f3S8 Report of the Depaetment of Entomology of the 



by being stripped of the foliage while the bare wood is covered by 

 the conspicuous webs or tents of the insects. In the leading plum- 

 growing districts of France, such as the " Departements " of Lot-et- 

 Garonne, Tarn-et-Garonne, Lot, Dordogne and Gironde, this species 

 constitutes one of the chief pests of this fruit. Rebate and Bernes 

 report that serious outbreaks of the insect occur periodically. In 

 an account of the history of the pest in the Departement of Lot-et- 

 Garonne they state that in 1843 all trees were attacked and from 

 1867 to 1871, in 1882 and again in 1888 much damage was done by it. 

 There was an outbreak in 1901 which was followed by a more severe 

 one in 1902, and it was not until 1904 that its injurious attacks 

 ceased. During 1908 the caterpillars again increased to destructive 

 numbers and serious depredations to plums occurred during 1909. 



The apple is especially susceptible to attacks by the ermine moth 

 and wherever this fruit is grown in Europe this insect is one of the 

 most common and destructive pests. In 1838 according to Maurice 

 Girard,^ "the farmers of Normandy [France] beheld the distressing 

 spectacle of [apple] trees stripped of their foliage and covered with 

 thousands of caterpillars. These, having nothing more on which 

 to subsist hung here and there suspended in enormous masses within 

 a web, while the trunks of the trees were enshrouded with a silken 

 web which concealed the bark. Not only was the crop destroyed 

 in various cantons for several years, but a large number of trees in 

 full bearing succuml)ed to the injuries." Marchal reports that in 

 certain areas of France malinellus appears almost every year in 

 more or less destructive numbers, and that in some communities 

 where there have been serious outbreaks for successive years almond 

 trees have been killed. This species was, in 1902, very abundant 

 and destructive throughout France. 



Theobald regards malinellus as an important pest of apples in 

 England. According to Whitehead ^ an Yponomeuta caused 

 " exceeding destruction in this country in 1865. It was also very 

 troublesome in most of the large apple-producing districts in the 

 year 1877 and in some few places again in 1880. * * * Whole 

 orchards were entirely devastated in the two first-named j^ears, so 

 that at the commencement of July the trees were as bare of foliage 

 as in December. Leaves, blossoms and fruit were all cleared off by 

 the innumerable caterpillars which not only devoured every particle 

 of these, but also actually began to gnaw the most tender portions 

 of the fruit-] )earing spurs. Not only did they utterly ruin the crop 

 in these seasons, but they also injured the trees so extensively that 

 they only yielded a small crop in the subsequent seasons." 



Reh ^ writes that malinellus was a great scourge in Germany 

 during 1910, and that apple trees were seriously affected. 



' Quoted from G. Barbut, Le Progres Agricole et Viticole, p. 307. 1899. 



2 Kept. Inj. Ins. to Fruit Crops No. 3, p. 68. 1886. 



3 Letter of Juue 27, 1910. 



