New species and subspecies of Rutelinae

 

Arvind Agrawal

Human Resource Development Centre, Pt. Ravishankar Shukla University, Raipur – 492 010, (C. G.)

 

Abstract:

Rutelinae constitutes the second largest subfamily of Scarabaeidae in India with around 400 described species in five tribes. The last comprehensive taxonomic revision of the group was by Arrow, 1917 through a fauna of British India Volume on the group. Since then there is no revision of the group. Arrow’s work had a reasonably good collection base covering most areas of India. But Chhattisgarh and many other states remain unrepresented in his work. Even the states represented are, however, poorly sampled. Since 1917, few additions made have also failed to properly sample the country.

 

 

 

INTRODUCTION:

Rutelinae is a group of beetles of high economic importance. They are all phytophagous and are of great significance agriculturally as pests of a wide variety of cultivated crops. Rutelines are phytophagous both as larvae and as adults. The larvae cut the roots of plants and kill them. Adults feed on foliage, reproductive parts. Many species, such as Anomala dimidiata (Hope), Anomala bengalensis Blanchard, Anomala ruficapilla Burmeister, Anomala varicolor (Gyllenhal), Popillia schizonycha Arrow, Mimela xanthorrhina Hope, Pachyrrhinadoretus rugipennis Ohaus, Adoretus versutus Harold, Adoretus horticola Arrow have been considered to be pests of various cultivated crops, particularly of the family Rosaceae, Papilionaceae, Vitiaceae, etc.

 

However, the identities of many species of Rutelinae damaging crops remain unsolved. This situation is primarily because of lack of a comprehensive treatise on the Rutelinae of India, after Arrow’s 1917 volume of Fauna of British India. Further, in our studies, so far, we have been encountering many species of uncertain identities. The major work by Arrow, published in 1917, has left large areas of India uncovered for sampling Rutelinae. From political India, states, such as Rajasthan, Madhya Pradesh, Bihar, Jharkhand and Chhattisgarh are virtually unrepresented. Further, from South India, most sampling is restricted to hilly areas and plains in particular are completely lacking in representation.

 

Rutelinae are elongated oval small to medium sized Scarabaeid beetles that are primarily distinguished on the basis of unequal and moveable claws.

 

Since Blanchard (1851) the group has been referred to as a subfamily of Scarabaeidae, although other treatments do exist. Tribal classification of the subfamily is stable, but some tribes may be paraphyletic (i.e., Rutelini Jameson 1998). The Ruteline tribe Anomalini is occasionally regarded as a subfamily of Scarabaeidae (i.e., Potts 1974, 1977) or a subfamily of Melolonthidae (i.e., Sabatinelli 1991). In addition, Hoplia and its congeners have occasionally been included as a tribe (Hopliini) and included in Rutelinae (i.e., Baraud 1985). Subtribal classification of the subfamily is, in many cases, based on diverse assemblages of taxa, and many subtribes are not monophyletic. Phylogenies for the Scarabaeoidea hypothesize three differing views for the relationship of the Rutelinae: 1) that the subfamily Dynastinae is ancestral to the Rutelinae, 2) that the Dynastinae and Rutelinae are sister groups, or 3) that the subfamilies are possible sister groups and that their relationships remain unresolved. The subfamily Rutelinae is composed of approximately 200 genera and 4,100 species that are distributed worldwide (Machatschke 1972).

 

Arrow’s 1917 volume on Rutelinae of British India is one of the major studies on the group in the world. His study indicated as many as five tribes (which he called Divisions). However, among the five tribes enlisted by him, one of them, Peltonotini, has been recently transferred to the subfamily Dynastinae. Peltonotini and Parastasini are treated as the base taxa for bifurcation of Rutelinae and Dynastinae. Both these groups are fortunately represented in India. A comprehensive study of these taxa should help resolve the evolution of the two subfamilies and should help in better higher classification of the Scarabaeidae of India. Further, studies have also indicated another tribe, Hopliini generally listed as a tribe of Melolonthinae, potentially belongs to Rutelinae. Hopliini are considered as the basic stock to the two major subfamilies of Scarabaeidae, Rutelinae and Melolonthinae. Thus the study of these groups should help resolve many problems in the hierarchic classification of the Scarabaeidae. A comprehensive recent view on the higher classification of the Scarabaeidae (Smith, 2006) is also in need of amalgamation of the known taxa of India into this or other potential natural hierarchic classification.

