Crane flies, often referred to as "mosquito hawks" or "daddy longlegs," are not typically harmful to lawns. In fact, they're mostly harmless to plants and humans alike. While crane flies themselves may not pose a threat, their larvae, known as leatherjackets, can feed on grassroots and cause damage to lawns, particularly in large numbers.

Here are some methods to manage crane flies and their larvae in your lawn:

Cultural Practices: Maintain a healthy lawn by regular mowing, watering deeply but infrequently, and aerating to improve soil drainage. Healthy lawns are more resilient to pests.

Biological Controls: Introducing natural predators like birds, ground beetles, and parasitic nematodes can help control crane fly larvae populations.

Chemical Treatments: In severe infestations, insecticides may be necessary. Apply insecticides labeled for leatherjackets or crane fly larvae according to the instructions provided. It's important to use these products responsibly and follow safety guidelines.

Physical Removal: Hand-picking larvae or using a vacuum cleaner on low settings can help reduce populations in localized areas.

Nematodes: Certain species of beneficial nematodes, such as Steinernema feltiae, are effective against crane fly larvae. These nematodes can be applied to the soil and will infect and kill the larvae.

Natural Predators: Encourage natural predators of crane flies, such as birds, bats, frogs, and predatory insects, by providing suitable habitats like birdhouses, bat boxes, and water features.

Diatomaceous Earth: This natural substance can be applied to the soil to deter and kill crane fly larvae by dehydrating them.

Before implementing any control method, it's essential to accurately identify the pest and assess the extent of the infestation. Integrated Pest Management (IPM) strategies that combine multiple approaches, including cultural, biological, and chemical methods, are often the most effective and environmentally friendly way to manage pests like crane flies in your lawn.