How deep is deep enough? Analysis of sea turtle eggs nest relocation procedure at Chagar Hutang Turtle Sanctuary.

Sea turtle eggs incubation involves natural and artificial incubation of eggs, and indeed the depth will be varied and presumably affect the development of hatchlings. For nest relocation, the researcher needs to decide on the depth to incubate the eggs. Sea turtle eggs clutches may vary between 40 and 120 eggs for the green turtle, thus using a single value as the standard procedure might affect the quality of hatchlings. Here we quantify the dimension of the natural (in-situ) nest constructed by the nester and the artificial (ex-situ) built by our ranger during nest relocation. We suggest a linear regression calculation of Y = 0.2366X + 59.3267, better predict a more accurate nest depth based on the number of eggs to imitate the natural nest.

Can plants fool artificial intelligence? Using machine learning to compare between bee orchids and bees.

Bee orchids have long been an excellent example of how dishonest signal works in plant-animal interaction. Many studies compared the flower structures that resemble female bees, leading toward pseudo-copulation of the male bees on the flower. Using Machine Learning, we tested whether nature is capable of besting artificial intelligence. A total of 2000 images of related bees, wasps, and Ophrys sp. were collected from the Google Image Repository. Unsuitable images were later filtered out manually, leaving a total of 995 images in the final selection. 80% of these images were used to build a supervised model using Logistic Regression, while the model accuracy was tested using 20% of the remaining images. Based on our results using Wolfram Mathematica, the Ophrys is not capable of fooling artificial intelligence. The accuracy, accuracy baseline, mean cross-entropy, Area Under ROC (receiver operating characteristic curve) curve (AUC) and the confusion matrix gave excellent image classification. However, we can now show the key points and highlights of the images and how the structures closely resemble actual bees using the SURF method. Rather than just a descriptive method, ML learning has enabled a more quantitative approach. Since this is a simple test, we encourage other scientists to adopt our approach using a larger dataset and better database samples.

Rattan spines as deterrence? A spinescence study on different species of rattans.

Rattan spines are most often regarded as an identification trait and perhaps as a physical protection structure. In this study, we study the spinescence traits from five different species rattan: Daemonorops lewisiana, Daemonorops geniculata, Calamus castaneus, Plectomia griffithii, and Korthalsia scortechinii. We tested length, width, angle, strength, spine density, cross-section surface, spine color, and leaf trichomes (only for D. lewisiana, C. castaneus and D. geniculata). We also tested whether the spines were capable of deterring small climbing mammals (for Plectomia griffithii and Calamus castaneus) by using a choice selection experiment. Due to a variety of spine traits, we could not categorize whether any species is more or less spinescent than the others. We suggest that spines have a much more significant role than merely as a physical defense and work together with other rattan characteristics. This is also evidenced by our choice selection experiment, in which the spines on a single stem donot deter small climbing mammals. However, this is a work in progress, and we have outlined several alternative methods to be used in future work.

Rattan litter-collecting structures attract nest-building and defending ants.

Rattan is an important climbing palm taxon in Malaysian tropical rain forests. Many rattan species have unique structures directly associated with certain ant species. In this study, four rattan species (Daemonorops lewisiana, Calamus castaneus, Daemonorops geniculata and Korthalsia scortechinii) were inspected and documented in a field survey concerning their relationships with several ant species. We noticed that two rattan species (D. lewisiana and C. castaneus) were more likely to be associated with ants compared to their neighbouring rattan (Plectomia griffithii). However, D. lewisiana and C. castaneus did not directly provide shelters for ant colonies, but possessed unique structures: upward-pointing spines and funnel-shaped leaves, which are equipped to collect more litter than P. griffithii. To test our litter collecting hypothesis, we measured the inclination of spines from the stem. Our results showed the presence of ant colonies in the litter-collecting rattans (D. lewisiana and C. castaneus), which was significantly higher compared to a non-litter-collecting rattan (P. griffithii). We propose a complex and novel type of adaptation (litter-collection and provision of nesting materials) for rattans, which promotes interactions between the rattan and ants through the arrangements of leaves, leaflets, and spines. In return, the rattan may benefit from ants' services, such as protection, nutrient enhancement, and pollination.

