Studying insects in general is entomology. Entomologists normally specialize in one group of insects. An entomologist who specializes in butterflies and moths is a Lepidopterist, one who specializes in flies is a Dipterist, etc.

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 5 words with the pattern D-PT-----. That is, nine letter words with 1st letter D and 3rd letter P and 4th letter T. In alphabetical order, they are:

depthless

dipterans

dipterist

dipterons

dipterous

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 4 words with the pattern --PT--IS-. That is, nine letter words with 3rd letter P and 4th letter T and 7th letter I and 8th letter S. In alphabetical order, they are:

dipterist

peptonise

rapturise

rapturist

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 7 words with the pattern --PT---S-. That is, nine letter words with 3rd letter P and 4th letter T and 8th letter S. In alphabetical order, they are:

depthless

dipterist

emptiness

peptidase

peptonise

rapturise

rapturist

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 8 words with the pattern D-P--R---. That is, nine letter words with 1st letter D and 3rd letter P and 6th letter R. In alphabetical order, they are:

dapperest

deplorers

deploring

dipperful

dipterans

dipterist

dipterons

dipterous