Protect against bites by land leeches

Quote:

Originally Posted by Silverstreak

Wow! I think we are the most well informed forum on leeches !!:)
Thank you Thiam Peng for doing all this research and sharing them with the forum! Cheers!

Thank you Sunny for your kind words.
I did suffered on many occasions bitten by the land leeches and knew the messiness have to clear up after bite. Any information that can help to prevent or against the bites from these blood suckers I will be glad to share with members. Sharing one more below:

A detailed study of the substances which evoke a reaction in leech species (Hirudo) was experimented by placing 5 leeches in 200ml of water in a dish and when they were at rest, test substances were added drop by drop. The results are shown below:

Substance (amount; 1 drop = 0.04ml): Reaction

Formic acid (1 drop): Quivering reaction, leave water.
Acetic acid (2 drops): Weaker reaction than above. After 5 mins anterior sucker out of water.
Proprionic acid (2 drops): As for acetic acid.
Iso-butyric acid (2 drops): As for acetic acid.
n-butyric acid (2 drops): Weaker reaction, leave water after 30 sec.
Oxalic acid (2 drops): Jerking and quivering, anterior sucker out of water.
Malonic acid (5-10 drops): As above.
Succinic acid (5-10 drops): As above.
Citric acid* (1 drop): As above.
Hydrochloric acid (1 drop): As above.
Phenol (1 drop): Shock reaction, leave the water.
Thymol (a crystal): No reaction.
Napthol (2 drops): Jerking and quivering, soon leave water.
Galactose; Glucose; Sucrose or Lactose (a crystal): No reaction.
Methanol; Buthanol or Glycerine (1 drop): No reaction.
Quinine; Caffeine; Atropine; Cocaine or Morphia (1 drop): Swim about restlessly then come to rest with anterior sucker out of water.
Ammonia (1 drop): Strong reaction,, leave water.
Urea (a crystal): Clear reaction.
Indol (2 drops): Leave water hastily.
Skatol (a crystal): Leave water hastily.
Champhor (1 drop): No reaction.

Leeches responded to acids with characteristic jerking and quivering movements, while various other substances evoked normal locomotory exploratory movements. Noxious substances caused the leeches to come to rest with their anterior sucker out of water but the rest of the body still immersed. This suggests that the chemoreceptors are confined to the head and the body in water and no longer aware of the noxious stimulus. Among the fatty acids the most marked effect was produced by formic acid. Sugars and alcohols produced no effect but alkaloids like quinine and caffeine gave rise to strong reactions. Substances such as ammonia and urea give rise to exploratory movements and substances which are distasteful to human, such as indol and skatol, evoked a strong reaction.

Teo T P

(Note: For sodium chloride, they reacted to a concentration of 7%).
* Agreeable with the use of lime juice to release the bite from land leeches.

(Reason of editing: Typing error and addition of "glucose".