Introduction

Introduction

INTRODUCTION Parasitic Hymenoptera constitutes the most the Neotropical Region close behind it. The important single group of biocontrol agents, Nearctic and the Oriental Regions have responsible for majority of the economic and approximately equal number of species. The environmental benefits arising through biocontrol Australian Region is also species rich (Johnson, programmes. Parasitoids comprise approximately 1992). Not much is known about their distribution 80% of the Hymenoptera developing on or in a in India. wide variety of hosts and are important in regulating their host popUlations (Gauld and Since these groups include parasitoids of both Bolton, 1988). According to Cornell and Hawkins agriCUltural and livestock pests, they have great (1993), parasitism is considered to be the most potential to be used as successful biocontrol likely cause identifiable for mortality in 30.8% of agents. But, towards meeting this goal, more data 123 holometabolous insect host species. Parasitic a, on their biological, ecological and ethological the largest group of hymenoptera includes many aspects are needed. As all pertinent studies diverse species, which are either entomophagous concerning biology, ecology, conservation, or phytophagous. Most members of this group genetics etc. rely upon the foundation made by a being very small, sometimes even less than Imm, good systematic study, a detailed systematic study their existence often remain unnoticed. Many of these groups has become imperative. members of Parasitic a act as keystone species, as The present work, which extended over a they regulate their host species populations that period of five years (1994 to 1999), was primarily may otherwise out-compete and eliminate other undertaken to register the diversity in species, thereby playing a major role in preserving Proctotrupoidea and Platygastroidea of Kerala.The ecological balance and also in maintaining study area included the whole geographic limits biological diversity in terrestrial ecosystems. of Kerala. The representati ve samples of Hymenoptera Parasitic a includes 49 families specimens were collected from all the fourteen under ten superfamilies. Despite their importance districts of this state. in nature as biocontrol agents, many members of The state of Kerala (Fig. 1) lies all along the group still ~emain little known. bounded, on one side, with the southern west coast The Proctotrupoidea and Platygastroidea are of India and on the other with the Western Ghats, two important superfamilies of micro­ approximately between the latitudes 8°17' and hymenoptera. They superficially resemble the 12°45'N and longitudes 75°11' and 77°20'E. It is Chalcidoidea to some extent. They are both bordered by Kamataka in the north, Tamil Nadu ubiquitous and highly diverse as well at the same in the south and the east, and the Lakshadweep time less known biologically than taxonomically. Sea in the west. The land area of the state is All members are egg, larval or pupal parasitoids about 38,863 sq. km. Physiographically, the state's of other insects belonging to Orthoptera, geographic area can be broadly divided into three Heteroptera, Coleoptera, Lepidoptera, Neuroptera, provinces namely the highlands (600-2500 m Diptera, or of other arthropods like centipedes above MSL), the midlands (300-600 m above and spiders. MSL) and the lowlands (30-300 m above MSL). As our knowledge about these groups is scanty, The climate of Kerala is of the tropical a generalised pattern regarding their distribution monsoon type, with abundant rainfall and hot is yet to be made. As regards their species diversity summer. The southwest monsoon pours over the and richness, the Palearctic Region tops, with state from June to September, which is the main 2 Memoirs zool. Surv. India KERALA Fig. 1. Map of Kerala RAJMOHANA : Studies on Proctotrupoidea and Platygastroidea (Hymenoptera: Insecta) of Kerala 3 rainy season. Rains also occur during October­ author was not fortunate enough to locate those December under the influence of the northeast holotypes and was unable to trace even the monsoon. March to May is the summer season. depository. Hence through out this work, all The state experiences an annual average rainfall confmnations and assumptions had to be made, ranging from 180 cm to 380 cm and a mean based on the original descriptions and illustrations. temperature varying from 19°-33°C. The present study has yielded taxonomic A detailed taxonomic work on two information of Proctotrupoidea pertaining to 65 superfamilies, viz., Proctotrupoidea and species under 20 genera, of which 44 species are Platygastroidea (Hymenoptera) of Kerala, was new to science, and as well that of Platygastroidea originally conceived at the time of initiating the comprising 53 species