This is an adult 'lace bug.' That would be Class Insecta, Order Hemiptera (true bugs), Family Tingidae, genus is Corythucha; the species might be pruni or something close to it.

With good magnification, you can see why this bug is aptly named. In addition to the paired forewings, the upper surface of the thorax plus a pair of wing-like flanges on the sides have elaborate ornamentation that looks like the fine fabric netting used in frilly petticoats, bridal veils---and even the home-made pot scrubbers and bath/shower 'sponges.' On the actual bug, all of the lace-like structures are solid, but the spaces between the 'veins' may be nearly transparent or slightly translucent, adding to the appearance of fancy lace. The top of the insect's head and thorax may be covered with short 'spines' which may serve as protection but also add to the illusion of a lacey plant part. It's certainly not for our enjoyment, but it makes one wonder whatever came about to produce that appearance---and maintain it---in the first place.

Lace bugs have a simple metamorphosis, beginning life as eggs inserted individually into the leaves of their particular host plants. If this insect is C. pruni, its likely host is a native plum, Prunus serotina. The first generation of the year may be deposited as eggs in mid-spring (May,probably) in the northeastern U.S. or a bit early farther south. These hatch to produce rather flattened bristly or spiny-looking nymphs that suck the sap of their plant host with their tiny needle-like mouthparts. As they suck the sap, they also inject their saliva into the plant. The saliva contains enzymes that probably predigest some of the plant tissues the lace bugs will be sucking shortly; this kills the cells where the insect is feeding. The end result is a green leaf that might look like the color has been sanded off; irregular patches of white or yellow that can turn brown, ultimately shortening the 'life span' of the affected leaf. These changing colors usually attract the attention of homeowners, ready to spray the little varmints for the visual damage they cause to their landscape. 

In the meantime, the nymph feeds, grows and molts its skin several times, gaining in size with each molt. These cast skins might accumulate---at least briefly---on the undersides of the affected leaves. Inky-black dots of the bugs' liquid excrement will also accumulate on the undersides of the affected foliage. The largest nymphs may appear as black-and-white dotted, flat, bristly or slightly spiny looking 'seeds' on the host plant. The nymphs can crawl around but cannot fly or reproduce. These are 'features' reserved for the adult stage---the end of the life cycle for any given generation. The adult stage is the one with all of the lacey texture on the upper surfaces of the body and wings---which was what you had in your photo.

Insect development rates are highly dependent on temperature. With eggs deposited in May, say, hatching could occur within the next month and nymphal development could be completed in 3-4 weeks after that. That puts us into July for this species in the northeastern U.S. There are other species that might be able to develop in less time, especially in warmer, southern states. It's likely there are 2-3, maybe more, generations of this species in various parts of the U.S. annually. Adults and various stages of nymphs might be found together on the same plant in late summer, where all would be feeding on sap with their short needle-like mouthparts.

Lastly, the bug you captured is about average for most of the lace bugs in North America. A 1/4" long adult lace bug  would be huge. Some are just over 1/8" in length as adults.

That should about do it for this critter.