I emerge as soon as the sun set this time of the year, and can often be seen hovering before flowers as I sip nectar. Occasionally I can be seen in daylight zooming around the garden, especially late in the season. I am an amazing flier and have often been compared to a nocturnal hummingbird.
I am easily recognized by my large size, big eyes, furry brown thorax and six white stripes, tan band down each forewing with a row of white-lined veins across the forewings and by my pink and black hindwings. Unlike my more svelt butterfly cousins…I have to beat my wings very fast just to stay aloft…a characteristic that enables me to hover in mid-air like a hummingbird.
Being a mainly nocturnal flier, I prefer white or other pale tubular flowers which are easier to see in the evening. During daylight I can often be seen feeding at red or other brightly colored flowers…quite a contrast to my night-time color preferences.
The larvae of some of my more distant cousins can be quite destructive when emerging in your tomato or pepper patch.
Please post your answer as a comment.
Monroe County Master Gardener Association 
I believe it to be the Hummingbird Clearwing Moth-“Hermaris thysbe”
hawk moth or hummingbird moth
The range of these Sphinx moths is truly amazing. The photo credits come from the Firefly Forest Conservatory in Arizona.
The correct identification is Hyles lineata or the White-lined Sphinx moth. Hermaris thysbe, or Hummingbird Clearwing Moth, is also in the Sphingidae (Sphinx Moth) family…but the genus and species are different. The important thing is that both Lenore and Georgeann identified the bug as a Sphinx moth, so I will award partial bragging rights to both. The common name of Hawk Moth is more often associated with its predator offspring, the tomato hornworm.
Taxonomy is quite important in making a positive identification of any plant or insect. Quite often two similar specimens can share a number of common attributes as you work your way down each of their respective botanical descriptions. For example, these two are described identically until the tribe, genus and species classifications, where the differences make up the positive and correct identification. Often only the species will give the answer, so close are the specimens to each other.
In this particular case, both belong to the Lepidoptera order of Butterflies and Moths, before splitting off into the separate Sphingidae family of Sphinx Moths. If you recall, Butterflies have relatively small, slender bodies with larger, broader wing surfaces when compared with their Moth cousins and their thicker, plumper bodies and smaller wing surfaces. It is because of these observed physical differences, that the Moths are separated out at this juncture and are further classified on their own.
As Master Gardeners we should be constantly sharpening our diagnostic skills. One of the best ways is to develop a keen eye for the common elements of specimens we are trying to identify. The next thing is to match the observations to a known reference source of photos, habitat and taxonomies…and see what you can turn up. With the internet at our disposal, this task has been greatly simplified.
Both of these specimens are relatively large and have the characteristic nectar feeding probe associated with these species of Sphinx Moths. The wing colors are quite different as is the striping pattern on the wings. Iowa State Entomology has an excellent reference site called “Bugguide” and is listed below for your information.
REFERENCES:
http://www.Bugguide.net/node/view/2638 for Hermaris thysbe
http://www.Bugguide.net/node/view/3071 for Hyles lineata
http://www.Bugguide.net
http://www.whatsthatbug.com
http://www.fireflyforest.net/firefly/2006/03/30/white-lined-sphinx-moths.
I agree, both Lenore and GB deserve partial bragging rights. Not many are that awake at 6:38am or 7:42pm. .