Mohammad Ali Al-Deeb

Effect of Bait Quantity and Trap Color on the Trapping Efficacy of the Pheromone Trap for the Red Palm Weevil, Rhynchophorus ferrugineus

Abstract The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Curculionidae: Coleoptera), is not native to the United Arab Emirates (UAE). Since its arrival in 1985, it has been causing major damage to date palm trees. A primary control strategy has been the use of pheromone baited traps. The objectives of this study were to determine the quantity of bait, and the best trap color, to obtain the maximum catch of R. ferrugineus under field conditions in the UAE. Traps with 100, 300, or 500 g of dates as bait collected the same number of R. ferrugineus adults. Captures in black traps were significantly higher than captures in red, yellow, or white traps. Thus, using a black pheromone trap containing 100 g of dates can significantly enhance R. ferrugineus control efforts, and can help considerably in reducing the red palm weevils deleterious impact on date palm production in UAE.

Interactions between Phoretic Mites and the Arabian Rhinoceros Beetle, Oryctes agamemnon arabicus

Abstract Oryctes agamemnon arabicus (Coleoptera: Scarabaeidae) is one of the main pests on date palm trees in the United Arab Emirates (UAE). Two mite species were found associated with this beetle: Sancassania sp. (Acari: Astigmata: Acaridae) and Hypoaspis rhinocerotis Oudemans (Acari: Mesostigmata: Laelapidae). Sancassania deutonymphs (hypopi) were phoretic on O. a. arabicus adults and larvae. However, they were also necromenic, because once the host dies they feed on its carcass. The highest deutonymph load was found in the subelytral space of O. a. arabicus adult. The phoretic and necromenic interactions between Sancassania sp. and O. a. arabicus need to be investigated in more detail. H. rhinocerotis was recorded for the first time in UAE. Its role has not yet been studied in the date palm agricultural ecosystem.

Use of Light Traps and Differing Light Color to Investigate Seasonal Abundance of the Date Palm Pest, Oryctes agamemnon arabicus (Coleoptera: Scarabaeidae)

ABSTRACT Oryctes agamemnon arabicus (Fairmaire) (Coleoptera: Scarabaeidae) is a date palm insect pest that causes damage to trunk and roots and can damage grass lawns in the United Arab Emirates (UAE) and other countries such as Oman, Saudi Arabia, and Tunisia. The goal of this study was to monitor population dynamics and to evaluate six light colors (white, green, red, yellow, blue, and infrared) and two lamp types (mercury and energy-saving) in light traps. Experiments were performed on a date palm farm during a 2 yr period (2010 and 2011). It was found that this insect is a univoltine pest with a single population peak. Adults appeared in the field around middle of April and early May and the population continued to build until maximum numbers were reached in mid June. No adults were found after the end of September. Photoperiod showed a significant correlation with the changes in adult population size. White light emitted from mercury lamps attracted significantly more O. agamemnon arabicus adults compared with the other tested light colors. Increasing the wattage of mercury lamps from 160 to 250 watt did not significantly increase the number of collected insects. The results demonstrated that light traps equipped with 160-watt mercury lamps emitting white light collected significantly the highest number of this insect among the other tested lamps.

DISTRIBUTION AND ABUNDANCE OF PHORETIC MITES (ASTIGMATA, MESOSTIGMATA) ON RHYNCHOPHORUS FERRUGINEUS (COLEOPTERA: CURCULIONIDAE)

ABSTRACT The red palm weevil, Rhynchophorus ferrugineus Olivier, is the most important insect pest on date palms. Weevils were collected from randomly selected infested date palms in Al Ain, United Arab Emirates (UAE). Mites from three families were recorded. Uroobovella sp. (Acari: Urodinychidae) were the most common phoretic mites. Curculanoetus sp. (Acari: Histiostomatidae) were second in abundance. Uropoda orbicularis (Acari: Uropodidae) was recorded on one beetle. The abundance of phoretic mites varied among body parts of R. ferrugineus, and the maximum numbers occurred in the subelytral space. The mean intensity, mean abundance, and prevalence of Uroobovella and Curculanoetus mites did not differ between male and female weevils. Uroobovella had significantly greater mean intensity, abundance and prevalence compared to Curculanoetus. Most Uroobovella and Curculanoetus aggregated under the sublytral space, which presumably offers protection from the hot and dry environment. This study is the first to document the presence of phoretic mites on R. ferrugineus in UAE and will help to direct future research on their interactions.

