August, 1910.] 



121 



Plant Sanitation. 



remainder being reddish brown with 

 longitudinal ochreous stripes. The accom- 

 panying figure gives a fair idea of its 

 general appearance and size. 



Some twelve or more years ago, the 

 late Mr. Oliver Collett liberated a few 

 specimens of this species (presumably re- 

 ceived from Africa) in his garden at 

 Watawella. They showed signs of esta- 

 blishing themselves ; but, upon my 

 advice, he collected and destroyed them 

 all ; and apparently exterminated them, 

 for no more have been seen in that 

 neighbourhood. The present outbreak 

 in the Kalutara district, situated — as it 

 is — many miles distant and without 

 direct water connection, is probably due 

 to some fresh (accidental) introduction, 

 but by what means— remains to be dis- 

 covered.* 



If, as seems probable, the snail is likely 

 to become a troublesome pest, every 

 possible means should be employed to 

 exterminate it before it has spread over 

 a wider area. When collected, the snails 

 can be killed by dropping them into 

 boiling water. Their dead bodies might 

 possibly be excellent food for ducks. 

 It is equally important to collect and 

 destroy the eggs, which will be found 

 usually at the base of tree trunks or 

 walls and, probably, in other similarly 

 sheltered portions. 



Dr. Annandale, of the Indian Museum, 

 to whom I sent specimens of the shell for 

 identification, replies as follows : — 



" The shell you send resembles what 

 we know in the Indian Museum as 

 Achatina fulica, Fer , but is distinctly 

 longer and narrower. We have nothing 

 that quite corresponds with your speci- 

 men, and I am doubtful whether ours 

 are correctly named ; probably they are 

 really A. pantherina, Fer. Our species, 

 whatever may be its proper name, is 

 now common in Calcutta and apparently 

 all over northern Bengal. I have heard 

 that it has been introduced into Bombay 

 with plants from the Calcutta Botanical 

 Gardens, but I have been unable to obtain 

 proof of this statement. As regards the 

 introduction of Achatina into Calcutta, 

 Godwin-Austen writes as follows (Proc. 

 Mai. Soc. VIII, p. 147, October, 1908) :— 

 'When I was in Calcutta in 1876-7 an 

 African species of Achatina had spread 

 all over the gardens in Chowringhi and 

 the suburbs to Howrah on the other 



* Since the foregoing note was written, the 

 connection between Watawella and .Kalutara has 

 been established. It appears that a dhoby who 

 worked near Watawella, paid a visit to his friends 

 near Kalutara, taking with him a present of vege- 

 tables from upcountry, A couple of these snails 

 were found amongst the cabbages and thrown 

 out into the garden. It was at this particular spot 

 that the first outbreak of the pest was noticed. 



16 



side of the River Hoogly and to Barrack- 

 pore, about 15 miles north. It had been 

 introduced originally into Calcutta by 

 Mr. Benson some 20 j*ears before, after 

 his arrival from the Cape and the 

 Mauritius. Among some shells in spirit 

 sent me last year by Dr. Annandale, 

 collected at Rajmahal, which is 170 miles 

 from Calcutta on the line of railway, 

 were three very young specimens of this 

 Achatina. In this case their transport 

 has pobably been on the railway trucks, 

 either by crawling on to them or their 

 being loaded up with country produce. 

 Spread of land shells in this way would 

 be very rapid.' Achatina here lays 

 numerous small hard-shelled eggs, appa- 

 rently only once a year, at the base of 

 walls or tree-trunks, or at the edge of 

 paths in shady places. The eggs are 

 usually deposited in June or July and 

 hatch in a few weeks. In a clutch I saw 

 a small snail laying in my garden on 

 Friday last, there are 99 eggs, some of 

 which I am sending you in spirit. The 

 young snails are destructive in a garden, 

 especially to ferns, but the adults, fortun- 

 ately, do not do much harm, feeding 

 chiefly on decaying vegetable matter. 

 Apparently the snails do not attain their 

 full size for at least two years, but in 

 one year they grow as large as the 

 specimen you have sent and are capable 

 of breeding. This year I have seen few 

 eggs about, but a large number of dead 

 snails apparently uninjured. Probably 

 this is due to the fact that our rains 

 have as yet been very feeble." 



In a postscript Dr. Annandale adds :— 

 " Since this letter was typed I obtained 

 a number of specimens of Achatina from 

 my own garden, and find them very 

 variable in shape. Some of them agree 

 exactly with yours, which may be taken 

 therefore to represent the same species." 



Another African species, Achatina 

 sinistrorsa, is said to lay eggs as large as 

 those of a pigeon, but probably few in 

 number. The production of a large 

 number of smaller eggs, as occurs with 

 the species under consideration, results 

 in a more rapid multiplication of the 

 species. 



The eggs sent to me by Dr. Annandale 

 are about the size of small peas, but of 

 oval form. They have a hard shell and 

 are of a very pale yellow tint. 



"Buprestid Beetle Attacking Crota- 

 i.aria and tephrosia. 

 Crotalaria striata plants on the Cotton 

 Experiment Station, Maha-Illuppalama, 

 were observed to be dying. An examina- 

 tion of the roots showed them to be in- 

 fested by the boring larva of a small 

 Buprestid beetle. This pest of Crota- 

 laria has not been observed before ; but, 



