With that heat tape and heat lamps those are going to be very expensive melons, but I understand you wanting to try to grow your own. (Somewhere along the line I got the feeling you went from real plans to fantasy, but I'm not totally sure!) I'd skip the green plastic and go with black plastic from your local harware store. Put it out early and and you'll be amazed at how warm it is below the plastic on cold (sunny) day. I'd also try using clear plastic instead of floating row covers (or both) early in the season to really heat things up.

Susan, To the rest of the world, the netted melons we call cantaloupes in this country are muskmelons. The rest of the world calls them muskmelons but we incorrectly call them cantaloupes. Actual cantaloupes aren't grown by a lot of people here in the USA. Most years I grow both. Here's a brief intro to the melon family tree. All melons are Cucurbitaceae and are either Cucumis melo or Citrullus lanatus. Cucumis melo includes melons classified as: Cantalupensis--(cantaloupes) and examples are Early Frame Prescott, Prescott Fond Blanc, Charentais, Ha'ogen and Petit Gris de Rennes. These are the true cantaloupes and are usually round, sutured, and have fairly prominent ribs. Netting, if any, is very sporadic. Most of them have salmon-orange flesh and they do not slip from the vine when ripe. Most of the ones I know of are originally from Europe. Reticulatus--(Muskmelons and Persian Melons). This group includes most melons erroneously referred to as cantaloupes in this country, like Jenny Lind, Emerald Gem, Schoon's Hard Shell, Cochiti Pueblo and Old Time Tennesee. These are usually netted to some degree. Most have some ribbing or suturing. Many are round but a few are quite oblong. Most of these will form an abscission layer and slip from the vine when ripe. Many have salmon-orange flesh but some are green and some have almost white flesh. Momordica--like Cob Melon are Asian melons (from India, I believe) and are seldom seen in the typical American garden. They are not sweet and split open easily as they ripen. Dudaim--This is a group of fragrant melons that are of poor eating quality. The only one of this group I've ever grown is Queen Anne's Pocket Melon which has a delightful aroma that will scent the whole yard and attract tons of wildlife but which isn't tasty at all. In olden times, ladies carried these in their pockets as a sort of walking air freshener. Flexosus--These are the ones we call Armenian Cucumbers or Snake Melons. These grow long and narrow. If you grow them on some sort of trellis, the melons hang down and grown straight. If you grow them on the ground, they curl and twist. In both flavor and texture, these are almost more cucumber-like than melon-like, only they don't have spines. Their flesh is not as watery as cucumber flesh, so they're a bit crunchier. Inodorus--These are the wonderfully flavored but not very aromatic melons that we often refer to as Winter Melons because they ripen late and have a long shelf life. This group includes Honeydews (probably their most famous member), but also Cranes, Crenshaws and Casabas. Some of the varieties of melons which are members of this group include Collective Farm Woman (one of my personal all-time favorite melons), Amarillo d'or, Bidwell Casaba, Sweet Freckles, Piel de Sapo (aka Frogskin melon) and Orange-Fleshed Honeydew. They have very hard rinds which helps them keep for a longer period of time than melons with softer rinds. Conomon--These are Asian melons and they are not sweet, but instead are crisp and sort of crunchy. They are pretty bland and if their flavor can be described at all (almost no flavor to speak of), it is bitter. In Japan, they are pickled. One of the sweeter ones (and it isn't that sweet compared to the melons we grow and eat here in the USA) is Sakata's Sweet. The melons classified a Citrullus lanatus are what we know as watermelons, and include Blacktail Mountain, Carolina Cross, Sugar Lump, Sugar Baby, Ali Baba, Chris Cross, Black Diamond, Georgia Rattlesnake and Yellow Doll. This group also includes Citron Melon which is grown strictly for processing as it has to be boiled in sugar to make it edible. Eaten raw, it is rock-hard and poorly flavored. That is much more than you asked, Susan, but I figured if I was going to describe Cantaloupes and Muskmelons, I might as well throw in the other members of the family. When I first had space to grow lots of melons, I experimented and grew up to 20 kinds per year, but now I just grow a few kinds each year. It is hard for just the two of us to keep up with the melon harvest so I try not to grow too many. I don't like them as much preserved as fresh, so a surplus is a headache to deal with. Of course, as I was typing this I kept thinking "ooh, I need to grow this one (and that one and that other one too) next year". Dawn

How deep is the mulch? And is water/rain getting through it to the roots? Perhaps dig up one plant to see what's going on underground. Oh yes, dahlias blacken if damaged by cold. Have you had colder than usual temps? As for the holes, finding out just what is chewing requires a bit of detective work. Look during the day, also at night, say about 10 pm or so. Be certain to investigate the undersides of the leaves as well as the tops.

Since this is not a photo of your actual insects and the insect in the photo is much larger than a grain of salt, identifying your insect will be impossible without further information. (The stray bits of pollen on the petals above are in the size range of salt grains) It would take a lot of these tiny insects ganging up on your melons all at once to have a negative effect. I lightened your photo by increasing the gamma and saw what could be pollen grains on the wing covers, so the insect in the photo could actually be beneficial to pollination.