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Subject: Entomology × Author: CHAUDHARY, MANISHA × End date: 2023 × Start date: 2020 × Type: Thesis ×
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    ThesisItemOpen Access
    Distribution and bioecology of tomato pinworm, Tuta absoluta (Meyrick) in Himachal Pradesh
    (Palampur, 2021-10-19) CHAUDHARY, MANISHA; Sood, Pankaj
    The present investigations entitled “Distribution and bioecology of tomato pinworm, Tuta absoluta (Meyrick) in Himachal Pradesh” were undertaken during the year 2020-21 in Department of Entomology, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur. Survey studies revealed that the infestation level was high in low hills (Sundernagar) under both protected as well as field conditions compared to mid hills (Palampur). The per cent leaf mine and fruit damage varied from 8.73 (open conditions) to 45.70 (protected conditions) and 4.40 (open conditions) to 21.94 per cent (protected conditions), respectively in tomato crop at Sundernagar and Palampur. Population estimation studies of T. absoluta revealed that light trap (with bulb of 100 Watt capacity) positioned at low canopy height during dusk and dawn hours was more effective for monitoring and mass trapping of tomato pinworm under protected conditions, whereas pheromone baited delta trap was found working efficiently under open conditions. Seasonal abundance studies revealed that the pest remained active throughout the year under protected conditions with peak activity during May to June. Studies on biology of the pest revealed that the incubation period of egg was 4.12, 4.40 and 5.95 days on tomato, potato and brinjal, respectively. The tomato pinworm had four larval instars with an average larval period of 13.67, 16.03 and 19.48 days on tomato, potato and brinjal, respectively. Total life cycle was completed in 28.15 days on tomato, 32.21 days on potato and 40.26 days on brinjal. Among the three hosts, the adult survived for significantly longer duration on tomato. The average durations of pre-oviposition, oviposition and post-oviposition period of T. absoluta varied from 1.40-1.60, 6.24-8.36 and 4.14-5.89 days on the three hosts. The average fecundity was recorded as 171.01, 67.35 and 45.12 eggs per female on tomato, potato and brinjal respectively. Adult female moth (4.39, 4.18 and 4.01 mm) was found to be bigger in size as compared to male moth (3.26, 3.06 and 3.05 mm) on tomato, potato and brinjal, respectively. The maximum gross reproductive rate was found on tomato (87.92) followed by potato (30.20) and brinjal (22.73 female eggs per female). The pest was able to double its population in 5.21, 8.15 and 12.60 on tomato, potato and brinjal respectively. Nutritional indices studies further validated that tomato is a better host for T. absoluta. Overall, it can be inferred that the pinworm's biological performance was best on tomato and it is the pinworm's preferred host.