Pa ge 1 Pa ge 1 American Journal of Life Science and Innovation (AJLSI) Diversity and Relative Abundance of Entomofauna of Four Ecologically Different Areas of Chittagong University Campus, Bangladesh Md. Ikram Ansar Tuhin1, Munira Nasiruddin1, Zannatul Nayem1* Volume 2 Issue 2, Year 2023 ISSN: 2833-1397 (Online) DOI: https://doi.org/10.54536/ajlsi.v2i2.1380 https://journals.e-palli.com/home/index.php/ajlsi Article Information ABSTRACT Received: March 11, 2023 Accepted: May 02, 2023 Published: May 04, 2023 The present study was conducted to find the relative abundance and diversity of insects in the four areas of the Chittagong University (CU) campus from January 2018 to December 2018. The entire study found six orders - Odonata, Orthoptera, Coleoptera, Lepidoptera, Diptera, and Hymenoptera. Three families under Odonata, two under Orthoptera, four under Coleoptera, five under Lepidoptera, five under Diptera, and three under Hymenoptera were collected from the four study spots. Among them, fifteen species of Odonata, seven species of Orthoptera, seven species of Coleoptera, thirty-five species of Lepidoptera, five species of Diptera, and four species of Hymenopteran were identified. The highest number of insects (478) were collected in January 2018, whereas the lowest number of insects (404) were collected in August 2018. The highest abundance (1598) of insects was found in spot 1 (ground area) and the lowest (990) in spot 2 (hilly area). Lepidoptera (2688) was the most dominant order in the four studied spots, followed by Odonata (1453), Orthoptera (505), Coleoptera (223), Diptera (202), and Hymenoptera (186). During the study period, the highest species richness was observed in Spot 3 (2.61 ± 0.01) and lowest in Spot 2 (2.03 ± 0.008); the highest species diversity was observed in Spot 1 (1.36 ± 0.02) and lowest in Spot 2 (1.09 ± 0.01); and the highest species evenness was observed in Spot 1 (0.53 ± 0.006) and lowest in Spot 2 (0.47 ± 0.006). Compared with the previous study, it can be concluded that the species diversity and abundance of Odonata, Orthoptera, and Lepidoptera were increased, whereas the diversity and abundance of Coleoptera and Hymenoptera were decreased. The abundance and diversity of insects depended on seasonal fluctuation and ecological and environmental conditions. Keywords Entomofauna, Ecological Area, Insect Diversity, Insect Abundance, Diversity Indices INTRODUCTION Insects have been an immensely successful animal group, with possibly 2-10 million species on earth today. Although evidence suggests that many insects died out at the end of the Cretaceous, most have survived many geological events over the last few millions of years. This is now changing, with the human impact estimated to threaten the survival of a quarter of all insect species. In the agricultural ecosystem, biodiversity is important for food production and other ecological services, including the recycling of nutrients, regulation of microclimate and local hydrological processes, suppression of undesirable organisms, and detoxification of harmful chemicals. So, the task is now urgent to conserve this immense variety of life which is so vital to many ecosystem functions. Threats are many and varied, with habitat destruction the worst threat, especially in the tropics where most insect diversity lives. Other threats include invasive alien organisms, certain biological control practices, the use of pathogens, genetically modified crops, and global climate change. Chittagong University (CU) Campus is enriched with diverse insect fauna. The present investigation was undertaken to study the abundance and diversity of insects in four ecologically different sites of the CU Campus, which were also widely separated by distance. The insects included in the study belonged to the orders- Odonata, Orthoptera, Coleoptera, Lepidoptera, Diptera and Hymenoptera. Several works on insect diversity and abundance abroad and in our country. Amin et al. (2018) research on the functional and group abundance of insects on Eggplant. In total 488 insects were collected from the eggplant field, which belonged to 20 species in 21 families and 10 orders. The abundance, richness and diversity of pest, predator, pollinator and other categories of insects differed significantly and the pest revealed the highest abundance and richness compared to others. Rahman et al. (2017) studied the abundance and diversity of beneficial insect and spider species in the rice ecosystem in the Sylhet region. Many beneficial insect and spider species were found abundant at all growing stages in both rice fields. Siregar et al. (2016) studied the diversity and abundance of insect pollinators in three different agricultural land uses, i.e., oil palm plantation, rubber plantation, and jungle-rubber in Jambi, Sumatera. A total of 497 individuals of insect pollinators were collected by them which belonged to 43 species in three orders (Hymenoptera, Diptera, and Lepidoptera). Siddiki (2015) studied the insect diversity and composition during the wet and dry seasons in three forest types of Johor, Malaysia. They focused on ten common insect orders. A total of 929 insects were found in the study of Balakrishnan et al. (2014) on diversity of some insect fauna in different coastal habitats