Y4 RESULTS FROM GIPSY MOTH PARASITE LABORATORY. 



FIRST EXPERIMENT. 



In the first experiment, on February 2, 5 females of L'tnuienutn 

 were confined in a small glass cylinder with 10 active brown-tail 

 caterpillars about 8 mm. long. The experiment was closed on 

 February 15, at which time the last of the caterpillars died. Nine 

 of the caterpillars were carefully dissected and a count made of the 

 easily discovered eggs and larvae of Lirrmerhnn. The largest num- 

 ber found in one caterpillar was 23 eggs and 11 larva? with the 

 empty eggshells, dissected from one that died on February 11. The 

 smallest number was 4 eggs and 5 larvir taken from a dead caterpillar 

 on February 15. One hundred and forty-six eggs and 72 larvae were 

 found in all, making a total of 218 eggs deposited by the 5 females 

 in the course of the 4 to 6 days that they remained alive, or an 

 average of nearly 44 eggs for each female, and about 24 to each 

 caterpillar. 



With this unusual number of eggs and larvae present, it is no won- 

 der that the caterpillars failed to survive. As the caterpillars in 

 every case died before the larvae had grown to any appreciable ex- 

 tent and even before all the eggs had hatched, it is not probable 

 that they were killed Ijy the feeding of the parasites. It is much 

 more probable that they succumbed to the mechanical irritation 

 produced by so many eggs and larva% which not only may have 

 caused a violent disturbance or pathological condition of the body 

 tissues, but also tended to keep them from feeding. 



SECOND EXPERIMENT. 



A second experiment wr.s started on Fe1)ruary 5, with 5 females and 

 13 active brown-tail caterpillars. By February 9, all the parasites 

 were dead, and 3 caterpillars were found dead 'on the 11th and 5 

 more on the 19th. In the 8 dead caterpillars 61 unhatched and 5 

 hatched eggs were found, but only 1 larva, which had grown to be 

 about five times the size of newly hatched larvae, although still in 

 the first stage. About 8 eggs, on an average, were thus found in 

 each caterpillar, and they were undoubtedly at least a strong con- 

 tributing factor in causing the death of the latter. 



Three of the 5 living caterpillars were dissected on February 19 

 and the remaining two on March 4. In these 5 caterpillars only 1 

 unhatched egg and 12 eggshells with only 4 larvae were found. This, 

 on an average, is only 2 or 3 to each caterpillar, for although 1 

 had been victimized 8 times, 1 had escaped altogether. Only 4 

 larvae were found, and of these 3 had died shortly after hatching 

 before growing to any extent, whereas 1 had managed to live 

 and increase in size about five times. In the 13 caterpillars dis- 

 sected, 72 unhatched eggs, 17 hatched eggs, and 5 larva? were found, 

 or nearly 7 to a caterpillar and 18 for each female Lhnnerium. 



