30 August 2022

Customer Question – What is it!!!!!!

Q. “I was hoping you could help me with something strange I found on the leaves of my pear tree? They look like small black slugs, really small, around 10 we found, and neither me or my husband have seen them before – see pictures below.  As always, thank you for any help/ advice you can give us.” thanks Karina

A. Thanks for the message and this is pear slug worms. They are a type of sawfly which looks like a wasp as an adult and a cross between a slug and a caterpillar as a larvae. They feed to on the leaves of pears, cherries, hawthorn and plums between July and October before dropping to the soil to pupate for the winter and then emerging as adults the following year. They do not normally need controlling i.e. they will attack so leaves but are not their in enough numbers to do any lasting damage. If they do become a problem then you should treat the soil under the tree in October with Nemasys Fruit and Veg Protection to target the larvae. Treating the larvae under the tree is much easier than trying to treat the pest in situ. Apply Nemasys Fruit and Veg Protection as a drench to the soil making sure you treat an area the same as the size of the canopy. Water the soil well first to help the nematodes soak in (especially if it is very dry) and then apply F&V as a drench to the soil. I would then re-apply 2 weeks later to get any late developing larvae, so ordering a TWIN Pack is the most cost effective soltuion.  I hope this helps and let me know if you need anymore information. You can see more about this pest on the RHS Website. 

Kind regards

Available to buy now