Documentation of the Major Insect Pest of Cabbage and Their Associated Natural Enemies in Bihar, North-eastern India

The present investigation was conducted at farm of ICAR-Research Centre for Eastern Region (ICAR-RCER), Patna, Bihar during 2020-21.Geographically, ICAR-RCER, Patna is located at 25o35`30`` N latitude, 85o05`03`` E longitude, at an altitude 52m above mean sea level. The climate of the region is warm and temperate which is characterized by extremes of the temperature both during summer and winter. During summer, temperature may rise as high as 390C and in winter it may fall as low as 2-30C.The total annual average rain fall is 1130mm. This region provides a safe long growing season for most of the crops. Diamond back moth was found to be the most serious insect pest of cabbage. The infestation appeared during first week of January (SMW1) at vegetative stage and remained present up to the harvesting of the crop i.e. 11th SMW. Among the natural enemies, two species of coccinellids (Coccinella septempunctata, C. transversalis), one larval parasitoid (Cotesia plutellae) and one Syrphid fly (Toxomerus geminatus) and one unidentified spider was observed during crop period.

EKSPLORASI DAN IDENTIFIKASI PARASITOID HAMA Plutella xylostella PADA TANAMAN KUBIS Brassica oleracea

This study aims at exploring and identifying parasitoid Plutella xylostella pest on cabbage plants Brassica oleracea in Nduaria Village and finding out the most dominant parasitoid associated with Plutella xylostella pest. Observation variables used included identification of parasitoid species being parasitic in each stage of Plutella xylostella pest life found in the field, parasitoid species abundance and domination of parasitoid. The result of exploration in three sub-villages of NduariaVillage indicated that there were three species of the parasitoid, namely eggof parasitoid Trichogrammatoidae cojuangcoi, the larva of parasitoid Diadegma semiclausum and Cotesia Plutellae. The dominant parasitoid is Diadegma semiclausumwith the value of 0,11. The most abundance in parasitoid larva Diadegma semiclausum is 5,7%. Damage intensity caused by Plutella xylostella was categorized as medium damage intensity of>25-?50%, and this kept rising along with the age of larva and population as well as supporting environment condition due to Plutella xylostella resistance to the pesticide.

Effect of light intensity and nutritional value of food resources on flight response of adult parasitoid, Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae)

Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) is the major larval parasitoid of Plutella xylostella (L) (Lepidoptera: Plutellidae), which is a serious pest of cruciferous plants throughout the world. We evaluated the influence of light intensities and feeding conditions on the vertical angle of flight in freshly emerged wasps in a cylinder having diameter 15cm and height 30cm. Light intensity was found to directly affects the flight activity. Increase in light intensity causes increase in vertical flight of the female wasps. However, Increase in light intensity did not influence the inclination of vertical flight in males. Feeding condition was also found to affect the vertical flight of the wasps. Honey odour, from below the flight chamber, arrested the flight of unfed or sucrose fed wasps. However, flight of honey fed wasps was not affected by honey odour. Male flight response was also influenced by feeding condition and light intensity but the response was not as higher as shown by females. The present study is useful for selecting suitable food prior to inundative release of parasitoid in the field at suitable time period of the day.