Abundance And Diversity Of Ephemeroptera, Plecoptera, Trichoptera (Insecta) In Relation To Environmental Quality Of Upstream Rivers In Kedah, Malaysia

A relatively rich assemblage of Ephemeroptera, Plecoptera and Trichoptera (EPT) (17,315) (Insecta) immatures were collected from Tupah, Batu Hampar and Teroi rivers in the Gunung Jerai Forest Reserve. From monthly collections starting September 2007 until August 2008 using a kick-net sampling technique, 29 genera representing 19 families of EPT were identified. The EPT community structure and specific sensitivity of EPT genera were not influenced by river water quality (Class I - II of WQI) of which more than 20 taxa were collected from each river. The EPT was most abundant but less diverse in Teroi River while the reverse was recorded from Tupah River

Monitoring heavy metal bioaccumulation in rivers using damselflies (Insecta: Odonata , Zygoptera) as biological indicator

Contamination by pollutants in freshwater ecosystem has been identified extensively in river, sediments, and freshwater biota. Pollutants may have incorporated into the sediments and accumulated in tissue of aquatic organisms which persist as difficult to degrade matter in upper trophic level. Therefore, few selected heavy metals were measured from the river sediment and tissue of damselflies larvae collected from the selected rivers using inductively coupled plasma optical emission spectrometry (ICP-OES). The results showed metals in damselflies tissue were higher than in the sediments. Mn and Zn were found in greatest concentrations both in sediment and damselflies ’s tissue. Biotasediment accumulation factors (BSAF) were computed based on these data, and it was discovered that all values of BSAF for Cd, Cu, Mn, and Zn were typically high (BSAF >1). In conclusion, the rivers contamination induced accumulation of heavy metal in the river sediments and damselflies larvae (Pseudagrion microcephalum, Pruinosum fraseri, and Copera marginipes). The highest concentration value was calculated as 29.23 for Cd in the C. marginipes. The high concentrations of this element in the insect body tissue has shown a trace of bioaccumulation and may pose biomagnification to organisms in the upper trophic level. The results of this study indicated that damselfly is reliable to become a bioindicator for heavy metals particularly pollution in the river

Abundance and infestation of rice stem borer in North Malaysia

The abundance and infestation of rice stem borer were monitored in MADA regions with the influence of weather parameters. The determination of the rice stem borer percentage infestation was recorded by dead heart (DH) and whitehead (WH) symptoms. In four regions of MADA area observations, a higher infestation of rice stem borer was observed during rice planting season one (7.1%) compared to rice planting season two (3.9%) on average. Both damage symptoms of the rice stem borer, DH, and WH were observed higher during the rice planting season one. The highest infestation of rice stem borer during season one was observed in Pendang with 18.60%. From the weather parameters recorded, a high infestation of rice stem borer occurred at 80.0% (RHmax), 8.2 °C of temperature differences (Tdiff), and a lower amount of rainfall (0.6 mm). The high infestation in Pendang in season one was influenced by the lower value of RH, higher range of temperature, and lower amount of rainfall compared to season two. Chilo polychrysus was the most abundant species of rice stem borer found in Region 1 and Scirpophaga incertulas were abundantly found in Region 2, 3, and 4

Seasonal influence on structuring aquatic insects communities in upstream rivers Belum-Temengor Forest Complex

The plausible effect of seasonal change (wet and dry) on the structure of aquatic insect community was investigated at rivers in Belum-Temengor Forest Complex (BTFC), Perak, Malaysia. The amount of rainfall received was considered as seasonal changes in the tropical regions. The rivers were visited twice in dry and wet seasons to sample aquatic insects using rectangular aquatic nets. Their abundance and richness varied significantly between both dry and wet seasons (P = 0.000; Mann-Whitney U test). More aquatic insect was collected in dry seasons (17,633 individuals) compared to wet seasons (6,542 individuals). The aquatic insect abundance decreased tremendously during the wet seasons (45% reduction) and diversity showed fewer species richness in the wet season (98 genera) compared to the dry season (114 genera). The most affected taxa caused by the heavy water flow were Ceratopsyche sp. (family Hydropschidae and subfamily Limoniinae which huge reduction in density occurred during the wet season. Water temperature, BOD3, DO and COD were significantly different between seasons (Kruskal Wallis test, P < 0.05). The presence of phosphorus and ammonia-nitrogen in water during dry season had major influence on the aquatic insect composition while rainfall was the main factor that regulated the insect communities in wet seasons

Aquatic insects assemblage in Penang Botanic Garden

This study investigated the diversity of aquatic insects as well as the chemical parameters of Sungai Air Terjun that runs in Penang Botanic Garden. Aquatic insects and chemical parameters of river were studied from April 2013 until January 2014. A total of twenty specimens were collected monthly using D and rectangular net following kick-net sampling technique. A total of 2966 individuals from 48 families of seven orders of aquatic insects were collected. The most abundant aquatic insects were recorded in July 2013 with 566 individuals from 44 genera, while the least abundant was in May 2013 with 156 individuals from 31 genera. The Diptera (996 individuals), Trichoptera (689 individuals) and Ephemeroptera (327 individuals) were very rich and diverse in this river during all the sampling months. This study provides a current situation of aquatic insect’s community and river condition of Sungai Air Terjun, Penang Botanic Garden

Diversity and guild structure of insects during rice flowering stage at a selected rice field in Penang, Malaysia

