Coleoptera: Elateridae

Position of Elateridae

Order Coleoptera Linnaeus, 1758
   Suborder Polyphaga Emery, 1886

     Series Elatiriformia Crowson, 1960

       Super family Elateroidea Leach, 1815

          Family Elateridae Leach, 1815

Subfamilies of Elateridae

Cebrioninae Latreille 1802

Tetralobinae Laporte 1840

Thylacosterninae Fleutiaux 1920

Lissominae Laporte 1835

Semiotinae Jacobson 1913

Pityobinae Hyslop 1917

Oxynopterinae Candeze 1857

Agrypninae Candeze 1857 / Lacordaire 1857

Denticollinae Stein & Wise 1877

Negastrinae Nakane & Kishi 1956

Diminae Candeze 1863

Elaterinae Leach 1815

Cardiophorinae Candeze 1859

Hemiopinae Fleutiaux 1941

Physodactylinae Lacordaire 1857

Incerte Sedis (Uncertain placement)

Eudichronychinae Girard 1971

Anischiinae Fleutiaux 1936

Subprotelaterinae Fleutiaux 1920

The family name dates back to Leach (1815). The name is based upon Greek word έλάτήρ for hurler or driver (elater). Due to the clicking ability of adult beetles, it is called by many names as click beetle, skip-jack, spring beetle, clicker or Blacksmith. Sometimes it is also called as Grasshopper beetle or Locust beetle. In Germany they are known as Schnellkafer or schmied (Calder 1996). All species of elaterid beetles have ability to click.

There is no common name to click beetles in Indian language.

General Characters 

The adult click beetles are primarily nocturnal and during daytime they hide in cool dark places like under the stones, in leaf litter, dead tree stumps, under the bark of trees etc. These nocturnal species are readily attracted towards light. Some species are diurnal and are found on flowers, foliage, tree stumps etc.The life cycle of click beetle is lengthy and complex. The eggs are laid in the soil. They hatch depending on the favorable conditions. The larvae are unique in shape. They are elongated wire like hence called as wireworms. Wireworms are cylindrical or slightly flattened usually with both sides of body i.e. dorsal and ventral sclerotized evenly; generally yellow, brownish yellow, dark brown to black in color. Their head is heavily sclerotized, with well developed strong mandibles, maxillae and labrum. Densely setose oral filter is present (Calder, 1996). Last abdominal segment i.e. number 9 is with or without fork apically. The wireworms eat out roots, young shoots of the forest vegetation as well as crops. Since grasslands and pastures are natural habitats of wireworms it is not surprising that many species of the click beetles have become agricultural pests. Sugarcane, maize, sorghum, sunflower, potato, sugar beat, sweet potato, radish, carrot, onion etc. are major target of species of Agrypnus, Conoderus, Selatosomus etc. Some wireworms are predatory eating other insect larvae, various other invertebrates etc. Donlan (1994) reported larvae of Lanelater sallei stalking and eating eggs of Loggerhead turtle Caretta caretta. The wireworms pupate in the soil or under the bark. The larval period depends on availability of food, temperature and moisture. The exarate pupae have varied pupal period from one week to a year.

Beetles of the family Elateridae have evolved to distinctly identifiable body form due to unique clicking mechanism. Though the family is one of the major families in coleoptera, it remains less studied because of extreme homogeneity in the morphology. Most of the workers rely on external ‘gestalt’ of characters rather than critically assigning a specific character or character state (Calder, 1996). Because of homogeneity of the characters and diversification among a genus, it becomes difficult for a worker to designate a specimen. In single genus also there is significant diversification in the morphology. Sometimes the characters which are described for a genus may secondarily disappear in a species under the genus. The species appears to be of different genus which is actually not. This homogeneity of the characters is sometimes misleading. Probably because of this reason Stibick (1979) called this family as ‘hopeless’.

