Testing Methods for Mosquito-Repellent Treated Textiles

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16.5

FIELD TESTING

The final step for evaluation of repellent treated textiles against mosquitos is conduct-

ing the field testing with a group of 6 - 13 human volunteers. The distance between each

volunteer should be ≥10 meters. The population density of the target species of mosquitos,

activity peak period, and biting pressure in the testing location should be checked before

conducting the field testing. The repellent treated textiles or uniforms will be worn by the

human volunteers. Based on the testing textile products and purpose, the specific body part

(i.e., arm or leg) of the participants will be selected to cover or wrap for the exposure.

Unused body parts will be protected by thick clothing or plastic cover. Usually, repellent

treated head netting, uniform, jackets, or t-shirt have been tested against mosquito bites in

the field. Sometimes a large piece of treated textile have been used to cover/wrap the low

part of legs or forearms and another one for untreated textile cover or wrap the other leg

or forearm as control. The volunteers will sit or stand in the field to expose themselves

to mosquitos for 5 minutes. This exposure is repeated at 1 hr interval until mosquitos land

and probe on the treated materials. The number of mosquitos landing/probing on the treated

and untreated body parts (arms or legs) are collected and counted. In the meantime, the air

temperature, humidity, wind speed, and other environmental condition will be detected and

recorded. The report about the repellent treated textiles/clothing should include the mate-

rials used, repellent, formulation and amount used, method of treatment, and method of

exposure (Govere and Durrheim 2006).

Figure 16.4: Cross-section view of the attractive blood feeding apparatus (JIS L1950-1).