Wine coolers are especially helpful at overwintering butterfly eggs and caterpillars that are susceptible to desiccation (drying up) under artificial conditions because of the humidity that they need and wine coolers can provide.

These sensitive early stages include eggs, unfed first instar caterpillars, half-grown caterpillars, mature caterpillars, and adult butterflies; the last of which is THE most difficult to overwinter and not advisable unless you know what you're doing.

At the same time, shelf space in wine coolers comes at a premium as compared to using refrigerator space or your own backyard which are much easier and less expensive to provide.  Therefore, it is overkill to overwinter chrysalids of those butterflies that naturally overwinter as pupa (including non-Parnassius swallowtails, some blues, some skippers, most pierids, etc.) in a wine cooler unless you already have plenty of extra space.

The immature stage of pupa is the least sensitive to desiccation of any other immature stage where the refrigerator technique works just fine and cannot desiccate a pupa unless the pupa was exposed to pathogens and became sick as a caterpillar.  Also, it is easy to expose pupae to intermittent humidity using a refrigerator or outside as explained in their subsections.

Because there are four stages that complete butterfly metamorphosis, there are a possibility of four stages that temperate butterflies, based upon genus, overwinter which includes egg, caterpillar, chrysalis, and adult.  The list below shows which butterfly groups (in some cases, genera) overwinter in these sensitive stages where a wine cooler can be extremely handy.

Eggs:
- Most species of copper butterflies (Genus: Lycaena)
- Some genera of hairstreak butterflies (Genus: Hypaurotis and Satyrium)
- Pine white butterflies (Neophasia menapia and Neophasia terlooti)
- Shasta blue butterfly (Plebejus shasta)

Unfed first instar caterpillars:
- Species of larger fritillaries (Genus: Speyeria)
- Species of wood nymph butterflies (Genus: Cercyonis)
- Wyoming satyr (Neominois wyomingo)
- Shasta blue butterfly (Plebejus shasta)

Half-grown caterpillars:
- Temperate zone checkerspots (Genera: Euphydryas, Chlosyne, Poladryas, etc.)
- Temperate zone crescentspots (Genera: Phyciodes, Anthanassa, etc.)
- Some checkered skippers (Pyrgus communis and Pyrgus albescens)
- Species of emperor butterflies (Genus: Asterocampa)
- Species of viceroy, true admiral, and purple hibernacula (Genus: Limenitis)
- Some species of copper butterflies including Lycaena cupreus and Lycaena phlaeus)
- Subspecies of the boisduval's blue( Plebejus icarioides)

Mature caterpillars:
- Temperate zone arctic and alpine butterflies (Genera: Oeneis, Erebia, Neominois, etc.)
- Spreadwing skippers (Genera: Pholisora and Hesperopsis)
- Grass feeding skippers (Genus: Amblyscirtes)
- Giant skippers (Genus: Megathymus)
- Mormon metalmark complex (Apodemia spp.)
- Subspecies of the boisduval's blue( Plebejus icarioides)