Manure and bedding treatment with larvicides

Any kind of manure as found in whatever livestock operation is an ideal breeding environment for houseflies and other nuisance flies. This is why one of the approaches to fly control consists in treating manure (slurry, dung, etc.) with larvicides that will kill the maggots.

To directly treat manure heaps, bedding mixed with excrements, and whatever organic waste products are used (liquids or powders) that contain an insecticide with effect against the fly larvae (maggots), i.e. a larvicide.

Manure heap: a breeding paradise for houseflies.

Most products used contain old generic larvicides such as organophosphates (e.g. chlorpyrifos, coumaphos, diazinon), carbamates (e.g. carbaryl, propoxur) or synthetic pyrethroids (e.g. cypermethrin, permethrin). Products containing insect development inhibitors are also used (e.g. cyromazine, diflubenzuron, triflumuron): they don't kill the maggots quickly, but interrupt their development by blocking the next larval molt.

Most larvicides have a significant drawback: they have a broad spectrum of activity and are also lethal for the natural enemies of the housefly maggots that proliferate in manure as well. A notable exception is cyromazine, because it is quite specific against fly larvae.

Instead of chemicals Bacillus thuringiensis, a microorganism lethal for many insects has also been used successfully for manure treatment, either as a powder or in a liquid formulation.

It the broader context of fly control it is highly advisable to combine manure treatment with other methods to control the flies, especially with insecticides that don't target the maggots but the adult flies.

Surface treatment with contact insecticides

The adult flies of all the species that proliferate in livestock environments spend most of their time not on the animals, but off the animals, resting in their vicinity. This is why treating such resting places with insecticides is usually more effective than treating the animals. Typical resting places that can be treated are walls, pillars, fences, tubing, windows, joists, etc.

For surface treatment veteran generic insecticides with contact effect are used: organophosphates (e.g. diazinon, chlorpyrifos, ethion), carbamates (e.g. carbaryl, propoxur) and synthetic pyrethroids (e.g. cypermethrin, cyfluthrin, deltamethrin, permethrin, etc.). Newer insecticides such as neonicotinoids (e.g. imidacloprid) are slowly replacing the old ones. Mixtures are also used, often including synergists.

The major target species in dairy, pig and poultry operations are houseflies (Musca domestica) and stable flies (Stomoxys calcitrans). Other filth and nuisance flies such as the lesser housefly (Fannia spp) and the false stable fly (Muscina stabulans) can also be a problem in particular properties.

It is important to treat those places where the flies prefer to rest. Different fly species may have different resting preferences.

After treatment of the surfaces, the residual effect, i.e. for how long the insecticide will remain effective depends on a lot of factors. The insecticide can break down by the effect of sunlight, temperature and other chemicals (e.g. detergents or disinfectants). Water (rain, humidity) can wash it away. Dust and dirt can cover it and make it ineffective. The type of surface treated (glass, wood, metal, plastics, concrete, paints, cardboard, etc.) affects the residual effect. As a rule of thumb, the more porous and irregular is a surface, the shorter the residual effect.

A problem with many contact insecticides is that houseflies have developed resistance to almost every active ingredient. Therefore it is highly recommended to periodically alternate insecticides of different chemical classes, and to combine contact insecticides with baits, larvicides, etc.

Power spraying of premises with insecticides

Power spraying of premises in livestock operations is often used to control numerous bloodsucking parasites that spend part of their time off the animals someweher in their vicinity, hiding in cracks, crevices, cavities, hollow tubes, etc. This is the case for red poultry mites, bed bugs and soft ticks that often infest poultry houses.

Products for premise treatment are mostly concentrates (liquids or wettable powders) containing old generic broad-spectrum insecticides such asorganophosphates (e.g. diazinon, chlorpyrifos, ethion), carbamates (e.g. carbaryl, propoxur) and synthetic pyrethroids (e.g. cypermethrin, cyfluthrin, deltamethrin, permethrin, etc.). Newer insecticides such as neonicotinoids (e.g. imidacloprid) are slowly replacing the old ones. Mixtures are also used, often including synergists.

Fumigation or fogging of premises with insecticides

Fumigation or fogging consists in treating not the surfaces or hiding places of the parasites but the "air". To this a kind of toxic cloud is produced that kills the parasites by contact or inhalation. The objective of fumigation or fogging in livestock operations is to rapidly kill large populations of flying insects such as flies and mosquitoes, but also crawling pests such as cockroaches, termites, beetles, etc, that do not harm livestock but are otherwise damaging.

