Complex sentence: Most of these small moths are inconspicuous and of no particular significance to humans with the possible exception of waxworms, which are the caterpillar larvae of the greater ("Galleria mellonella ") and lesser ("Achroia grisella") wax moths (subfamily Galleriinae).
Split into simpler sentences: Most of these small moths are inconspicuous and of no particular significance to humans. Perhaps the most familiar are waxworms, which are the caterpillar larvae of the greater ("Galleria mellonella ") and lesser ("Achroia grisella") wax moths (subfamily Galleriinae).