The insect appears to be a ladybug -- the 20-spotted lady beetle,

Psyllobora vigintimaculata.

Compare these images

http://bugguide.net/node/view/39631

A Lady Beetle, a beneficial insect.

The leaf appears to have Leaf Scorch, a condition caused when the leaf looses more moisture than the roots can supply.

http://www.mortonarb.org/trees-plants/tree-and-plant-advice/horticulture-care/leaf-scorch

kimmq is kimmsr

are you growing the cukes and squash in pots???

if so.. you are not watering enough.. or your media is failing ... not holding enough water for the time in between waterings ...

i really cant fathom growing squash in a pot.. due to how big it can get ...

ken

Isn't that interesting....a ladybug that feeds on powdery mildew! That's a great thing to see in your garden.

Be very vary about any advice that you aren't watering enough. In the summer, large leaves of plants can transpire moisture at a faster rate than the roots can absorb. Soaking the soil or potting mix will not solve the problem. Just be sure that the soil IS moist, and that your plant is fully hydrated.

I spray my garden plants with a kaolin clay product called Surround every summer. The heat can be very stressful here in the south....the white coating reflects the sun and makes a gigantic difference.

one other thing for sure.. when you say infesting... i expected to see the entire leaf covered in bugs..

one per leaf is NOT an infestation ...

and no matter the bug.. NEVER a reason for action ...

unless perhaps.. it was laying eggs ...

ken