Utdrag ur ”Guidelines for efficacy testing of mosquito repellents for human skin”
World Health Organization (WHO) 2009
Testing of repellents on human subjects is the method of choice as it utilizes the repellent end-user in the testing process and yields results that are relevant to the actual conditions of use.
Use of laboratory animals or artificial membranes may inadequately simulate the situation in which repellents for use on human skin are intended to perform”.
Detta betyder i korthet att myggmedel ska testas på människohud, inte på försöksdjur i lab eller konstgjort material, som ex vis skumplast.

Mosquito spray shall be tested on human skin. / Myggmedel skall testas på människohud.”
Walborg Thorsell, Docent in Experimental Parasitology

 

Mosquito repellent test with microencapsulated Icaridin 20% applied on skin

An orientation.
The study was performed on the mosquito Aedes aegypti, strain Senemaganga.
About 40 female mosquitoes, starved for 2 to 3 days were kept in a net cage. The test person cleaned the hands with 70 per cent ethanol  w/w. After air drying the hands were covered with surgical gloves with a dorsal opening of 49 cm2. One of the hands was treated with 0, 25 ml microencapsulated Icaridin on the dorsal opening- tost-(t)-, where as the other hand was untreated and served as a control – (c)- .
After airdrylng the test hand was introduced into the mosquito cage. After 5 minutes adaptation without allowing any bloodsucking the number of sucking mosquitoes was counted the following 5 minutes -t-. The same procedure was used for the control hand -c-. The repellent effect was expressed as 100x (l-t/c) per cent. The test was performed at 0, 4, 6 and 8 hours after microencapsulated Icaridin application.
During the whole test period- 8 hours no mosquitoes were sucking blood on the test hand where as the control showed 9 bloodsucking mosquitoes.
In summery the orientated study showed protection against Aides aegypti mosquito for at least 8 hours at the dose of 5A/cm2 of microencapsulated Icaridin 20 per cent.

Stockholm 07 02 10


Walborg Thorsell,
Docent in Experimental Parasitology

 

Ticks repellent effect of microencapsulated Icaridin 20%

An orientation – Study performed on the nymphal stages of Ixodes Ricinus

Nymphal stages of the tick Ixodes Ricinus were collected in the archipelago of Stockholm. They were kept in small net cages supported with wet filter papers and grass at a temperature of about +22°C.

The test procedure was the following: Petri dishes with an inner diameter of 9.5 cm were provided with 3 pieces of filter paper (Munktell No. 3, 9 cm). The test solutions, 20% microencapsulated Icaridin, were applied along the periphery of the papers. After airdrying, 6 nymphs were placed in the centre of the papers and their behaviour with regard to avoiding the treated area was observed.

After the test, which usually lasted for about 5 min, the nymphs were replaced in the net cages. The Petri dishes were uncovered and exposed to open air. The procedure with the nymphs was repeated after 4, 6, and 8 hours. At each occasion the number of nymphs avoiding the treated area was estimated. The repellency was expressed as the number of avoiding nymphs in relation to the total number of nymphs at each occasion. Thus 6 nymphs avoiding out of a total number of 6 is recorded as 100% repellency. The test was performed mainly induplicate. Controls with only ethanol were always used. The range was about ±17%.

Results

The nymphs avoided the Icaridin treated area after 0, 4, and 6 hours, giving repellency of 100%. After 8 hours only one avoided the treated area, where as the other nymphs passed the treated area, corresponding to a repellency of 16.7%. Thus Icaridin in the tested concentration gave repelling effect for at least 6 hours.

Stockholm 07 08 20


Walborg Thorsell,
Docent in Experimental Parasitology

 

Mosquito repellent test with microencapsulated Icaridin 20% impregnated cotton cloth

An orientation – Study performed on the mosquito Aedes Aegypti strain Senemaganga

About 40 female mosquitoes, starved for 2 or 3 days, were kept in a net cage.

The test person cleaned the hands with 70% ethanol w/w. After airdrying, the hands were covered with special surgical gloves, with a dorsal opening of 49 cm2. The free surface of one glove was covered with a piece of white cotton cloth, 49 cm2, with the aid of surgical tape. This glove served as a control, (c). The other glove had the dorsal opening covered with a piece of white cotton cloth, 49 cm2, treated with 0,25 ml microencapsulated Icariclin 20% (5u1/cm2). This glove served as the test glove, (t), after air drying.