of Tamil Nadu, southeast coast of India. Zou (2014) focused on two distinct taxa: ground beetles (Coleoptera: Carabidae) and geometrid moths (Lepidoptera: Geometridae) to study the diversity patterns along environmental gradients in the temperate forests of Northern China. Hong et al. 1 Department of Zoology, University of Chittagong , Bangladesh * Corresponding author’s e-mail: zannatul.nayem29@gmail.com https://doi.org/10.54536/ajlsi.v2i2.1380 https://journals.e-palli.com/home/index.php/ajlsi Pa ge 2 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 (2012) worked on insect diversity of Mt. Oseosan where a total 446 species of 108 families belonging to 11 orders were identified. Park et al. (2012) surveyed insect diversity of Yeonpyeong-do Island in Korea and the total of 209 species of 65 families under 10 orders were identified. Aim and Objectives 1. To study the morphological and structural characteristics of Insect species from the four selected sampling sites in CU Campus. 2. To investigate the abundance of identified species of the selected sampling sites during one year study period. 3. To investigate the variation in abundance among the species of the four selected Spots. 4. To investigate the Shanon-Weiner diversity of the orders in the sampling sites. 5. To investigate community dominance of the identified species in the sampling sites. 6. To know and use fundamental concepts and information in areas of abundance and diversity of Insects. METHODOLOGY The present study was conducted in the CU campus, which is situated in close proximity of Sitakunda hill forest. The area lies between about 22o27’30’’ and 22o29’0’’ North latitudes and 91o46’30’’ and 91o47’45’’ East longitudes. The campus is dominated by hills, valleys, creeks and streams, lakes, crop fields, and grass and fallow lands. This is the junction of hills and plains adorned with hilly streams. These features constitute a suitable habitat for insect diversity. Approximately 72% of the total land is constituted by hillocks, which are 15-90 m high. The rest of the land is valley and/or plain. The campus consists of many secondary forests with woody trees, flowering plants, fruit plants, medicinal plants, herbs, and shrubs. The campus area has received great attention in various aspects of biodiversity and species richness, particularly for insects, birds, and wild mammals. During the study period, samplings were done for one year, from January-2018 to December-2018. A collection of data was done once in a month from four ecologically different areas in the four-terminal area (North, East, South and West) of CU Campus (spot-1: Garden Area, spot-2: Hilly Forest area, spot-3: Botanical Garden with Hilly Stream, spot-4: Pond area with agricultural crop field). Figure-1 shows the four studied spot in a map. Spot- 1 was located at the northern side of the campus. There was beautiful flower garden in front of the agricultural field which consisted of many flowering plants like- Golap (Rosa sinensis), Gada (Tagetes erecta), Togor (Tabernaemontena divaricata), Hasna-hena (Cestrum nacturnum), Kamini (Murraya paniculata), Belly (Jesminus sambac), herbs, shrubs, and few tall trees such as- Mahagoni (Sweitenia mahagoni), Teak (Tectona grandis), Neem (Azadirachta indica), Jarul (Lagerstroemia speciosa), Krishnochura (Delonix regia), etc. Plenty of small plants were available, especially Mikania micrantha, Asparagus racemosus, and so on. Some wild flowering plants, including Lantana camara and Ficus benghalensis were also found in this semi-hilly area. Spot- 2 was the hilly forest area on the campus’s eastern side. There was a dense growth of bush, tall and short trees, herbs, shrubs, and also wild flowering trees. Many kinds of valuable trees such as- Eucalyptus (Eucalyptus citriodora), Jarul (Lagerstroemia speciosa), Bamboo (Bambusa sp.), Cycas (Cycas pectinata), Hortoki (Terminalia chebula), Polash (Butea monosperma), Nagessor (Mesua nagassarium), Teak (Tectona grandis), Debdaru (Polytthia longifolia), Krishnochura (Delonix regia), Garjon (Dipterocarpus turbinatus), Akashmoni (Accacia racemosus) were seen throughout the entire area. Wildflowers and grassland were also found in this hilly forest area. Spot-3 was an ideal botanical garden established on the southern side beside a hilly stream with more than 10,000 plants of about 400 species comprising over 150 families of both exotic and indigenous species of timber, medicinal, fruits, spices, beverage, latex, orchids, novelty etc. have been preserved or are growing naturally and used as experimental materials. Many kinds of flower plants such as- Joba (Hibiscus rosa-sinensis), Chondromollika (Chrysanthemum coronarium), Golap (Rosa sinensis), Gada (Tagetes erecta), Togor (Tabernaemontena divaricata), Hasna-hena (Cestrum nacturnum), Rongon (Ixora coccinea), Bakul (Mimusops elengi), Gondhoraj (Gardenia jasuninoides), Kamini (Murraya paniculata), Dahlia (Dahlia), Belly (Jesminus sambac), Rojonigondha (Polianthes tuberose) etc. were planted in the garden which increased the beauty of the garden. Spot-4 was situated at the western and south-western parts of the campus area. The Spot was occupied by wetland and crop fields. The rice crop fields were occupied with seasonal rice (Oryza sativa) plants i.e., Aus, Aman