After-bite preparations to reduce stinging and itching. Oral rehydration solution. Come prepared for the unexpected. Carry a few extra plastic bags for used sanitary supplies. Perhaps the safest form is 'ultrathon' in which a low percentage of Deet in a time release surface preparation.
Many insects love rich, dark colors.
Bring at least two and bring one full for the first night in Iquitos. A detailed list of packing suggestions is included in your applictaion packet.