General Perceptions and Awareness Level among Local Residents in Penang Island toward Bats Conservation Efforts.

The population of bats has declined from year to year caused by human activities such as logging and hunting activities. Since the human factor is linked to the issues of population decline in many animal species, a community-based conservation strategy that involved local communities is needed. We conducted face-to-face surveys among residents in Penang Island to assess knowledge and awareness level toward bats conservation efforts. We collected demographic values such as age, gender, level of education, length of residency as well as their monthly income, since different group in these variable might have different perception. We found that age groups, level of education and monthly income have shown significant differences among the respondents. However, no other significant differences were indicated for by gender and length of residency. Respondent's knowledge of bats showed that the majority of the respondents were less likely to value the importance of bats in the ecosystem. We recommended stronger legal system, earlier exposure towards environmental education, well-planned urbanisation implementation and long-term monitoring programs to strengthen efforts in conserving bats in Malaysia.

Some Biological Aspects of Bigeye Scad, Selar crumenophthalmus from Bangaa Faru, Maldives.

In this paper, we studied some biological aspects of big eye scad (Selar crumenophthalmus) from Maldives. The fish sample was collected from the local fish market at Bangaa Faru, Male, Maldives. The length of the samples were ranged from 7.7 cm to 24.5 cm (mean value = 16.85 ± 2.82 cm) in fork length. Body weight ranged between 8 g to 255.6 g (mean value = 87.76 ± 40.41 g). The exponent values (b slope) of lengthweight relationship of S. crumenophthalmus are 2.9838 for females and 2.7687 for males; indicating negative allometric growth pattern for both sexes. Synchronous reproductive behaviour was observed in both sexes and a pronounced peak of Gonadosomatic index was observed in females in January 2013. It is estimated that length at first maturity (L50) for females is at 19.39 cm FL and for males at 21.76 cm FL. Our result also suggest that big eye scad have a reduced swimming capability, resulting the species to be easily caught. Careful planning and management should be implemented to prevent the big eye scad from being overfished.

Presence of a predator image in potential breeding sites and oviposition responses of a dengue vector.

In dengue vector control, attempts to minimize or replace the use of pesticides have mostly involved use of predators, but success has been severely impeded by difficulties associated with financial and environmental costs, predator mass production, and persistence in target habitats. Visual deterrents have been used successfully to control animal pests, in some cases in an effort to replace pesticide use. Despite evidence that visual signals are crucial in site choice for egg deposition by dengue vectors, and that female mosquitoes respond to artificial predation, the role of predator intimidation as it affects the oviposition behavior of dengue vectors remains largely unexplored. Here, we examined the oviposition responses of Aedes aegypti exposed to various mosquito predator pictures. Gravid females were presented with equal opportunities to oviposit in two cups with predator images [Toxorhynchites splendens-TXI, Goldfish (Carassius auratus)-small (SFI) and large (LFI) and Tx. splendens+Goldfish-TXFI] and two others without pictures. Differences in egg deposition were examined between sites with and without these images. When given a chance to oviposit in cups with and without TXI, Ae. aegypti females were similarly attracted to both sites. When provided an opportunity to oviposit in cups displaying pictures of fish (SFI or LFI) and blank cups, egg deposition rates were much lower in the fish picture sites. Females showed a preference for blank cups over TXFI for egg deposition. They also equally avoided cups with pictures of fish, regardless of the size of the picture. Our results indicate that the presence of images of goldfish and their association with Tx. larvae significantly reduced egg deposition by Ae. aegypti, and this was not the case with the predatory larvae alone. The observations that the images of natural predators can repel gravid females of a dengue vector provide novel possibilities to develop effective and inexpensive alternative tools to harmful insecticides.