 

Arrow in his 1917 treatise on the taxonomy of Indian Rutelinae dealt with 395 species that are distributed over 31 genera and five divisions (=tribes). As many as 26 authors have contributed for these taxa. Of these 266 species are represented from Political India as it is today. The earliest species was described in 1776 and the last of the Indian species was only described in 1994 and during the intervening period 31 species have been described (See Table 1). As the number of additions to Rutelinae from India since Arrow’s work is very minimal a pertinent question would be “How exhaustive Arrow’s work was on the fauna of Indian Rutelinae?” Although, there is no way by which we can clearly figure out this aspect, one simple way is to check on the area explored for rutelines in his work. A detailed analysis of his work indicated that Arrow’s work accounted for 216 locations within India. Most of these locations were aligned with the European settlements. A number of states of India such as Rajasthan, Madhya Pradesh, Goa, Chhattisgarh, Jharkhand, and Kerala have not been represented in his work. Secondly, even the states represented are poorly sampled. But for the North- Eastern states and the hilly areas of West Bengal, most of India remains to be properly explored for the Rutelinae. In this context it is desirable that an intensive study be taken up to cover the gaps in the first place.

 

A second factor that calls for intensive and taxonomic studies on the group is the need for redescriptions. Any beginner in India who makes an attempt to explore Arrow’s work for identification of Rutelinae would understand that the keys are extremely difficult to follow due to insufficient descriptions or the language. Male genitalia which are currently used the main distinguishing feature for most species of Scarabaeidae are not available in his work for all the species. Further, his diagrams of male genitalia are incomplete and make it difficult to use for a novices. Keeping these things in mind, it is felt that there is a need to revamp the taxonomy of Rutelinae of India.

 

In addition, some major changes that have taken place in the recent past, such as transfer of Desmonycinae as a tribe under Rutelinae, transfer of Peltonotini to Dynastinae and inclusion of Hopliini under Rutelinae all make it necessary that the Indian Rutelinae be re-examined in the light of these major changes. During the last two decades, significant activity in these groups has led to many changes at the generic level, with re-erection of old genera (ex. Adoretosoma, Euchlora, Callisthetus, etc,), merger of some genera and discovery of new genera in several Asian countries.

 

Table: 1. New species and subspecies of Rutelinae published from India since the publication of Arrow’s work in 1917.

 

REFERENCE:

1.     Arrow G.J. (1917). The Fauna of British India, Including Ceylon and Burma. Coleoptera Lamellicornia, part II (Rutelinae, Desmonycinae and Euchirinae). Taylor and Francis, London 1-387.

2.     Blanchard E. (1851). Published in Gay,Hist Chile, 6

3.     Baraud, J. (1985) Coléoptères Scarabaeoidea, Faune du Nord de l'Afrique du Maroc au Sinai. 652 Seiten, 213 Abbildungen, Paris 1985 Éditions LECHEVALIER

4.     Jameson, M. L. (1998). Phylogenetic analysis of the subtribe Rutelina and revision of the Rutela generic groups (Coleoptera: Scarabaeoidea: Rutelinae: Rutelini). Bulletin of the University of Nebraska State Museum.

5.     Machatschke, J.W. (1972). Beiträge zur Kenntnis der afrikanischen Anomala Arten IX. Entomologische Arbeiten aus dem Museum G.Frey 23:217-246.

6.     Potts R.W.L. (1974). Revision of the Scarabaeidae: Anomalinae. 1.The genera occurring in the United States and Canada The Pan-Pacific Entomologist 50:148-154.

7.     Potts R.W.L. (1977). Revision of the Scarabaeidae: Anomalinae. 3.A key of the speciesAnomala of America North of mexico (Coleoptera) The Pan-Pacific Entomology 53 129-134.

8.     Sabatinelli G. (1991). Note sul genere Haplidia Burm. Con descrizione di H baraudi sp. (Scarabaeoidea Melolonthidae) Bollettino della Societa Entomologica Italiana 123: 45-50.

 

Received on 05.07.2022       Modified on 23.08.2022 Accepted on 10.10.2022      ©A&V Publications All right reserved Research J. Science and Tech. 2023; 15(1):54-56. DOI: 10.52711/2349-2988.2023.00010