190 Insect Pests. 



by the caterpillars burrowing under the bark, where they feed on the 

 inner bark and cause an exudation of the sap. Masses of gum appear 

 in the cherry, swellings and rugosities in the others, and the trees will 

 gradually decay under the attack. 



The burrows formed by the larvre are of irregular form, some- 

 times chamber-like. Air-holes are made by them, and out of these 

 a brown granular " frass " is extruded. These " frass " heaps were 

 particularly noticeable on some pitched trees at Borden Hall, the 

 larvae eating their way through the pitch for air, and to pass out the 

 excrement. The tunnels formed by the larvse in some cases passed 

 deep down, and some chambers examined were nearly 2^ inches 

 across. 



The attack mainly seems to be on the base of the trunk, and up 

 to about five feet. As many as ten openings were found on the trunk 

 of one tree at Borden which I saw in 1906. The majority of openings 

 are from one to four feet up the trunk. 



LIFE- HISTORY. 



The moths appear in May and again in September, there being- 

 two broods during the year. They settle when at rest on the trunks 

 of the trees, and are then very inconspicuous. 



The wing expanse varies from ^ to nearly -f inch. In colour they 

 are dull orange-brown to chestnut-brown on the fore wings, with dark 

 markings, small dull yellow streaks on the costa, an eye-like spot 

 on the tip of each wing, and a pearly border 

 enclosing three dark lines ; the under wings 

 are unicolorous brown. The moths appeared in 

 1901 and 1906 on the 21st of May and con- 

 tinued until the 6th of June. They lay their 

 eggs in crevices in the bark or under the rind, 

 and in six days the small caterpillars appear 

 and tunnel at once into the inner bark, where 

 P u P ate iu late August and in September. 

 The caterpillars are dull pinkish-white to 

 pale dusky-brown, with a dark bi-lobed head and two large median 

 and small lateral dusky tubercles on the first six segments, a simple 

 hair arising from each ; on the four following segments are two 

 small extra dorsal spots behind the two large ones, and the tail 

 end is darker than the rest of the body. The legs and the prolegs 

 are normal. In length they measure a little over ^ inch. 



The chestnut-brown pupa works its way partly out of the exit 

 hole before the moth emerges. The pupa is enclosed in a cocoon. 



