Zoology. — “Technical experiences in the breeding of Tenebrio 
molitor’. By S. A. ARENDSEN Hern. (Communicated by Prof. 
JW Morr). 
(Communicated at the meeting of April 23, 1920). 
Studies on variation in Tenebrio molitor, of which the results are 
published in the Journal of Genetics, gave occasion to make some 
observations with respect to the practice of the breeding of this 
insect. Though these facts are not very suitable for being treated in 
a genetical periodical, as they deal especially with technical particulars, 
1 thought their publication to be of some value for those who wish 
to experiment with this beetle. 
CON TENTS: 
1. Choice of the culture vessels. 
2. The food. 
3. The number of moults of the larva. 
4. The infection with Tyroglyphus farinae 
5. The gathering of Pupae and beetles. 
6. The gathering of the Eggs. 
7. The mortality. a. amongst the Eggs. 
b. - „ Larvae. 
DE se » Pupae, 
1. Choice of the culture vessels. 
Larvae. For the culture of larvae, glass erystallizing jars are 
preferable to any other kind. From these jars with their perpendi- 
‘cular slippery wall the larvae cannot escape. 
Porcelain pots with perpendicular smooth walls also give satis- 
faction. Tin boxes with lids not fitting too close (for the air circulation) 
are serviceable only when the inner wall is perfectly smooth (not 
varnished or painted), without any rust-stains, solder or rough con- 
necting seam, so that the larvae lack any support in crawling up 
the wall. 
The fulfilment of these conditions is of great importance when the 
perfect purity of the cultures is aimed at. Close attention should 
. 13 
Proceedings Royal Acad. Amsterdam. Vol XXIII. 
