Explanation:
Diaphragms, cervical caps and vaults are also barriers made of rubber that are inserted into the female reproductive tract to cover the cervix during coitus. They prevent conception by blocking the entry of sperms through the cervix. They are reusable. Spermicidal creams, jellies and foams are usually used along with these barriers to increase their contraceptive efficiency.

Reference: NCERT Biology Text, Class: XII, Unit VI: Reproduction, Chapter 4: Reproductive Health, Page no: 60.

Explanation:

Trypanosoma gambiense is the causative agent of the disease known as West African sleeping sickness and is found in the western part of Africa. T. gambiense is essentially transmitted between humans and tsetse flies sharing riverine vegetation habitats. In the case of T. gambiense, two tsetse flies (Glossina palpalis and Glossina tachinoides) serve as the primary vectors and are capable of transmitting the trypanosome.

Reference: Encyclopedia of Entomology By John L Capinera, Page no: 3946.