Sunday, June 28, 2009

Snails and not fruit flies?

This could be the real culprit that's been damaging my precious phals, and not the fruit flies as I previously suspected. A very tiny snail species!

Tiny snails - the real culprit? by you.
The one above was found under a leaf. Below it are minute snail and spider faeces along with other small debris trapped by gossamer.

They could be small juveniles of a larger species or they could be a totally different species which grow to only about 2-3mm across.


Tiny snails - the real culprit? by you.
The tiniest that my naked eye can see are less than 1mm in diameter.

I began noticing them on every damaged phal or under the damaged leaves recently. They are so small that they are easily obscured from view, hidden in nooks and crannies, between roots, fern fiber and under leaves. Few days ago, I found quite a few hidden from the day's heat one one phal mount.


Tiny snails - the real culprit? by you.
Something this small can easily find lots of places to hide on an orchid plant. They also find plenty of hiding places on the orhcid mount or in the potting medium.


Tiny snails - the real culprit? by you.
The largest ones measure 2-3mm while the tiniest, less than 1mm. Some are so tiny that a magnifying glass is needed to see them clearly.

I found another one of my phals, a P. corningiana with a damaged new leaf yesterday. Just as I suspected, I found one of these snails lurking under one of the leaves.


DSCF2217DSCF2214DSCF2202DSCF2200
The damage to my phals range from mild to severe. They mostly attack new, tender and succulent leaves as well as the flowers and buds.

Tiny snails - the real culprit? by you.

Tiny snails - the real culprit? by you.
Flowers are also attacked. Unopened buds may abort and drop off, or they may be resistant enough to survive but open as a damaged flower.

The worst kind of damage is when a leaf gets infected and the infection spreads like wild fire from within the leaf, turning it translucent and mushy inside. Rot then spreads and in the worst cases, the crown will be destroyed. If the plant is resistant enough or the damage isn't too serious, the leaf will continue to grow but severely disfigured.

Tiny snails - the real culprit? by you.
The leaves are attacked on the underside. It could bacteria present in the snail's mucous that causes the rapid damage and spread. The leaves of my large hybrid phals are tough and leathery yet they too are easily damaged as pictured above.

DSCF2203 by you.
Sometimes the damage extends to the crown and destroys it. If the phal is resistant, it will later put out a new side shoot or keiki after several weeks or months.

Tiny snails - the real culprit? by you.
To combat snails, i use snail poison/pellets. The pellets swiftly kill slugs and larger snails but the tiny 1-3mm ones usually are not affected, possibly because they are so tiny that they cover less ground compared to the larger species. Hence, they have a lower chance of encountering the snail pellets.

Lastly, other pests also cause damage to the succulent leaves such as sap sucking insects and their larvae (one particular kind looks like tiny black mites and they can quickly suck and turn a leaf green-white with tiny overlapping pale dots) so really, it's quite a challenge to keep the phals perfect, shiny and healthy!

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