and Boro in the three stages i.e., nursery, transplanting and ripening. In this area, rice was extensively cultivated throughout the year. Insects were collected once in a month from each sampling location mainly in the morning for one hour. Sweeping process in each collection accomplished the collection of samples. Insect sweeping net was used for this purpose. Hand-picking collection was also followed for the small insects occupied in the leaf, grass as well as in the soil. The captured insects were chloroformed, killed, sorted, stretched, mounted, labeled, and preserved following general entomological procedures (Borror et al. 1989). A total of 5257 insect specimens were collected during the study period. The insects were identified with the help of taxonomic keys and characters. Firstly, specimens were identified up to family level. Then each specimen was examined up to genus and species level by comparison with previously identified specimens preserved at the Department of Zoology, University of Chittagong. The collected insect specimens were classified up to family following Borror et al. (1989), Richards and Davies (1977), and then up to generic level. Identification was made following Bingham (1908) and Talbot (1975) for lepidopterans, Kirby (1914) for orthopterans and hymenopterans, Maulik (1919) for coleopterans, Fraser (1936) for odonates, Van Emden https://journals.e-palli.com/home/index.php/ajlsi Pa ge 3 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 (1965) for dipterans, Richards and Davies (1977) for butterflies, dragonflies, damselflies and beetles and Burton (1974). Help from internet sources was also taken for identification. Figure 2: The workflow Figure 1: Map of the Study Area showing the Study Spots Shannon-Weiner Species Diversity Indices and Community Dominance were calculated to know the abundance and diversity status of the insect fauna of the CU campus area. https://journals.e-palli.com/home/index.php/ajlsi Pa ge 4 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 RESULT AND DISCUSSION The present study deals with the faunistic study of the insect community in CU campus. The study of the abundance and diversity of insects helps to gather information on the statistics of entomofauna. Sánchez- Bayo, F. and Wyckhuys, K. A. G. (2019) studied the entomofauna and found that over 40% of insect species were threatened with extinction. Their findings showed that habitat loss by conversion to intensive agriculture was the main driver of the decline, while agrochemical pollutants, invasive species and climate change were the additional causes. A total of 5257 insect specimens were collected during the study period. The collected specimens were primarily sorted into 6 orders. Then they were identified into several different families within these orders. The orders are- Odonata, Orthoptera, Coleoptera, Lepidoptera, Diptera and Hymenoptera. 3 families under order Odonata, 2 families under order Orthoptera, 4 families under order Coleoptera, 5 families under order Lepidoptera, 5 families under order Diptera and 3 families under order Hymenoptera were identified. For each order, families, genus and species a diagnosis is given. The collection included 73 species which are listed below: Table 1: List of the insects collected during the study period Order Family Scientific name Common name Odonata Libellulidae Orthetrum sabina (Drury, 1770) Green Marsh Hawk Orthetrum pruinosum (Burmeister, 1839) Crimson-tailed Marsh Hawk Neurothemis tullia (Drury, 1773) Pied Paddy Skimmer Neurothemis fulvia (Drury, 1773) Fulvous Forest Skimmer Rhyothemis variegata (Linnaeus, 1763) Common Picturewing Rhodothemis rufa (Rambur, 1842) Rufous Marsh Glider Brachydiplax chalybea (Brauer, 1868) Rufous-Backed Marsh Hawk Crocothemis servilia (Drury, 1770) Scarlet Skimmer Brachythemis contaminata (Fabricius, 1793) Ditch Jewel Coenagrionidae Ceriagrion coromandelianum (Farbicius, 1798) Coromandel Marsh Dart Mortonagrion aborense (Laidlaw, 1914) N/A Agriocnemis lacteola (Selys, 1877) Milky Dartlet Platycnemididae Onychargia atrocyana (Selys, 1865) Black Marsh Dart Copera marginipes (Rambur, 1842) Yellow Bush Dart Copera vittata (Selys, 1863) Blue bush Dart Orthoptera Acrididae Dissosteira carolina (Linnaeus, 1758) Road-duster Oxya velox (Fabricius, 1787) Paddy Field Grasshopper Oxya chinensis (Thunberg, 1825) Short Horned Grasshopper Oxya hyla hyla (Serville, 1831) Rice Grasshopper Paratettix sp. (Bolivar, 1887) Creek Pygmy Grasshopper Atractomorpha sp. (Saussure, 1862) Vegetable Grasshopper Gryllidae Gryllus pennsylvanicus (Burmeister, 1838) Field Cricket Coleoptera Chrysomelidae Aulacophora frontalis (Baly, 1888) Pumpkin Beetle Aulacophora indica (Gmelin, 1790) Orange Pumpkin Beetle Aspidomorpha sanctaecrucis (Fabricius, 1792) Golden Tortoise Beetle Aspidomorpha miliaris (Fabricius, 1775) Green Tortoise Beetle Coccinellidae Menochilus sexmaculatus (Fabricius, 1781) Lady Bird Beetle Carabidae Harpalus distinguendus (Duftschmid, 1812) Ground Beetle Tenebrionidae Eleodes hispilabris (Say,1824) Darkling Beetle Lepidoptera Papilionidae Papilio helenus (Linnaeus, 1758) Red Helen Papilio polytes (Cramer, 1775) Common Mormon Papilio demoleus (Linnaeus, 1758) Lemon Butterfly Papilio clytia (Linnaeus, 1758) Common Mime Graphium agamemnon (Linnaeus, 1758) Green-Spotted triangle Pieridae Leptosia nina (Fabricius, 1781) Psyche Eurema hecabe (Linnaeus, 1758) Common Grass Yellow https://journals.e-palli.com/home/index.php/ajlsi Pa ge 5 https://journals.e-palli.com/home/index.php/ajlsi Am. 