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BETTER FRUIT 



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Figure 2— PORTIONS OF APPLES, ENLARGED TWO AND ONE-HALF TIMES, SHOWING 

 "STINGS" AND SCARS FROM CURCLTLIO 

 (I'rom Stedman, Bulletin 64, Missouri Agricultural Experiment Station) 



appear. They are illustrated upon fruit 

 in Fig. 7. They are somewhat smaller 

 than the head of a common pin, nearly 

 circular in outline, slightly convex and 

 when laid are stuck down tightly upon 

 the surface. Without closer examination 

 they look like minute drops of milk or 

 specks of spray. It requires very close 

 search to discover them, though it is 

 sometimes possible, by turning the leaf 

 or apple in the sun in a certain way, to 

 make the tiny glistening egg very con- 

 spicuous. When first laid the eggs are 

 of milky-white color. About three or 

 four days from deposition they show the 

 body of the larva as a reddish ring 

 within them, and at about the fifth or 

 sixth day the black head of the embry- 

 onic larva shows as a black spot near 

 the center of the egg. At about the 

 seventh day from laying codling moth 

 eggs usually hatch. The eggs from the 

 spring moths begin to appear when the 

 apples are about half an inch in diameter, 

 though at this time they are laid only 

 upon the smooth surface of the leaves 

 near the fruit. As soon as smooth 

 patches appear upon the little apples, 

 eggs may be found upon the fruit itself, 

 and from this time forward the propor- 

 tion of eggs laid upon the fruit increases. 

 Occasionally eggs are deposited upon 

 portions of twigs bearing apples. 



The young larva upon emerging from 

 the egg crawls about over the surface 

 of leaves or fruit for a short time, where 

 it sometimes feeds sparingly, then enters 

 the apple. A majority of these first gen- 

 eration worms enter the apples at their 

 calyces. At least two-thirds of the early 

 worms enter at this point, some writers 

 placing the ratio of calyx worms much 

 higher from the early generation, and 

 from counts made by the. writer in Mis- 

 souri last summer, 72% showed apples 

 with worm holes at the calyx. Some of 

 these had also holes at the side or stem, 

 evidently made by the same larva. The 

 larvae bore their way into the fruit push- 



ing back to the opening of their burrows 

 bits of brown voidings which appear 

 upon the surface. They finally reach the 

 seeds, often devouring them and much 

 of the tissue at the core. Upon an aver- 

 age about 17 days are spent by these 

 larvae within the fruit when they push 

 the plug of brown dust from the opening 

 into the burrow and crawl out. The full 

 grown worm crawls to a place of con- 

 cealment, where it spins a light cocoon 

 and after a few days transforms to pupa. 

 About two weeks are spent within the 

 cocoon — about four days as larva and 

 ten as pupa — when the second genera- 



tion moth emerges. The moths again 

 mate and lay eggs, which produce the 

 second generation of worms. They very 

 greatly outnumber those of the first gen- 

 eration, and so in unsprayed orchards 

 their damage to fruit is correspondingly 

 greater. In Southern Missouri, at least, 

 there is a third generation of worms. 

 In the fall, after attaining their growth, 

 the worms leave the apples and spin their 

 tough winter cocoons, within which they 

 remain as larvae until spring. 



The codling moth, as will be seen from 

 what is given, passes through two, and 

 in parts of the state, three, complete gen- 

 erations in Missouri each year. For the 

 summer generation from six to seven 

 weeks is the average length of the total 

 life cycle. 



In connection with life history observa- 

 tion several important dates at which the 

 changes of the insect took place at Olden 

 in 1908 will be of interest, though the 

 dates would probably be some weeks 

 later for points in Northern Missouri, 

 and, as stated in referring to the curculio, 

 weather conditions from one j^ear to 

 another will make the dates of changes 

 somewhat variable. 



The first hibernating larvae which was 

 found changed to pupae in the orchard 

 at Olden were on April 6, and the first 

 moth was seen in the orchard May 5. 

 At this date the first few scattering eggs 

 were found on apple leaves of early 

 blooming varieties. The first eggs were 

 found hatched on Ingrams, May 23, when 

 this variety measured about one-half to 

 three-quarters inch in diameter. The 

 maximum hatching of eggs did not take 

 place for ten days to two weeks follow- 

 ing, and a few stragglers were entering 

 the apples well into the month of June. 

 The dates at which the first generation 

 larvae enter apples has a very important 



l-iGURE 5— MATURE APPLE CUT OPEN, SHOWING APPLE WORM AND ITS WORK 

 Somewhat reduced. (After Ouaintance, U. S. Department of Agriculture Year Book. 1907) 