The dual defensive strategy of Amorphophallus throughout its ontogeny.

Amorphophallus bufo is a rarely studied plant in Malaysian tropical rainforests. We measured the spectral reflectance of different developmental stages of A. bufo (seedlings, juveniles and adults), background soil/ debris and leaves from other neighboring plant species. Results show that the leaves of A. bufo seedling have a similar reflectance curve as the background soil and debris. Adults and juveniles of A. bufo are similar to other neighboring plants' leaf colors. We hypothesize that the cryptic coloration of A. bufo seedlings plays an important role in camouflage and that the numerous black spots on the surface of the petioles and rachises, may serve as a defensive mimicry against herbivores.

Attraction factors for Paederus fuscipes ' dispersal, a vector of Paederus dermatitis towards human residential premises.

Paederus fuscipes, a vector of Paederus dermatitis in most tropical and subtropical countries of the world have a high prevalence in human dwellings due to their positively phototaxic behaviour which has caused a tremendous impact on human health. In this paper, P. fuscipes dispersal flights were studied for two seasons of the rice cultivation phases in residential premises built close to rice field areas (≈32-60 m and 164 m) in mainland Penang, Malaysia. We examined the effects of different light illuminance, building floor level and their association with rice stages as a focal cause of P. fuscipes dispersion from the rice fields towards human dwellings. The present study showed a significant interaction between different light illuminances and rice cultivation phases in attracting P. fuscipes to disperse and invade human dwellings. The highest number of P. fuscipes was captured near the bright light. P. fuscipes flights increased in line with each floor level, and the highest captures took place at higher building floor levels (levels 2 and 3) compared to lower building floor levels (ground floor and level 1) of a three storey apartment in both rice seasons. This finding not only conveys a better understanding on P. fuscipes dispersal pattern, but also draws public attention on the occurrence of dermatitis linearis caused by the Paederus beetles.

Attraction factors for Paederus fuscipes ' dispersal, a vector of Paederus dermatitis towards human residential premises

ABSTRACT Paederus fuscipes, a vector of Paederus dermatitis in most tropical and subtropical countries of the world have a high prevalence in human dwellings due to their positively phototaxic behaviour which has caused a tremendous impact on human health. In this paper, P. fuscipes dispersal flights were studied for two seasons of the rice cultivation phases in residential premises built close to rice field areas (≈32-60 m and 164 m) in mainland Penang, Malaysia. We examined the effects of different light illuminance, building floor level and their association with rice stages as a focal cause of P. fuscipes dispersion from the rice fields towards human dwellings. The present study showed a significant interaction between different light illuminances and rice cultivation phases in attracting P. fuscipes to disperse and invade human dwellings. The highest number of P. fuscipes was captured near the bright light. P. fuscipes flights increased in line with each floor level, and the highest captures took place at higher building floor levels (levels 2 and 3) compared to lower building floor levels (ground floor and level 1) of a three storey apartment in both rice seasons. This finding not only conveys a better understanding on P. fuscipes dispersal pattern, but also draws public attention on the occurrence of dermatitis linearis caused by the Paederus beetles.

The Effects of Light and Height of Building in Attracting Paederus fuscipes Curtis to Disperse towards Human Residential Areas.

Paederus fuscipes Curtis is a nocturnal insect. The attractiveness of artificial light sources from residential premises eventually causes the risk of severe dermatitis effect, once Paederus is in contact with human skin. The objective of this study is to investigate whether the light and height factors of residential buildings and its' association to rice cultivation phases are primary reasons for P. fuscipes's mass dispersal into human residential areas. The study site was located in residential premises that were built adjacent to rice field areas (≈ 32-60 m and 164 m) north of the rice field located in Teluk Air Tawar, mainland of Pulau Pinang. Overall, both light sources and rice cultivation phases caused a significant effect for P. fuscipes beetles dispersal flight to invade human settlements. More P. fuscipes were captured near the bright light source with the highest number of beetles found during harvesting stage. Whereas, significantly higher number of P. fuscipes were captured at level 2 and 3 compared to ground and level 1 of the apartment building and P. fuscipes was also found significantly affected by the rice cultivation phases at different elevation levels. This indicates that bright light sources and higher elevation levels are the main factors in attracting P. fuscipes beetles to disperse and causes infestations in residential areas. This finding could create awareness among the public on P. fuscipes dispersal pattern.

