Ponderosa Pine Seedworm
Cydia piperana (Kearfott)

Host:  Ponderosa pine

Figure 154. Larvae of ponderosa pine seedworm.

Symptoms/Signs:  There is no external evidence of infestation. Inside the cones, frass and mining can be seen in the cone axis. Seed pairs on the same scales can become fused together by the silk lined tunnels produced by the larvae. Often these seeds tend to stick to the scales and remain in the cones.

Adult moths have a wingspan of 10 to 20 mm. The fore wings are metallic gray with silver bands. Larvae are 10 to 15 mm when mature, white to cream colored, with a mottled head capsule.

Biology:  One generation is produced annually. Eggs are laid at the base of cone scales, on the surface of the scale, or on the cone stalk. Newly hatched larvae bore between the cone scales, enter a seed, consume it, and leave it filled with frass. It then moves on to another seed leaving a silk lined trail. As the larva matures, it burrows into the cone axis and overwinters.

Figure 155. Damage of ponderosa pine seed by ponderosa pine seedworm.

Effects:  In some years this insect can consume a large proportion of the seed crop.

Similar Insects and Diseases:  A number of insects affect cones. This insect is distinguished by the presence of the frass packed seeds, larvae or mining in the cone axis.

Reference:  37