Dynastid Beetle Pests

Two main species of dynastid or rhinoceros beetle (Coleoptera: Scarabaeoidea: Scarabaeidae: Dynastinae: Tribe Oryctini) Oryctes elegans, and subspecies of Oryctes agamemnon, attack date palms causing significant and documented damage. Adults of O. elegans bore into the stalks of inflorescences and fruit bunches to feed, and oviposit in leaf axils where the larvae develop and may invade the trunk. Oryctes agamemnon larvae bore into frond bases, the trunk, and respiratory roots where their tunnelling may cause the palm to fall. It is difficult to distinguish the larvae of the two species in regions where both coexist. For control, annual servicing of palms includes cutting off old fronds at their bases using the correct technique which enables removal of larvae and their breeding places, and this may be integrated with light trapping for catching adults. Quarantine measures may hinder the spread of these pests to uninfested areas. In India, adults of a third species, O. rhinoceros, have been noted boring into the soft tissue of the growing point, and this species has also been reported from Yemen. Pheromone trapping is available for O. elegans but for effectiveness it requires the addition of fresh date palm tissue to the traps as a synergist. The entomopathogenic fungus Metarhizium anisopliae and the nematode Rhabditis sp. may have potential in integrated pest management but their possible natural occurrence in an area should be determined, prior to propagation and release. The pathogenic Oryctes Nudivirus, was successful against Oryctes rhinoceros in lowering its populations and damage to coconut palms when introduced into areas where this virus did not previously exist, and should be tested against date palm dynastids. Oryctes agamemnon and O. elegans adults attacking date palms do not appear to bore into the heart or meristem causing V-cuts to unfurling fronds or the death of the palm, in contrast to attacks by O. rhinoceros on coconut and young oil palms. Also O. rhinoceros larvae are found only in dead decomposing wood or other organic material, whereas larvae of date palm pests O. elegans and O. agamemnon may tunnel in living tissues.

First Record of a Spotted Fever Group Rickettsia sp. and Theileria annulata in Hyalomma dromedarii (Acari: Ixodidae) Ticks in the United Arab Emirates

Abstract Rickettsiosis and theileriosis can cause mortalities in camel populations. This study was conducted to achieve 2 objectives: (1) to detect the presence of SFG Rickettsia sp. and Theileria sp. in Hyalomma dromedarii Koch, 1844 (Acari: Ixodidae) ticks and (2) to determine their prevalence in the tick population on the sampled camel farms in Al-Ain, United Arab Emirates (UAE). Camel ticks (H. dromedarii) were collected from a total of 625 one-humped camels (Camelus dromedarius) in 22 sampling locations in Al-Ain, UAE. Tick samples were analyzed by Polymerase Chain Reaction (PCR). An SFG Rickettsia sp., which was 99% similar to Candidatus ‘Rickettsia andeanae’ and Rickettsia endosymbionts, was detected only in 2011 and its prevalence in the sampled ticks was 1.12%, while Theileria annulata was detected in both years with a prevalence of 2.3% and 1.60%, respectively. Additionally, T. annulata was present in all of the sampling zones (east, west, north, and south) of the study area, whereas SFG Rickettsia sp. was limited to 2 zones only (east and south). The geographic distributions of SFG Rickettsia sp. and T. annulata showed no overlap throughout the entire study area except in one location in which both of the disease agents were present. This study is the first published record on the presence of SFG Rickettsia sp. and T. annulata in camel ticks in the UAE. In addition, the current study should serve as a foundation for more studies leading to a better understanding of the reservoir potential of camels and the risk posed by these 2 disease agents to camels and other livestock.

Longhorn Stem Borer and Frond Borer of Date Palm

Date palm trees are attacked by the longhorn date palm stem borer, Jebusaea hammerschmidtii, and the frond borer, Phonapate frontalis in several countries. The frond borer is not a major economic pest of date palm trees, however, the larvae of J. hammerschmidtii cause severe damage by boring and feeding on plant tissues, which leads to infection by pathogens and also breaking of fronds and trunks. Both the larvae and adults of P. frontalis cause damage by feeding on green fronds and the infestation by this pest results in either the breaking or the gradual drying of the frond. Management of J. hammerschmidtii relies mainly on the use of light traps, which attract the male and female adults at night, and can be used successfully for monitoring and mass trapping. Moreover, balanced and adequate irrigation as well as proper fertilization of date palm trees appear to be important factors in reducing the infestation levels. Similarly, light traps were found to be highly efficient in attracting the adults of P. frontalis. Other methods such as biological and chemical control are also effective against J. hammerschmidtii and P. frontalis.