Miner Matters

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Overwintering larvae and pupae:

a) Eriocraniidae:

The Eriocraniidae are considered difficult species to rear as the time between larva leaving its mine, burrowing into the soil, then emerging next season is very long.

Traditional methods include half filling a pot with soil, covering it with nylon and burying it in the garden until next season. Some rain protection is provided by polythene.

Ben Smart has had some success with a variation on this method. He says:

 

'I filled a plant pot one third with soil, then filled a pop sock with an equal amount of soil. The sock was then lowered into the pot so the sock was the only thing
separating the two layers of soil (to stop larvae escaping and intruders from entering).

 

 

 

 

I placed the mines on top of the soil in the pop sock and then tied a knot in the sock (see top photo opposite) and left them outside in semi-shade (see bottom photo opposite) between garage and shed.

 

In Early March I untied the sock and rolled it over the side of the pot. I taped a strip of card to the side of the pot to raise the edges and covered the lot with another popsock (plenty of these are essential!). (see photo opposite).

I brought the pots into the shed and hoped for the best! So far E.sangii and E.semipurpurella have emerged (see photos below)

 

Essential points include correct id of the mines and making sure that only mines of one species go into each pot. I marked each pot with different coloured elastic bands and recorded which was which. This saves a lot of hard work when the adults emerge as they are very difficult to differentiate.

 

 I used a variety of flowerpots - different sizes, partly to help differentiate between species. It's too early yet to say whether one size was more successful than another. The ones shown are about 12cm diameter. This housed the sangii and has so far produced two adults.'

The moths which have emerged are pictured below:

 

 

Eriocrania sangii
Eriocrania semipurpurella

 

 

 

 

 

 

 

Images: Ben Smart  
a) Phyllonorycters:
Rob Edmunds has had a high success rate with rearing Phyllonorycter species over the winter by a very simple method.

The usual way to achieve this is by placing the mined leaves in a popsock or tights and then tying it outside for the winter.

Rob merely placed the mined leaves (or pupae) in a specimen container (or polythene bag) in a slightly open drawer in a cool (unheated) greenhouse.

In March he brought the containers inside for emergence.

It is important to carefully label the containers either with a piece of paper, written on in pencil, or using a garden plant label.

The photo opposite shows over wintered P.platani, with an exuvia and pupa on the floor of the specimen container, along with a mined leaf. The moth is seen at the top of the container.

Image: Rob Edmunds

Newsletter of leafmines.co.uk                                                                                       April 2005