Tipula paludosa Meigen A common crane fly

This well-known pest is often abundant in wet grassland and pastures. The soil-inhabiting larvae (known as 'leatherjackets') often attack the roots and germinating seeds of cereals planted in recently ploughed-up grassland, and can cause considerable damage. At night, they also come to the surface and may then sever or otherwise damage the basal parts of stems; leaves in contact with the soil may also be holed or shredded. Damage is particularly severe in spring, when attacked plants turn yellow, wilt or die; dead or dying plants frequently occur in patches. Attacks

Fig. 242 Outline of the anal segment of leatherjackets: (a) Nephrotoma appendiculata; (b) Tipula paludosa.

are often reported on reseeded grassland and on cereal and vegetable crops which follow ploughed-up infested grassland; they also occur on strawberry, on various outdoor ornamentals (including bedding plants) and on containerized plants grown in plastic tunnels and under other protective structures.

BIOLOGY

Unlike the following species, Tipula paludosa is univoltine, most adults occurring in late August and September. Eggs are laid at random in the soil, each female depositing up to 300 or more. The eggs hatch in approximately 2 weeks but they are very susceptible to desiccation and require high humidity to survive. The larvae feed from autumn onwards and are usually fully grown by the following summer. They then pupate in the soil, and adults emerge about 3 weeks later. Gravid females do not fly, so that eggs tend to be laid close to where the adults emerged from the pupa and mated; consequently, populations of the pest can quickly build up in suitable sites (cf. T. oleracea, below).

DESCRIPTION

Adult 17-25 mm long, grey with a yellowish-red or brownish tinge and indistinct longitudinal

stripes on the thorax; antennae 14-segmented; wings up to 23 mm long, shorter than the abdomen (cf. Tipula oleracea, below); legs very long, narrow and fragile. Egg 1.1 x 0.4 mm, elongate-oval, shiny black (Fig. 241b). Larva up to 45 mm long, dull brownish-grey, plump with a soft but tough skin; head black but indistinct; posterior papillae fleshy and often tapered - the dorsal and lateral pair on the spiracular disc elongated and of similar length, the dorsal pair of anal papillae elongate and the ventral pair rounded (Fig. 242b) (cf. spotted crane fly, Nephrotoma appendiculata, p. 163).

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