INSECTS INJURIOUS TO AGRICULTURE IN JAPAN 13 



and June, the second from the middle of July to early August, and 

 the third from the middle of August to early in September. The 

 egg stage ranges from 6 to 8 days, the combined larval stages 12 to 

 18 days, and the pupal stage (in spindle-shaped cocoons) 10 days. 

 The eggs are laid in small groups upon the fruit, these being placed 

 in an}' position upon the varieties of peach having a very hairy skin, 

 whereas upon the smooth-skinned forms and upon apple and pear 

 the preferred place is in the vicinity of the calyx cup and also near 

 the cavity at the stem end. The newly hatched larvae immediately 

 enter the fruit and feed largely upon the seed. Upon the peach 

 the entrance hole is noticeable because of the presence of a small 

 amount of excrement upon the surface at that point, but upon apple 

 there is only a light, brownish-colored secretion. The larva feeds 

 throughout its life within a single fruit only, and when mature 

 enters the soil for hibernation. The adults are nocturnal in habit 

 and live from 4 to 18 davs. 



According to Okamoto (14*9), there are but two generations per 

 year in Hokkaido, the adults of the first brood emerging in July 

 and those of the second in late August and September. Here also 

 the two types of cocoons previously mentioned are found. 



The egg is ovoid in shape, 0.5 millimeter in length, and greenish- 

 white, with a tinge of red at the posterior end. The surface is 

 covered with tuberculate projections at the anterior end, 10 or more 

 of greater size and distinctive form being found. The mature larva 

 is pink, with the head and dorsal plate of the first thoracic segment 

 dark brown. It is about 12 millimeters in length. The cocoons are 

 grayish, 10 millimeters in length, either spindle shaped or oval in 

 form, and very elastic. A covering of soil usually adheres to the 

 surface. 



Control measures recommended by Matsumoto and Watanabe in- 

 clude hand collection of the moths, the bagging of fruit sufficiently 

 early to prevent oviposition upon them, and the removal of all 

 fallen fruit and rubbish from beneath the trees. Inasmuch as the 

 moths are nocturnal in habit, it is doubtful whether the first-men- 

 tioned remedy is practicable. 



Argyresthia conjugella (73, 147, 148, 149, 194), the well-known 

 apple fruit miner of Europe and North America (British Columbia), 

 is confined in its Japanese distribution to the island of Hokkaido 

 and the northern provinces of Honshu, in which districts it attacks 

 apple, and in Honshu cherry and plum to a slight extent also. 

 According to Okamoto (148) and Kuwayama (73) there is a single 

 generation each year, and the winter is passed in the mature larval 

 stage in cocoons in the soil. The adult' moths appear about the 

 middle of July. These are nocturnal in habit and deposit their 

 eggs in groups of three or four, and occasionally more, upon the 

 young fruit. Each moth lays in all 30 or more eggs. These hatch 

 in about seven days and the young larvae immediately enter the 

 young fruit, the place of entrance being indicated by a light-brown 

 secretion at that point. As many as 20 larvae have been found in a 

 single fruit in commercial orchards. The feeding period covers about 

 50 days, and when mature the larvae leave the fruit and enter the 

 soil to spin their cocoons. Late-developing individuals may form 

 their cocoons in crevices in the packing cases. 