Fumigation and fogging are always a kind of quick fix with almost no residual effect, i.e., it kills insects only as long as the toxic cloud fills the treated air around them, usually a few minutes or a few hours indoors. Once the toxic cloud has cleared or is evacuated, arriving insects won't be affected. In fact, such treatments bring a short-term relief, but do not solve the real problem, i.e. the source of the parasites.

For indoor fumigation or fogging to be effective air circulation has to be stopped (ventilation, air conditioning, air currents, etc.).

Fumigation is often done with chemicals (fumigants) that are toxic not only for insects, ticks or mites, but also for many other organisms that can be a problem in livestock premises or in domestic or industrial buildings.

Insecticides used for fumigation or fogging are mostly old generic compounds, usually volatile ones belonging to the organophosphates (e.g. dichlorvos) and synthetic pyrethroids (e.g. cypermethrin, cyfluthrin, deltamethrin, fenvalerate). Natural natural pyrethrins as well as mixtures including synergists are also used.

Dusting with insecticides

In poultry and pig operations dusts are sometimes used for off-animal treatment of manure, bedding and premises as well as for on-animal treatment of the animals.

Dust bathing is a natural behavior of hens (much less of roosters!), many other birds and even mammals. Many animals do this to eliminate skin parasites. Taking advantage of this, if an insecticidal dust is added to sand boxes or to the bedding of the birds, their spontaneous behavior will result in insecticidal self-treatment. Dusting ist often used to contol poultry lice and mites.

Pigs do not dust themselves as hens, but dusts are sometimes used on them too, also against lice and mites.

As a general rule, dusting is less effective than power spraying, especially against mites and lice species than may infest the ears and other hidden body parts, as well as against parasites that remain on the animals only for bloodsucking and otherwise rest in their hiding places (e.g. the red poultry mites, bed bugs, etc.).

Insecticidal dusts contain mostly old generic active ingredients such as organophosphates (e.g. coumaphos, malathion), carbamates (e.g. carbaryl, propoxur), and synthetic pyrethroids (e.g. permethrin). Natural pyrethrins as well as mixtures including synergists are also used. 

Pond treatment with larvicides (larviciding)

Watering ponds are ideal places for mosquito breeding

Slurry ponds are often used in dairy, feedlot, pig, and poultry operations to collect manure and other organic waste until it is sprayed on the fields or otherwise processed. Ponds for watering livestock are also frequent in cattle and sheep properties to ensure the supply of drinking water.

Any type of ponds are is an ideal breeding place for numerous insects, including various mosquito species.

To stop mosquito breeding such ponds can be treated with various chemicals that kill or interrupt the development of mosquito larvae. This kind of treatment is also called larviciding. Generic insect development inhibitors (e.g. methoprene) and a few organophosphates (e.g. temephos) are often used for this purpose. Equally effective against mosquito larvae are biological products containing spores or toxins from Bacillus thuringiensis or Bacillus sphaericus, two soil bacteria vastly used in agriculture as biological pesticides.

Plastic strips impregnated with parasiticides

Plastic strips impregnated with parasiticides (mostly synthetic pyrethroids) have been used successfully to control poultry mites in layer houses. They can be hung inside or around the birdcages and can provide sufficient control of the mite populations. However, many poultry mite populations have developed strong resistance to synthetic pyrethroids. And such insecticide-impregnated plastic strips are not commercially available in many countries.

Pasture treatment with tickicides or insecticides?

In certain countries (e.g. the USA) there are pesticides approved for lawn and pasture treatment in private properties or recreational areas that have tick problems (caused mainly by Ixodes and Dermacentor ticks). Such tick species are known to transmit various human and pet diseases and are often carried by wildlife (deer, rodents, foxes, etc.) that visit such places as well. Chemicals products approved for this indication contain mostly veteran generic synthetic pyrethroids (e.g. cyfluthrin, deltamethrin, permethrin), carbamates(e.g. carbaryl, propoxur) or organophosphates (e.g. chlorpyrifos, diazinon; both compounds were withdrawn in the USA for residential lawn use).

However, it is not at all advisable to do something similar in order to control cattle or sheep tick infestations in livestock properties. There are many reasons for not doing it. Such treatments would kill most invertebrate fauna in the property, including beneficial insects necessary for development and survival of the vegetation. And grass would become contaminated with pesticides. In addition it is virtually impossible to treat all groves, forest spots and corners, shrubs, bushes, etc. that grow in a property where ticks can hide, as well as it is impossible to treat all wildlife that can carry ticks. And it would be quite expensive.

Summarizing, pasture treatment with tickicides is not a not a good idea to control cattle or sheep ticks.