508 



THE GARDENERS' MAGAZINE. 



July 6, 1912. 



of pests, namely, those which, though present 

 in England, are of very slight economic im- 

 portance here, but> which are regarded as 

 serious by other countries. It ifi considered 

 that the Board should ana themselves with 

 powers to deal with pests of this order for 

 two reasons; first, that they may have power 

 to act promptly should any of these pestci 

 assume undue proportions, and, secondly, 

 that they may be in a position to give an 

 oificial certificate of freedom from disease 

 to those nurserymen who wish to trade 

 abroad. These pests may, therefore, be clas- 

 sified under two heads, those which we wish 

 to keep out of this country, and those which 

 other Governments wish to keep out of their 

 countries. 



Tlie pests which comes under the first head- 

 ing include several which are well known to 

 alf horticulturists who have studied foreign 

 and colonial writings, though they may pos- 

 sibly be unfamiliar with the appearance of 

 the devastation they cause. They are, first, 

 the San Jose Scale (Aspidiotus pernici<^us), 

 a dangerous parasite which attacks many 

 kinds of deciduous trees, but is specially in- 

 jurious to fruit trees. It is supposed to be a na- 

 tive of Eastern Asia, but it has caused untold 

 damage in Western America, and has spread 

 to the Eastern States, and Canada, through 

 the introduction of nursery stock. It pre- 

 vails in Australia, and has recently been dis- 

 covered in South Africa, though it is sup- 

 posed to have been present there for about 

 six years. It is not infrequently found on 

 imported fruit in the market, but as inquiry 

 has failed to reveal any case of infestation 

 from that source in any country where it 

 has established itself, no real danger is ap- 

 prehended from that quarter. Another pest 

 is the Mediterranean Eruit Fly (Oeratitis 

 capitata), possibly a native of Northern 

 Africa, which now causes considerable in- 

 jury on both shores of the Mediterranean, 

 and has been reported as near to England 

 as Paris. It is known in Australia and in 

 South Africa, and might very well cause 

 much damage in the South of England. A 

 third is the Colorado Beetle (Dodyphora de- 

 cemlineata), an American pest, which has 

 twice been introduced into England, and was 

 only stamped out with some difficulty and ex- 

 pense. As already stated, it was the dis- 

 covery of this beetle in England that led to 

 the passing of the Destructive Insectfl Act 

 of 1877, but the danger of a fresh importa- 

 tion is less probable now since the United 

 States have become a purchaser of potatoes 

 in England instead of a seller. Another 

 parasite of the potato, the Potato Moth 

 {Phthorimaea operculella), is also scheduled. 

 This pest, which rivals the Phylloxera and 

 the pernicious scale in the amount of damage 

 it can and does cause, is believed to have 

 originated in Northern Africa. It has been 

 recorded from Spain, Portugal, Italy, and 

 ore recently from Erance, where it appears 

 to be spreading, and is known to have caused 

 considerable lo^ in Algiers. It was intro- 

 duced into India from Italy, and spread so 

 fast that it became impossible to control it. 

 It exists in South Africa, and throughout 

 Australia from Victoria to Tasmania. It is 

 well known in New Zealand. In America it 

 attacks not only potatoes but tobacco 

 plants, and, in view of the ease and rapidity 

 with which it spreads, and the difficulty in 

 combating it, it may be said to be the 

 most dangerous foreign pest that we have to 

 fear. A fourth pest is the Cherry Fly (Eha- 

 goletis cerasi), which abounds in France and 

 Germany, and probably elsewhere. The 

 larval form is familiar to all purchasers of 

 the first cherries that come on the English 

 market, for it is imported in great numbers 

 every year in foreign fruit. Careful inquiry 

 however, has failed to detect a single case of 

 infestation in English orchards, though it is 

 impossible to say how long this immunity 

 will last. One fungus disease has been in- 

 cluded, viz,. Black Knot, caused by Plow- 

 rightia morbosa, which is known to be a 

 serious pest in America, and one bacterial 

 disease, American pear blight. Both of these 

 are pests of fruit trees, and are known to 

 cause much damage. 



