Ahmad Abu Hassan

Physical trapping is an important first step in controlling pest populations and species identification; and bait preferences are crucial information for effective management. This study was conducted to explore species diversity and bait preferences of commensal species in urban areas on Penang Island. Live trapping was carried out in eight sampling sites on Penang Island in commercial and residential areas. Eight different type of baits were used; apple and peanut butter (APB), white bread and peanut butter (BPB), salted fish (SF), salted fish and peanut butter (SFPB), white bread and fish extract (BFE), fried chicken leftover (FCL), vegetables and peanut butter (VPB) and sausages (S). The most successful bait was the high protein bait, fried chicken leftover (FCL), with a capture success rate of 35.56%. We also analysed the bait preferences for the different species of small mammals captured in our study. Five species of small mammals were captured in our study sites: Rattus norvegicus, Rattus rattus, Mus musculus, Bandicota bengalensis and Suncus murinus. Norway rats, R. norvegicus was the most trapped species in commercial areas whereas lesser bandicoot rats, B. bengalensis was the most captured species in residential areas.

This study investigated the diet of introduced barn owls ( Tyto alba javanica , Gmelin) in the urban area of the Main Campus of Universiti Sains Malaysia, Penang, Malaysia, based on collected regurgitated pellets. We also compared the diet of introduced urban barn owls with the diet of barn owls from two agricultural areas, i.e. oil palm plantations and rice fields. Pellet analysis of barn owls introduced in the urban area showed that commensal Norway rats, Rattus norvegicus , made up the highest proportion of the diet (65.37% prey biomass) while common shrews, Suncus murinus were the second highest consumed prey (30.12% prey biomass). Common plantain squirrel, Callosciurus notatus , made up 4.45% of the diet while insects were taken in a relatively small amount (0.046% prey biomass). Introduced barn owls showed a preference for medium-sized prey, i.e. 40 to 120g (52.96% biomass and 38.71% total). In agricultural areas, Rattus argentiventer predominated the diet of barn owls (98.24% prey biomass) in rice fields while Malayan wood rats, Rattus tiomanicus , were the most consumed prey in oil palm plantations (99.5% prey biomass). Food niche breadth value was highest for barn owls introduced in an urban area with a value of 2.90, and 1.06 in rice fields and 1.22 in oil palm plantations. Our analysis reiterates the prey preference of barn owls in various landscapes for small mammals. Our results also indicate the suitability of utilizing barn owls as a biological control not only in agricultural areas, but also as a biological control agent for commensal rodent pests in urban areas.

The cases of dengue reported earlier in the late 1990s from the Kingdom of Saudi Arabia (KSA) occurred in the cities of Jeddah and Makkah. Although the kingdom has ample financial resources to establish effective control measures for the dengue vector, numerous cases of dengue occur and fluctuate in numbers from year to year. This necessitates a serious review of the current vector control strategies being practiced in order to identify the existing shortcomings. This short report provides an update on epidemiology of dengue in KSA (specifically in cities of Jeddah and Makkah) with a critical look at the current vector control strategies.

Mating is a physiological process of crucial importance underlying the size and maintenance of mosquito populations. In sterile and incompatible insect technologies (SIT and IIT), mating is essential for mass production, persistence, and success of released individuals, and is a central parameter for judging the effectiveness of SIT/IIT programs. Some mosquitoes have an enormous reproductive potential for both themselves and pathogens and mating may contribute to persistence of infection in nature. As Aedes albopictus can transmit flaviviruses both sexually and horizontally, and as infected insects are usually derived from laboratory colonies, we investigated the implications of mating between a long-term laboratory colony of Ae. albopictus and wild populations.

Background: Mosquito-borne viruses are transmitted to human hosts via blood-feeding behavior of female mosquitoes. Female mosquitoes seek a host to take blood meals (host-seeking behavior). In order to prevent virus infections, it is important to understand how they modulate host-seeking behavior. Dopamine (DA) in the central nervous system acts as a neuromediator that regulates a variety of behaviors in insects. In female mosquitoes, host-seeking behavior increases when DA levels in the head decline after emergence. However, it remains unclear whether DA directly modulates host-seeking behavior in female mosquitoes. The aim of this study was to examine whether changes in DA levels in the head affects host-seeking activity in the adult female mosquito Aedes albopictus (Ae. albopictus). Findings: We compared host-seeking behavior in one group of emerging female adults treated with l-β-3,4-dihydroxyphenylalanine (l-DOPA), the precursor of DA, (l-DOPA group), with that in an untreated control (control group) after confirming elevation of head DA in l-DOPA group by using high-performance liquid chromatography. The content of head DA in l-DOPA group significantly remained higher than that in controls on all days examined. The host-seeking activity in the control group showed a gradual increase over the 6-day experimental period. In contrast, there was no such increase in the host-seeking activity in the l-DOPA group. Therefore, the host-seeking activity of l-DOPA group was significantly lower than that of the controls between day 3 and 6 post-emergence. Conclusion: Our results indicate that elevation of DA level reduces host-seeking activity in adult female mosquito Ae. albopictus.

