So it's been about 3 months or so now since the last growth flush at the apical tip of my tree and it's not for lack of trying. There's something going on up there that is causing the tip to wither and die back whenever it tries to flush. This is the case for the lateral tips that are trying to shoot off near the top as well. I believe this to be a localized issue because lateral tips that shot out from near the bottom are growing fine and healthy, but again as they get closer to the top, the leaves are noticeably smaller.

I initially suspected some sort of fungal issue and took the advice to use some copper spray. The exact formulation I used was 10% Copper Octonate from Bonide:

http://www.bonide.com/lbonide/backlabels/l811.pdf (Label)

http://www.bonide.com/lbonide/msds/sds811.pdf (SDS)

I've sprayed in 10 day intervals for the past 4 weeks and nothing has changed. So I did some further digging and came across Mango Malformation Disease (MMD) which can be caused by Mango Bud Mites (?) I examined the tips a little closer and did notice one really tiny black insect moving around, but was unsure if that meant anything. I've managed to get more precise images of the tip in the hopes that it'll be a little easier to diagnose what exactly is going on here and to find the appropriate solution:

Any help would be much appreciated!