails for orientation between nest and
resources. The current study demonstrated that workers of the venomous samsum ant,
Pachycondyla sennaarensis (Mayr) (Hymenoptera: Formicidae), employ recruitment trail
pheromones discharged from the Dufour’s gland. Secretions of other abdomen complex glands,
as well as hindgut gland secretions, did not evoke trail following. The optimum concentration of
trail pheromone was found to be 0.1 gland equivalent/40 cm trail. This concentration

Black ant (Samsum), Pachycodyla sennarrensis, stings and injects venom and inflicts allergy (a rare clinical problem) due to its local and systemic reaction, which is considered as a health hazard amongst Saudi society. Thus, black ant is a source of serious concern for the government and experts as well. Ultramorphological variations, distribution, differential sensillae counts (DSC) and total sensillae counts (TSC), were identified and estimated as a complementary part of the peripheral nervous system on the antennae of worker samsum ant, P.