Management of fly infestations in cattle population

Alok Kumar Singh^1#, Snigdha Shrivastava², Deepali Tiwari³, Pradeep Kumar⁴ and Nitin D. Hirani⁵

¹Department of Veterinary Parasitology, College of Veterinary Science & A.H., Rewa

²Ph.D. Scholar, Department of Veterinary Medicine, COVSc & A.H., Rewa

³B.V.Sc & A.H., Student, College of Veterinary Science & A.H., Rewa

⁴Department of Veterinary Parasitology, DUVASU, Mathura

⁵Department of Veterinary Parasitology, Veterinary College, Kamdhenu University, Anand ^#corresponding author- email: alok122@gmail.com

Introduction

Control of fly populations especially during late spring as been a tedious task. Flies are not only a nuisance but due to their irritating bites, they also transmit diseases, such as pinkeye and anaplasmosis. Flies predominantly includes- face flies, horn flies, stable flies and house flies but house flies are lesser problematic. These flies have different life cycles, feeding patterns and resting habits, which make control more challenging, due to this, a multipronged approach is typically needed for control of these flies.

Types of flies

Horn flies

These are small, bloodsucking flies which stay with animal and leave only to lay eggs in fresh manure. These are found on the neck, top line and underline of cattle. This fly causes heavy losses as they ectoparasites on beef producers. The development of these flies from egg to sexual maturity takes about 10 to 14 days, depending on weather conditions. Each female lives 14 to 28 days and can produce 200 to 500 eggs that are deposited in fresh and undisturbed manure.

This short and highly productive life cycle can result in a very rapid increase in horn fly populations. Each fly averages more than 30 meals and removes in excess of 1 cc of blood per day. Horn fly causes skin irritation, anaemia, decreased feed intake, diminished weight gains, and lower milk production. Implementation of control strategy is necessary as it leads to severe arm to animals.

Face flies

Face flies likes areas of higher humidity and more rainfall than other major fly species. They can be found feeding on body secretions such as tears, saliva, nasal mucus, blood serum from wounds and perspiration and transmits diseases like pinkeye. Face flies are capable of traveling several miles from adjacent properties and from animal to animal, that elevates the challenge in their control and management.

Stable flies

Stable flies are a bloodsucking fly that cause significant pain to animals. They are found on cattle legs, they can feed several times per day. Stable flies develop where there is decaying organic matter, such as manure and wasted feed around feed bunks, feed storage areas, hay feeders, and runoff drainage retention structures. When there is a significant stable fly population, cattle can be found huddling together or standing in water to minimize their exposure.

House flies

The development of house flies occurs in fresh manure and decaying organic matter. They feed on organic waste material, which includes tears and mucous around the eyes and nose and are known to diseases including pinkeye, mastitis, anthrax, and salmonella.

Methods of Control

Sanitation and Management of the Environment

• Minimizing the breeding areas of flies is of prime importance of fly control for confinement operations.
• For the development of flies, moisture is much needed, hence, minimizing wet areas and maintaining a “dry” lot surface enhances fly control efficacy.
• Surrounding areas must be ensured to be well drained and have minimal accumulation of decaying plant materials, manure piles, as well as soiled and uneaten feed.
• Poor sanitation can lead to fly populations that are difficult to control by other methods as house flies and stable flies develop quickly in warm weather, so cleanup should be done every seven days to disrupt their life cycle.

Self-applicators

• Insecticide containing dust bags, back rubbers, face strips, fly bullets (different version of a rub), and mineral feeder covers can be effective when properly installed and maintained.
• To be effective, however, cattle must be forced to use the self-applicator.
• Dust bags and back rubbers can be used to reduce face and horn fly populations, but must be placed in forced-use traffic areas for effective control.
• Fly strips and fly bullets attached to back rubbers can increase their effectiveness for animals of various sizes.
• These back rubbers, fly strips and fly bullets need to be checked and recharged weekly with an oil-based insecticide to ensure its effectiveness.
• Insecticide-saturated covers can also be used on mineral feeders to manage against pinkeye.

