Taxonomical Identification of the Genus: Myrmeleon Present on The Campus of the PRSU Up to the Species Level

 ^1,*Priyanka Chakradhari, ²Bhupendra Kumar Sahu, ³Atanu Kumar Pati, ⁴Arti Parganiha

^1,4School of Studies in Life Science, Pandit Ravishankar Shukla University, Raipur-492010, India

²Department of Zoology, Government College Ramchandrapur, Balrampur- 497220, India

³Kalinga Institute of Social Sciences- Deemed to be University, Bhubaneswar- 751024, India

¹priyankachakradhari12@gmail.com, ²bhupi5march92@gmail.com, ³akpati19@gmail.com,  ⁴arti.parganiha@gmail.com

Abstract

The current research was conducted to identify the species of antlion present on the campus of Pandit Ravishankar Shukla University (PRSU) in Raipur, Chhattisgarh. We first obtained a well-planned map of PRSU campus (employed with 500 m² grids) from the administrative section of the university. Further, we randomly selected five different locations from those grids where the pits were found more frequently. We collected two larvae of each instar stage and two adults from each of the study locations. In this way, we collected a total of six larvae and two adults from each of the locations. We had a total of 40 specimens from five locations. We preserved all those larvae and adults in 70% alcohol. These specimens were sent to the Zoological Survey of India for their identification up to species level. All specimens were identified as Myrmeleon tenuipennis species by ZSI. In addition to antlion species (Stenares improbus), for the very first time, our current study represents the distribution of another species of antlion (i.e., Myrmeleon tenuipennis) in Raipur district. This study holds great importance from a taxonomical perspective. It aids in exploratory investigations regarding Neuroptera and provides additional taxonomic information on antlion species. Specifically, the study offers comparative morphological characteristics of the larvae of M. tenuipennis. A better understanding of the distribution of antlion larvae in Chhattisgarh and central India is needed for further exploration.

Keywords: antlion larvae, pit-building behavior, antlion species, antlion adult

Introduction

Phylum Arthropoda has the most excellent variety and number of species in the animal kingdom and antlion is one of them. The Antlion is a well-known insect for creating pits and utilizes them to catch ants and other prey (Chandra et al., 2014). The larvae of antlion are found in sandy habitats and create conical shaped pits in dry and loose sand. There are roughly 5,000 species of Neuroptera worldwide, out of which 335 species are found in India and they belong to 125 genera and 13 families. There are 33 species of Neuroptera out of which 17 species belonging to the family Myrmeleontidae have been reported from Madhya Pradesh and Chhattisgarh region (Chandra et al., 2014).

According to Stange (2004), the largest family of Neuroptera is the Myrmeleontidae, also referred to as the antlion family. Acevedo et al. (2013) studied two European species of genus Diolein (i.e., D. annulatus and D. tetragrammicus). Both species can be clearly distinguished by their unique body patterns and colors. D. annulatus is yellowish and sand-like, and the median stripe on the dorsal side of the abdomen is only made up of a series of dark spots. In contrast, D. tetragrammicus is overall dark brown, and the annulated pattern of the dorsal side of the abdomen is a diagnostic characteristic of all three larval stages.

Myrmecaelurus, a genus of antlions having 50 species, is restricted to Central and Southern Europe, North Africa, and significant portions of Asia (Stange, 2004). According to Machado et al. (2019), Myrmeleontidae (antlions or doodlebugs) is the largest family having more than 1600 known species in the order Neuroptera.

As with most neuropterans, a holometabolous development (complete development) is found in antlion (Kaleka et al., 2019). The female deposits around 20 eggs in the ground (Gotelli, 1997; Hollis et al., 2015). After emergence from the egg, the antlion goes through three different stages (Gotelli, 1997). The first stage is the larval stage, which lasts for a very long time, maturing after one to three years. Larvae follow the molting process and go through three instar stages, i.e., first, second, and third instar larvae, before becoming a pupa (Hollis et al., 2015). Ants and other tiny insects are major prey during their larval stage. The second stage is pupa, which lasts for approximately a month. A pupa creates a cocoon made up of sand, and an adult emerges from it after about a month (Hollis et al., 2015). The third one is the adult imago stage, which is a tiny, winged creature with weak wings and a short lifespan. Adults live for 25 to 45 days only on average. They are weak flying insects that mostly fly at night (Hollis et al., 2015). Adults consume nectar.

Larvae live in the sand and because of their unusual prey-capturing habit as well as their peculiar patterns, the antlion larvae are sometimes known as sit-and-wait predators. An ability of antlion larva to dig pits is a distinctive trait and it is very crucial for its survival, development, and transformation. The parameters known to affect the pit-building behavior of antlion include sand particle size, density, temperature, rain, the presence or absence of prey, habit, and environment (Lucas, 1982, 1989; Day and Zalucki, 2000).

