29 replies to this topic

[valerie]

Any engineers out there? Is there a possible issue with having air curtains in facilities that keep their doors open and negative or positive air pressure inside the building?
Thanks!
Valerie

[walabies]

I doubt it unless the air pressure is very strong...

[YongYM]

Dear Valerie:

What pest are you are trying to control by using the air curtain? Flies and flying insects?

I agreed with Walabies that the air pressure must be strong enough to be effective.

Any comment from the rest?


Yong

[AS NUR]

Dear Valerie...

The function of air curtains is to Protect your area from pest... and the air pressure must be strong enough to be effective ... I think plastic curtain (yellow color) is effective to protect your area from pestand cheaper than air curtain...so you can use plastic curtain

and about pressure inside the building must be positive pressure.. according hygiene zone.. The most hygiene have to positive pressure than negative ones.. and delta pressure minimal is 75 mpas...

[Simon]

I think plastic curtain (yellow color) is effective to protect your area from pestand cheaper than air curtain...so you can use plastic curtain

Any special reason for yellow AS NUR?

[kspay]

Dear Valerie...

and about pressure inside the building must be positive pressure.. according hygiene zone.. The most hygiene have to positive pressure than negative ones.. and delta pressure minimal is 75 mpas...

May I know what is positive pressure and negative pressure? o.0

[GMO]

Positive pressure means that if you check between your production area and the outside or a lower risk area, there should be air forcing its way out to the lower risk side.

There is a big note of caution here though, positive air pressure wherever I have used it has only been to control pathogens / micro, not pests. Remember there are plenty of pests; e.g. rats, mice who will not be bothered by some positive air pressure!

[GMO]

(...and I'd seriously be worried that a bluebottle could cope with a small breeze as well!)

[AS NUR]

Any special reason for yellow AS NUR?

Dear Simon..

Yellow is color of sun.. most of pest (insect ) dont like yellow color..

[GMO]

I disagree - after going outside in a high visibility yellow jacket a few weeks ago and being mobbed by flies and bees who thought I was a flower, I think yellow is a very popular insect colour!!!

[Charles Chew]

I have to disagree with AS NUR. You would need to understand that flies have compound eyes and they do not see images in manners that our insects do. Hence they are attracted to "bright colors" and yellow would probably be one of the worse colors to use.

Valerie - You could use the "black tunnel" to buffer insects entry and it works all the time. Have you ever seen any flies in the night or in the dark? Black curtains are the best but not recommended for food safety hygiene monitoring

[AS NUR]

dear all..

I mean about yelllow color is yellow shine ... that color like sun shine... that curtain make pest( Insect ) eyes dazzled and the pest (insect) dont want to go to the room inside.. and if you observe the pest (insect), they never fly to sun shine....
and if you ask to plastic curtain manufacturer, they must be suggest using yellow curtain for pest and blue for dust (sorry if i am mistake, because i dont know what the reasons is)....


Thanks for your comment

[GMO]

AS NUR - I would never use yellow curtains because insects in general are attracted to them. Just like you wouldn't put an electric fly killer near an entrance (as it attracts flies in), I wouldn't use yellow curtains.

Anyway, the only surefire method is surely having well sealed doors which are closed and treating any external infestations.

[Charles.C]

Dear All,

Perhaps I can add a little validation for AS NUR's suggestion -

Tips for Controlling Flies

I would like to contribute a couple of suggestions for fly control in the kitchen. I'm not too sure if these will work in a cool environment, but they were effective in a Caribbean setting, Jamaica. My mother and I read about them in a local newspaper and decided to give them a shot.
The first one is the use of yellow in the kitchen. I know that sounds a little too simple to be true, but the amount of flies in the kitchen was cut down visibly. All we did to try it out was put up yellow curtains and the results were amazing.
The second suggestion from the paper we tried was a Lignum Vitae plant in the kitchen. Lignum Vitae is the national flower of Jamaica, which is actually a small sturdy tree with
small purple flowers. Those two suggestions worked wonders for us.
Meisha Paul

http://eartheasy.com...he_envelope.htm

Rgds / Charles.C

[GMO]

If you had a UK customer, there's no way they'd go for yellow curtains without some solid scientific evidence, not anectodal.

[Charles.C]

Dear GMO,

It’s an interesting subject. After some more investigation, must agree that yellow is accepted as being a very popular colour in the insect world. The Encyclopaedia of Pest Management (Pimentel.D) comments –

"Many herbivorous insects are attracted to yellow. The attraction is considered to be a natural response to plant foliage (1). For example, yellow sticky traps have been effective for controlling leafminer populations in greenhouses. In Texas, a whitefly monitoring program used yellow sticky cards to determine that the activity of migrating adult whiteflies correlated with the maturation and defoliation of the cotton crop (2). Studies using a range of colours determined that a light shade of blue was the most attractive colour to adult thrips. "

Similarly “Fruit Flies (Aluja.M et al) has –

"Many species of Rhagoletis flies are strongly attracted to yellow colour, either as a response to yellow as the supernormal equivalent of reflection by green leaves or possibly in part as a consequence of selective responses to sites most likely to harbour insects that secrete honeydew (eg aphids) which also are highly attracted to yellow colour (eg yellowish foliage)."