Feed-through products

• Insect growth regulators (IGR) can be used as a feed additive in vitamin-mineral mixes and supplements to disrupt the life-cycle of both face and horn flies as they develop in fresh manure.
• Feeding the IGR products before the beginning of fly season is most effective in controlling face and horn fly populations.
• Another important aspect is that flies, and especially face flies, can travel several miles to find a host. So, for an IGR product to be effective, fly control measures on nearby farms must also be in place and each animal must consume the labelled amount daily.
• Assurance of the label for proper dosage and active ingredients should be done to control the fly populations of concern.

Producer applied products

• For direct animal application many products available like- Pour-on sprays and projectile capsules that burst on impact.
• The key to successful fly control with these products is applying enough insecticide to be effective and administration with proper frequency.
• Most of these products have been formulated to have residual activity, but rain events do shorten their effectiveness.
• Pour-on contains concentrated forms of insecticide that are applied down the top line and then disperse to cover the skin surface.
• The challenge of using livestock sprays is getting adequate coverage of each animal and applying the insecticide so that no feed or water is contaminated.
• Some anthelmintic (dewormer) products have claims for external parasite control, but producers should avoid both overuse and application of reduced dosages to minimize future internal parasite resistance.
• The use of projectile capsules that burst on impact is less likely to provide effective control because of their placement and dosage.

Insecticide impregnated ear tags

• These tags are designed to release insecticide over time, but they typically last only eight to 12 weeks and the fly season can last for more than six months, which poses a challenge in using fly control tags.
• To obtain maximum horn and face fly control, two tags per adult animal are typically needed. If face flies are present, the calf may also need a tag.
• The three main product classes are pyrethroids, organophosphates and microcyclic lactones.
• Proper confirmation must be made contain the active insecticide ingredients of the tags for effective control of the flies of concern, and use protective clothing and gloves when handling insecticides.
• The primary issue with insecticide ear tags is horn fly resistance to the insecticides impregnated in the tags, especially the parethyroid insecticides.
• It is advised to rotate product classes annually due to resistance, which is a major concern.

Premise control

• This diversified category is intended to help control flies around premises and includes premise sprays, fly traps, insecticide baits and predator wasps.
• Premise sprays contain insecticides with residual activity that typically kill flies when they land on a surface – but remain effective for no more than two to three weeks.
• Careful implementation of residual sprays must be done to avoid contaminating feed and water resources.
• Low-pressure sprayers, mist blower sprayers and foggers can be used as an area control measure to cover large drylot spaces and fly resting areas for quick knockdown of both house and stable fly populations.
• Fly traps as either a sticky trap that catch flies as they land on them, or an odor-attractant trap that entices flies into an inescapable container can be used.
• Fly baits contain an attractant that can be used in bait stations, as scatter bait, or mixed with water and applied to surfaces and found to be effective only for house and blow flies.

Resistance

• Fly resistance to insecticides is a heritable change in the sensitivity of a pest population reflected in repeated failure of a product to achieve the expected level of control when used according to the recommended dose for that pest species.
• When used repeatedly, flies can develop resistance to a given class of insecticide.

Biological Control

• Small parasitic wasps can be used in and around premises to control both house and stable fly populations.
• Parasitic wasps insert their eggs into fly pupae and after hatching, the wasp larvae parasitize and kill the developing house and stable fly pupae.
• Good sanitation and manure management and timely parasitic wasp release, can be an effective control combination for house and stable fly control in and around drylots.

Alternative Fly Control Methods

• There has been an increased interest in identifying non-insecticide fly control alternatives like- Garlic, cinnamon, and other essential oil-based extracts but the research on their effectiveness is limited.

Summary

For achieving effective fly control, a multi-pronged approach is typically needed. Selecting the most effective control method for any given operation will depend on type of flies, product efficacy for each fly population, product cost, ease of product administration, level of resistance to insecticides within class, their mode of action and herd management practices. Always ensure that products are applied in the right way, at the right time, and that the product will control fly populations of concern and protective clothing and gloves must be worn when handling insecticides to prevent absorption into the skin. Management practices such as sanitation, management of the environment and parasitic wasps are logical first steps to minimizing premise fly populations. As even products available on the market become significantly less effective when the environment is not managed to control fly breeding areas. Development of resistance of fly populations to current insecticides must be considered as they can develop reduced susceptibility to the active ingredients in fly control products when used repeatedly over time.