According to Fisher (1989), the antlion species are one of the most significant insects in terms of ecology. Sandy soil is a good place to look for antlions. They are powerful predators, so they are crucial biological pest controllers. The antlion largely consumes ants and other tiny insects, but are themselves a tasty prey for nocturnal animals like birds, bats, and other nocturnal fly eaters. The weak-flying adult antlion competes with other individuals in the colony for mate selection and egg production (Fisher, 1989).

An antlion is a common fly in the central part of Chhattisgarh. When we searched for the published record on antlion, we found only a single report regarding antlion species in this region. Only Chandra et al. (2014) reported that 17 species belonging to the family Myrmeleontidae. They have reported these 17 species in Madhya Pradesh and Chhattisgarh as a combined region mostly in forest and rural areas. In the current study, we highlighted the species found in the central Chhattisgarh region to extend the study of Chandra et al. (2014). We wanted to explore whether the species of antlion present in the PRSU campus (i.e., situated in an urban area) is different or the same. From a taxonomical extension point of view, the current study was aimed to identify the species of antlion larvae.

Materials and methods

Study area

The current research was conducted on the campus of Pandit Ravishankar Shukla University (PRSU) in Raipur, Chhattisgarh (Figure 1). It is located in the central part of India.

Figure 1. The figure illustrates the exact location of Chhattisgarh state over the map of India. Raipur city is the capital of Chhattisgarh. The inset (right-hand side) is the map of the Pandit Ravishankar Shukla University (PRSU) campus situated in Raipur city. It represents a well-planned map of the campus employed with 500 m² grids.

Identification and selection of location

We first obtained the map of PRSU campus from the administrative section of the university. They provided a well-planned map employed with 500 m² grids. We followed all the grids systematically and observed the whole PRSU campus to search the locations where antlion larval pits were found. We noted down the grids having pits of antlion larvae. Further, we identified various locations within the grid where pits were found more frequently. For collecting specimen, we randomly selected five different locations where we found the most frequent pits during our preliminary field observation. The five different study locations used in this study are: (1) C.G. State Antyavasai Sahakari Vitta Evm Vikas Nigam (Latitude: 21.24254° N; Longitude: 81.59437° E), (2) Exam cell (Latitude: 21.242537° N; Longitude: 81.594128° E), (3) Parking (Latitude: 21.245622° N; Longitude: 81.593855° E) in School of Studies in Life Science, (4) School of Studies in Computer Science and Information Technology (Latitude: 21.247419° N; Longitude: 81.593517° E), and (5) Animal House, School of Studies in Life Science (Latitude 21.253006° N, Longitude 81.593896° E). Figure 2 represents the exact positions of all five locations studied in the PRSU campus.

Figure 2. The red circles with numbers within the Pandit Ravishankar Shukla University (PRSU) campus map represent the exact position of the five randomly selected study locations. These locations had the most frequent pits during our preliminary field observation.

Collection and storage of specimens

We identified the conical pit of antlions and collected larvae. We collected two larvae of each instar stage and two adults from each of the above-mentioned locations (Figure 3). In this way, we had a total of six larvae and two adults from each of the locations. We had a total of 40 specimens (30 larvae and 10 adult) from five locations. We preserved all those larvae and adults in 70% alcohol (Hauber, 1999; Aldini, 2005; Satar et al., 2006) and kept them in small individual bottles (Figure 4). These small individual bottles were further kept in large-sized bottles with respective locations. Finally, we sent all specimens to the Zoological Survey of India (ZSI), Kolkata, for identification of the species. The antlion larvae were found observed in all three seasons of the year in the PRSU campus but adults were mostly observed in rainy season. Therefore, the specimen collection was carried out during Rainy season at 10.00 AM to 02.00 PM for collecting both larvae and adults.

Figure 3. The life cycle of an antlion includes three different stages, i.e., larvae, cocoon, and adult. A larva [a-1^st instar, b- 2^nd instar, c- 3^rd instar] has well-developed mandibles and forms conical-shaped pits (d) to capture their prey. They go through three instars by metamorphosis, i.e., first, second, and third instar stages. Third instar larvae form a cocoon or pupa (e). From the cocoon, a newly folded winged adult emerged (f). This newly hatched adult developed an adult imago which lays eggs in the soil to continue the next life cycle.

Figure 4. Depicting the preservation method used in this study. Eight specimens (L1- 2 individuals; L2- 2 individuals; L3- 2 individuals; adult- 2 individuals) were collected from each of all five locations, (a) Location 1, (b) Location 2, (c) Location 3, (d) Location 4, and (e) Location 5. (f) Representing all 5 large-sized bottles containing eight small bottles each.

