102 Indian Economic Entomology. [Vol. I. 



generations begins very early in the season, and we soon find the worms in the field 

 in all stages. Accidental circumstances may favor the development of the descend- 

 ants of one moth and retard that of another. Generation after generation is produced 

 until the approach of cold weather, and consequently much depends on the length of 

 the season. The average length of time occupied by the insect in all of its transforma- 

 tions is, say, 38 days, and this, allowing from the 15th of April to the middle of October 

 as the active period of its life, would give us five broods. This is, so far as we can 

 ascertain from actual observation, the normal number throughout the more southern 

 portions of the cotton belt." 



The insect usually hybernates in the pupa state, and it is possible 

 also that a few of the moths which happen to issue late in the autumn 

 may survive the winter. 



In the case of maize the eggs are deposited in the early spring upon 

 the leaves, and the larvae of the first generation feed upon the tender 

 leaves and buds ; it is the secoud and third generations of larvse, how- 

 ever, appearing, as they do, when the grain is more advanced, that occa- 

 sion most of the injury. In affected maize cobs the husks are pierced 

 by circular holes, and upon opening them the grain is found to be eaten 

 in furrows, principally at the end of the cob. The worm does not con- 

 fine itself to a single cob, but often moves in the night time and attacks 

 a fresh one, into which it enters by a circular hole, which it bores through 

 the husk, as in the cob it has left. Several worms in different stages of 

 development are often found in a single cob. When full fed, the worms 

 bore their way out, and crawl down to the ground, in which they 

 pupate. 



When the caterpillars attack tomatoes they bore into both ripe and 

 unripe fruit, thereby causing it to rot. When they attack Leguniinosse 

 they bore into the seed-pods. They have also been found eating the 

 flowers of melons, and boring into the stems of geraniums, besides feed- 

 ing upon the leaves of geraniums, tobacco, and many other plants. 

 In addition to feeding upon plants, the caterpillars of the Boll Worm 

 have been known occasionally to devour the pupse of the Cotton Worm 

 (Jletia xylina), while the larger individuals often prey upon the 

 smaller members of their own species. The species, therefore, may be 

 looked upon as practically omnivorous. Amongst the natural enemies 

 of Heliothis armigera may be noticed bats and poultry, which destroy 

 large numbers of the pest ; some Tachinid, Ichneumon, and Chalcid 

 flies have been recorded as parasitic upon the worm, and some wild 

 birds also assist. None of these, however, appear to have much effect in 

 keeping down the numbers of the pest. 



Amongst remedies, topping the cotton plants is noticed as having 

 been much advocated, though Dr. Riley himself is of opinion that this 

 measure is not of much use. Fall ploughing, to destroy the hibernating 

 pupse, by exposing them to the cold of winter, is recommended in 

 countries where there is frost; this remedy is of course inapplicable in 