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Innov. 2(2) 1-11, 2023 Catopsilia pomona (Fabricius, 1775) Lemon Emigrant Pieris canidia (Evans,1912) Indian Cabbage White Delias hyparete (Wallace, 1867) Painted Jezebel Cepora nerissa (Fabricius, 1775) Common Gull Appias libythea (Swinhoe,1890) Striped Albatross Nymphalidae Athyma inara (Westwood, 1850) Himalayan Colour Sergeant Junonia lemonias (Linnaeus, 1758) Lemon Pansy Junonia almana (Linnaeus, 1758) Peacock Pansy Junonia atlites (Linnaeus, 1763) Grey Pansy Junonia hierta (Fabricius, 1798) Yellow Pansy Junonia iphita (Cramer, 1779) Chocolate Pansy Ypthima baldus (Fabricius, 1775) Common Five-ring Lebadea martha (Fabricius, 1787) Knight Mycalesis perseus (Fabricius, 1798) Common Bushbrown Polyura athamas (Drury, 1770) Common Nawab Hypolimnas bolina jacintha (Drury, 1773) Orienta Great Eggfly Neptis hylas (Moore, 1872) Common Sailor Phalanta phalantha (Drury, 1770) Common Leopard Hypolimnas bolina bolina (Linnaeus, 1758) Sunda Great Eggfly Parantica melaneus (Cramer, 1775) Chocolate Tiger Euploea core (Cramer, 1780) Common Crow Elymnias sp. (Hubner, 1818) Palmfly Lycaenidae Neozephyrus quercus (Linnaeus, 1758) Purple Hairstreak Castalius rosimon (Fabricius, 1775) Common Pierrot Spindasis sp. (Tytler, 1915) Rufous Silverine Hesperiidae Notocrypta paralysos (Fruhstorfer, 1911) Banded Demon Baoris farri (Moore, 1878) Paintbrush Swift Telicota bambusae (Moore, 1878) Dark Palm Dart Diptera Sarcophagidae Saracophaga sp. (Meigen, 1826) True Fly Muscidae Musca domestica (Linnaeus, 1758) House Fly Drosophillidae Drosophila melanogaster (Meigen, 1830) Common Fruit Fly Tabanidae Tabanus sp. (Linnaeus, 1758) Horse Fly Calliphoridae Calliphora vicina (Robineau-Desvoidy, 1830) Blue Bottle Blowfly Hymenoptera Sphecidae Sphex lobatus (Fabricius, 1775) Digger Wasp Sceliphron violaceum (Fabricius, 1775) Fassorial Wasp Apidae Xylocopa latipes (Drury, 1773) Tropical Carpenter Bee Vespidae Polistes sp. (Latreille, 1802) Paper Nest Wasp During the collection period, a total of 5257 insects were collected (Table-2). January and April were the most dominant months. In January and April, 478 (9.10%) and 465 (8.85%) insects were collected where Lepidoptera, Odonata and Orthoptera insects were mostly available. In February, March, July, November and December, 452 (8.60%), 454 (8.64%), 418 (7.95%), 430 (8.18%) and 416 (7.91%) the abundance was medium. In the month of August 404 (7.68%), September 412 (7.84%) and October 407 (7.74%) the abundance of the insects was lower. From 12 months observation (Table-3) the highest abundance of insects was found in Spot 1, medium abundance of insects was found at Spot 2 and Spot 4 and lowest abundance of insects was found in Spot 3. From this study it is seen that the maximum numbers of insects were collected in the months of January (478), April (465) and May (462) when the temperature and weather condition was suitable and minimum number were collected in the months of August (404), October (407) and September (412) due to monsoon season. https://journals.e-palli.com/home/index.php/ajlsi Pa ge 6 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 Table 2: Number of insects collected per order and month wise % composition of the collected insect orders during the study period. Order Ja n 20 18 Fe b 20 18 Mar 2018 Apr 2018 May 2018 Jun 2018 Jul 2018 Aug 2018 Sep 2018 Oct 2018 Nov 2018 Dec 2018 Total % (m on th ) Odonata 123 117 118 117 121 120 124 119 123 122 121 128 1453 27.64 O rt ho pt er a 56 43 35 44 45 46 39 36 39 42 45 35 505 9.61 C ol eo pt er a 27 21 17 20 20 13 16 17 18 17 20 17 223 4.24 Le pi do pt er a 244 244 251 244 244 251 207 202 203 193 205 200 26 88 5 1. 13 Diptera 16 13 15 23 17 17 12 14 16 14 25 20 202 3.84 H ym en op te ra 12 14 18 17 15 12 20 16 13 19 14 16 186 3.54 Total 478 452 454 465 462 459 418 404 412 407 430 416 % (Order) 9.10 8.60 8.64 8.85 8.79 8.73 7.95 7.68 7.84 7.74 8.18 7.91 Table-3 shows the order wise distribution of the collected insects in the four study Spots during the study period. Butterflies (Lepidoptera) were the most abundant group in Spot 4 (834), Spot 1 (762), Spot 2 (655) and Spot 3 (437). The lowest insect abundance order was Hymenoptera which was found very few in number in different study Spots, such as 62 from Spot 4, 45 from Spot 2, 43 from Spot 3 and 36 from Spot 1 respectively. Amongst the orders, a total of 2688 lepidopterans, 1453 odonates, 505 orthopteran, 223 coleopterans, 202 dipterans, 186 hymenopterans were collected during the study period. Of the total collected insects, maximum numbers of insects were collected from Spot-1 and minimum numbers from Spot-3. Spot-1 had more insect species than were found at other sites. These differences could be the result of habitat and microhabitat differences among the sites. This Spot consisted of several flower gardens, grassland and was also rich in small to big sized plants which were the natural breeding ground and food source of butterflies, bees, wasps and beetles which may explain the