THE GKAN/ULATED CUTWORM. 



11 



HABITS OF THE LARVA. 



The larvae feed at night, and during the day usually are found in 

 the soil near the plants upon which they have fed the previous night. 

 At Baton Rouge larvae have been taken in the field during all months 

 except March, May, ancl September, and it is believed that they 

 may be found throughout the year. There are apparently five and 

 possibly six generations a year in this locality, and these so overlap 

 that, at certain times, all stages are present in the field simultaneously. 



There has been considerable variation in the number of times 

 larvae have molted in confinement. Some were observed to have 5, 

 some 6, and others 7 larval instars. Larvae from the same lot of eggs 

 varied in this respect, though usually there was a variation of only 

 one instar. Generally the individuals that spent the longest time in 

 the larva stage underwent the least number of molts. 



LENGTH OF EGG, LARVA, AND PUPA STAGES. 



The length of time spent in the egg, larva, and pupa stages is 

 governed apparently by the temperatures to which these stages are 

 ■exposed. Table II, collated from notes, gives data on eggs, larvae, 

 and pupae under observation at different seasons of the year in the 

 insectary at Baton Rouge. The minimum period for the egg, larva, 

 and pupa stages combined was as low as 38 days during July and 

 August, while a period of 54 days was spent in the egg stage alone 

 during December, 1917, and January, 1918. At this time tempera- 

 tures below 30° F. were several times recorded on a near-by thermo- 

 graph and during this period 8° F. and 11° F. were registered. 

 These low temperatures prevailed during a period of weather un- 

 usually cool for Baton Rouge and were apparently the cause of the 

 failure of many of the eggs to hatch. Some larvae that issued on 

 January 6 also were killed, apparently by these temperatures, 

 although others survived. 



Table II. — Lengths of 



larva, and pupa stages of Feltia annexa, Baton 

 Rouge, La., 1917. 



Eggs de- 

 posited. 



July 14,1917 

 Aug. 25,1916 

 Oct. 22,1916 

 Dec. 6,1917 



Eggs hatched. 



Number 

 days in 



egg stage. 



July 18,1917 

 Aug. 31,1916 

 Nov. 3,1916 

 Jan. 29,1918 



4 

 6 

 12 

 54 



Larvae issued. 



July 18, 1917. 

 Aug. 31, 1916 

 Nov. 10, 1915 

 Mar. 13, 1917. 



Larvae pupated. 



Aug. 10-14, 19171.... 

 Sept. 24-0ct. 6, 1916 



Jan. 13-29, 1916 



Apr. 25-30, 1917 



Number 

 larvae 

 under obser- 

 vation. 



USTumber 



days in 



larva 



stage. 



Larvae pupated. 



Adults emerged. 



Number 

 pupae 

 under obser- 

 vation. 



Number 



days in 



pupa 



stage. 



23-27 



Aug. 10-14, 19171 



Aug. 21-26, 1917 



12 

 19 

 11 

 19 



11-14 



24-36 



Sept. 24-Oct. 6, 1916... 



Oct. 12-26, 1916 



18-20 



64-80 



Jan. 13-29, 1916 



Mar. 6-20, 1916 



45-53 



43-48 



Apr. 25-30, 1917 



May 12-20, 1917 



19-21 











i Larvae stopped feeding and entered soil Aug. 8-12 and it is assumed that they pupated two days later. 



