Species Composition and Relative Abundance of Beetles in Non-Crop Habitats

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Published on International Journal of Agriculture & Agribusiness
Publication Date: April 23, 2019

Khin Myint Mar
Associate Professor, Department of Zoology
University of Magway
Myanmar

Journal Full Text PDF: Species Composition and Relative Abundance of Beetles in Non-Crop Habitats (Study at Myitkyina University Campus).

Abstract
A total of 296 beetles belonging to 35 species, 32 genera, 11 families under Order Coleoptera were collected from grasslands, shrub and garden vegetables at Myitkyina University Campus, Kachin State during October 2016 to November 2017. The study site was chosen randomly within the University Campus. The specimens were collected by hand picking and sweep net. The percent composition of species in different families was described as the highest in Family Chrysomelidae (28.57 %), followed by Scarabaeidae (17.14 %), Curculionidae and Coccinellidae (14.29 % each), Carabidae (8.57 %) and the lowest in Families Cerambycidae, Endomychidae, Elateridae, Hydrophilidae, Meloidae and Tenebrionidae (2.86 % each) respectively. Among the collected beetles sampled, Aulacophora foveicollis (6.76 %) was the most abundance while Anomala antiqua (0.68 %) was the least. In the present work, 46% of the studied species was high status of pests and 54% was low. Three species of the genus Sagra, Chrysina and Sphodrus were not clearly identified down to species level. Identification will enable the pest status of the beetles to be established and give the baseline information for future research.

Keywords: Beetle, Myitkyina University, Kachin State, Species Composition & Abundance.

1. INTRODUCTION
There are more than 850,000 species of insects on earth, more than all the other plants and animals combined. Great number of the insects, nearly half are beetles. Contrasting other insects, beetles have a pair of leathery protective wings called elytra that cover their membranous flight wings. Beetles are included in the Order Coleoptera, about 400, 000, the largest of all orders in the Superorder Endopterygota. Their front pair of wings, elytra is hardened into wing-cases, elytra. Adult beetles are usually easily recognized by their strongly sclerotized forewings, which form a strong protection shield. During flight, elytra are spread apart and two flight wings are unfolded and extended. Beetles come in a variety of shapes and colors, from red “lady bugs” and metallic green fig beetles to lightning beetles that glow in the dark and huge horned beetles resembling a miniature rhinoceros. Colorful beetles are used for jewelry and pins, and shiny tropical scarab beetles are strung together to make unusual necklaces. The beetles range in size from less than a millimeter (1/100 of an inch) to tropical giants over six inches long. The largest giants may weigh 40 million times more than their lilliputian relatives..
The Order Coleoptera is represented by some 370,000 known species (Lawrence et al., 1999), but recent estimates suggest that there are hundreds of thousands and even millions of undescribed species. Beetles are not only rich in species, but also, extremely rich with respect to diversity in size, form, and ecological strategies. The largest beetles, Longhorn Beetles (Cerambycidae) from the Amazon, may be as long as 18 cm, while the smallest ones, feather wing beetles (Ptiliidae), measure less than half a millimeter (Sörensson, 1997). The oldest beetle fossils are known from the Lower Permian (~ 280 million years) (Lawrence et al., 1999). Beetles are holometabolous insects, i.e. their life stages are egg – larva – pupa – adult. Although the vast majority of beetles are terrestrial, at least 10,000 species are regarded to be aquatic in one or more of their developmental stages (cited by Balke et al., 2014).
Myitkyina University is located on the eastward of Myitkyina, west bank of Ayeyawady River, northern Myanmar. Many variety of vegetables, grasslands, shrubs and trees were grown in the University Campus in all the year-round.
This paper reviews the occurrence of beetles prevalent in northern Myanmar and to pay the basic information to students. For these reasons, the aims of this study are:
a. to record and identify the occurrence of some beetles and
b. to analyze the species composition and relative abundance of beetles.

1.1 Statement of the problem
The statement of the problem is a survey of beetles in the Myitkyina University, northern Myanmar.

1.2 Objective
The objective of this study was to survey and record the species composition, relative abundance and the pest status of the species studied.

2. REVIEW OF LITERATURE
Leather et al. (1999) published the distribution and abundance of ladybirds (Coleoptera: Coccinellidae) in non-crop habitats. They informed coccinellids were most frequently found on grassland habitats. In 1999, Waterhouse described major arthropod pests and weeds of agriculture in Southeast Asia. In 2002, Rao et al. reviewed the population of different insect pests was reduced in intercropping if suitable intercrop was selected.
Chanthy et al. (2010) described Insects of Upland crops in Combodia. A field guide to identifying insect pests and beneficial insects and spiders in the upland cropping systems of Cambodia. Mulerčikas et al. (2012) documented Species Composition and Abundance of Click-Beetles (Coleoptera, Elateridae) in Agrobiocenozes in Southern Lithuania in which 13 species and 10 genera examined and the highest abundance of click-beetles was detected in the seminatural meadow with light granulometric structure soil.
Jagdale and Magdum (2017) studied the diversity and abundance of Coleopteran insects belonging to Family Scarabaeidae, Geotrupidae, Hybosoridae from Nashik, Maharashtra, India in which they identified the 24 types of dung beetles.