highest total number of species captured at this site. From the study, it was seen that lepidopteran, odonate, orthopteran and coleopteran species were most abundant in Spot-1. Thus, the large number of Table 3: Showing number of insects collected per order from the four Spots and % composition of the collected insects during the study period. Order Spot 1 Spot 2 Spot 3 Spot 4 Total %(Spot) Odonata 431 313 322 387 1453 27.64 Orthoptera 163 89 98 155 505 9.61 Coleoptera 134 0 49 40 223 4.24 Lepidoptera 762 655 437 834 2688 51.13 Diptera 72 39 41 50 202 3.84 Hymenoptera 36 45 43 62 186 3.54 Total 1598 1141 990 1528 5257 % (Order) 30.40 21.70 18.83 29.07 https://journals.e-palli.com/home/index.php/ajlsi Pa ge 7 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 Figure 1: Percentage of the total insect found in each four Spots lepidopteran and odonate insects was collected from Spot-4 which was rich in grass areas. Orthopteran and hymenopteran insects were mostly collected from Spot-2 because of forest hilly areas. The large sized butterflies and other large sized insects were the inhabitants of forest and hilly areas and medium to small sized insects were the inhabitants of plain land and flower garden. The most significant characters were that the abundance of hymenopteran species very low in all Spots and also in the study months. Lepidopteran species were the most abundant insect order in almost all the months except July, August, September, October, November and December. Hymenoptera is the lowest abundant insect order which was found in very low number except the month of March, April, July, and October. Except Hymenoptera, insects of all orders were found more or less in almost all the months. James (2011) while studying the diversity and abundance of insect fauna in Rajshahi University Campus illustrated that the highest number of insects was found in November 2008 followed by February 2009 and the lowest population of insects was found in January 2009. Table – 4 showed the community dominance value with the dominant species found in each month in the studying spots.The community dominance value was 8.8% in the Spot-1 in October, which was recorded as the highest value of the year. Dissosteira Carolina and Ceriagrion coromandelianum were found in October. The second dominant species Ceriagrion coromandelianum was used to calculate the community dominance value in the month October. In July, the most dominating insects were Crocothemis servilia and Aulacophora indica in the Spot-1 and the community dominance value was 5.83%, which was the lowest value in the Spot-1. The lowest value of community dominance indicated the diversity of species in the respective month. In Spot-1, the most dominating species were Oxya hyla hyla, Crocothemis servilia and Brachythemis contaminate. The second most dominating species was the Copera spp. In Spot-2, Leptosia nina and Papilio clytia were found in the month of August and the dominance value was 10.11%. The community dominance was low i.e., 8.41% in November. The most dominating insects were Hypolimnas bolina jacinth and Junonia iphita So, the most diversified month was November in Spot-2. In Spot-2, the most dominating species were Athyma inara, Pieris canidia and Junonia atlites. The second most dominating species were Junonia spp. and Papilio spp. In Spot-3, Oxya hyla hyla and Brachydiplax chalybea were found in the month of August and the dominance value was 12.79%. The community dominance was low i.e., 8.05% in January. The most dominating insect were Copera marginipes and Orthetrum pruinosum. So, the most diversified month was January in Spot-3. In Spot-3, the most dominating species was Mortonagrion aborense. The second most dominating species were Copera marginipes, Rhyothemis variegate, Copera vittata and Brachythemis contaminate. In Spot-4, Oxya velox and Mortonagrion aborense were found in the month of January and the dominance value was 8.61%. The community dominance was low i.e., 7.53% in June. The most dominating insects were Catopsilia Pomona and Junonia almana. So, the most diversified month was January in Spot-4. In Spot-4, the most dominating species was Ceriagrion coromandelianum. The second most dominating species were Brachydiplax chalybea and Orthetrum sabina. Species richness varied from month to month. But throughout the year the species richness was highest in the Spot 3 and lowest in the Spot-2 (Table-5). The highest species richness value was 2.66 found in Spot 3 in November and lowest value was 1.97 which was also found in November in Spot 2. The average highest species richness value was observed in the months of September and October (2.38 ± 0.14) and lowest value in January (2.31±0.13) and April (2.31 ± 0.11) during the study period. Species richness value (average) fluctuated between 2.32 (±0.13) to 2.37 (±0.15) in the rest of the months (According to Table-5). Species diversity (H′) values in the twelve months study period in the four study areas was also given in Table-5. The species diversity value was lowest in Spot 2 throughout the year. The species diversity value was highest in the Spot 1 in the month of January, February, March, June, July, September, November and December and in the Spot 3 in the rest of the months. The highest species