Phenology of Migration and Decline in Colony Numbers and Crop Hosts of Giant Honeybee (Apis dorsata F.) in Semiarid Environment of Northwest India

The colonies of the giant honeybee (Apis dorsata) immigrate in the semiarid environment of Northwest India in October-November with the onset of flowering on pigeon pea (Cajanus cajan)/toria (Brassica campestris var. toria), stay here during the rich pollen and nectar flow period from December to mid-May, and emigrate in late May/early June when floral dearth is witnessed. This honeybee was free from any conspicuous viral, bacterial, and fungal diseases and also did not have any serious predators and enemies. However, about 20 percent of the old colonies were infested with Tropilaelaps clareae and 100 percent of the old colonies with Galleria mellonella; none of the swarm colonies had these pests. While the migration schedule of this honeybee remained similar year after year, the number of colonies immigrating in this region declined markedly over the years; the number in 2012 was even less than half of that recorded in 1984. During its stay in this region, this honeybee acted as an important pollinator of more than 30 crop plants of this region. The causes of seasonal migration and decline in the number of colonies of this honeybee and its importance in crop pollination have been discussed.

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Insect pollinators' diversity of rapeseed (Brassica campestris var. toria) in Chitwan, Nepal

Journal of the Institute of Agriculture and Animal Science ◽

10.3126/jiaas.v33i0.20688 ◽

2018 ◽

pp. 73-78

Author(s):

R. Pudasaini ◽

R. B. Thapa ◽

N. K. Chaudhary ◽

S. Tiwari

Keyword(s):

Brassica Campestris ◽

Apis Cerana ◽

Apis Dorsata ◽

Dominant Group ◽

Animal Science ◽

Insect Pollinators ◽

Abundance And Diversity ◽

Pollinator Fauna ◽

Conservation And Management ◽

Pan Traps

The abundance and diversity of rapeseed insect flower visitors were assessed by using insect pan traps, sweep net and visual observations at different blooming stage of rapeseed at Jutpani VDC, Chitwan district, Nepal during 2012-013. The pollinator fauna of rapeseed included twenty one species from six different insect orders. Hymenopteran (77.95%) species were the most abundant insects visiting rapeseed followed by Diptera (12.23%) and Lepidoptera (3.49%). Honeybees were the dominant group of pollinators and among honeybees, Apis mellifera L. was the most dominant one (36.34%) followed by Apis florea F. (12.45%), Apis cerana F. (11.14%) and Apis dorsata F. (5.68%). The higher abundance and diversity of pollinators were observed at 12:00 to 1:00 pm and the diversity was related to the crop blooming stage. Therefore, pollinator's friendly cultivation practices should be followed for conservation and management of insect pollinators for higher production and productivity of rapeseed crop under Chitwan condition. Journal of the Institute of Agriculture and Animal Science. Vol. 33-34, 2015, 73-78

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Growth and productivity as influenced by nutrient management practices on Pigeon pea [Cajanus cajan (L.) Millsp.] in upland alfisols of Tripura

SAARC Journal of Agriculture ◽

10.3329/sja.v13i1.24186 ◽

2015 ◽

Vol 13 (1) ◽

pp. 123-134

Author(s):

S Ray ◽

Biman De ◽

S Hazari

Keyword(s):

