"Phassus" Borer

All in BLUE is the note from Dr.A.BABU, Head, Division of Entomology, UPASI Tea Research Foundation Tamilnadu, India

The "Phassus” Borer - Hepialid Borer,”Sahyadrassus malabaricus (Moore) Hepialidae :
Lepidoptera), a large caterpillar, endemic to south India. It is often referred by its previous generic name "Phassus" which attacks several forest trees including the teak and eucalyptus. More than 50 species of plants are recorded as host for this pest.Adults have grey forewings with faint mottlings Male produce sharp, pungent, mustard like smell by the scent glands Young caterpillars bore into the stems, excavate long cylindrical tunnels, eating of bark and sapwood resulted in cankers. Top end of the tunnel opens into cankers. Feeding takes place at night . It can move forward and backward with equal ease Attacked bushes can be easily located by the frassy mat, formed of powdered wood and silk, hanging near the holes.
Eggs are broadcast by the female in flight. A few succeed in tunneling the tea stems. Caterpillars make very long galleries that can go down to the roots Mature larva is pale yellow, pencil thick and 6-10 cm long. (We have found some mature larva that are pinkish/red too). Larval duration is 10 months. Pupates in the lower part of the tunnel. Pupal period lasts for 3-5 weeks. “Control measures: The tunneling was found deep into laterals too. And the newly hatched grubs were also seen way up in the tunnels. So that gives us the following two options for now(till we learn more about the pest):
1. Cultural –
a. The affected branches may be cut to sound wood & the cut pasted for protection.
b. The branches /plants pruned off should be removed onto an open area and burnt. The branches should be carried out in bags..
2. Chemical –
a. “The larvae may be killed in situ by pouring a strong solution of an insecticide like Endosulfan/Quinalphos by using an ink filler and plugging the holes”. A syringe could be used with advantage.
b. However, after seeing the extent of tunneling & the location of the grubs I would not recommend this – maybe when there are only isolated cases of infestation, this could work...