Could it be racoons, or some kind of small animal? If the pineapple is yellow, then it probably ready to eat.

I’ve begun noticing itsy, bitsy, teeny weeny black bugs crawling around on my Mandevilla leaves … leaving behind eaten away places. No white, sticky, cottony material as mentioned for “mealybugs”, though! Any thoughts?
RnH

Hi Rick
Is there any clear sticky material on the leaves?

You may need to use a stronger pesticide (systemic) that is effective and can be used in your area. A strong pressurized sprayer can dislodge some of the cotton masses. Mealy bugs can winterover in colder temperatures. Here’s a recipe for tobacco tea I found on line . I have not tired it and don’t know if it works:
Take 3 fingers of chewing tobacco-place in a nylon stocking and steep in 1 cup of water for 20 minutes. Add 1 cup of mouthwash (antiseptic) to the tea and 1 cup of Murphy’s oil soap. Add 2 tbspns of this solution to 1 gallon of water and spray the plants. (Don’t use on edible plants). It is a strong insecticide so use caution when applying. You may have to spray several times at 7-10 day intervals. Let us know if it worked.

From the description, you may have mealy bugs a difficult insect to control. See above for control suggestions.

You may have mealybugs-white cottony “stuff” in leaf axils that also secrete honeydew (the sticky stuff). You can cut your mandevilla back as it will help control the insect. Continue your treatment of alcohol dip and insecticidal soap for at least 3 weeks even if you don’t see the insect. More mandevilla info

Mealy bugs are a difficult pest to get rid of because the white cottony fluff is a protective waterproof material contains the female with her egg case. The adult bug is covered with a waxy coating that is also impervious to water. The insect is vulnerable when the crawlers hatch and come out, but they don’t all come out all at once. They move quickly and are difficult to spot. Try Neem Oil, or insecticidal soap for the crawler stage once a week for 3-4 weeks. Use of both alcohol and oil is a safe control for indoor use. Persistance is the key to eliminate mealy bugs in all stages of their life cycle. You can also try a systemic insecticide. Be sure it is safe to use indoors on your plants and take proper precautions when using systemics.. Heavily infested plants should be discarded.

Are these white bugs in the axils (joints) of leaves in a cottony white mass? Is there sticky stuff on the leaves? If so, you may have mealy bugs, see the above post on Mealy Bug. It will tell you a safe way to treat the problem indoors.