- THE ORCHID REVIEW. 231 
prove that the beetle will, and does, breed in our Orchid houses, which has 
previously been doubted, a preliminary note is published, warning those 
interested in Orchid cultivation to be on their guard. 
Diaxenes dendrobii is a pretty brownish-grey beetle from } to -inch 
long, with long antennz, and with whitish or yellowish lines along its upper 
surface. The grub, which lies inside the pseudobulb, is whitish and legless 
(but still very active), with scaly brown head and biting jaws. When full 
fed it makes a cocoon out of the fibres of the hollowed-out pseudobulb, from 
which cocoon, after pupation, the beetle emerges. It is injurious, both as 
imago and as larva. The grub mines into and tunnels out the pseudobulbs 
till, it may be, merely the outer skin is left, while the beetles feed on pseudo- 
bulb, and leaf, and root. 
The pest has been introduced in Orchids imported from Burma, and in 
March last larve were found at the Edinburgh Botanic Garden in some 
freshly-imported Dendrobium nobile, which had been bought at a sale in 
London, and these larve have now reached the beetle stage. As other 
plants have doubtless been distributed over the country a careful outlook 
should be kept. The beetles should be killed whenever found, but careful 
looking is necessary, for, feeding chiefly by night and resting by day (often 
at the base of the plant), they escape notice, and as, in addition, they are 
protectively coloured, great difficulty is experienced in picking them out 
until the eye gets accustomed to them. Its presence, however, may be 
detected by its work. The infected pseudobulbs can be detected by the 
withered appearance, and, to begin with, by the blackish or brownish dis- 
colouration of one side, which marks the progress of the enclosed grub, 
which, of course, should be cut out and destroyed. Squeezing the pseudo- 
bulbs a little between the fingers, too, is useful, as affected bulbs lack the 
firmness of sound ones. 
‘¢ From what I have seen,” the author concludes, “ I have no hesitation 
in describing Diaxenes dendrobii as the very worst of Orchid pests, and 
should it once get a footing in an Orchid house there is much discourage- 
ment and disappcintment in store for the owner or cultivator. Diaxenes 
dendrobii takes its name from its infecting the genus Dendrobium, but I 
am sorry I have to add'that the beetle seems willingly to feed upon almost 
any Orchid with marked pseudobulbs. In my experiments, Dendrobium, 
Ceelogyne, Cattleya, and Lelia have all been attacked, and at present I 
have a brood of my own rearing in Lelia anceps. As I am desirous not 
only to get a complete knowledge of the spread of Diaxenes in Britain, but 
also to make my report, when issued, as helpful as possible, I will be much 
obliged if anybody who has had experience of the beetle or its work will 
communicate with me here. I need hardly add that any information thus 
received which might prove helpful will be fully acknowledged.” 