The test person with the test glove introduced the hand into the mosquito cage for 5 minutes adaptIon without allowing any blood sucking, followed by 5 minutes mosquito exposure.

The number of bloodsucking mosquitoes was counted, (t). The same procedure was used with the control, (c).

The repellent effect was expressed as 100(1-t/c)%, where t is the number of bloodsucking mosquitoes in the test, and c Is the number of bloodsucking mosquitoes in the control.

The tests were performed at 0, 2, 3, 4, 5 and 6 days, at the dose of Sul/cm2, and it showed 100% protection. The results showed that the first mosquito, which tried to suck blood on the test hand appeared after 6 days, where as the control hand at each occasion showed 10 ±4 bloodsucking mosquitoes.

Summary

The microencapsulated Icaridin 20% treated white cotton doth protected from bloodsucking Aedls Aegypti for at least 6 days, at the dose of Sul/cm2.

Stockholm 07 02 10


Walborg Thorsell,
Docent in Experimental Parasitology

 

Mosquito repellent test with microencapsulated Icaridin 20% applied on the skin

An orientation – Study performed on the malaria mosquito Anopheles Gambiae

About 50 female mosquitoes, starved for 2 or 3 days, were kept in a net cage.

The test person cleaned the hands with 70% ethanol w/w. After airdrying, the hands were covered with surgical gloves, with a dorsal opening of 49 cm2. One of the hands, test (t), was treated with 0,25 ml mkroencapsulated Icarldln on the dorsal opening, where as the other hand was untreated and served as a control, (c).

After airdrying the test hand was introduced into the mosquito cage. After five minutes adoption without allowing any bloodsucking the number of sucking mosquitoes was counted for the following five minutes (t). The same procedure was used for the control hand (c).

The repellent effect was expressed as 100(1-t/c)%. The test was performed at 0, 4, 6 and 8 hours after microencapsulated Icaridin application.
The protection was 100% up to 8 hours.

Summary

The orientated study showed protection against malaria mosquitoes Anopheles Gambiae up to 8 hours at the dose of 5u1/cm2 of microencapsulated Icor’din 20%.

Stockholm 08 02 04


Walborg Thorsell,
Docent in Experimental Parasitology

 

Further tests previously  performed

 

 

ASSAY ON TRIAL WITH BIONIM AGAINST TOMATO LEAF MINER

Trial performed on behalf of Svenska Predator AB, Helsingborg.
Translation in English from original document dated Feb. 3, 1998.

Material And Methods

The effect of the botanical insecticide BIONIM on the Tomato Leaf Miner (Liriomyza Bryoniae) on tomato was examined. The tomato plants of species Tiny Tim and Gemini about 60 cm of height, were used as host plants. The plants were exposed to egg-laying flies during 6 – 7 days.

The spraying was performed twice with a hand spray bottle to full coverage. Two concentrations ofBIONIM were used, 0.25% and 0.50% respectively, which is normally recommended, at 6 days interval.
Of the total number of larvae in the untreated row, 67% resulted in hatched flies. Corresponding numbers for BIONIM treated rows were 7% and 1% respectively. (See diagram below).

 

TEST OF BIONIM AGAINST WESTERN FLOWER THRIPS (FRANKLINELLA OCCIDENTALIS) ON CHRYSANTHEMUM (ROYAL DAVIS)

First diagram shows development of adult thrips, while the second diagram indicates population of thrips larvae on treated plants. The plants were sprayed on August 14, (week 33) and August 23, (week 34) by a hand spray bottle to complete coverage.

 

EFFECTIVITY OF BIONIM AGAINST GREENHOUSE WHITEFLY (TRIALEURODES VAPORARIORUM) IN POINSETTIA PLANTS

Poinsettia plants were placed into insect-proofed cages, three plants per cage and four cages per row. They were infected with greenhouse whiteflies, 12 adults per cage. The plants were sprayed on June 13, (week 24) and June 24, (week 26) by a hand spray to full coverage. Control row was sprayed with water.

