Monday, 5 November 2012

The Micro World

An article by Heather Martin

Last month the upper surface of some bramble leaves in our wood became covered with tiny orange blisters and on closer inspection I noticed that a range of minute insects were drawn to them to feed including the Springtail, Flower Bug and Parasitic Wasp in the photographs.

Patrick Roper (link to Patrick's comments on Ash Dieback disease  here) explained the insects were eating the spores produced by a rust fungus most probably called Phragmidium violaceum and recommended a book 'Microfungi on Land Plants' by M. B. Ellis and J. P. Ellis.

Rust fungi are a microscopic species with a complex life cycle that can involve up to five different spore producing stages and two different host plants.

The orange spores (uredospores) are the main dispersal phase.

To positively identify most rusts you need to locate and magnify teliospores from the following life stage.In the case of Blackberry leaf rust fungus the teliospores are black and found in small clusters on the underside of the leaf.

Corresponding with these, on the upper surface there are conspicuous purple and crimson spots.
While I was busy looking for infected bramble leaves last week I also came across a Barkfly less than 3mm in length. I think it is possibly Ectopsocus petersi, a species commonly found all year round on a wide range of trees and shrubs.

I was also pleased to find the larval case of Coleophora gryphipennella on a Dog Rose leaf. The larva of this brown micro moth builds itself a successively larger portable case from leaf fragments, eventually fixing it to a stem.
It will pupate inside the case next May or June.

All Pictures by Heather Martin 05/11/2012