Candeze (1857, 1859, 1860, 1863) in his monographs classified Elateridae in eight tribes. The key developed by him is based on metasternum acuminate or rounded between mesocoxae. The same criterion was adapted by Vats (1991) but slightly modified by adapting the raised status of tribe to the subfamily level as proposed by Fleutiaux (1941).

Schwarz (1907) didn’t raise tribes to subfamily level but the criterion used by him for the key to tribes was the number of visible abdominal sternites five or six. ‘Tribus Lepturoidini’ according to him has 6 abdominal sternites. This tribe had some genera like Hemiops and Plectrosternus which were later placed in subfamily Denticollinae (Vats, 1991).

Calder (1996) developed key to the Australian genera based on presence or absence of basal setae on tarsal claws. By this key one directly reaches to the genus instead to the subfamily. According to Calder (1996), the subfamilies Conoderinae, Dicrepidinae, Physorrhininae, Ampedinae, Melanotinae are included in the subfamily Elaterinae and Crepidomeninae is included in Denticollinae.

Indian Elateridae

Study on Elateridae in India has been started by foreign workers.

Fabricius (1775) first described and named a click beetle as Elater fuscipes (now Lanelater fuscipes) which was collected by his student Koenig from South India. Fabricius also described Elater fuscus (now Melanotus fuscus) and Lanelater luridus (now Lanelater moestus). Candeze (1857, 1859, 1860, 1863, 1878) described many species from Indian region. But Indian region at that time included Pakistan, Bhutan, Bangladesh as well. He described species from Bombay (=Mumbai), Poona (=Pune), Belgaum (=Belgao), Neelgherris (=Niligiri), Pundjab (=Punjab), Darjeeling, Assam (This can include all NE Indian states), Chota Nagpur, Kashmir, Madras (=Chennai), Pondycheri etc. Stebbling (1906) described 10 species of click beetles including notes on their life history, morphology and damage to the forest trees. In Fauna of British India (Flower, 1912) there is over all description of Elateridae including allied families. Flower hasn’t described detailed morphological characters or key to Indian elaterids. Fleutiaux (1918b, 1927c, 1928, 1936, 1941 and 1947) studied elaterid fauna of the Indo-chinese region. The recent studies on Indian elaterids include the work by R.L. Vats and co workers (1991) from Kurukshetra University, Haryana. His most of the collected specimens were from the states of Rajasthan, Punjab, Haryana, Uttar Pradesh, Himachal Pradesh and Jammu & Kashmir. In his report he has described 168 species under 37 genera and 19 sub families, of which 139 species were new. In the report he has given key to the family and key to the species. He has also described male and female genitalia. However, the description of the species is very short and also there are no illustrative diagram to compare hence the use of the report becomes limited.Another problem of this report is that, it does not give morphological description of species previously identified by Candeze, or Schwarz or Hope etc.Dolin (1998) synonymized species of Hypnoidus viz. H. fouqueti Fleutiaux, 1918 with Zorochrus indicus Motschulsky, 1858 and H. incommodus Fleutiaux, 1905 with Z. aenescence Motschulsky, 1858. Zorochrus ecarinatus was a new species described by Dolin (1999) from Southeast India. Schimmel (1998) described Neoathousius minisculus n.sp. from Kashmir and Parapenia sausai n.sp., Penia foveolata n.sp., P. jowaiensis n.sp., P. necessa n.sp., P.oblonga n.sp. and P.horrida n.sp. from Meghalaya (1999). Hypnoidus problematicus n.sp. was the new species reported from north India by Dolin (2003).

Garg (1998) described four new species of Silesis Candeze from north India. Punam (1998) added a new species Cardiorhinus emarginalus n.sp. (emarginatus ?) to the single species described by Vats (1991). Punam (1999) added two new species of Agonischius Candeze to six species previously described by Vats (1991). Punam and Saini (1996) added three new species of Megapenthes Kiesenwetter. Chakraborty (2000) listed 140 species of Agrypninae from India. Biswas (1995) has listed 5 species as part of Himalayan insect fauna. Schimmel and Platia have described Penia, Priopus, Melanotus from NE India (www.elateridae.com).