diversity was 1.45 in January which was found in Spot 1 and in August which was found in Spot 3. On the other hand, the lowest species diversity was 1.01 in March. The average highest species diversity value was observed in the month of October (1.31 ± 0.09) and the lowest value in the month of June (1.20 ± 0.05) during the entire study period. Species diversity value (average) fluctuated between 1.21 (±0.08) to 1.29 (±0.13) in the rest of the months (According to Table-5). Species evenness values varied from month to month during the entire study period in the four study areas. The highest species evenness value was found in Spot 1 in the months of January, February, March, June, September and December. The value was highest in July in spot 1 and 4 and in November in spot 1 and 3. The value was highest in the remaining months in spot 3. The lowest species evenness value was in spot 4 in the months of February https://journals.e-palli.com/home/index.php/ajlsi Pa ge 8 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 Table 4: Monthly % Community Dominance (DC) of entomofauna of four ecologically different areas in CU Campus collected from January 2018 to December 2018. Spot-1 Month Most dominating species DC (%) Jan Oxya hyla hyla, Rhodothemis rufa 7.33 Feb Agriocnemis lacteola, Onychargia atrocyana 6.43 Mar Copera marginipes, Rhyothemis variegata 6.57 Apr Brachythemis contaminate, Ceriagrion coromandelianum 6.43 May Oxya velox, Brachydiplax chalybea 6.43 Jun Crocothemis servilia, Copera vittata 6.57 Jul Crocothemis servilia, Aulacophora indica 5.83 Aug Copera marginipes, Agriocnemis lacteola 7.44 Sep Brachythemis contaminate, Menochilus sexmaculatus 7.03 Oct Dissosteira Carolina, Ceriagrion coromandelianum 8.8 Nov Onychargia atrocyana, Oxya hyla hyla 6.77 Dec Orthetrum Sabina, Menochilus sexmaculatus 7.09 Spot-2 Month Most dominating species DC (%) Jan Athyma inara, Junonia atlites 10 Feb Pieris canidia, Junonia lemonias 9.47 Mar Pieris canidia, Cepora nerissa 9.47 Apr Catopsilia Pomona, Graphium agamemnon 9.89 May Junonia almanac, Mycalesis perseus 9.38 Jun Athyma inara, Hypolimnas bolina jacintha 9.38 Jul Junonia almanac, Junonia atlites 9.18 Aug Leptosia nina, Papilio clytia 10.11 Sep Catopsilia Pomona, Papilio helenus 9.57 Oct Graphium Agamemnon, Papilio demoleus 10 Nov Hypolimnas bolina jacintha, Junonia iphita 8.41 Dec Leptosia nina, Parantica melaneus 9 Spot-3 Month Most dominating species DC (%) Jan Copera marginipes, Orthetrum pruinosum 8.05 Feb Rhyothemis variegate, Crocothemis servilia 8.64 Mar Brachythemis contaminate, Mortonagrion aborense 8.43 Apr Tabanus sp., Oxya velox 10.11 May Rhodothemis rufa, Ceriagrion coromandelianum 8.14 Jun Neurothemis fulvia, Copera marginipes 8.75 Jul Ceriagrion coromandelianum, Copera marginipes 10.47 Aug Oxya hyla hyla, Brachydiplax chalybea 12.79 Sep Copera vittata, Mortonagrion aborense 11.54 Oct Onychargia atrocyana Oxya velox 11.69 Nov Rhyothemis variegate, Mortonagrion aborense 11.84 Dec Brachythemis contaminate, Copera vittata 11.11 Spot-4 Month Most dominating species DC (%) Jan Oxya velox, Mortonagrion aborense 8.61 Feb Onychargia atrocyana, Ceriagrion coromandelianum 8.09 https://journals.e-palli.com/home/index.php/ajlsi Pa ge 9 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 Mar Rhyothemis variegate, Rhodothemis rufa 7.91 Apr Ceriagrion coromandelianum, Copera vittata 7.59 May Brachydiplax chalybea, Crocothemis servilia 7.86 Jun Catopsilia Pomona, Junonia almana 7.53 Jul Eurema hecabe, Paratettix sp. 7.89 Aug Papilio clytia, Ceriagrion coromandelianum 8.33 Sep Oxya velox, Brachydiplax chalybea 8.04 Oct Papilio demoleus, Brachythemis contaminata 7.83 Nov Orthetrum Sabina, Copera marginipes 7.89 Dec Graphium Agamemnon, Orthetrum sabina 8.33 and May while it is lowest in spot 3 in December. The value was lowest in both spot 3 and 4 in June and spot 2 and 4 in May. The lowest value was found in spot 2 for the rest of the month. The highest value was 0.56 and the lowest value was 0.43, found in spot 2 in March. The average highest species evenness value was observed in October (0.52 ± 0.02) and the lowest value in the month of March (0.48 ± 0.03) during the entire study period. Species evenness value (average) fluctuated between 0.49 (±0.03) to 0.51 (±0.04) in the rest of-the months (According to Table-5). From Figure-2, it has been seen that Spot 3 had more species richness (2.61 ± 0.01) with low insect abundance (990) whereas spot 2 was less species rich (2.03 ± 0.008) with moderate Insect abundance (1141). Spot 1 was most diversified (1.36 ± 0.02) with high insect abundance (1598, 30.40%). On the contrary, spot 2 showed low species diversity (1.09 ± 0.01) with comparatively low insect abundance (1141, 21.70%). Though the present study showed that the collected specimens were poorly distributed in all spots, the highest species evenness was found in the Spot 1 (0.53 ± 0.006) with highest insect abundance (1598, 30.40%). Species evenness was low in the Spot 2 (0.47 ± 0.006) with low abundance (1141, 2170%). The environmental factor (both biotic and abiotic) like temperature, rainfall, humidity, vegetations and food sources directly affect the diversity and distribution of insect populations, which was also supported by Morais et al. (1999), Kittleson (2004), Bispo and Olivera (2007) and Goldsmith (2007). The influence of humidity on density and diversity in the environment is likely to be an indirect effect operating via effects on availability. The differences could be the result of habitat and microhabitat differences among the sites. Table 5: Average (±SE) Monthly fluctuation in Species richness (SR), Species diversity (H′), and Species evenness (E/J′) of the collected insects in four study Spots. Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average Sp ec ie s r ic hn es s ( SR ) Spot 1 2.30 2.33 2.34 2.33 2.33 2.34 2.40 2.40 2.37 2.38 2.35 2.38 2.35±0.009 Spot 2 2.05 2.02 2.02 2.04 2.02 2.02 2.01 2.05 2.06 2.05 1.97 2.00 2.03±0.008 Spot 3 2.58 2.61 2.60 2.56 2.58 2.63 2.58 2.58 2.64 2.65 2.66 2.62 2.61±0.01 Spot 4 2.29 2.34 2.33 2.31 2.32 2.31 2.43 2.46 2.43 2.43 2.43 2.46 2.38±0.02 Av er ag e 2. 31 ± 0. 13 2. 33 ± 0. 14 2. 32 ± 0. 14 2. 31 ± 0. 11 2. 32 ± 0. 13 2. 33 ± 0. 14 2. 36 ± 0. 14 2. 37 ± 0. 15 2. 38 ± 0. 14 2. 38 ± 0. 14 2. 35 ± 0. 17 2. 37 ± 0. 15 Sp ec ie s di ve rs ity (H ′) Spot 1 1.45 1.37 1.35 1.34 1.38 1.29 1.32 1.28 1.36 1.36 1.44 1.38 1.36±0.02 Spot 2 1.05 1.07 1.01 1.06 1.09 1.13 1.10 1.08 1.11 1.14 1.06 1.17 1.09±0.01 Spot 3 1.30 1.30 1.27 1.42 1.42 1.18 1.25 1.45 1.29 1.43 1.44 1.22 1.33±0.03 Spot 4 1.22 1.17 1.19 1.30 1.23 1.19 1.30 1.22 1.28 1.31 1.22 1.23 1.24±0.01 Av er ag e 1. 26 ± 0. 09 1. 23 ± 0. 07 1. 21 ± 0. 08 1. 28 ± 0. 11 1. 28 ± 0. 11 1. 20 ± 0. 05 1. 25 ± 0. 07 1. 26 ± 0. 10 1. 26 ± 0. 05 1. 31 ± 0. 09 1. 29 ± 0. 13 1. 25 ± 0. 06 Sp ec ie s e ve nn es s ( E /J ′) Spot 1 0.56 0.53 0.52 0.51 0.53 0.50 0.51 0.50 0.52 0.53 0.56 0.53 0.53±0.006 Spot 2 0.45 0.46 0.43 0.45 0.47 0.49 0.47 0.46 0.48 0.49 0.46 0.50 0.47±0.006 Spot 3 0.50 0.50 0.49 0.54 0.55 0.46 0.48 0.56 0.50 0.55 0.56 0.47 0.51±0.01 Spot 4 0.47 0.45 0.45 0.50 0.47 0.46 0.51 0.47 0.49 0.51 0.47 0.48 0.48±0.006 Av er ag e 0. 50 ± 0. 03 0. 49 ± 0. 03 0. 48 ± 0. 03 0. 50 ± 0. 03 0. 51 ± 0. 03 0. 48 ± 0. 01 0. 50 ± 0. 01 0. 50 ± 0. 04 0. 50 ± 0. 02 0. 52 ± 0. 02 0. 51 ± 0. 04 0. 50 ± 0. 02 https://journals.e-palli.com/home/index.php/ajlsi Pa ge 10 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 The climate condition of the campus is characterized by moderately high temperature, with plenty of sunshine in summer, moderate to excessive humidity, heavy rainfall in rainy season and charming cool dry weather in winter. During the study period temperature varied from 19o C in January to 28o C in May to September and 27o C in October to 20o C in December and mean annual rainfall was 225 mm. Ecologically the campus is a tropical green forest area but the ecology has been suffering badly due to various biotic and abiotic factors and manmade causes. Data of average monthly temperature, rainfall, humidity and wind speed for the entire study period were collected from the practical field study. The data is given below: In the present study, it was seen that some species were Figure 2: Spot-wise Species richness (SR), Species diversity (H), and Species evenness (J) of the collected insects. Table 6: Meteorological Data Month Average Minimum Temperature (˚C) Average Maximum Temperature (˚C) Average Temperature (˚C) Average Rainfall/ Precipitation (mm) Wet Days (>0.1 mm) Relative Humidity (%) Average Wind Speed (mph) Jan’18 13.7 26.4 20.0 6 2 58 1 Feb’18 16.1 28.9 22.5 15 3 58 1 Mar’18 20.4 31.6 26.0 50 5 65 2 Apr’18 23.6 32.3 27.9 120 7 71 2 May’18 25.0 32.4 28.7 233 13 77 2 Jun’18 25.3 30.8 28.0 578 22 83 2 Jul’18 25.2 30.4 27.8 707 26 85 2 Aug’18 25.2 30.5 27.8 517 25 86 2 Sep’18 25.2 31.3 28.2 270 21 84 2 Oct’18 24.0 31.2 27.6 205 8 78 1 Nov’18 19.5 29.3 24.4 52 2 71 1 Dec’18 15.1 26.8 20.9 9 1 68 1 Mean 25.8 230.17 11.25 73.67 1.58 collected regularly while others were rare. These findings are consistent with many community studies, which show that a small number of species dominates the community, whilst the majority of species are relatively rare (El-Moursy et al. 1999). Five out of six insect orders showed seasonal variability. The only insect order Hymenoptera did not show any significant seasonal variation in abundance. Four broad patterns were distinct in the seasonal distribution of fauna. Most of Odonata and Lepidoptera members were significantly higher during pre-summer (January to March, November, and December). Orthoptera and Coleoptera peaked during pre-summer and summer (March-May, November and December). Diptera peaked during the monsoon period (April to June). The number of insects fluctuated in different months of the year due to several reasons. Fluctuations in rainfall appeared to play a role in deciding the abundance of individual and overall fauna, along with other variables such as litter depth, litter moisture, humidity, and temperature that are directly or indirectly related to rainfall and insect population densities (Wagner et al. 2003, Vineesh et al. 2007). On the basis of the present observation and data collection, it can be said insect availability depends not only depended on seasonal fluctuation but also on suitable host plants. Hence, their presence or absence, their abundance serves to monitor ecological changes in habitat thus warning about the deterioration of habitat. CONCLUSION The present study indicates that the insect diversity is https://journals.e-palli.com/home/index.php/ajlsi Pa ge 11 https://journals.e-palli.com/home/index.php/ajlsi Am. J. Life Sci. Innov. 