474 ANIMALS INTRODUCED UNAWARES 



and exuberant growth of which has choked ponds and rivers 

 and blocked canals to traffic, of the American Blight upon 

 our apple trees, of the Pea Beetle, and most damaging of 

 all, of the Plant-bug or Phylloxera of the vine (see also intro- 

 ductions from America, in Fig. 85, p. 473). 



Many years' experience of the damage caused by unfore- 

 seen introductions from other countries, has led progres- 

 sive nations whose wealth depends largely upon the products 

 of their fields and orchards, to endeavour to check by all 

 means in their power the constant stream of undesirable 

 immigrants amongst animals. Believing the old saw that 

 prevention is better than cure, the agricultural departments 

 of various States, prominent among them California and 

 Hawaii, have set up strict quarantines, so that each intended 

 import passes under the scrutiny of experts and is declared 

 clear before it is admitted to the State. 



The monthly reports of the quarantine inspections in 

 California and Hawaii make interesting reading, not only 

 because they demonstrate the value of this method of com- 

 bating noxious stowaways, but because they show, more 

 strikingly than one could have imagined, the efficiency of 

 commerce as a distributor of animal life. I cannot do better, 

 in closing this chapter on the camp-followers of commerce, 

 than state, in summary form, the insect pests detected during 

 a single month on the point of entering California from 

 abroad. I take one at random from the reports before me ; 

 it chances to contain the pests intercepted during November 

 1916, a month, it is to be remembered, in the midst of a 

 great war which has upset traffic and the ways of commerce. 

 Nevertheless these are the month's visitors. From Belgium, 

 seven species of Leafminers, Thrips, Scales of azaleas and 

 bay trees ; from Holland, the Narcissus Fly in narcissus 

 bulbs, and the Mussel Scale on box shrubs ; from China, 

 Scales upon oranges, the Sweet Potato Weevil in 

 sweet potatoes, and the Rice Weevil in rice ; from Japan, 

 Weevil larvae, Pine-cone and unidentified Weevils on chest- 

 nuts, a Coccid on oranges, and Lepidopterous larvae in 

 Chili peppers ; from Hawaii two kinds of Scale Insects on 

 pine-apples, Scales on betel leaves, Red- Spotted Scale and two 

 other kinds on bananas, Fruit-Fly (Trypetid) larvae in string 

 beans, the Scarabee Beetle (Euscepes batatae] in sweet 



