Thumbnail Image

Theses

Browse

2009 - 200912010 - 20131
Reset filters
Subject: Entomology × Author: Joshi, Sanjay Kumar × End date: 2024 × Type: Thesis ×
Reset filters

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ThesisItemOpen Access
    Studies on nesting behaviour and floral resources of stingless bee Trigona laeviceps Smith at Pantnagar
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2009-07) Joshi, Sanjay Kumar; Khan, M.S.
    The studies were carried out during 2008-09 at G.B.P.U.A. & T. Pantnagar, Uttarakhand, India, to study the nesting behavior, floral resources and foraging activity of stingless bee Trigona laeviceps Smith. The nesting behaviour of T. laeviceps is different from Apis bees. A total of 64 colonies (42 terrestrial and 22 arboreal) were located and one colony was hived in apiary for studying nesting behavior and nest structure. Terrestrial colonies were associated with residential (16 sites, 19 colonies) and non residential sites (19 sites, 23 colonies). In the terrestrial structures colonies were located at a height between 10 to 50 ft with preferred nest entrance in East direction (13 colonies, 30.9%). Maximum number of colonies (22; 52.3%)were located at a height between 11 to 20 ft. Arboreal colonies were associated with living trees having preformed cavities in trunks of varying girth (5-25 ft). Banyan (Ficus bengaleiensis) (girth 22.5 ft) and Shishum (Dalbergia sishoo) (girth 8.0 ft) were most preferred shelter tree species where in each 6 colonies were located. On arboreal shelters colonies were located at a height between 1 to 30 ft with preferred nest entrance in south, west and south-west directions (5; 22.7% colonies in each). Maximum number of colonies (17; 77.2%) was located at a height between 1 to 10 ft. Observations on T. laeviceps colony hived in apiary revealed that most parts of colony were built with a mixture of wax and propolis known as cerumen. Brood cells were supported by the pillars made of cerumen. Brood cells, honey cups and pollen cups were oval in shape but different in size with diameter of 2.4 mm, 5.0 mm and 6.5mm per cell/cup respectively. Extensive surveys were made in Model Floriculture Centre, Vegetable Research Centre, Crop Research Centre, Garden Section and various university parks from September 2008 to May 2009 to find out the floral resources visited by stingless bee, T. laeviceps. A total of 43 plants were recorded which included 23 ornamental plants, 10 vegetable plants, 7 forest and avenue trees and 3 crop plants. Since more ornamental and vegetable plants were visited by stingless bees, so the scope to utilize these bees for pollination is envisaged. Microscopic analysis of sample pollen slides was also in accordance with the surveys. The foraging activity of T. laeviceps was observed during Feb-May, 2009. Foraging activity started at 9.00 AM with a gradual rise in activity reaching its first peak at 11.00 AM (87.2 bees). A decline in activity was observed at 12.00 PM (83.81 bees) then increased until it reached its second peak at 3.00 PM (81.36 bees). There was very low activity at 6.00 PM (40.82 bees). The maximum number of pollen foragers was observed in the morning (10.00 AM, 59.46 bees) and the nectar foragers (5.00 PM, 48.13 bees) after mid day. It reveals that T. laeviceps prefers to collect pollen during morning hours and nectar after mid day.
  • Thumbnail Image
    ThesisItemOpen Access
    Population dynamics of insect pests and pollinators associated with Litchi chinensis Sonn.
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2013-06) Joshi, Sanjay Kumar; Singh, C.P.
    The leaf infestation pattern as well as population dynamics of five different foliage feeders (Statherotis leucaspis Meyrick, Dudua aprobola Meyrick, Acrocercops cramerella Snellen, Popillia japonica Newman and Weevils) was observed in litchi crop at Horticulture Research Centre Pattharchatta during 2011-013. The incidence of all insect pests once in a year except in leaf roller where it was twice in a year. The incidence of all the pests was maximum in East direction and minimum incidence was recorded in North direction. The population as well as leaf infestation was minimum in high density orchard (1.0 × 0.5 Metre). Low density orchard (8.0 × 8.0 Metre) was preferred for maximum infestation by all pests. The abiotic factors (Temperature and Relative humidity) had significant impact on pest incidence. Rainfall was a limiting factor for all the insect pests. The relative abundance of different insect pollinators during the flowering season was found maximum in the end of March in East direction. The maximum abundance of Apis mellifera (3.1 and 4.2 foragers/inflorescence/3minute), Apis dorsata (1.4 and 0.8 foragers/inflorescence/3minute) and Syrphid flies (10.4 and 0.9 foragers/inflorescence/3minute) was recorded at 1100 hours during the year 2011 and 2012 respectively. The maximum abundance of Trigona laeviceps Smith and Coccinella septempunctata was in the evening hours (1400 and 1700 hours). The surrounding environment of inflorescence had more impact on the relative abundance of pollinators than the open environment of location.