3. Materials and Methods
3.1 study area
The study area was located at Myitkyina University Campus (25˚ 26΄18.928˝ N latitude and 97˚ 25΄51.901˝ E longitude), Kachin State, northern Myanmar (Fig.1).

3.2 Study period
Survey period was lasted during October 2016 to March 2017.a University Campus, northern Myanmar)

3.3 Specimen Collection
The specimens were collected randomly by hand picking and insect net. The collected specimens were placed in the plastic containers and transported to Department of Zoology for identification. The specimens were examined and recorded the size, antennae, coloration and the patterns on the wings. Then, the specimens were taken photo, measured and killed by soap solution and mounted for further study (Hopkins et al., 2012).

3.4 Species Identification
The identification was followed after Ghosh, (1940), Imms (1963), Borror and Delong, (1964), Heisswolf et al. (2010) and Nair (2012). The physical appearances of insects were noted down and photos were also taken immediately after capturing the insects. The collected specimens were mounted for further studies.

3.5 Killing and mounting methods
Collected insects were killed in a jar containing ethyl acetate following after Hopkins et al. (internet accessed Hopkins et al., July 25, 2012). Leaf beetles were pinned down and stored in insect box and moths were dried and mounted. Some of the pests collected at nymph or larval stages were reared in the laboratory until the adults emerged.
Insects were collected alive for study alive. To do this, the specimens were collected into suitable plastics containers and transport them. For preservation, the specimens collected were killed rapidly to prevent damage.
Large specimens were killed in a jar with closely fitting lid using a volatile toxicant such as 70% alcohol or soapy water. Plastic vials were very useful in the field.

3.6 Data Analysis
Data obtained was analyzed using Microsoft Excel (2013). Descriptive statistics, the relative abundance and percent composition of species were presented. Relative abundance (dominance or relative density) was calculated following the formula of Fager (1957) and Wallwork (1976).

4. RESULTS AND DISCUSSION
In the field survey, a total of 296 specimens belonging to 35 species, 32 genera, 11 families under Order Coleoptera were collected and identified from Myitkyina University Campus during October 2016 to November 2017 (Table 1). The colored photos of each species were presented in Appendix. A total of 35 coleopteran species from 11 families were recorded during the present investigation (Table 2). Of these 32 coleopteran insects were identified up to the species level and three up to the genus level. Three species of the genus Sagra, Chrysina and Sphodrus were not clearly identified down to species level.
In the present investigation, family Chrysomelidae showed prominent species richness and abundance amongst the eleven families trailed by Scarabaeidae with 6 species, Curculionidae and Coccinellidae were with 5 species each, Carabidae with three species and the least prominent families Cerambycidae, Endomychidae, Elateridae, Hydrophilidae, Meloidae and Tenebrionidae with one species each respectively. The percent composition of species in different families was described as the highest in Family Chrysomelidae (10 species, 28.57 %), followed by Scarabaeidae (6 species, 17.14 %), Curculionidae and Coccinellidae (5 species, 14.29 % each), Carabidae (3 species, 8.57 %) and the lowest in Families Cerambycidae, Endomychidae, Elateridae, Hydrophilidae, Meloidae and Tenebrionidae (one species, 2.86 % each) respectively (Table 2 & Fig. 2). Among the collected beetles sampled, Aulacophora foveicollis (6.76 %) was the most abundance while Anomala antiqua (0.68 %) was the least. Concerning with pest status, 46% of the studied species showed high status of pests and 54% was low status (Fig. 3).
During the study period, Aulacophora foveicollis was the most abundant species (20 individuals, 6.76%) while Anomala antiqua was the least one (2 individuals, 0.68%) (Table 3). The coleopteran beetle collection at Myitkyina University Campus were dominated by family Chrysomelidae.
In this study, the highest number of species was found in January 2017 while the lowest number of that in December 2016. This could be the reason why low temperature and humidity seems to be favorable for the species occurred during this month.
It was seem to be considerable variation in composition and abundance in different collection time of the study period. Within the time limits of the present work it was impossible to identify the some specimens. The species composition of beetles may be different among different time of the year in any long-term study depending on the amount of rainfall, temperature and humidity.