Flies attracted to human remains during death investigations were surveyed in north Peninsular Malaysia. Six families, eight genera, and 16 species were identified from human remains, with the greatest fly diversity occurring on remains recovered indoors. The total relative frequency of species was led by Chrysomya megacephala (Fabricius, 1794) (46%), followed by Chrysomya rufifacies (Macquart, 1842) (22%), Sarcophaga (Liopygia) ruficornis (Fabricius, 1974) (5%), Sarcophaga spp. (4%), Synthesiomyia nudiseta Wulp, 1883 (6%), Megaselia spp. (3%), Megaselia scalaris (Loew, 1866), (2%), Megaselia spiracularis Schmitz, 1938 (2%), and Chrysomya villeneuvi Patton, 1922 (2%). Hemipyrellia tagaliana (Bigot, 1877), Desmometopa sp., Megaselia curtineura (Brues, 1909), Hemipyrellia ligurriens Wiedemann 1830, Ophyra sp., Sarcophaga princeps Wiedemann 1830, Piophila casei (Linnaeus, 1758), and unidentified pupae each represented 1%, respectively.

A burned human remain was found outdoor (5 degrees 27' N, 100 degrees 16' E) in Penang Island. The deceased was last seen alive on 23 April 2010 at 2230 h and was found burned on 24 April 2010 at 1920 h. Larval aggregation of second instar Chrysomya megacephala was observed on the chest of the deceased.

The life history of the male and female of the indoor forensic fly, Synthesiomyia nudiseta was studied under fluctuating temperature of indoor environments and analysed based on the age-stage and two sex life table. The life cycle of S. nudiseta was 14.0 +/- 1.0 days from the egg stage to adult emergence. The population parameters calculated were; net reproduction rate (R-o=108.6), mean generation time (T-o=12.2), intrinsic rate of increase (r(m)=0.38), and finite rate of increase (lambda=1.46). The pre-oviposition period (APOP) was 6.0 +/- 0.1 days. All population parameters suggested that S. nudiseta exhibits the r-strategist characteristics.

A study was carried out to evaluate the incidence of termite attack on an Araucaria cunninghamii plantation at Teluk Bahang Forest Park (TBFP), Penang. The hilly plantation area was surveyed to determine the diversity of termite species present. Termite specimens were collected from standin Araucaria trees, underground monitoring (aggregation) stations, fallen logs, forest litter and mounds (nests). Seven species of termites were identified from 6 genera; Coptotermes curvignathus, Schedorhinotermes medioobscurus, Schedorhinotermes malaccensis, Odontotermes sarawakensis Parrhinotermes aequalis, Macrotermes malaccensis and Hospitalitermes hospitalis. A total of 289 Araucaria trees were inspected for signs of termite attack. Termite infestation of trees was determined mainly by the presence of mud on the trunk, but particularly around their butts at ground line. The most dominant termite species discovered infesting the Araucaria trees was Coptotermes curvignathus; accountable for 74% of all infestations. Schedorhinotermes medioobscurus and Odontotermes sarawakensis were commonly found infesting dead trees and/or tree stumps. Approximately 21.5% of all Araucaria trees in the plantation forest at Teluk Bahang were infested by termites.

Phlebotomine sand flies were collected using CO2 baited CDC light trap in 2000 and 2001 in limestone areas and caves of western Malaysia. A total of 1,548 specimens were collected comprising 18 species from two genera: Phlebotomus (6 spp) and Sergentomyia (12 spp). Phlebotomus major major (38.9%) was the predominant species followed by Sergentomyia perturbans (20.1%), P. stantoni (15.3%) and others. Biting activity of the sand flies at the Gua Senyum caves, Gua Kota Gelanggi, Batu caves and Gua Kelam were observed using the bare leg landing catch (BLC) technique. Four Phlebotomus spp at Gua Senyum were found to bite humans with a unimodal biting peak (between 01:00 and 04:00 AM). At Gua Kota Gelanggi P. major major was observed to bite humans, but at Batu Caves and Gua Kelam no sand flies were observed to bite humans. Sergentomyia spp did not feed on humans even though high numbers were caught in light traps. The populations of phleobotomine sand flies fluctuated, with several peaks especially among P. major major which peaked in December and was low in February and August. Phlebotomus stantoni was abundant throughout 2001. Most species populations were weakly related to rainfall because they inhabited caves.