Bugs that bug citrus trees
I commonly see two pest bugs on my citrus trees – the bronze orange bug (or stinkbug) and the spined citrus bug. This year it seems to be mostly the latter, probably because our hot spring knocked back the numbers of stinkbug nymphs.
Spined citrus bugs are the green ones, about 2cm long, with obvious spines protruding from each of their ‘shoulders’. They pierce citrus fruits and leave brown, dry or gummy bits in the flesh. Check all fallen fruit for this as well as for fruit fly maggots. My normal preferred method of dealing with large numbers of bugs – knocking them off and treading on them – doesn’t work well, because they fly very readily. If you disturb them, they just buzz off and come back later.
However, they are vulnerable to pyrethrum spray. It might not kill them outright, but will certainly make them dozy and easy to catch and dispatch. Ordinary pyrethrum based fly-spray, while not approved or registered for the purpose (so I can’t recommend it!), might well do the job.
The stinkbug is another matter. These are the sinister dark bronze coloured bugs that just stand there and look at you when disturbed. You will know you have these when you see strong young shoots drooping and dying back. The bugs pierce the stems and suck the sap.
If you have a lot of stinkbugs, make a note to spray the tree with soap spray this winter to get rid of some of the early-stage nymphs All you can do now is pick the adults off by hand, remembering that they will spray you with noxious-smelling goo that you don’t want to get in your eyes. Wear long sleeves, disposable gloves and eye protection, pick the bugs off into a bag and then tread on them.