Paper Title
Some Studies on Distribution and Behaviour of Earwig (Dermapteran) North District of Bihar

Earwig is the most common pest of vegetables crop growing in north district of Bihar viz Saran .It is mostly known as nuisance because it feed on valuable vegetable crop plants. Earwig is thus ,a serious constraint to the to the production and productivity of vegetable in concerned areas. Its significance is based on the peculiarities of its biology, mobility ,Polyphagy, rapid and high rate of reproduction and diapause. Its preference for flowering and fruiting parts of highly valuable vegetable crop fertilizers and large scale production and planting of alternate host crop contribute towards greater and increased severity. The survey were conducted during 2007-08 in various seasons (spring,autumn and winter) district Saran to work out the distribution and behavior of earwig prevalent in vegetable crop field. During survey ,the nymph and adult insects were collected from the field and brought to the laboratory for their ecological and behavioural studies. The nymph were greatly resembling to the adult in from but differing primarily in size. Wing pads were absent .all instars have 10 abdominal segments . the head and abdomen were dark , brown . The Pronotum was considerably lighter in color. Usually greyish brown.Normally ,five instars were found, but six are observed occasionally.The number of antennal segments was about 8,1nd 14-11,13,14-15,15-16 and 14-17 in instars one to six. The body length was 3.0-4.7,3.9-6.9,5.7-7.7,6.7-10.8,8.7-13.2and 9.8-12.9 mm respectively, for instars one to six ,when reared at 20-230c the mean development times of one to six respectively for a total of about 99 days. The adult were dark brown in color and wingless .They measure 12-16mm in length ,with female averaging slightly larger than male. Adult generally bear 16 antennal segments. The cerci of adult can be used to distinguish the sexes. In males, the cerci were more curved ,with the right branch of forceps turned sharply inward at the tip. The males also 10 abdominal segments where as females possessed eight segment. The earwig are nocturnal insects .mating occurs one to two days after attainment of adult stages. The adult construct a small cell in the soil in which eggs are deposited . The female protects the egg clutch. The nymph comes out after about 10 days of laying. Adult are long-lived and capable of living over 200 days. The earwig is omnivorous its feeding habitat, taking both plants and animal material readily. It was found to be documented to feed on roots or tubers of radish, potato, sweet potato and the pods of peanut. The earwig cause little (about 30-35%) and but significant injury to the growing vegetable crops . it also feed on both the above ground and below ground portion of plants. The sometimes defecate on leafy green vegetable and contaminant them. The fast rate of reproduction and increasing population of earwig is alarming which has become a menance for vegetable growing areas of north Bihar . The distributional and behavioral studies conducted may be helpful in the management of above insect in the vegetables field.