Oviposition Habitat Selection of Dengue Vectors, Aedes aegypti and Aedes albopictus in Response to Fish Predator.

To understand the effects of fish predator's kairomones on Aedes mosquitoes' oviposition, we established an experiment using gravid Aedes females. Kairomones concentrations were established using Hampala macrolepidota. One individual fish was placed inside containers with varying water levels (1 L, 5 L, and 10 L of water). The fish were kept in the containers for 24 hours and were removed immediately at the start of each trial in order to have the kairomones remnants. Twenty gravid adult females of Aedes aegypti and Aedes albopictus were allowed to lay eggs on oviposition site with various treatments: (1) control without any kairomones; (2) kairomone remnant in 1 L of water; (3) kairomone remnant in 5 L of water; and (4) kairomone remnant in 10 L of water. There are significant differences between the numbers of eggs laid by both Aedes species for each different treatment (F = 9.131, df = 16, p<0.001). However, fewer eggs were laid by Ae. albopictus compared to Ae. aegypti in the presence of kairomone remnants. This suggested that Ae. albopictus are significantly affected by the kairomones itself and have ability to detect the residual kairomone presence from H. macrolepidota.

Counting with Colours? Effect of Colours on the Numerical Abilities of House Crows (Corvus splendens) and Common Myna (Acridotheres tristis).

We conducted several aviary experiments to investigate the influence of colours in quantity judgments of two species of birds; house crow (Corvus splendens) and common myna (Acridotheres tristis). Different quantity (in seven different food proportions) of mealworms were presented nonsequentially to all birds using artificially coloured red mealworms, for experiment 1, and using artificially coloured green mealworms, for experiment 2. Both red and green coloured mealworms have no significant effect on house crow's quantity judgments (red: ANOVA: F6,30 = 1.748, p = 0.144; and green: ANOVA: F6,30= 1.085, p = 0.394). Common myna, however, showed a strong influence of red colour in their quantity judgment ( ANOVA: F6,30 = 2.922, p = 0.023) as they succeeded in choosing the largest amount of food between two cups, but not when offered food using green coloured mealworms ( ANOVA: F6,30 = 1.183, p = 0.342). In the next experiment, we hypothesised that both house crow and common myna will prefer red coloured food items over green coloured food items, when factors such as the amount of food is equal. We chose to test red and green colours because both colours play an important role in most avian food selections. Results showed that there were no significant differences in the selection of red or green coloured mealworms for both house crows ( ANOVA: F6,30 = 2.310, p = 0.06) and common myna ( ANOVA: F6,30 = 0.823, p = 0.561).

Colour Cues: Effects of Ipomoea Plant Extract on Culex quinquefasciatus Say Gravid Females in Choosing Oviposition Site.

The interaction between plants and insects is dynamic, and may favour either the plant or the insect. Plant chemicals are deeply implicated in this relationship and influence insect behaviour. Here, we investigated the oviposition behaviour response of Culex quinquefasciatus mosquitoes based on the colour cues produced by Ipomoea cairica leaves extract. In this study, two sets of oviposition choice experiments were conducted: (1) single solution in a cage; and (2) multiple concentration solutions in a cage. In the single solution experiment, only 1 available oviposition site was offered to 5 gravid females and in the multiple concentration tests, 4 available oviposition sites were offered to 20 gravid females. The tested concentrations were set up at 100 mL of: (1) control (distilled water only); (2) 50 ppm; (3) 150 ppm; and (4) 300 ppm of I. cairica plant extracts. The highest concentration of 300 ppm appeared to show the highest intensity with the darkest colour followed by 150 ppm and 50 ppm concentrations. More gravid females were found drowned in the highest concentration, 300 ppm of acethonilic leaves extract, compared to 150 ppm and 50 ppm of the tested extract. No eggs were found in all tested solutions. The studied extract was found to effectively attract gravid Cx. quinquefasciatus females and subsequently cause mortality and inhibit egg deposition. The interference caused by the acethonilic extract of I. cairica on the oviposition activity of Cx. quinquefasciatus can result in better control of the vector insect.

