Self-Assessment Questions (SAQs) for Study Session 9

Now that you have completed this study session, you can assess how well you have achieved its Learning Outcomes by answering these questions. Write your answers in your Study Diary and discuss them with your Tutor at the next Study Support Meeting. You can check your answers with the Notes on the Self-Assessment Questions at the end of this Module.

SAQ 9.1 (tests Learning Outcomes 9.1 and 9.5)

Which of the following statements about larviciding is false? In each case, explain what is incorrect.

A  Larviciding means applying chemicals to kill adult vector mosquitoes.

B  Temephos is a chemical used as a larvicide to kill larvae of vector mosquitoes.

C  Temephos is sprayed onto water collections using spray pumps.

D  Temephos can only be sprayed by trained experts/professionals.

E  Larvicides are applied to all vector breeding sites, including those that can be removed by environmental management activities.


A is false. Larviciding is a method of killing mosquito larvae using chemicals or toxins; not the adults.

B is true. Temephos is a chemical widely used as larvicide in Ethiopia.

C is true. Temephos is sprayed to vector breeding water collections using spray pumps.

D is false. Temephos can be sprayed by HEWs or community health workers.

E is false. Larviciding is done in vector breeding sites that cannot be treated through environmental management measures.

SAQ 9.2 (tests Learning Outcome 9.2)

You know that mosquitoes require water collections for breeding and different types of vector breeding grounds can serve as breeding habitats. From the list below, identify places that cannot be breeding grounds for the vectors that transmit malaria, and explain why.

  • Borrow-pits
  • Houses
  • Micro-ponds
  • Trees
  • Stream beds
  • Irrigation canals
  • Foul smelling polluted water
  • Swamps
  • Road ditches.


Borrow-pits, micro-ponds, stream beds, irrigation canals, swamps, and road ditches can serve as water collection sites and thus vector breeding grounds. Houses and trees are not water collection places and cannot be vector breeding sites. Foul smelling polluted water is not good for breeding of malaria transmitting mosquitoes.

SAQ 9.3 (tests Learning Outcome 9.2)

In most parts of Ethiopia, vector populations increase following the rainy season. What could be the reason for an increase in the vector population after the rains? What is the most important type of water collection that is very good for breeding and development of the main malaria vector in Ethiopia?


Rainfall creates several water collections that serve as vector breeding grounds. Small rain water pools are the most important breeding sites for the main vector of malaria in Ethiopia.

SAQ 9.4 (tests Learning Outcomes 9.1 and 9.3)

You have learned that environmental manipulation refers to making temporary changes to the environment to make it unfavourable for the vector to complete its life cycle in water. List three environmental manipulation techniques with this effect.


You may have thought of removing water plants from water collections, removing obstructions from streams, flushing, shading ponds and river banks, etc.

SAQ 9.5 (tests Learning Outcomes 9.1 and 9.4)

Environmental modification refers to making permanent changes to the environment to make it unfavourable for the vector to complete its life cycle in water. List two examples of environmental modification measures with this effect.


You may have thought of filling of pits and depressions, levelling uneven ground, shore lining, planting trees to drink up ground water, etc.

SAQ 9.6 (tests Learning Outcome 9.5)

Imagine that you have a vector breeding site in your community that cannot be eliminated through environmental management methods and you have to use larviciding to kill the larvae. The surface area of the water in the breeding site is 960 square metres (m2). You have learned that 8 ml of the chemical Temephos mixed in 8 litres of water in one spray pump is enough to treat 320 m2 surface area of water in the breeding site.

  • a.How many spray pumps of Temephos chemical do you need to spray in order to treat the breeding site?
  • b.What is the amount of Temephos (in ml) you need to treat the breeding site?


  • a.960 m2 divided by 320 m2 = 3, so you need three spray pumps of Temephos to treat the vector breeding site.
  • b.3 multiplied by 8 ml of Temephos in each spray pump = 24 ml of the chemical to treat the vector breeding site.

SAQ 9.7 (tests Learning Outcome 9.6)

You learned that most larval control activities are undertaken through community participation and you have to mobilise and convince the community to participate. What are the community organisations that can help you to mobilise local people to participate in larval control activities?


Women’s and youth associations, cooperatives, health committees, schools and religious leaders and community leaders, all may help you to mobilize local people to undertake larval control activities.

Summary of Study Session 9