Cajanus Cajan ◽

Seed Treatment ◽

Management Practices ◽

Nutrient Management ◽

Soil Health ◽

Pigeon Pea ◽

College Of Agriculture ◽

Main Plot ◽

The Rich ◽

The Cost

Pigeon pea [Cajanus cajan (L.) Millsp.] is the rich sources of dietary protein, carbohydrate & certain minerals but its poor yield needs to formulate a nutrient management practices for higher productivity in upland alfisols of Tripura and to combat it, an experiment was conducted during three consecutive kharif seasons at College of Agriculture, Lembucherra, Tripura comprising of two levels of Lime (150 and 200 kg ha-1) in main plot and two levels of molybdenum seed treatment (0 and 4g kg-1 of seed) in sub plot and 4 levels of recommended doses, viz., 0% of RDF ha-1, 50% of RDF ha-1, 75% of RDF ha-1 and 100% of RDF ha-1 (Recommended dose @ 20:60:40 of NPK). It was revealed that by the use of 100% RDF ha-1 with 150 kg ha-1 lime and 4g kg-1 of molybdenum seed treatment leads to higher yield and return per rupee respectively. But by the use of 100% RDF ha-1 with 200 kg ha-1 lime and 4g kg-1 of molybdenum seed treatment, return per rupee was recorded at 2.98. The investigation reflects that by the use of 75% RDF ha-1 return per rupee (3.78) was less compared to 100% RDF ha-1 but significant with saving the cost of 25% RDF ha-1 and soil health from the excessive use of fertilizer for sustaining the agricultural growth.SAARC J. Agri., 13(1): 123-134 (2015)

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Partial seasonal migration in high-arctic Svalbard reindeer (Rangifer tarandus platyrhynchus)

Canadian Journal of Zoology ◽

10.1139/z10-086 ◽

2010 ◽

Vol 88 (12) ◽

pp. 1202-1209 ◽

Cited By ~ 24

Author(s):

B. B. Hansen ◽

R. Aanes ◽

B.-E. Sæther

Keyword(s):

Rangifer Tarandus ◽

High Arctic ◽

Population Trend ◽

Seasonal Migration ◽

Migration Route ◽

Free System ◽

Svalbard Reindeer ◽

The Poor ◽

Trade Offs ◽

The Rich

We examined seasonal range use and calving success in wild Svalbard reindeer ( Rangifer tarandus platyrhynchus Vrolik, 1829) on two contrasting ranges separated by risky barriers (open sea, thin sea ice, and glaciers). One (“poor”) range had a depleted lichen resource and negative reindeer population trend, whereas the neighbouring (“rich”) range was recently occupied with initially high lichen abundance and positive population trend. Winter foraging conditions limit survival and reproduction in this predator-free system and lichens are the preferred winter food by reindeer. Accordingly, marked female reindeer that switched between the ranges (“migrants”) spent most winters on the lichen-rich range, yet most summers on the poor range (possibly owing to fidelity to calving area). While facing high mortality risk along the migration route, migrants spending the winter on the rich range and subsequent summer on the poor range had improved calving success compared with residents on the poor range. The partial seasonal migration pattern diminished as lichens were reduced and reindeer carrying capacity reached on the rich range. Besides this apparent density-dependence in migratory behaviour, spatial strategy seems shaped by past experience and trade-offs between current survival (safe habitat) and future reproduction (food-rich habitat).

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Pollinators diversity and their effects on rapeseed (Brassica campestris L. var. toria) production and productivity in Chitwan, Nepal

Journal of Agriculture and Environment ◽

10.3126/aej.v18i0.19900 ◽

2018 ◽

Vol 18 ◽

pp. 151-161

Author(s):

Shiva P. Rijal ◽

Resam B. Thapa ◽

Moha D. Sharma ◽

Shrawan K. Sah ◽

Yubak Dhoj GC

Keyword(s):

Brassica Campestris ◽

Block Design ◽

Crop Pollination ◽

Branch Number ◽

Yield Attributes ◽

Ecological Sites ◽

Hand Pollination ◽

Randomized Complete Block Design ◽

Rapeseed Production ◽

The Impact

Crop pollination is crucial for increasing yield, ensuring food security and improving livelihoods. To quantify the response of pollinators on rapeseed, an experiment was conducted in randomized complete block design (RCBD) at three agro-ecological sites: Semi-natural (Megauli), organic (Fulbari) and intensive agriculture (Jutpani) Village Development Committees of Chitwan district in 2012/013 and 20013/014. The treatments were: i) open pollination; ii) plants caged with honeybees (Apis melifera L.); iii) hand pollination; and iv) control (plots caged without pollinators) replicated four times. Pollinators visiting rapeseed flowers, plant height, branch number, siliqua/plant, pods weight/ siliqua, test weight, and seed yield/hectare were recorded. The dominant pollinators were Hymenopterans mostly honeybees. The impact of pollinators on each system resulted in significantly increased yield attributes compared to no-pollination, which clearly indicates the need of integrating managed pollination and pollinators' conservation to sustain rapeseed production in Chitwan through biodiversity-based ecosystem services.

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