Really can't say from looking at photos. The best way I know to confirm spider mites are causing a problem is to get a sheet of blank white paper and turn the plant sideways over it, then tap it or give it a gentle shake. Then look at the paper. If you see tiny dots moving around on it and running for the edges, you've got mites.

Spraying a sharp stream of water, aimed at the undersides of the foliage, will knock spider mites off the foliage, but you have to do it night after night to really discourage them repeatedly from coming back. I've never found that it had an adverse effect on pollination. If fertilization is not occurring, either your plants have a sexual problem (more about that in a minute) or it is just heat stress, moisture stress or both. Back to the cucumber and melon pollination issues. With many cucumber varieties, the blooms are not perfect, so are not self-pollinating. Some flowers are males and some are females, and bees and other pollinators normally transfer the pollen from the male flowers to the female flowes. Usually there are many more males than females, and the male flowers appear first. However, there are some newer varieties that are gynoecious and produce only female flowers. If you planted a gynoecious variety without realizing it was a plant that produces female flowers only and you didn't plant 100% of the seeds in the packet, you may not have any male flowers. Normally, a few seeds of a monoecious variety is thrown into a packet of a gynoecious variety so that you'll have some plants with male flowers to pollinate the gynoecious flowers. However, it is not unheard of to occasionally get an odd plant that makes all male flowers while you wait in vain for females to appear or vice versa. Usually though, a lot of males flowers appeared first, followed a few days to a week or so later by the females. So, if your cukes are not pollinating/fertilizing, it is possible you have one of the oddball plants with all male or all female blooms. It is more likely you have a lack of bees. Generally in weather like this, the bees are out pollinating in the early morning hours. If you're not seeing bees and you have both male and female blooms that are not, apparently, pollinating and fertilizing and giving you cukes, you may need to hand-pollinate the flowers. I don't know if the male cuke flowers' pollen is viable for more than one day, but it is always best, if hand-pollinating, to use freshly-openly flowers because that pollen is most viable. When you say 'melons', what kind of melons are you talking about? Watermelons? Muskmelons? True Cantaloupes? Other 'minor' melons like Christmas or Santa Claus melons or something else? If you're growing muskmelons (generally erroneously referred to as cantaloupes in the USA even though they are not true cantaloupes), they are generally thought of as monoecious with bees (and other pollinators) transferring the pollen from the male flowers to the female flowers (pollination) so that fruit set (fertilization) occurs. However, muskmelons actually can be andromonoecious, with female flowers, male flowers, and perfect (self-pollinating/self-fertilizing) flowers all on the same vine, so you could get fruitset even if no bees are present although maybe not a lot of it. With the female muskmelon flowers, the females open for one day only, so they are only receptive to pollen from the male flower on that day and generally are most receptive early in the day. You normally get good pollination and fertilization because there are a great many male flowers for each female flower. My best guess is that based on my experience with spraying water on the backs of leaves to deter spider mites, you will not adversely affect pollination and fertilization, unless you are in the garden spraying early in the day when the pollinators normally are active. If you aren't getting good fruitset, it likely is a lack of bees. We are very hot here (highs the last week have been about 102-108) and my watermelons, muskmelons and cukes are pollinating and fertilizing like crazy. I know I have a good bee population because I see them in the garden when I'm there. Are you seeing bees? There's a slim chance that if your cukes and melons are terribly heavily infested with spider mites, then the plant is so stressed it won't set fruit. \ If you're talking about watermelons, make sure you are not overfertilizing with nitrogen. Too much nitrogen produces excess foliage than can hide the flowers from the bees, which obviously interferes with pollination and fertilization. With most watermelons, you get relatively few female flowers since a plant can only support a limited number of enlarging fruit, so it is essential adequate bees be present and also able to find the flowers. And, it goes without saying, the the use of pesticides may be killing off your bees, even if you are not the one using the pesticides. A neighbor could be spraying with a pesticide that is killing the bees.

Hello spider and camera people. That pretty little Phidippus regius (sp?) looks just like the jumping spiders that I keep in my kitchen/dining rooms to eat flies at night. I've been doing it for years. They are such wonderful fly eliminators! I'd probably keep them even if I didn't have flies. But it's always good to have a back-up story ready for the ones who freak at the sight of "SPIDER!!!". :)

It is normal to see spider crazing, and they will disapear as soon as the area becomes hydrated.There is no need to "call them back asap"