EVALUATION OF SUBLETHAL EFFECTS OF Ipomoea cairica LINN. EXTRACT ON LIFE HISTORY TRAITS OF DENGUE VECTORS.

Plant derived insecticides have considerable potential for mosquito control because these products are safer than conventional insecticides. This study aimed to investigate sublethal activities of Ipomoea carica or railway creeper crude acethonilic extract against life history trait of dengue vectors, Aedes albopictus and Aedes aegypti. The late third instar larvae of Ae. albopictus and Ae. aegypti were exposed to a sublethal dose at LC50 and larvae that survived were further cultured. Overall, Ipomea cairica crude extracts affected the whole life history of both Aedes species. The study demonstrated significantly lower egg production (fecundity) and eggs hatchability (fertility) in Ae. albopictus. The sublethal dose of crude extracts reduced significantly the width of larval head capsule and the wing length of both sexes in both Aedes species. The significance of sublethal effects of I. cairica against Aedes mosquitoes was an additional hallmark to demonstrate further activity of this plant despite its direct toxicity to the larvae. The reduced reproductive capacity as well as morphological and physiological anomalies are some of the effects that make I. cairica a potential candidate to be used as a new plant-based insecticide to control dengue vectors.

Cryptic coloration of Macaranga bancana seedlings: A unique strategy for a pioneer species.

Macaranga bancana is considered as a successful pioneer plant species. Usually found in disturbed and open areas, most of the current research focused on its relations with ants. One of the unique feature of the plants is that the seedling leaves are red, resembling and almost matching the background. Using a portable spectrometer, we measured the color reflectance of M. bancana seedlings (less than 20 cm in height). We also measured the leaf litter reflectance, adult M. bancana leaves and also seedlings of several other species found in the vicinity of M. bancana seedlings. The reflectances of M. bancana seedlings are very similar to that of the leaf litter background. We suggest that this cryptic coloration is crucial during the early stages of the plant when it still cannot rely on the protection of ants.

Risky behaviors: effects of Toxorhynchites splendens (Diptera: Culicidae) predator on the behavior of three mosquito species.

Viable biocontrol agents for mosquito control are quite rare, therefore improving the efficacy of existing biological agents is an important study. We need to have a better understanding of the predation-risk behavioral responses toward prey. This research examined prey choices by Toxorhynchites splendens by monitoring the behavioral responses of Aedes aegypti, Aedes albopictus, and Anopheles sinensis larvae when exposed to the predator. The results show that Tx. splendens prefers to consume Ae. aegypti larvae. The larvae exhibited different behavioral responses when Tx. splendens was present which suggest vulnerability in the presence of predators. "Thrashing" and "browsing" activities were greater in Ae. aegypti larvae. Such active and risky movements could cause vulnerability for the Ae. aegypti larvae due to increasing of water disturbance. In contrast, Ae. albopictus and An. sinensis larvae exhibited passive, low-risk behaviors, spending most of the time on the "wall" position near the edges of the container. We postulated that Ae. aegypti has less ability to perceive cues from predation and could not successfully alter its behavior to reduce risk of predation risk compared with Ae. albopictus and An. sinensis. Our results suggest that Tx. splendens is a suitable biocontrol agent in controlling dengue hemorrhagic vector, Ae. aegypti.

Oviposition deterring and oviciding potentials of Ipomoea cairica L. leaf extract against dengue vectors.

