308 INSECTS AND MAN 



was placed on the table, and, by means of a lead pencil, 

 a continuous record of its movements was made throughout 

 its active life of seventy -two hours. The larva travelled 

 more rapidly than expected, eleven rolls of paper were 

 used, and careful measurements showed that it travelled 

 nine thousand and fifty-eight feet. Its greatest speed, for 

 a four-and-a-half-hour period, was four and nine-tenths 

 feet per minute; whilst for the first twenty-four hours 

 it averaged over three and a half feet per minute. Weighed 

 before and after the experiment, the larva was found to 

 have lost weight to the extent of eleven grains or one- 

 third of its original weight. 



Of the imported parasites of the gipsy moth, we must 

 rest content with a brief notice of but three. Two of them, 

 Anastatus bifasciatus and Schedius kuvance are worthy 

 of mention on account of their innate interest, and Apan- 

 teles fulvipes because of its " unquestioned importance as 

 an enemy of the gipsy moth." 



Anastatus bifasciatus (fig. 97) was introduced into 

 America from Europe and Japan in 1908. The insect is 

 a diminutive member of the order Hymenoptera, that is to 

 say, it is related to the bees, wasps, and ants. The female 

 oviposits in the eggs of the gipsy moth, soon after the latter 

 have been deposited and before the embryo has developed. 

 Within the lepidopterous eggs the greater part of the 

 life-cycle of Anastatus is enacted, with the result that the 

 adults do not emerge till some time after the healthy gipsy 

 moth eggs have hatched. The fact that the life-cycle of 

 this parasite is correlated, perfectly, with that of its host, 

 renders it especially valuable as a beneficial insect. By 

 the time the new generation of moths are attending to 

 their maternal duties, the female Anastatus is on the 

 watch for host eggs in which to deposit her own. It is 

 a curious coincidence that the females, of parasite and host, 

 are of exceeding feebleness on the wing. Two phenomena 

 have mitigated against the complete success of Anastatus 