Other Insect Pests. 



Two insect pests have been scheduled 

 which are found in England occasionally, 

 namely, the Vine Louse (Phylloxera vasta- 

 trix), and the Large Larch Sawfly (Nematus 

 erichsoni). The former pest is known over 

 the whole world wherever vines are grown, 

 and is perhaps the most notorious of all 

 destructive insects. The second is a parasite 

 on larch trees, and has caused the death of 

 thousands of trees in Cumberland and in 

 Wales. Some years ago it nearly destroyed 

 the larch forests in Denmark, and it is now 

 devastating the woods of Canada. The im- 

 portance of both of these pests is increased 

 by the fact that they are regarded as serious 

 by foreign countries, and in the case of the 

 former stringest regulations have been 

 passed to prevent its importation by the 

 Government of every vine-growing State. 



The remaining pests dealt with in the 

 Order, viz., the Gipsy Moth, the Brown Tail 

 Moth,' the Nun Moth, and the Narcissus Fly, 

 have all been scheduled for the same reason. 

 As is well known, the first two insects have 

 proved to be very destructive in the United 

 States and in Canada. The third moth is 

 occasionally very troublesome on the Conti- 

 nent of Europe,' and the last has proved in- 

 jurious in British Columbia, and is much 

 feared in New Zealand, to which country 

 large quantities of bulbs are sent from Eng- 

 land. In no case do they cause any great 

 injury in England. The Brown Tail Moth is 

 rare, and is getting scarcer. The Gipsy Moth 

 is almost extinct. Only two cases of injury 

 from the former have been reported to the 

 Board during the last six years, one of which 

 was complicated by the presence of the 

 Lackey Moth in large numbers, and no case 

 of damage by the latter has been reported at 

 all. Tlie Nun Moth is not known as an in- 

 jurious pest. The Narcissus Fly, though 

 abundant, has not caused widespread injury. 

 But the fact that all these pests are regarded 

 as serious in countries with which English 

 iutrseryinen trade is one which the Board are 

 bound to take ivito consideration. In recent 

 years British colonies and foreign countries 

 have imposed regulations dealing with the 

 iirportation of plants which rival in number 

 and hardness the rules called the Pie, and it 

 is to be feared that in some cases nurserymen 

 have abandoned their overseas connections on 



trade 



D ' 



trouble involved. 



Assistance from Government. 



Now it will probably not be contended by 

 anyone that it is the duty of the Government 

 to push the business of any particular trader, 

 or even the business of any class of traders, 

 except in a general way. Those who make 

 private profits must depend on their own 

 tic 13 s, and the reputation which the high 

 quality of the goods they offer brings them. 

 But it may reasonably be urged that it is the 

 duty of every Government to smooth away 

 the difficulties which other Governments lay 

 in the path, and that the Board should help 

 exporters to surmount the barriers imposed 

 on importation when they can properly do 

 so. With this object, therefore, the Board 

 have been at same pains to collect, 

 and publish as complete a collection as 

 possible of all the regulations in force in 

 other countries dealing with the importation 

 of plants. A study of these regulations 

 shows that they may roughly be divided 

 under three heads, namely, those vj^hich re- 

 quire that the actual plants to be imported 

 have teen inspected by an officer of the 

 Board and are certified to be healthy, those 

 which require that the plant shall come from 

 a nursery which has been inspected by an 

 officer of the Board, and declared to be free 

 from disease; and those which require a 

 certificate that no rase of certain specified 

 diseases has occurred within a certain dis- 

 tance of the place where the plants were 

 grown. There are, of course, other cases 

 where a quarantine or an inspection is im- 

 posed on arrival, but these affect the foreign 

 purchaser rather than the English exporter. 



