Friday 28 September 2018

Wax moth and Honeybees in France

Wax moths of both species Achroia grisella and Galleria mellonella which are commonly known as Lesser Wax Moth and Greater Wax Moth have one brood per year but this leads to successive generations as they complete their life cycle and the offspring breed. The adult moths live for about a week and are mainly nocturnal.
In both cases the development time between egg and adult hatching is temperature dependent and can vary considerably but can be as little as 45 days with an average daytime temperature of 28 – 30°C  but can take up to 7 or 8 months. Essentially higher temperatures speed up the development. Eggs always hatch in less than 2 weeks and it can be as little as 2 or 3 days.  The larval, (or grub), stage has the most flexible lifespan and generally the longest, anything from about 4 weeks to 6 months and of course as any beekeeper knows beeswax is their food. 

Click images to enlarge

Photo Wax Moth

Both species overwinter in the larval stage. This is usually from August or September to May when pupation takes place. Lesser Wax Moth is the earlier of the two to be on the wing from late May to September with Greater Wax Moth on the wing from July to October.

Photo Wax Moth Larva about to pupate

Photo of Wax Moth Pupae on hive frames

At no stage in their life cycle can they tolerate temperatures in excess of 45°C or below 0°C. This is important to know for beekeepers as it provides 2 methods to be certain that frames are clear of them. The frames can be frozen if they have comb in them and they can be gone over with a heat gun if they have no comb in them as can the interior of the hive. 

So we can see that there is really not a huge difference in their basic biology and life cycle. 

Now we come to the frequently misunderstood question of honeybees and wax moth.

Anyone that knows anything about honeybees will know that they are fastidiously hygienic in the management of their colony and the space it occupies including sealing all un-required spaces, holes and fissures with Propolis as well as coating the entire enclosed interior with a thin coat of it. Any damaged or unhealthy bee larvae and bees are continuously removed from the colony.  What this means is that there is absolutely no chance of wax moth establishing themselves in a healthy colony. Should a female moth sneak her way in and lay a few eggs they will be quickly dealt with. Any eggs that escape the cleaners and manage to hatch will be dragged out of the colony and dumped outside or if they are wedged in a small space they will be coated in Propolis.

Only when a colony has failed and died or is at the point of dying can wax moth move in and their larvae consume the old wax. This will not prevent a new swarm from occupying the hive or empty space; they will happily move in and within a day or two will have ripped out the entire damaged comb with any pupae and larvae that are present.

Photo contents of a Wax Moth infested hive ripped out of a hive by a swarm within 48 hours

Another possible point of entry for wax moth is following the extraction of honey from the honey supers, (the boxes that are placed on top of the main hive to collect honey). Careful extraction should result in very little damage to the comb allowing the same comb frames to be used again which requires that these be stored and kept in good condition over winter. Different beekeepers have their own methods of dealing with the extracted frames, some putting them back for a short while either over or under the actual hive for the bees to remove all the residual honey. I’m not a fan of this as it creates extra work with no obvious merit and as such I prefer to store my extracted frames “wet”, that is to say with the residual honey left in place on the frames. When these go back on the hives the following spring it encourages the bees to clean and restore any damaged comb.

The important thing is to store them free of wax moth by keeping the supers with the comb frames in them sealed immediately after extraction. This is not complicated, requires very little other than a little preparation. Bearing in mind that “wet” frames will drip a little I use a plain metal hive lid to put underneath and either another or a piece of flat plywood to put on top of each stack of supers making sure there are no gaps. Whether the supers and frames are stored “wet or dry” the same principle applies of making sure they are stacked and sealed immediately and not left lying around open to the air. 


Tuesday 18 September 2018

Map Butterfly - Carte géographique 2018, Blanzay, France

16th September 2018

Overall this year has been very poor at our place for butterflies and moths with even our usual common species such as Speckled Wood, Meadow Brown, Large and Small Whites, Peacocks, Gatekeepers, Marbled Whites and Red Admirals all in short supply.

Early in the summer both types of Swallowtail made brief appearances as did Painted Ladies, a handful of Common Blue and Holly Blues whilst in June Some Lesser Purple Emperors graced us with their presence, always welcome as they come down from the treetops to search for minerals that they usually get from any excrement that is to be found. 

Click photos to expand.

Above -  Lesser Purple Emperor on dog excrement.

