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Evidence of an 'invitation' effect in feeding sylvatic Stegomyia albopicta from Cambodia.

Charlwood JD, Tomás EV, Kelly-Hope L, Briët OJ - Parasit Vectors (2014)

Bottom Line: Orientation of haematophagous insects towards a potential host is largely mediated by kairomones that, in some groups or species may include chemicals produced during feeding by the insects themselves, the so called 'invitation' effect.This preference did not vary with collector or pyrethroid.The 'invitation' effect may be due to a semio-chemical produced early in the feeding process.

View Article: PubMed Central - HTML - PubMed

Affiliation: Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK. jdcharlwood@gmail.com.

ABSTRACT

Background: Orientation of haematophagous insects towards a potential host is largely mediated by kairomones that, in some groups or species may include chemicals produced during feeding by the insects themselves, the so called 'invitation' effect.

Methods: The 'invitation' effect in blood-feeding diurnally active Stegomyia albopicta was investigated over 33 days in secondary forest in Mondolkiri Province, Cambodia. Two human volunteers sitting inside a shelter collected mosquitoes and noted where and when they landed. A 10% emanator of a synthetic pyrethroid with high vapour action was in use on alternate days.

Results: Overall, 2726 mosquitoes were collected, 1654 of which had the landing site recorded. The heads of the volunteers were the locations with the highest density of landings per surface area whilst the knees and elbows accounted for most of the landings received on the arms and legs. Landings recorded within three minutes of each other on a collector were about 2.5 times more likely to be on the same body part than on a random body part, weighted for landing site preference. This preference did not vary with collector or pyrethroid.

Conclusions: The 'invitation' effect may be due to a semio-chemical produced early in the feeding process. Incorporation of such a chemical into traps designed to control this important vector of dengue and chikungunya viruses might potentially improve their attractiveness.

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Related in: MedlinePlus

Photograph of the rear of the experimental shelter.
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Related In: Results  -  Collection

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Figure 2: Photograph of the rear of the experimental shelter.

Mentions: Most of the trees in the forest had a girth of less than 30 cm and there was only limited undergrowth. Water-filled tree holes provided a suitable habitat for mosquito larvae. In order to avoid the annoyance of sweat bees (Halictidae), a variety of horseflies (Tabanidae) and day biting mosquitoes, they constructed a 2x3x4 m (24 m3) shelter of 1.3 m wide overlapping plastic mosquito netting strips with a tarpaulin roof for their daytime living area. All but two of the strips were tied together with thin wire to make a sealed wall. The two remaining strips could be raised and lowered and acted as a door. The door of the shelter was left open from nightfall to midday at which time it was closed. Between noon and nightfall the strips were lowered and the shelter effectively closed. There was, however, a horizontal opening at the height of the wall, in the form of an isosceles triangular extension of the walls away from the roof at one end of the shelter (Figures 1, 2 and 3). Despite this opening, the entry of the bees and horseflies was curtailed. Mosquitoes, however, continued to enter the shelter through this opening. The half of the shelter where landing collections were performed had a floor of yellow and white empty polythene rice sacks. On alternate days, a slow-release emanator made of polyethylene mesh impregnated with a high vapour action pyrethroid was suspended in the shelter close to the opening.


Evidence of an 'invitation' effect in feeding sylvatic Stegomyia albopicta from Cambodia.

Charlwood JD, Tomás EV, Kelly-Hope L, Briët OJ - Parasit Vectors (2014)

Photograph of the rear of the experimental shelter.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4230241&req=5

Figure 2: Photograph of the rear of the experimental shelter.
Mentions: Most of the trees in the forest had a girth of less than 30 cm and there was only limited undergrowth. Water-filled tree holes provided a suitable habitat for mosquito larvae. In order to avoid the annoyance of sweat bees (Halictidae), a variety of horseflies (Tabanidae) and day biting mosquitoes, they constructed a 2x3x4 m (24 m3) shelter of 1.3 m wide overlapping plastic mosquito netting strips with a tarpaulin roof for their daytime living area. All but two of the strips were tied together with thin wire to make a sealed wall. The two remaining strips could be raised and lowered and acted as a door. The door of the shelter was left open from nightfall to midday at which time it was closed. Between noon and nightfall the strips were lowered and the shelter effectively closed. There was, however, a horizontal opening at the height of the wall, in the form of an isosceles triangular extension of the walls away from the roof at one end of the shelter (Figures 1, 2 and 3). Despite this opening, the entry of the bees and horseflies was curtailed. Mosquitoes, however, continued to enter the shelter through this opening. The half of the shelter where landing collections were performed had a floor of yellow and white empty polythene rice sacks. On alternate days, a slow-release emanator made of polyethylene mesh impregnated with a high vapour action pyrethroid was suspended in the shelter close to the opening.

Bottom Line: Orientation of haematophagous insects towards a potential host is largely mediated by kairomones that, in some groups or species may include chemicals produced during feeding by the insects themselves, the so called 'invitation' effect.This preference did not vary with collector or pyrethroid.The 'invitation' effect may be due to a semio-chemical produced early in the feeding process.

View Article: PubMed Central - HTML - PubMed

Affiliation: Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK. jdcharlwood@gmail.com.

ABSTRACT

Background: Orientation of haematophagous insects towards a potential host is largely mediated by kairomones that, in some groups or species may include chemicals produced during feeding by the insects themselves, the so called 'invitation' effect.

Methods: The 'invitation' effect in blood-feeding diurnally active Stegomyia albopicta was investigated over 33 days in secondary forest in Mondolkiri Province, Cambodia. Two human volunteers sitting inside a shelter collected mosquitoes and noted where and when they landed. A 10% emanator of a synthetic pyrethroid with high vapour action was in use on alternate days.

Results: Overall, 2726 mosquitoes were collected, 1654 of which had the landing site recorded. The heads of the volunteers were the locations with the highest density of landings per surface area whilst the knees and elbows accounted for most of the landings received on the arms and legs. Landings recorded within three minutes of each other on a collector were about 2.5 times more likely to be on the same body part than on a random body part, weighted for landing site preference. This preference did not vary with collector or pyrethroid.

Conclusions: The 'invitation' effect may be due to a semio-chemical produced early in the feeding process. Incorporation of such a chemical into traps designed to control this important vector of dengue and chikungunya viruses might potentially improve their attractiveness.

Show MeSH
Related in: MedlinePlus