Horseflies areflying insects belonging to the tabanidae family, known to
                            be major pests in rural areas, particularly in regions where livestock or
                            domestic animals are kept. Not only do these insect pests cause inconvenience
                            to animals and humans through their painful bites, but they can
                            also transmit diseases, affecting livestock productivity.
                        They are found almost everywhere in the world, although they prefer
                            humid climates and, once adults, the presence of animals is needed to
                            survive. They are commonly found on farms, cowsheds, meadows,
                            paddocks, riding clubs, cow barns, golf courses, lakeside and riverside
                            parks, etc.
                        
                            Morphology and biology
                            Horseflies have a similar morphology to large flies, with a length of up to
                                2.5 cm. Their bodies are sturdy and dark (black, brown or grey) or, in some
                                cases, metallic green or yellow.
                            They exhibit sexual dimorphism, which influences two aspects of their
                                anatomy. The first is linked to their diet. Females are mainly haematophagous,
                                namely, they have powerful mouthparts that enable them to sting
                                (bite) mammals and birds. Males, on the other hand, feed only on sugary
                                substances such as pollen and flower nectar.
                            The second difference is in
                                the eyes. In males, they are grouped together at the top of the head, which
                                is not the case in females.
                                They have a single generation
                                per year, generally
                                appearing during the
                                summer months when
                                atmospheric conditions are
                                particularly favourable: hot
                                weather, high relative
                                humidity and low pressure.
                                They need soggy soil to
                                develop their eggs, larvae
                                and pupae.
                            
                                
                                    
                                        
                                            
                                            Morphology details of horseflies. Left: male without separation between the eyes. Right: female with separation between the eyes.
                                         
                                     
                                 
                                
                            The latters are initially white, then turn brown or black within a few hours;
                                they are generally elongated and cylindrical and measure between 1 and
                                3 mm in length. They take a week to transform into nymphs, where they
                                hibernate until summer, when they hatch into larvae.
                            The life cycle of
                                horseflies varies according to environmental conditions, but it generally
                                lasts from a few weeks to over a year. Adult females live for 30 to 60 days,
                                while males have a shorter lifespan, dying after mating.
                            
                                
                                    
                                        
                                             Life cycle of horseflies
                                            Life cycle of horseflies
                                         
                                     
                                  
                                  
            
                         
                        
                            Damages
                            The main damage is caused by female horseflies which, by feeding
                                on the cattle blood , can lead to a reduction in weight and milk
                                production due to the continuous stress they cause the animals. In addition to this, the bites can
                                cause secondary infections.
 
                            Meat and milk producers
                                suffer significant economic
                                losses as a result of these
                                factors. As far as humans are
                                concerned, horseflies do not
                                generally transmit serious
                                diseases in these latitudes.
 
                            In some countries outside Europe, horseflies transmit diseases to
                                humans, their bites are painful and can in some cases cause allergic
                                reactions and inflammation. The presence of horseflies can make
                                agricultural, tourist or outdoor leisure activities uncomfortable
                                because of the nuisance caused by these insects.
                            
                                
                                    
                                    
                                        Damage caused by horseflies to animals