 

EFFECTIVITY TEST OF BIONIM AGAINST APHIDS (MACROSIPHUM EUPHORBIAE) ON CHRYSANTHEMUM (REGAL DAVIS)

Chrysanthemum plants were placed in insect-proofed cages, three plants per cage and four cages per row. They were infected with aphids, six cotton aphids (Aphis Gossypii) and six green peach aphids (Myzus Persicae) per cage. Lighting: 14 hours per day. The plants were sprayed on October 16, (week 42) and October 25, (week 43) to coverage by a hand spray bottle. Mesurements of the number of aphids were effected during week 42 (before first treatment) and on.

 

TEST OF BIONIM AGAINST THE TWOSPOTTED SPIDER MITE (TETRANYCHUS URTICAE) ON CUCUMBER PLANTS

The plants were treated with BIONIM on November 12, (week 46) and November 22, (week 47) on coverage, with a hand spray bottle. The control was sprayed with water.

 

AZADIRACHTIN – A RESIDUE ANALYSES IN TREATED TOMATOES

A residue analyses in treated tomatoes indicates that no detectable residue is seen even two days after spraying of substantially high amount of azadirachtin

 

MYGG & SÅNT – STUDY PERFORMED ON AEDES AEGYPTI

Study of the mosquito repellent effect of “MYGG & SÅNT” – An orientation.

The study was performed on the mosquito Aedes Aegypti, strain Senemanga.
About 30 female mosquitoes, starved for 2 to 3 days, were kept in a net cage.
The test person cleaned the hand with 70% ethanol w/w. After airdrying the hands of the test person were covered with special gloves with a dorsal quadratic opening of 45 cm2.
The free surface of one hand was treated with 0.5 ml of the test solution corresponding to 0.01 ml/cm2. The free surface of the other hand served as a control.

After airdrying the test hand was introduced into the mosquito cage after 0, 4, 6 and 8 hours. At each occasion the mosquitoes were adapted for one minute without allowing any bloodsucking. During the following minute the number of sucking mosquitoes was counted, (t). Corresponding number of bloodsucking mosquitoes was counted on the control hand after 8 hours, (c). The repellent effect was expressed as 100(1-t/c)%.

The results showed that no mosquitoes were sucking blood on the test hand at 0, 4, 6 and 8 hours. At 8 hours 1 mosquito was sucking blood. The control hand was at at the same time attacked by 11 bloodsucking mosquitoes.

The protecting effect of “MYGG & SÅNT” lasted for 6 hours at the amount applied. After 8 hours a slight decrease to 90.9% was observed.

Stockholm 04 10 17

Walborg Thorsell,
Docent in Experimental Parasitology

 

MK 19 – STUDY PERFORMED ON AEDES AEGYPTI

Study of the mosquito repellent effect of the microencapsulated DEET-preparation MK 19 – An orientation.

The study was performed on the mosquito Aedes Aegypti, strain Senemanga.
About 30 female mosquitoes, starved for 2 to 3 days, were kept in a net cage.

The test person cleaned the hand with 70% ethanol w/w. After airdrying the hands of the test person were covered with special gloves with a dorsal quadratic opening of 45 cm2.
The free surface of one hand was treated with 0.5 ml of the test suspension corresponding to 0.01 ml/cm2. The free surface of the other hand served as a control.

After airdrying the test hand was introduced into the mosquito cage after 0, 4, 6 and 8 hours. At each occasion the mosquitoes were adapted for one minute without allowing any bloodsucking. During the following minute the number of sucking mosquitoes was counted, (t). Corresponding number of bloodsucking mosquitoes on the control hand was noted at 8 hours, (c). The repellent effect was expressed as 100(1-t/c)%.

The results showed that no mosquitoes were sucking blood on the test hand at 0, 4, 6 and 8 hours, whereas the control hand at 8 hours was attacked by 12 bloodsucking mosquitoes.
This corresponds to a repellent effect of 100% of MK 19 against the yellow fever mosquito, Aedes Aegypti, for at least 8 hours.

Stockholm 04 09 27

Walborg Thorsell,
Docent in Experimental Parasitology