These photos below clearly show what is a ‘good’ cocoon and a cocoon that needs to be discarded. In one cocoon a bee is clearly outlined showing its feet and mouth parts. The next photo is empty with the remains of a dead larvae. These are discarded. (You may want to have a closer look at what is inside these cocoons). The most common parasitic wasp species have about 10 little wasps per cocoon.
by margriet dogterom on
This candling video shows the technique of candling. Set up a 6V flashlight in a dark room. Place washed and cleaned cocoons in a petri dish. Rotate petri dish over light to more clearly see what is inside cocoons. Remove parasitized cocoons. Go to shop beediverse on this web site to order petri dishes.
A comment on this blog asked for more pictures on candling cocoons.
Just today I candled 4000 cocoons. It seems like an awful lot, but when they are in petri dishes it is easy to do candle them- about 30 mins or so. I did see some duds that are of some interest. I call anything that is not a fully developed bee a ‘dud’. The percent ‘duds’ in this batch was 2.5%. Anything under 5% is excellent. But even with 107 duds there are some interesting ones. Few had fully developed parasitic wasps- ready to emerge in spring. Others were bee larvae that had not completed development into an adult. In the next day or so I will take some photos and put them on this blog.
I was teaching a group of people about candling the other day. It is a straight forward procedure but the conditions have to be right. The room that you do the candling in has to be completely dark- a bathroom without a window for example. Any extra light besides the flashlight is too much light and you cannot candle the cocoons.
I have had some questions about candling mason bee cocoons. Joe Sadowski from Burnaby, BC thought of this idea- and it works. Candling is just like candling eggs. In a dark room you shine a bright light under the cocoon. With some experience, you can see the adult mason bee in a fetal position inside the cocoon. You can also see empty cocoons or non- viable cocoons, where the larva has died and not developed into a adult bee.
Here is a batch of mason bee cocoons. Mud has been washed off, and mites have been removed. After washing them, cocoons take about an hour or so to dry and then candling can be done.
Place dry cocoons on a petri dish or similar container,over a 6 Volt flashlight. It is easiest to do the candling in a room without windows.
Turn the lights off in the room and look at the cocoons. You will be able to see right through empty cocoons. In normal light, these cocoons look like normal viable cocoons.
You can also see the viable cocoons with the bee inside the cocoon.
Rock, move and rotate petri dish over the light. The light scatters and allows you to see the non- viable cocoons.
All cocoons sold at Beediverse are candled and non-viable cocoons removed.