Crane fly :

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Status : Enemy

Description : 

- Larva : cylindrical body like a worm, 3 to 4 cm lenght, earthy grey colour. 

- Adult : often called "daddy longlegs", greyish brown, resembles a mosquito but larger (16 to 25 mm long) with very long and fragile legs. These insects don't bites you as for mosquitos.

Biology and life cycle :

- Host plants : crane flies are seen in summer on marshy ground, on grass in fields and on lawns. The larvae attack nearly everything.
- Adult : flies in the morning and at nightfall in humid locations. One female can lay  300 to 400 eggs. Fron the egg to the larvae, it last approximately 15 days and requires high humidity.
- Larvae : the young larvae lives under the surface.

According to the litterature : 

-1 generation yearly for T. paludosa, the most harmful and widespread crane fly in Northern Europe, the larvae of which can cause severe damage from January to May, the adults flying from July, numbers reaching a maximum in September.
- 2 generations yearly for T. oleracea a more southerly species. Favoured by the climate, the larvae of this species continue to grow during the winter and become fully developed in March. The adults fly in April, a second generation in October.

Damage

Only the underground larvae are dangerous for our plants. Highly resistant to cold, it overwinters near the surface of the ground and wait for cooler temperature in spring. 

It digs underground galleries open to the air allowing it to emerge at night. This is this fact that will be used to poison the pests with baits. 

It devours germinating seeds, the roots and some aerial parts in the collar area of young plants. Once growth is completed, it emerge from the soil to live his flying life.

 

Typical damage of a Tipula larvae, on a  temperate Pinguicula hibernaculum. Photo : Eric Partrat

I only noted damages in winter on temperate Pinguicula hibernaculum (sometimes with the lost of all the plant) and in early spring on young developped rosettes. If you grow your Mexican Pinguicula in a peat basis mix, your plants can be attacked also. Mineral basis mix seems to be prevented from atacks as drier than peat mix.

Solutions :

First of all, you must prevent Tipula from laying around your plants. They really love the wet peat of your bog than the drier lawn. You can use the fact that these insects have really long legs and put a grid over your plants.

 

Temperate Pinguicula protected by grids against blackbirds are also protection against crane flies from laying.

 

You can also grow around some varieties of Drosera binata really active in catching the Crane flies but outside it is not easy. 

Biological fight :   

I have not heard of a possible predator of Tipula larvae

Suppliers : unknown 

Chemical fight : 

There are many products sold to kill the larvae in the soil with poison baits. I am not really sure that it works for our larvae as most of the time the larvae don't stop to damage the hibernaculum. Maybe only a slightly reduction. On the other way, I have been told that watering the plants with Gaucho® or Confidor® (same active substance imidacloprid) will really kill all the larvae in the soil. Try to avoid to watering the rosettes for not burning the leaves. 

Pokon vermicid is also active but be very carefull as it can really burned the leaves of your plants. 

Suppliers :

- Bayer Confidor® 200 SL

Hom. n° 8686/B

200g/l imidacloprid 

 

- Pokon 

Hom. n° ?

90 g/l Diazinon

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