SCIENCE-GOSSIP. 



A MOTH-CATCHING PLANT. 



TN your issue for May, 1894, P a g e 64, Miss 

 *■ Eliza Vogan asks a question regarding what 

 is known in New Zealand as the " moth-catching 

 plant." I venture to send you a note which may 

 be interesting to your correspondent and possibly 

 to others. 



The plant in question is, as I understand, Araugia 

 aliens : it is a native of the Cape of Good Hope, or, 

 at least, Southern Africa. It seems to have been 

 first introduced accidentally to New Zealand, and 

 about six or seven years ago Major Lockwood, of 

 Wanganui, sent down to me a few flowers containing 

 imprisoned moths, suggesting that the plant might 

 perhaps become very useful as a trap for that 

 dreaded and rapidily-increasing pest, the Codlin 

 moth (Carpocapsa pomonclla). I suggested to several 

 persons an experimental trial of the plant with this 

 object, and it has been extensively grown ; but the 

 result has not been a success in that instance, as 

 the Codlin moth refuses to frequent the plant. 

 Araugia, however, is an exceedingly free grower in 

 at least our Northern Island where the climate is 

 mild ; it twines and climbs with great luxuriance, 

 and produces immense numbers of white or pinkish 

 flowers, which have a very agreeable scent. These 

 flowers attract innumerable moths. I have seen a 

 hedge of A raugia in Auckland covered by a perfect 

 cloud of hundreds and thousands of moths in a 

 summer evening, and in the morning there was not 

 a single flower which did not hold imprisoned one 

 or two, or sometimes as many as four, different 

 moths, of various sizes and genera. 



The action of Araugia is purely mechanical. The 

 calyx of the flower is rather deep, and the nectary 

 (not being a botanist I am, perhaps, not using the 

 proper terms) is placed at the base of it. Attracted 

 by the powerful scent and the prospect of honey, 

 the moth dives down the calyx and protrudes the 

 proboscis to reach the desired food. But before it 

 can do so the proboscis is nipped between two 

 strong, hard, black pincers, which protect the 

 nectary ; and once nipped, there is not the least 

 chance of escape: the moth is held as in a vice, 

 by the extreme end of the proboscis, and dies 

 miserably. 



The rationale of this process is obscure. The 

 proboscis is so very slightly inserted between the 

 pincers (only a very minute fraction of an inch) 

 that it cannot apparently affect the generative 

 organs of the plant, unless these may be the 

 pincers themselves, whose actual contact may be 

 necessary for reproduction. I have dissected a 

 good many flowers, and find that even in their 

 ordinary position the pincers are almost in contact ; 

 the separating interval is only appareat under a 

 strong lens. It is therefore hard to understand 

 why so violent and murderous a process as the 

 destruction of a moth should be necessary to close 

 this already minute gap, and indeed, as the 

 proboscis is itself usually of some thickness, 

 the pincers do not seem even then to closely 

 adhere. But at all events the thing is done, and 

 done thoroughly, and I dare say a plant of 

 Araugia, covering a space ten yards in length, 

 may frequently destroy as many hundreds of 

 moths every night, and consequently prevent the 

 ravages of fifty times as many larvae. Whether 

 the plant would grow as luxuriantly in your 

 English climate is a point on which I can say 

 nothing. 



W. M. Maskell, Wellington, New Zealand ; June 29th, 1894. 



During one of the severe gales which visited us 

 in the early part of this year, an old ash tree was 

 blown down in the Witham Valley, near Grantham. 

 On being removed a few weeks ago, an examination 

 was made, when a large portion of the trunk was 



Borings of Larvae of Cossus. 



found to be completely honey-combed with borings 

 about half-an-inch in diameter. A large specimen 

 of the larva of the goat moth, Cossus ligniperda, was 

 found embedded in a sound part of the tree. It 

 had a smooth reddish body, with a patch of warm 

 umber on the upper surface of each joint, and 

 there is no doubt the whole of the excavations 

 were made by larvae of this moth. Since this 

 specimen has been under observation it has 

 excavated fresh holes in the sound piece of wood 

 brought away with it ; but as the larval condition 

 of these moths lasts for three years it is doubtful 

 when the chrysalis stage will be reached. The 

 photograph, a reproduction of which is given 

 above, of the honey-combed wood, together with 

 the larva, are now in the museum of the Grantham 

 Scientific Society. — Henry Preston, Grantham. 