I also noticed this company offering a rather impressive looking range of aluminium fly screens stated as EHO approved / used all over UK. The surprising thing is that they were available in all colours of the rainbow including golden-yellow.

http://www.chainscre...ain-screens.php

added - with respect to the original topic, I also noticed this claimed v.effective air-curtain product, only 3000USD -

http://www.ars.usda....2004/040309.htm


Rgds / Charles.C

[D-D]

Can anyone recommend any UK suppliers of air curtain equipment? Thanks.

[GMO]

Can anyone recommend any UK suppliers of air curtain equipment? Thanks.

Blimey, why do you want it? Please don't tell me as pest control!

[D-D]

Well BRC6 is quite clear about doors not opening directly onto production areas and even though we are low risk with closed processes, we will probably need to make some changes.

We can think about air locks for pedestrian access but we also have large loading doors for big pieces of equipment and pallet movement that need better protection. If the door seals are good and they are only open for a short time our rodent control should be fine but the main issue is keeping out flies/flying insects.

[saqibfst]

whats the reason behind the yellow curtain ?

Dear Valerie...

The function of air curtains is to Protect your area from pest... and the air pressure must be strong enough to be effective ... I think plastic curtain (yellow color) is effective to protect your area from pestand cheaper than air curtain...so you can use plastic curtain

and about pressure inside the building must be positive pressure.. according hygiene zone.. The most hygiene have to positive pressure than negative ones.. and delta pressure minimal is 75 mpas...

[GMO]

Well BRC6 is quite clear about doors not opening directly onto production areas and even though we are low risk with closed processes, we will probably need to make some changes.

We can think about air locks for pedestrian access but we also have large loading doors for big pieces of equipment and pallet movement that need better protection. If the door seals are good and they are only open for a short time our rodent control should be fine but the main issue is keeping out flies/flying insects.

I would suggest a double door, e.g. two rapid rise doors. Or at worst, a strip curtain as previously suggested and controls on ensuring the door is closed as much as possible (although I'd only have the latter opening onto closed product areas e.g. stores.

[D-D]

A double door is the ideal option but building airlocks for all fork lift access points would take away large amounts of floor space. Strip curtains are possible on some doors but nobody likes them. We have one on an internal door separating areas and the drivers practically go through it hands-free as they have one arm up to protect against getting slapped in the face and another hand over the FLT controls to stop the flaps hitting them and whacking it into reverse (okay, we could modify the FLTs). Also they are difficult to see through and that is another safety concern. On other doors we can't use curtains as the FLT is used for lifting vessels in and out of the side of the building.
For all these reasons we wonder if air dams could work.
Personally I'd knock the place down and start again but I'm not allowed...

[Barry Fair]

thanks

[Marshenko]

Yellow/Amber is effective because "insects perceive amber coloring as black/opaque and will not try to enter the area."
At least... according to one strip door manufacturer: http://www.globalind...riers-bug-doors

Here's from the University of Florida... they were actually designing a more effective trap as an attractant:

http://news.ufl.edu/...02/15/fly-trap/

"A key to making the device effective was the discovery that flies are three times more attracted to the color blue than to yellow and that yellow actually seemed to repel flies."

http://www.bioone.or...10.1603/ME10257


ABSTRACT
A better understanding of the visual attraction of house flies to colors and patterns is needed to improve fly trap performance. This study combined physiological responses measured with electroretinogram studies of the house fly's compound eyes and ocelli with behavioral attraction of flies to reflective colors and patterns in light tunnel assays. Compound eye and ocellar electroretinogram responses to reflected light were similar, with the largest responses to white and blue followed by yellow, red, green, and black. However, data from light tunnel behavioral assays showed that flies were attracted to white and blue light but were repelled by yellow. The addition of a black line pattern enhanced the attractiveness of blue visual targets, whereas yellow lines decreased attractiveness. Sensory input from the compound eye and the ocellus seems to be integrated to direct fly behavior. There is a direct correlation of house fly attractiveness to visual targets and the intensity of electrophysiological response, except for the yellow targets, which repel flies despite of intense electrophysiological response.

[Charles.C]

Dear Marshenko,

Magnificent post and searching.
This whole topic seems to fascinate the Bug Loving Community. With apologies, I took the liberty of adding a few more delicacies.

Quickest Sub-link to suggest Joke-Site Warning -
http://www.redorbit....n-laser-113012/
(via Marshenko’s 2nd URL)

Most Innovative Website Name –
http://pestcemetery....ght-bulbs-bugs/
(via the well-known web-site http://www.ehow.com/...el-insects.html

Grossest (and probably Incorrect) Response -
http://uk.answers.ya...11030220AA38Upg

Rgds / Charles.C