Clearwing moth

Taxonomy

Economic importance

Synanthedon spp. are found in many localities, but are seldom a serious pest.

Geographical distribution

Kenya, Tanzania, Uganda.

Damage

The larvae burrow into the vines and sometimes into the tip of the storage roots via the vine. The vine base is characteristically swollen and traversed with feeding galleries. With heavy infestation, the stem cracks and  breaks off easily at the base.

Morphology

The eggs are yellowish, while the larvae are whitish with transparent skin and a brown head capsule. They can grow up to 2.5 cm long. The pupae are covered by a greyish brown pupal case. The adult moths have distinctive transparent wings with a wingspan of about 20 mm.

Biology and ecology

Synanthedon damage is seldom serious, but can discourage farmers who for food security reasons try to keep their sweetpotato crop in the field for a long period.

Eggs are laid in clusters of 70-100 on the stems and leaf stalks; hatching takes a few days. The caterpillars bore into the vines, where they tunnel down to the vine base. Pupation occurs mostly at the vine base just above ground level.

Detection and inspection

Synanthedon damage is often attributed to Cylas spp. However, the swelling of the stem base is mostly more severe and brown pupal cases can be seen protruding from the swollen vine.

Management

Control of this pest is seldom necessary. 

Cultural control

Measures like sufficient rotation, use of clean planting material, field sanitation and timely harvesting should be effective in reducing incidence of this pest.

References

Ames, T., Smit, N.E.J.M., Braun, A.R., O’Sullivan, J.N., and Skoglund, L.G. 1996. Sweetpotato: Major pests diseases, and nutritional disorders. International Potato Center (CIP). Lima, Perú. 152 p.

Bradley, J.D. 1968. Two new species of clearwing moths (Lepidoptera; Sesiidae) associated with sweetpotato (Ipomoea batatas) in East Africa. Bull. ent. Res. 58: 47-53.

Hill, D.S. 1983. Agricultural insect pests of the tropics and their control - 2nd ed. 290 p.

Contributed by: Nicole E.J.M. Smit

Economic importance

Geographical distribution

Damage

Morphology

Biology and ecology

Detection and inspection

Management

References

Damage on stem by the larva of clearwing  moth (K. P.U. de Silva).

  Clearwing moth larva (N. Smit).

  Pupal case in swollen vine (N. Smit).

Adult clearwing moth  (N. Smit).