Cherry tree gunge

[Sue Smith]

We have a huge cherry tree which is heaving with "would be" cherries. Last year it produced two cherries, right at the top, which of course the birds ate gleefully. Neighbours reckon they've never seen the tree laden with such a potentially huge crop, due they inform us to there being no frosts this May. So, we're now very down in the mouth as an infestion of black fly-like insects has descended. They seem to be concentrated at the ends of branches where the newest shoots are. The gunge from this infestation is actually oozing from the tree to the ground. However, the majority of the fruits seem to be unaffected. Does anyone know - will we have cherries, are these ordinary black flies? The tree is far too big to spray, although the ladybirds do seem to be gathering! Any help/advice/good news would be most gratefully received.
Regards,
Sue.

[Sooner or later!]

These sound like cherry tree blackflies. They are sap sucking little black aphids (MYSUS CERASI), and will target the newer parts of the branch system which is usually at the tips. There is i am afraid no easy cure apart from pinching off the tips but that sounds like a lot of work as i get the impression the tree is very large !. The only other way to deal with these is to spray in the winter to control the eggs prior to hatching. Or as soon as you see any in spring then treat with pirimicarb, malathion or bifenthrin. To treat the tree during fruit production may harm the yield so book early to avoid dissapointment and sort it out in the winter.

Good luck
Paul Johnson (RHS Cert)

[Sue Smith]

Spent most of the day picking the first flush of our cherries (more to come!) so don't think the gunge did much harm. Spoiled the appearance of the tree for a while though.
Regards,
Sue.