Broad-leaved stringybark, white stringybark

Eucalyptus caliginosa

;

Broad-leaved stringybark (Clemson, p. 66) is a valuable honey and pollen tree which flowers during late autumn into winter on Northern Tablelands of NSW. The crude protein level of its pollen ranges from 23% to 30% (Table 6). Hives collect large quantities of this pollen.

Although the iso-leucine level of broad-leaved stringybark is very low (between 2.7% and 3.7%), the high crude protein and the plentiful supplies of pollen allow for satisfactory quantities of protein to be made available to the bees

Bees that forage on this species in the autumn usually overwinter well and come into spring as strong hives. Beekeepers also breed their bees on this floral source before later winter honey flows such as white box, blue top and Caley's ironbark. However, bees foraging on this species during a wet autumn will develop nosema disease. To control the disease, select dry sites for the hives, keep bee stress to a minimum and do not harvest the honey until spring.

Although the bees collect large quantities of this pollen they seem to need it all. Harvesting of this pollen is not recommended.

Table 6: Broad-leaved stringybark, white stringybark Eucalyptus caliginosa

Amino-acid
Minimum % of Amino-Acid from De Groot (1953)
Glen Elgin

June 1986

Torrington

June 1989

Torrington

June 1989

Glen Elgin

May 1992

Pinket 

May 1993t

Threonine 3.0 3.6  3.9  3.6  3.4 3.7 
Valine 4.0 3.5* 4.7  4.3  3.8 4.2
Methionine 1.5 1.7  1.5  1.5  1.9 2.7 
Leucine 4.5 6.5  6.6  6.0  5.7 6.4 
Iso-leucine 4.0 2.7* 3.7* 3.3* 3.0* 3.2*
Phenylalanine 2.5 4.0  4.2  3.8  3.5 3.7 
Lysine 3.0 6.0  5.8  5.2  5.0 6.0 
Histidine 1.5 2.4  3.0  2.8  2.0 4.6 
Arginine 3.0 10.2  8.3  7.3  5.9 7.9 
Tryptophan 1.0 1.3 - -
Crude protein - 29.9% 22.6% 24.25% 26.1% 26.9%

* Low level of this amino-acid


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