Nectarine

Multiple generations a season; the early shoot-flagging is your early warning to act before fruit damage.

Wilting, dying shoot tips (flagging) in late spring, and larval tunnels and frass inside picked fruit, especially near the pit.

Bt or spinosad timed to egg hatch (traps signal the window); mating disruption is highly effective in larger plantings.

Pheromone traps to time sprays and pheromone mating-disruption dispensers; prune out and destroy wilted shoot tips; clean up drops.

A small moth whose larvae bore into shoot tips early in the season (wilting the tips, called flagging) and then tunnel into ripening fruit, often entering near the stem with little external sign.

An eastern and midwestern pest, largely absent in the arid West.

Crescent- or half-moon-shaped scars on newly set fruit within a few weeks of petal fall, a heavy premature fruit drop, and small grubs inside the dropped fruit when you cut one open.

Spread a sheet under the tree at dawn and jar the branches: the beetles play dead and drop, and you can collect them. Where damage is heavy, a targeted insecticide at petal fall and again shortly after is timed to adult activity - use only a product labeled for the crop you are treating, follow the label exactly, and observe the pre-harvest interval before you pick.

Pick up and destroy dropped fruit promptly and consistently - the larvae finish developing in the drops, so leaving them under the tree simply raises next year's population. Kaolin clay applied to the young fruit deters egg-laying without an insecticide.

A small snout beetle of the eastern and midwestern US that cuts distinctive crescent- or half-moon-shaped scars into newly set fruit to lay its eggs. The larvae tunnel inside, so the fruit comes out misshapen and wormy or drops early, and the larvae then finish their development in the fallen fruit. It attacks stone fruit and pome fruit alike, and it is largely absent from the arid West.

Because the crop ripens in a short window, a few days of unchecked bird and wasp pressure can take a big share - and pecked fruit invites brown rot. The smooth, fragrant skin is even more attractive to birds than a fuzzy peach.

Fruit disappearing from the outermost, most exposed parts of the plant first, and from the top of a tree where you cannot reach anyway. Single neat pecks and gouges in ripening fruit, with several fruits sampled rather than one eaten through - the classic sign that it was birds rather than an animal. Heads of grain or seed going visibly lighter and emptier as they ripen, with hulls and chaff scattered underneath. Freshly sown seed vanishing off the surface of a bed before it germinates. Bird traffic in and out of the plant picking up as the crop colors, and birds waiting on nearby wires and branches. Wasps arriving at the pecked and split fruit shortly afterward.

There is no treatment once a crop is being taken - only protection and timing, so the answer is to get netting on and to pick what is ready. Reflective tape, flash ribbon, spinners, and decoy predators do work, but only for a few days at a time: birds habituate fast, so move and rotate them and never rely on them as the main defense for a crop you care about. Cut and gather grain or seed heads a little early, at firm dough, and finish drying them under cover instead of leaving them standing for the flocks. Plant a little extra, or a decoy crop the birds prefer, and accept sharing anything that crops heavily. On a wild or foraged patch, fruit going to birds and small mammals is the point of the plant rather than a problem to solve.

Net, and net early. Bird netting draped over a frame or hoops so it stands off the fruit, with the edges closed at ground level, is the only thing that reliably works at harvest scale - and it has to go on before the crop starts to color, because once birds have found the food they are far harder to displace. Keep fruit trees small enough that netting them is actually feasible; that decision gets made years earlier, at planting. Bags of mesh, organza, or paper slipped over individual heads, clusters, or prize fruit protect a small crop without netting the whole plant. Then shorten the exposure: pick promptly and completely rather than leaving ripe fruit hanging as a lure, clear split and dropped fruit that draws birds and wasps alike, and where a crop can finish off the plant, harvest a little early and ripen or dry it under cover. Rake in or cover broadcast seed so it is not lying in plain view.

Birds find ripening fruit and seed before you do. Robins, waxwings, starlings, catbirds, jays, sparrows, finches, blackbirds, and doves all work a garden, and the pressure arrives in a narrow window - the last days before harvest, when sugar rises, color changes, and the crop softens or the grain hardens. A flock can strip a small planting in a day or two, and birds that only peck rather than take whole fruit still leave wounds that rot or draw wasps. Squirrels, chipmunks, and other wildlife usually turn up on the same crop at the same time. This is competition rather than disease: the birds are not harming the plant, and a big tree or a heavy-cropping bush often has enough for everyone - but on a small planting it can be the difference between a harvest and none.