International Journal of Scientific Research in ______Research Paper . Biological Sciences Vol.6, Issue.6, pp.23-25, December (2019) E-ISSN: 2347-7520 DOI: https://doi.org/10.26438/ijsrbs/v6i6.2325

The Effect of Weather Factors On the Population Dynamics of Reduviids (Insecta: : ) From Semi-Arid Area of Sivakasi Taluk, Virudhunagar District, Tamil Nadu

S. Jaya Durkga1*, D.N.P. Sudarmani2, C. Sundareswari3

1,2,3Dept. of Zoology, Ayya Nadar Janaki Ammal College (Autonomous), Sivakasi - 626 124

*Corresponding Author: [email protected]

Available online at: www.isroset.org

Received: 18/Aug/2019, Accepted: 16/Dec/2019, Online: 31/Dec/2019 Abstract: The species of the reduviid bugs of family Reduviidae under Order Heteroptera (Insecta: Reduviidae) is not only one of the most abundant groups but also showing significant economics and high scientific value. Many reduviid species play an important role in the food chain of and plants, as well as the ecological balance. Population dynamics of reduviid bugs were studied during June 2018- March 2019 in semi-arid area in Sivakasi Taluk. The reduviids were randomly collected and identified some field records. A total of 11 species belonging to 5 subfamilies were identified in selected study area. During the study period maximum numbers of reduviid bugs were recorded during the November 2018 and minimum numbers of reduviid bugs were recorded during March 2019. Monthly variation in relative abundance of reduviid population also noted. Various diversity indices were recorded and correlation co-efficient studies were carried out between reduviid bug diversity and weather parameters.

Keywords: Reduviid bugs, diversity, relative abundance, diversity indices, correlation coefficient.

I. INTRODUCTION

Insects began to settle in the lower Devonian period these are the presiding species in the Kingdom Animalia, because of their potential to withstand all kinds of climatic conditions [9]. Reduviid bugs often constitute a large and diverse group, have many fascinating specialized habits and as predators have considerable but unrealized potential as biocontrol agents. Reduviid (: Reduviidae) predators are the largest terrestrial bugs consisting of 7000 species and subspecies, 913 genera and 25 subfamilies [1]. In India, there are about 464 species belonging to 144 genera and 14 subfamilies [2]. Despite the abundance of the world’s reduviid fauna and its rich taxonomic, geographical, ecological, trophic, morphological, biological and behavior diversity, studies regarding the temperature effects on reduviid are relatively meager [3]. If the reduviids have to be conserved and augmented [4], a comprehensive and elaborate understanding of bioecology vis-a-vis climate is needed [5]. In the present study is to analyse the diversity and population dynamics and impact of abiotic factors, in on semi-arid area of sivakasi taluk, Virudhunagar District, Tamil Nadu.

II. MATERIALS AND METHODS

The study area Sivakasi is located between longitude 9.45 ⁰ N, latitude 77.8167 ⁰ E, with an elevation of 101 meters (331 feet). The study was conducted in the months of June 2018 to March 2019. Semi-arid area spreading over an area of 2ha were selected for sampling. Samples were collected fortnightly by hand picking method. The reduviid species were identified using already available literature and some field records. Statistical analysis was conducted to determine diversity, richness (margalef index), evenness, abundance and Correlation coefficient using the software PAST.

III. RESULTS AND DISCUSSION

A total of 314 species belonging to five different subfamilies and 11 species were captured throughout the study period. The subfamily Peiratinae was the most abundant subfamily comprised of 4 species. Among the five subfamilies, Harpactorinae

© 2019, IJSRBS All Rights Reserved 23 Int. J. Sci. Res. in Biological Sciences Vol. 6(6), Dec 2019, ISSN: 2347-7520 which is represented by three species was most abundantly present in the study area, Reduviinae which is represented by two species present in the study area, the subfamily Ectrichodinae and Tribelocephalinae were each represented by single species (Table 1). Previously [6] reported that 57 reduviid species distributed in 28 genera in Central Highlands of Vietnam, among them, 28 species distributed in 17 genera of subfamily Harpactorinae. In Vietnam, the Harpactorinae is the largest reduviid subfamily, including more than 34 genera and 62 species. Formerly, [7] collected 95 nontibiaroliate reduviids and majority of them are harpactorines, out of which, 24 species from scrub jungles, 18 species from semiarid zones, 47 species from tropical rainforest and 39 species from agroecosystems of South India. Likewise the evaluated value for species evenness ranged from 0.8083 to 0.9386 and the calculated value of Shannon - Weiener index was ranged between 1.6- 2.3. The lowest diversity index was calculated in the month of March (1.676). The highest value was found in the month of November (2.334) (Table 2). Population dynamics of Reduviid bug shows negative correlation with the minimum and maximum temperature, -0.132 and - 0.278 respectively (Table 3), which means when the temperature increases the reduviid bug population suffers and decreases in number. Population of reduviid bug gives positive correlation with rainfall (0.016) (Table 3),that means when rainfall occurs the favourable condition for reduviid bug arises then the reduviid bug increases in numbers. Similarly [8] reported that physical factors like temperature, relative humidity, rainfall and wind velocity have no correlation with reduviid population under study in semiarid zones.