2(2) 1-11, 2023 rich in the CU campus. Moreover, insects play a vital role in the food chain and food web of any ecosystem. So, the present study is providing a clear checklist for environmentalists to understand the present condition of the ecosystem of the CU campus area. RECOMMENDATION This research may help to make a further checklist of insect fauna of the CU campus. Additionally, from the comparative analysis with the previous study it is distinguishable that whether the faunistic diversity increases or decreases as the university developed many infrastructures consequently the human settlement increases day by day. REFERENCES Amin, M.R., Miah, M.S. and Rahman, H. (2018). Functional and group abundance of insects on Eggplant. Bangladesh J. Agril. Res., 43(4), 647-653. Balakrishnan, S., Srinivasan, M. and Mohanraj, J. (2014). Diversity of some insect fauna in different coastal habitat of Tamil Nadu, southeast coast of India. Journal of Asia-Pacific Biodiversity., 7(4), 408-414. Bingham, C. T. (1908). The fauna of British India Including Ceylon and Burma (Butterflies) 2. Taylor and Francis, London, 8. Borror, D. J., Delong, D. M. and Tripplehorn, C. A. (1989). An Introduction to the Study of Insects. Saunders College Publishing. New York. 588-827. Burton, J. (1974). The Oxford Book of Insects. Oxford University Press, Ely House, London. 208. El-Morsey, A.A., Gilbert, F., Zalat, S. and El-Hawagry, M.S. (1999). Foraging behavior of anthacine flies (Diptera:Boombyliidae) in southern Sinai, Egypt. Egyptian Journal of Biology, 1, 87-95. Gleason, H.A. (1922). On the relation between species and area. Ecol., 3, 156-162. Fraser, F.C. (1936). The Fauna of British India including Ceylon and Burma. Odonata., 2, Today and tomorrow’s printers and publishers. 461. Hong, E., Jeon, Y. Yoon, J. Kim, J. Lee, J. Park, S. Kim, K. Kim, J. Kim, B. (2012). Insect Diversity of Mt. Seosan. Journal of Korean Nature, 5(3), 251-266. Kittleson, J.M. (2004). The Role of Discourse in Group Knowledge Construction: A Case Study of Engineering Students. Journal of Research in Science Teaching, 41(3), 267–293. Kirby, W.F. (1914). The Fauna of British India including Ceylon and Burma. Orthoptera., 1, (Acrididae).Today and Tomorrows pinters and publishers, 276. Lloyd, M. and Ghelard, R. J. (1964). A table for calculating the eaitability component of species diversity. Journal of Animal Ecology, 33, 217-225. Maulik, S. (1919). The Fauna of British India including Ceylon and Burma. Coleoptera, Chrysomelidae. Today and tomorrow’s printers and publishers, 439. Nasiruddin, M. and Hoque, H. (2015). Abundance and Diversity of Insect Fauna in Four Spots of Chittagong University Campus. J. Biod. Cons. Biores. Manang., 1(1), Nasiruddin, M. and Shiuli, F. A. (2017). Entomofauna of four spots of Chittagong University Campus and their relative abundance and diversity. J. biodivers. conserv. bioresour. manag., 3(1). Park, S., Lim, H., Hong, E.J. and Jeon, Y. (2012). Survey on Insect Diversity of Yeonpyeong-do Island, Korea. Journal of Korean Nature, 5(1), 17-26. Pielou, E.C. (1966). The Measurement of Diversity in Different Types of Biological Collections. Journal of Theoretical Biology, 13, 131-144. Rahman. M., Maleque, M.A., Uddin, M.S. and Ahmed, J. (2017). Abundance and diversity of beneficial insect and spider species on rice ecosystem in Sylhet region. J. Sylhet Agril. Univ., 4(1), 63-70. Resh, V. H. and Carde, H. T. (2003). Lepidoptera; Encyclopedia of Insects. J. A. Powell. Academic Press. 631-664. Richards, O.W. and Davies, R.G. (1977). Imm’s General Textbook of Entomology. 2, 10th ed. Classification and biology Chapman and Hall, London, England. 1354. Sánchez-Bayo, F. and Wyckhuys, K. A. G. (2019). Worldwide decline of the entomofauna: A review of its drivers. Biological Conservation., 232, 8-27. Siddiki, A. (2015). Insect diversity and composition during the wet and dry seasons in three forest types of Johor, Malaysia. M.S. Thesis. Faculty of Science, Technology and Human Development Universiti Tun Hussein Onn Malaysia. Siregar, E.H., Atmowidi, T. and Kahono, S. (2016). Diversity and Abundance of Insect Pollinators in Different Agricultural Lands in Jambi, Sumatera. Hayati Journal of Biosciences, 23(1), 13-17. Talbot, G. (1975). The Fauna of British India Including Ceylon and Burma. Butterflies, 1, First Indian reprint edition. Today and tomorrow’s printers and publishers, 600. Van Emden, F.I. (1965). The Fauna of India and adjacent countries. Diptera. Vol. 7. Muscidae. Part 1. Today and tomorrow’s printers and publishers, 647. Vineesh, P.J., Thomas, S.K. and Karmaly, K.A. (2007). Community structure and functional group classification of litter ants in the montane evergreen and deciduous forests of Wayanad region of Western Ghats, Southern India. Oriental Insects, 41, 185-200. Wagner, J.D., Toft, W.S. and Wise, D.H. (2003). Spatial stratification in litter depth by forest floor spiders. Journal of arachnology, 31, 28-39. Zou, Y. (2014). Insect diversity patterns along environmental gradients in the temperate forests of Northern China. Ph.D. Thesis. University of London. https://journals.e-palli.com/home/index.php/ajlsi