A study on diversity of insects in rice field was conducted at Kg Terus, Guar Perahu in Penang. This study aims to determine the diurnality and guild structure of insect in rice field specifically during the flowering stage of rice. Insects were collected using sweep net method and light trap method. Overall, a total of 1936 insect specimens representing 28 species, 19 families and seven orders were collected. Twenty five species from 19 families were caught during day time while 17 species from 13 families were trapped at night. Coleopterans were the dominant insect captured during day time sampling with Micraspis crocea from family Coccinellidae captured in highest number (223). In contrast, Hemipterans was dominant during night time with Nilaparvata lugens from family Delphacidae found in highest number (258). The Odonata recorded the highest diversity index (H’= 1.2587) while Coleoptera recorded the highest richness index (Imargalef = 5.8390) values for diurnal insect. For nocturnal insect, Hemiptera recorded the highest values for both diversity index (H’= 1.2655) and richness index (Imargalef = 5.8390). In term of guild structure, the rice pest was the most dominant insect found in rice field for both diurnal and nocturnal group. This followed by predator, others (visitor/pollinator) and parasitoid groups. Result of this study will identify the classification of insect present during the flowering stage of rice allowing farmers to forecast pest population build up to assist in the pesticides selection that will be generally applied at the end of flowering stage. This consequently will help to conserve beneficial insects and lower the pest management cost

The global EPTO database: Worldwide occurrences of aquatic insects

Motivation: Aquatic insects comprise 64% of freshwater animal diversity and are widely used as bioindicators to assess water quality impairment and freshwater ecosystem health, as well as to test ecological hypotheses. Despite their importance, a comprehensive, global database of aquatic insect occurrences for mapping freshwater biodiversity in macroecological studies and applied freshwater research is missing. We aim to fill this gap and present the Global EPTO Database, which includes worldwide geo-referenced aquatic insect occurrence records for four major taxa groups: Ephemeroptera, Plecoptera, Trichoptera and Odonata (EPTO). Main type of variables contained: A total of 8,368,467 occurrence records globally, of which 8,319,689 (99%) are publicly available. The records are attributed to the corresponding drainage basin and sub-catchment based on the Hydrography90m dataset and are accompanied by the elevation value, the freshwater ecoregion and the protection status of their location. Spatial location and grain: The database covers the global extent, with 86% of the observation records having coordinates with at least four decimal digits (11.1 m precision at the equator) in the World Geodetic System 1984 (WGS84) coordinate reference system. Time period and grain: Sampling years span from 1951 to 2021. Ninety-nine percent of the records have information on the year of the observation, 95% on the year and month, while 94% have a complete date. In the case of seven sub-datasets, exact dates can be retrieved upon communication with the data contributors.Major taxa and level of measurement: Ephemeroptera, Plecoptera, Trichoptera and Odonata, standardized at the genus taxonomic level. We provide species names for 7,727,980 (93%) records without further taxonomic verification. Software format: The entire tab-separated value (.csv) database can be downloaded and visualized at https://glowa bio.org/proje ct/epto_datab ase/. Fifty individual datasets are also available at https://fred.igb-berlin. de, while six datasets have restricted access. For the latter, we share metadata and the contact details of the authors

Trichoptera larvae diversity in rivers at various elevation of Gunung Jerai Forest Reserve, Kedah, Malaysia

The abundance and composition of Trichoptera in selected rivers play a significant ecological role in the study of streams, therefore, a study was conducted in three rivers of Gunung Jerai Forest Reserve; Tupah, Batu Hampar and Teroi rivers at altitude range from 200 m to 1214 m above sea level. A total of 2,623 Trichoptera larvae from 11 genera and eight families were collected from the three rivers using a D-frame net. Tupah River recorded the greatest prevalence of Trichoptera (52.3%), followed by Batu Hampar River (42.9%) and Teroi River with the least prevalence (4.8%). Certain genera of Trichoptera such as Cheumatopsyche, Hydropsyche, Macrostemum, Ganonema, Chimarra, Diplectrona and Lepidostoma corresponds to river physical parameters such as altitude, water velocity and water temperature (P<0.05). Results showed Cheumatopsyche from Hydropsychidae had the greatest abundance and diversity associated with high composition in Tupah River which located at lower altitude (200 m above sea level) (r=-0.739, P<0.05). From the number of Trichoptera genera collected in the three rivers at different altitude, clearly show that these caddisflies genera have adapted to live in river with different altitude with stony substrates

Next generation insect taxonomic classification by comparing different deep learning algorithms.

Insect taxonomy lies at the heart of many aspects of ecology, and identification tasks are challenging due to the enormous inter- and intraspecies variation of insects. Conventional methods used to study insect taxonomy are often tedious, time-consuming, labor intensive, and expensive, and recently, computer vision with deep learning algorithms has offered an alternative way to identify and classify insect images into their taxonomic levels. We designed the classification task according to the taxonomic ranks of insects-order, family, and genus-and compared the generalization of four state-of-the-art deep convolutional neural network (DCNN) architectures. The results show that different taxonomic ranks require different deep learning (DL) algorithms to generate high-performance models, which indicates that the design of an automated systematic classification pipeline requires the integration of different algorithms. The InceptionV3 model has advantages over other models due to its high performance in distinguishing insect order and family, which is having F1-score of 0.75 and 0.79, respectively. Referring to the performance per class, Hemiptera (order), Rhiniidae (family), and Lucilia (genus) had the lowest performance, and we discuss the possible rationale and suggest future works to improve the generalization of a DL model for taxonomic rank classification