L1 - First instar, L2 - Second instar, L3 - Third instar

Results

The whole PRSU campus is imposed by 8 grids. We found antlion distribution (i.e., pits of larvae) at 11 different locations of grid numbers 3, 4 and 7. All those identified 11 locations has sandy soil (composed of sand particles of various size). Others grids were devoid of sandy soil and most surface were covered with concrete. This might be the reason behind non-appearance of pit distribution of antlion larvae. We randomly selected 5 locations from 11 identified locations for the further specimen collection purpose.

Identification report of ZSI

The details of specimens identified by the Zoological Survey of India (ZSI, Lot No. 53/2019) are mentioned in Table 1.

Identification and classification

The Zoological Survey of India (ZSI) identified the species and classified them as follows:

Phylum       : Arthropoda

Class           : Insecta

Order          : Neuroptera

Family        : Myrmeleontidae

Subfamily   : Myrmeleontinae

Tribe           : Myrmeleontini

Genus         : Myrmeleon

Species       : tenuipennis

As per the previously published article, only a single species (i.e., Stenares improbus) was identified in Raipur district. For the very first time, our current study represents the distribution of another species of antlion (i.e., Myrmeleon tenuipennis) in Raipur district. Previously, this species (Myrmeleon tenuipennis) was only identified in the Bastar region of the Chhattisgarh state.

Discussion

Antlion is characterized by its larval behavior regarding building pitfall traps. As a predator they control the pest (i.e., they eat other insects, including potentially dangerous pests of crops and forest plants. In this way, the antlion is an extremely significant creature from both economic and ecological perspectives.

The tribe Myrmeleontini is diverse and has a cosmopolitan distribution. The IUCN has not assigned formal conservation status to this species, i.e., has not listed it on the IUCN Red List. The reason behind it is that Myrmeleon is distributed in most parts of Asia, and it is not currently classified as an endangered species. However, the local population is being threatened by habitat destruction due to the process of constructing surfaces, roads, drains, or passages using cement concrete.

There are about 2,000 species of antlion that have already been described worldwide but the authentic documentation of the antlion species is very much limited in Chhattisgarh state. We found only a single report regarding antlion species in this region. Only Chandra et al. (2014) explored and described 17 species belonging to the family Myrmeleontidae. They have reported these 17 species in Madhya Pradesh and Chhattisgarh as a combined region mostly focused on forest and rural area. Distribution of some species of antlions such as Palpares pardus (Rambur) in Koriya, Surguja, Bilaspur, Raipur, Kabirdham districts; Stiphroneura inclusa (Walker) in Koriya, Kabirdham district; both Hagenomyia sagax (Walker) and Hagenomyia marginicollis (Gerstaecker) in Bilaspur district; Creoleon griseus (Klug) in Bastar region has already been identified. In the current study, we highlighted the species found in the central Chhattisgarh region to extend the study of Chandra et al. (2014). Previously, only a single species (i.e., Stenares improbus) was identified in Raipur district. For the very first time, we highlighted the distribution of another species of antlion (i.e., Myrmeleon tenuipennis) in Raipur district especially in PRSU campus. Previously, the species Myrmeleon tenuipennis was only identified in the Bastar region of the Chhattisgarh state. From a taxonomical extension point of view, the current study is very important for highlighting and exploring the antlion species found in the central part of Chhattisgarh.

M. tenuipennis is a common species in the central region of Chhattisgarh as we found most of the places other than the PRSU campus (not published). The larvae of the M. tenuipennis are noticeably similar in morphology to the D. tetragrammicus which were studied by Acevedo et al. (2013), however, they can be easily distinguished by their distinctive body coloration and pattern. D. tetragrammicus appears dark brown whereas we observed that M. tenuipennis is light brown.

The species M. tenuipennis in the Raipur district of Chhattisgarh region is described for the first time in our current study. This report will help to study antlion distribution pattern in central part of the country as well as globally.

Conclusions

The Zoological Survey of India (ZSI) identified the species as Myrmeleon tenuipennis. This study holds great importance from a taxonomical perspective. It aids in exploratory investigations regarding Neuroptera and provides additional taxonomic information on antlion species and its distribution.

Future direction

The current study offers further taxonomical extension and comparative morphological characteristics of the larvae of M. tenuipennis. A better understanding of the distribution of antlion larvae in Chhattisgarh and India is needed for further exploration. An exploratory study on unusual prey-capturing behavior of Myrmeleon tenuipennis larvae is remain to be highlight.

Disclosure statement

 All authors agree with the contents of the manuscript and declare no conflict of interest

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