New Zealand Beech Honeydew

Bee Species:

The western honey bee, Apis mellifera, in managed hives and in feral colonies. “Honeybees (Apis mellifera) collect the honeydew and transform it into honey,” Crozier wrote in 1981, and a Nelson study of the 1980s names feral honey bees among the insects using it (Moller and Tilley 1989).

Color:

Amber

Flavor Profile:

Earthy, with caramel and treacle notes, as the trade describes it

Tasting Notes:

Honey and Bees New Zealand, the industry body, describes New Zealand’s honeydew honey as “complex and treacly” and adds that “some have described its flavour as being like ‘Christmas cake’.” One South Island retailer lists “notes of maple, caramel and butterscotch” for a honeydew from the Southern Alps beech forests.

Aroma:

Strong and earthy, with hints of berries and caramel, as one Nelson producer describes it

Defining Compounds:

Minerals. Of ten New Zealand honeys collected in 2007 and analysed for a 2010 thesis, the honeydew sample had the most minerals and was the least acidic (Emmertz 2010). It was one sample.

Forage Origin:

The honeydew is made by two scale insects, Ultracoelostoma assimile and U. brittini, the sooty beech scales, of the family Coelostomidiidae; the genus is found only in New Zealand (Gardner-Gee and Beggs 2009). The insect lives in the bark of trunk and branches. Its feeding stages, second- and third-instar females and second-instar males, push their mouthparts into the tree’s phloem and pass the excess sugar out in solution through a waxy anal tube, at whose tip it gathers as a droplet (Beggs et al. 2005; Dungan and Kelly 2003). Every female stage has been found in every month of the year (Wardhaugh and Didham 2006), so the sugar is on the trees in winter as in summer. How bees gather honeydew and turn it into honey is set out on Honeydew - Forest Honeys.

Spilt honeydew feeds a sooty mould that coats heavily infested trees and gives them, in the words of a 1981 forestry paper, “a fire-blackened appearance” (Crozier 1981).

These are southern beeches, a separate lineage from the European beech, Fagus, and which of them carry the insect depends on the district. In the eastern foothill forests of Canterbury and Nelson the scale is densest on black beech (Fuscospora solandri, formerly Nothofagus solandri) and mountain beech (F. cliffortioides); a 2006 study suggested that mountain beech is “the optimal host species” (Wardhaugh and Didham 2006). At Lake Rotoroa in Nelson Lakes National Park, Beggs and colleagues estimated that the solandri beeches, black and mountain together, gave most of the honeydew and large red beech a small share (Beggs et al. 2005). On the West Coast, in a mixed stand east of Greymouth, the insect was “much more common on red beech” (F. fusca) than on black beech, but at about a hundredth of the density of Canterbury’s solandri beech forest (Kelly 1990). Hard beech (F. truncata) carries it lightly and silver beech (Lophozonia menziesii) rarely (Gaze and Clout 1983; Beggs 2001). Flora of New Zealand now places these beeches in Fuscospora and Lophozonia; older sources call them all Nothofagus.

The insect covers about a million hectares, some 15 per cent of New Zealand’s native forest today (Beggs 2001), mainly in the low to moderate rainfall country of the northern half of the South Island: on the West Coast north of Greymouth, and east of the main ranges north of Mount Somers (Crozier 1981). Bees reach part of it: a 2015 model for the Department of Conservation (DOC) and the Ministry for Primary Industries (MPI) put their share at well under half, set by terrain, other land uses and where roads and tracks run (MacIntyre and Hellstrom 2015).

The flow follows the weather. At Craigieburn in 1996, the warmth of the previous day explained most of the rise and fall in honeydew production (Dungan and Kelly 2003). Heavy rain washes the droplets off and breaks the wax tubes; hot, dry, windy weather concentrates the sugar and humid air dilutes it, so that in a Nelson study the droplets ranged from thin to thick syrup across the seasons (Gaze and Clout 1983). The scale thins with height and becomes uncommon above about 800 metres, and it is denser on the north side of the trunk; Crozier added that observations suggest more on solitary trees, at forest edges, on open ridges and stream banks and under an open canopy (Crozier 1981).

Where conditions suit it the quantity is large. At one site on Lake Rotoroa, studied from 1999 to 2001, researchers estimated several tonnes of honeydew, dry weight, per hectare a year, by their comparison at least ten times what dense aphids give in the Norway spruce forests of the Northern Hemisphere (Beggs et al. 2005).

Whether some jars also carry flower nectar is unsettled. Airborne Honey notes that “there are some areas that do produce darker honeydew. Whether this is due to local conditions or blends of lighter (non honeydew) honeys is uncertain.”

The bees share the droplets. Bellbirds and tūī, both native honeyeaters, were commoner in Nelson forests with more honeydew (Gaze and Clout 1983). Honeydew is “a key food source” for kākā, a native forest parrot, in the words of Beggs and colleagues, who concluded that the scale insects “have the potential to function as keystone species in these forests” (Beggs et al. 2005). DOC lists lizards, possums, rats, honeybees and wasps among the other animals recorded feeding on it.

Pairings:

Mountain Valley Honey suggests it as “the perfect complement for strong flavours, such as pears, apples and blue cheese,” and at breakfast with muesli or on toast. Other New Zealand sellers suggest eating it with soft cheeses such as brie and camembert, on a feta salad or roast pears or with aged cheddar, and taking it in coffee or tea; as an ingredient, they suggest it for marinades.