The utmost the Board can do is to ascer- 

 tain the nature of the regulations, and <ffer 



the nurserymen facilities for complying wita 

 those that require some inspection or report 

 as regards the freedom from disease of that 

 part of England from which they come. Ar- 

 rangements hav\> accordingly been made for 

 si:ch inspection, and the issue of such x^^va- 

 ficat'p"' and a memorandum setting out what 

 the Board ar^ prepared to undertake ha.s 

 been circulated to all the principal nursery- 

 nien in England. It is in order that tiie 

 Board's inspectors may be in a position to 

 enter on premises where disease may exist 

 and search all plaoes where it may be found 

 that the pests lecently referred to have been 

 scheduled, for in some cases at any rate it 

 is necessary to examine not only the premises 

 or the plants in respect of which an apphca- 

 tion for a certificate has been made, but the 

 adjoining pre mises as well. It is in this con- 

 nection also that the system described above 

 for obtaining a survey of diseases is of general 

 benefit. Certain countries require a certifi- 

 cate with each consignment of potatoes which 

 reaches their shores to the effect that no case 

 of wart disease (Synchytrium endobioticum) 

 has occurred in the neighbourhood where the 

 potatoes were grown. Under the present 

 organisation it is possible, except in a few 

 cases, to issue the certificate or to report the 

 Board's inability to do so on receipt of the 

 application. By this means a very real secu- 

 rity is given to the importing country against 

 the introduction of disease, without imposing 

 any undue delay or hindrance on trade. It i^ 

 possible that the system might be extended 

 with advantage. In England we do not 

 b'L'lieve in quarantine stations for imported 

 I^lants. Such imports as do reach this coun- 

 try from abroad generally arrive at a season 

 when nearly all insect and fungus pests are 

 in a dormant condition. If the plants are 

 to be examined at the port or at a quarantine 

 station they would have to be unpacked, 

 often to the great danger of the life of the 

 plant, and examined under a microscope by 

 a highly skilled expert, who would have to be 

 familiar with, the eggs and young stages of 

 many foreign pests, and the appearance of 

 the damage caused bv many invisible fungi. 

 He would have to identify in their immature 

 state many diseases which many experts can- 

 not always determine when mature, and he 

 wciild be haunted by a constant fear of over- 

 looking some dangerous pest. 



If the Government of the importing coun- 

 try can only be satisfied by the reports baeed 

 on such a system as has been described that 

 tiio plants proceed from a district free from 

 certain diseases, or from a nursery kept 

 under constant supervision and declared to 

 be clean, the plants could be taken direct to 

 the premises where they are to be planted 

 permanently and there examined by duly- 

 qualified inspectors at a season w-hen the pests 

 that are feared resume their activity, ana 

 ehow by the injury to the plant or by their 

 visible presence that they have been intro- 

 duced. There are few, if any, pests that can 

 bo introduced from or into countries with a 

 temperate climate th^t would breed or epreaa 

 to neighbouring plants so rapidly that they 

 could not be -eadily stamped out on such a 

 STstem as has been described. In the case 

 of the few pests to which this does not appjy 

 the introduction of the host plant should »>e 

 prohibited altogether. 



mi - double Pelargonium 



The Speaker.— Since the advent ot tn^ 

 sturdv growing semi-double, salmon-colourea 

 variety King of Denmark in the middle oi 

 the 'nineties many members of this class Jla^e 

 been brought forward. This comparatively 

 old kind still maintains its place as one oi 

 the best in its colour, which is just now very 

 popular. A variety recently shown oy 

 Messrs. Cannell and Sons, of Swanley, unacr 



• The Speaker promises, Tvnen 

 L, to be extensively grown. |^ 

 is of stout growth, while the semi-doubie 

 flowers, borne in bold erect trusses, are oi^ 

 brilliant fiery salmon colour. With so many 

 varieties it may by some be thought tnau 

 we have enough, but there is always rooiu 

 for such as this, the new pink fin^roaia oi 

 tho salmon form of Paul Crampel.— b. w. 



better know 



