Yadav, S. S.Sunidhi2021-08-112021-08-112020-09https://krishikosh.egranth.ac.in/handle/1/5810171726The investigations on biometrics, avoidable losses and bio-ecological management of cucumber moth, Diaphania indica on bitter gourd were conducted during, 2019 at CCS HAU, Hisar. Studies on biometrics of cucumber moth revealed that the female moths laid 93.6 ± 44.14 eggs. The length and breadth of eggs were 0.7 ± 0.02 and 0.42 ± 0.02 mm, respectively. The mean incubation period and hatching per cent was observed to be 4.1 ± 0.66 days and 85.32 ± 4.74 per cent, respectively. The larvae were observed to pass five instars. The newly hatched larvae were creamy white and the further larval instars were observed from pale green to dark green in colour. Two white sub-dorsal lines appeared from the third instar onwards. The mean larval duration of 1st, 2nd, 3rd, 4th and 5th instar was observed as 1.49, 2.41, 3.59, 2.54 and 3.3 days, respectively with the total mean larval period of 13.33 days. The mean length and breadth of larval instars varied from 1.75 to 21.65 and 0.26 to 2.94 mm for 1st to 5th instar. The mean length and breadth of pre-pupa was observed as 14.38 ± 0.67 mm and 3.05 ± 0.28 mm, respectively. The mean length and breadth of pupa was measured 13.54 ± 0.81 mm and 2.86 ± 0.23 mm, respectively. The mean duration of pre-pupa and pupa was recorded as 1.55 ± 0.35 and 7.93 ± 1.06 days, respectively. The average of total life cycle of D. indica was calculated as 26.91 ± 1.01 days. The adults of D. indica were medium sized with pearly white translucent wings having brown margins and a tuft of yellowish orange hairs on tip of abdomen. Female moths were larger in size as compared to males with length, breadth and wingspan of 13.59 ± 0.94, 2.72 ± 0.18 and 24.46 ± 0.85 mm in females and 12.83 ± 0.64, 2.27 ± 0.13 and 23.27 ± 0.85 mm in males, respectively. The pre-oviposition, oviposition and post-oviposition periods were observed to be 1.5 ± 0.53, 3.9 ± 0.74 and 1.9 ± 0.74 days, respectively with sex ratio of 1:1.1 (male: female). The longevity of male and female moths was 6.1 ± 0.71 and 7.69 ± 1.22 days, respectively while the total life period from egg to adult death was 33.01 ± 1.25 days in males and 34.6 ± 1.38 days in females. For the management strategies, six different bio-rational pesticides were evaluated which revealed that Bacillus thuringiensis was the most effective treatment with least larval population i.e. 1.65 larvae/ plant as per pooled data and highest yield of 8.26 t/ha while, nimbecidine 0.03% EC showed the lowest per cent fruit infestation i.e. 6.41%. The avoidable yield loss due to D. indica was 29.04 per cent in bitter gourd.EnglishThesis