Anyway, the purpose of this little note is to mention one butterfly species that have been abundant here this year, in fact exceptionally so and that is the Map Butterfly, Araschnia levana, a pretty little butterfly that has two distinct forms, Araschnia.f. levana and Araschnia.f. prorsa that represent the spring and summer broods respectively. levana individuals are primarily orange in colour, giving them the appearance of a small fritillary, whereas prorsa individuals look more like a very small White Admiral and many people confuse them as such.

Above - Map butterflies 2nd generation

The eggs are laid in little strings bunched together under nettle leaves which are the caterpillar food plant in shaded or partially shaded areas. Late season caterpillars overwinter as pupae that emerge in the following April/May providing the first generation butterflies. The 2nd generation flies from June to August. In the South and Southwest of France a third generation may be produced in some years. The caterpillars in some stages bear some resemblance to Peacock caterpillars that share the same food plant of nettles so it’s worth a closer look.

 Above- Map butterfly caterpillar & Eggs

As mentioned there have never been so many here before for what has previously been a scarce species at our place where we rarely see more than a few in a season and it’s hard to see what if anything has changed. 

It is a species that may be benefitting from climate change, who knows? I'll see what happens next year.


Saturday 8 September 2018

Buckwheat and Phacelia late cover crop in France

8th September 2018

It’s no exaggeration to say that increasingly the arable lands of France are becoming environmental wastelands as the same crops are grown time and time again, often on the same land with no rotation and an ever-increasing input of chemical fertilisers and use of pesticides. Manure from cattle and goat sheds is often added to the land in a raw form without being composted which greatly reduces its usefulness and in recent years with the growth in industrial poultry farming and egg production, the vast quantities of waste from these processes are often used. Even if we leave aside the manner in which livestock is treated these days the use of the waste in such a manner, whilst it may have apparent short-term gain, leads to imbalances in the soil that is already little more than compacted dust.

The main autumn sown crops of barley, wheat and oilseed rape tend to be harvested by the end of July with maize and sunflowers usually harvested in September and October. Other crops are grown in very much smaller quantities such as Buckwheat, Hemp, Tobacco, Sorghum, Fodder Peas, Field Beans, Alfalfa and others. A more concise list will be provided at a later date with their uses as well as any benefits or negative effects on the wider environment.

Click images to expand.

Photos above of dry August fields in France with not a flower to be seen.

A major problem is that by the start of August there are no flowers, or very few, and only vast expanses of bare ground or crops, (maize and sunflower), that are turning brown. Overall this leaves the environment seriously depleted of anything to provide nourishment for other species whatever they may be and we have all seen the reports of the decline in bird and insect numbers.

As a Beekeeper as well as being passionate about the environment and our native species I would be dishonest if I didn’t admit that I find the situation disheartening at times but this isn’t a groan or a moan, it’s about simple things that can change everything and in understanding that we can make things better, not ideal or perfect, just a bit better.

One such action took me by surprise 3 or 4 weeks ago when following the wheat harvest one of the local farmers sowed a field of around 20 to 25 hectares with a buckwheat and phacelia mix as a cover crop. This is something completely new around here and the difference it has made is outstanding and not just for my bees and all the other honeybee colonies in the close proximity.   

Photo above of field with buckwheat and phacelia

This mixture sown as a cover crop has a range of benefits and is ideal in this situation; both are fast growing and accept poor low fertility soils.
Buckwheat starts to flower in 3 to 4 weeks following sowing and continues for 3 to 4 weeks.
Phacelia is somewhat slower to mature and starts flowering in about 6 to 8 weeks following sowing and can continue for another 6 to 8 weeks.  

Photos above - Buckwheat on top, Phacelia beneath.

Both plants prevent nitrate leaching and take up useful minerals that are incorporated back into the soil when turned in and they both produce abundant biomass as well as acting as weed suppressants.  Of particular interest is the ability of Buckwheat to solubilise and take up phosphorus that is otherwise unavailable to crops and then release these nutrients to later crops as the residue breaks down.

The wildlife value when sown in late summer cannot be overstated at this critical time of year when little if anything else is flowering. They have incredibly high nectar and pollen production that provides for honeybees, solitary bees and bumblebees as well as hoverflies, butterflies and a vast range of other insects many of which provide valuable food for other species and of course the swallows as they prepare for their long migration.

If all arable farmers did the same with part of their land the cumulative effect could go some way towards helping prevent the continuing declines we have been witnessing in recent years. I will certainly be saying a big Merci to the farmer when I see him next in the hope he may continue or even expand this process in future years.