under 25 genera. This forms programme of study. But, as the study material of the first consolidated document dealing with the both these groups gradually got built up during taxonomy and systematics of the two superfamilies the period, the enormity of the species richness of in Kerala, India. these two superfamilies got revealed, necessitating The types of all the new species described each group to be studied separately. In the present here, along with all the specimens studied in this document, the superfamily Proctotrupoidea has work, are deposited at Zoological Survey of India, been dealt-with in detail. As regard the taxonomy Western Ghats Field Research Station, Calicut, of the superfamily Platygastroidea of India, and Kerala. Kerala in particular, no appreciable work has been done in the past. Although considerable material belonging to this group could be accumulated REVIEW OF LITERATURE during the study period, it was practically not possible in the present study to deal with them in Some of the prominent early works on detail, mainly because of the extreme diversity Proctotrupoidea and Platygastroidea include that exhibited by them. Hence the section under of Ashmead (1893) and Dallatore (1898). Kieffer Platygastroidea at present needs to be considered dominated the field for a period from 1904 only as a taxonomic account, with an updated 1926. Though his keys to world genera (1916a, compilation of information on the genera and 1926) were largely of historic value, there exists species hitherto known from Kerala. no other world generic keys even to this day. Nixon's handbooks for the identification of British Most of the species studies undertaken in this fauna of Belytinae and Diapriinae (1957, 1980) work have been based on taxonomy of female serve as essential identification aids. Johnson specimens only, for two reasons. First, it was not (1992) published a catalogue to the world genera always possible to accurately associate the sexes of Proctotrupoidea and Platygastroidea excluding in each species, for the collections were mostly Platygastridae while Vlug (1995), brought out a made from the field, than by rearing hosts. Second, catalogue on Platygastridae of the world. Other the females showed more consistency in major works in the group include that of Masner taxonomic characters than the males. (1976b, 1980, 1991, 1993), Masner and Garcia (2002), Masner and Huggert (1989), Galloway The taxonomic works of Sharma (1979, 1980), and Austin (1984), Kozlov (1971, 1978, 1994). Mani (1941a, 1941b), Mani and Sharma (1982) and Mukerjee (1978, 1979, 1981, 1994) give us a In India some major works were by Mani glimpse of the species composition and diversity (1941a, 1941b), Sharma (1979, 1980), Mani and exhibited by both Proctotrupoidea and Sharma (1982) and Mukerjee (1978, 1979, 1981, Platygastroidea in India. Sharma (1979) in his 1994). Saraswat and Sharma (1978) also described monograph had mentioned that his types were some new Scelionidae from India. The monograph retained, for the time being, at the School of on Indian Diapriidae by Sharma (1979), dealt with Entomology, Agra. In spite of having made a 42 species, representing 15 genera. The review of couple of personal visits to the institution, the Indian Proctotrupoidea by Mani and Sharnla 4 Memoirs zool. SUTV. India (1982) exists as the only critical annotated and Main collecting technique: By sweeping with illustrated catalogue summarising all the available an insect net (The net with a triangular frame information on the taxonomy of Proctotrupoidea used in the present study is a modified model and Platygastroidea sensu lato from India. The designed by Noyes, 1982). work included over 170 species belonging to 69 The insect specimens collected were stored in genera, with synoptic keys to families, subfamilies, 70% alcohol in small vials and kept in a tribes, genera and species, along with notes on refrigerator. diagnostic characters and distribution. Mounting of specimens : Card mounting : The method followed in the present work was that MATERIALS AND METHODS adopted by Boucek and Noyes (Noyes, 1982). The specimens were mounted on a small white CoUection Methodology rectangular card, tilted slightly on its side (at about Minimum needs: Insect net for collection of 45° to the plane of the card) in such a way that flying insects (Fig. 2a). Toxic chemical for the the face and mandibles were clearly visible. killing of insects. Temporary labels were written in the field at the Supplementary materials : Small containers time of collecting specimens. After mounting the with 70% alcohol, to preserve insects after killing. specimens, permanent labels indicating the name Thin Painting Brush to enable easy transfer of of the country, state, date

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