Table 1: Showing different reduviid bugs in study area of Sivakasi taluk: S. No Sub-family Species Name 1 Ectrichodinae Ectrychotes dispar Reuter 2 Harpactorinae Rhynocoris marginatus (Fabricius) 3 Harpactorinae Rhynocoris kumarii (Fabricius) 4 Harpactorinae Rhynocoris longifrons (Stal) 5 peiratinae Catamiarus brevipennis (Serville) 6 peiratinae Ectomocoris quadriguttatus (Fabricius) 7 peiratinae Ectomocoris tibialis 8 peiratinae Ectomocoris cordiger 9 Reduviinae Acanthaspis pedestris 10 Reduviinae Acanthaspis siva Distant 11 Tribelocephalinae Tribelocephala sp.

Table 2: Species richness, Evenness, Shannon diversity indices of Reduviids on study area: Diversity June July 2018 Aug Sep 2018 Oct 2018 Nov Dec 2018 Jan 2019 Feb 2019 Mar indices 2018 2018 2018 2019 Number of 35 29 21 28 35 68 47 25 14 12 individuals Species 2.531 2.376 2.628 2.401 2.531 2.37 2.338 2.175 2.274 2.012 richness Evenness 0.8901 0.8555 0.8924 0.8455 0.8966 0.9386 0.8503 0.8083 0.928 0.8909

Shannon 2.186 2.041 2.083 2.029 2.193 2.334 2.14 1.867 1.871 1.676 diversity index Relative 11.14 9.23 6.68 8.91 11.14 21.65 14.96 7.96 4.45 3.82 Abundance %

Table 3: Correlation coefficient of reduviid bug population with weather parameters Weather Parameters Correlation coefficient (r) Temperature (⁰C) Maximum -0.132 Minimum -0.278 Rainfall (mm) Monthly 0.016

IV. CONCLUSION

The main objective of the study was the species diversity of Reduviids in semi-arid area of Sivakasi Taluk in relation to weather factors was studied. From the relative abundance, species richenss, evenness index, Shannon index it was concluded that there is more or less similar diversity was occur throughout the study period. When focus on correlation coefficient this clearly indicates that increase in rainfall and temperature affects the Reduviid bugs population in the study area.

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ACKNOWLEDGEMENT

I wish to express my immeasurable gratitude and special tribute to Principal and management of Ayya Nadar Janaki Ammal College (Autonomous), Sivakasi for the facilities provided.

REFERANCES

[1] Capriles, J. M. Systematic Catalogue of the Reduviidae of the World (Insecta: Heteroptera), University of Puerto Rico, p. 694, 1990 [2] Sahayaraj, K. Reduviids and their merits in biological control. In Basic and Applied Aspects of Biopesticides, Springer India, pp. 195–214, 2014 [3] Ambrose, D. P. A checklist of Indian assassin bugs (Insecta: Hemiptera: Reduviidae) with taxonomic status, distribution and diagnostic morphological characteristics. Zoos Print Journal., 21, 2388–2406, 2006 [4] Schaefer, C. W. Reduviidae (Hemiptera: Heteroptera) as agents of biological control. Bicovas, 1, 27–33, 1988 [5] Ambrose, D. P. Biocontrol potential of assassin bugs (Hemiptera: Reduviidae). Journal of Experimental Zoology., 6, 1–44, 2003 [6] Ambrose, D.P. and D. Livingstone. Population dynamics of three reduviids from Pennisular India. Bulletin of Entomology., 19: 201-203, 1978 [7] Ravichandran, G. Biosystematics and ecophysiology of the non tibiaroliate assassin bugs (Heteroptera: Reduviidae) of southern India. Ph. D., Thesis. Bharathiar University, Coimbatore, India. 1988 [8] Truong Xuan Lam, Wanzhi Cai, Massaki Tomokuni & Tadashi Isikawa. The assassin bug subfamily Harpactorinae (Hemiptera: Reduviidae) from Vietnam: an annotated checklist of species. Zootaxa 3931(1): 101–116, 2015 [9] Riyaz. E, Mathew. P, Paulraj. G and S. Ignacimuthu. Entomophily of apple ecosystem in Kashmir Valley, India: A review. International Journal of Scientific Research in Biological Sciences, Vol.5, Issue.5, pp.155-163. 2018

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