citrus mealybug vs mealybug

citrus mealybug and mealybug both are nouns.

Word	Noun	Adjective	Verb	Adverb
citrus mealybug	Yes	No	No	No
mealybug	Yes	No	No	No

As nouns, mealybug is a hypernym of citrus mealybug; that is, mealybug is a word with a broader meaning than citrus mealybug:

citrus mealybug: feeds on a wide variety of cultivated plants but especially destructive to citrus
mealybug: scalelike plant-eating insect coated with a powdery waxy secretion; destructive especially of fruit trees

Other hypernyms of citrus mealybug include mealy bug.

citrus mealybug (noun)	mealybug (noun)
feeds on a wide variety of cultivated plants but especially destructive to citrus	scalelike plant-eating insect coated with a powdery waxy secretion; destructive especially of fruit trees