Bioprospecting of plant-based insecticides for vector control has become an area of interest within the last two decades. Due to drawbacks of chemical insecticides, phytochemicals of plant origin with mosquito control potential are being utilized as alternative sources in integrated vector control. In this regard, the present study aimed to investigate oviposition deterring and oviciding potentials of Ipomoea cairica (L.) (Family: Convolvulaceae) crude leaf extract against dengue vectors, Aedes aegypti and Aedes albopictus. Ipomoea cairica is an indigenous plant that has demonstrated marked toxicity towards larvae of Ae. aegypti and Ae. albopictus. Leaves of I. cairica were extracted using Soxhlet apparatus with acetone as solvent. Oviposition deterrent activity and ovicidal assay was carried out in oviposition site choice tests with three different concentrations (50, 100, 450 ppm). Acetone extract of I. cairica leaf strongly inhibited oviposition with 100% repellence to Ae. aegypti at lower concentration of 100 ppm, while for Ae. albopictus was at 450 ppm. The oviposition activity index (OAI) values which ranged from -0.69 to -1.00 revealed that I. cairica demonstrated deterrent effect. In ovicidal assay, similar trend was observed whereby zero hatchability was recorded for Ae. aegypti and Ae. albopictus eggs at 100 and 450 ppm, respectively. It is noteworthy that I. cairica leaf extract had significantly elicited dual properties as oviposition deterrent and oviciding agent in both Aedes species. Reduction in egg number through oviposition deterring activity, reduction in hatching percentage and survival rates, suggested an additional hallmark of this plant to be integrated in Aedes mosquito control. Ipomoea cairica deserved to be considered as one of the potential alternative sources for the new development of novel plant based insecticides in future.

Assessment of residual bio-efficacy and persistence of Ipomoea cairica plant extract against Culex quinquefasciatus Say mosquito.

Specification on residual action of a possible alternative insecticide derived from plant materials is important to determine minimum interval time between applications and the environmental persistence of the biopesticides. The objective of this study is to evaluate crude acethonilic extract of Ipomoea cairica leaves for its residual and persistence effects against Culex quinquefasciatus larvae. Wild strain of Cx. quinquefasciatus larvae were used for the purpose of the study. Two test designs, replenishment of water and without replenishment of water were carried out. For the first design, a total of 10 ml of test solution containing Ip. cairica extracts was replenished daily and replaced with 10 ml of distilled water. For the second design, treatment water was maintained at 1500 ml and only evaporated water was refilled. Larval mortality was recorded at 24 hours post-treatment after each introduction period and trials were terminated when mortality rate falls below 50%. Adult emergences from survived larvae were observed and number of survivals was recorded. For the non-replenishment design, mortality rate significantly reduced to below 50% after 28 days, meanwhile for replenishment of water declined significantly after 21 days (P < 0.05). There was no adult emergence observed up to seven days for non-replenishment and first two days for replenishment of water design. The short period of residual effectiveness of crude acethonilic extract of Ip. cairica leaves with high percentage of larval mortality on the first few days, endorses fewer concerns of having excess residues in the environment which may carry the risk of insecticide resistance and environmental pollution.

The Numerical Competency of Two Bird Species (Corvus splendens and Acridotheres tristis).

We conducted a series of experiments to test the numerical competency of two species of birds, Corvus splendens (House Crow) and Acridotheres tristis (Common Myna). Both species were allowed to choose from seven different groups of mealworms with varying proportions. We considered the birds to have made a correct choice when it selected the food group with the highest number of mealworms. Our overall results indicated that the Common Myna is able to count numbers (161 successful choices out of 247 trials) better than House Crows (133 successful choices out of 241 trials). We suspect that House Crows do not rely on a numerical sense when selecting food. Although House Crows mostly chose the cup with more mealworms (from seven food item proportions), only one proportion was chosen at rate above random chance. The Common Myna, however, were slow performers at the beginning but became increasingly more capable of numerical sense during the remainder of the experiment (four out of seven food proportion groups were chosen at a rate above random chance).