89 



duur van het eistadiuni 4 à 5 dagen 



„ ,, ,, actieve larvestadium 9 ,, 10 „ 



„ „ „ inactfeve larvestadium 4 ,, 6 „ 



„ „ „ popstadium - 6 „ 7 „ 



verblijf van den kever in de cocon 2 ,, 3 ,, 



totaal 25 à 31 dagen. 



Deze laatste waarnemingen werden alle te Padang verricTit. 



SUMMARY. 



Crioceris sp. (sabpolita Motsch?^ was received from different localities: 

 Fadang (Sumatra), Buitenzorg, Tjilatjap, (Java); it was reared at Padang. 



The ground colour of the beetle is shinig testaceous or yellowish; in some 

 specimens the head, the pronotum, the underside cf the body including the legs 

 are more or less variegated with black. 



Both beetles and larvae are destructive to various kinds of Orchids 

 (Spathoglottis, Vanda, Grammatophyllum, Dendrobum, Phalaenopsis) eatinç 

 the flowers (by preference) and also the fruits and leaves if there were no 

 flowers. 



The eggs are deposited on the flowers or on the flower stems; they are 

 covered with a dark greenish mucous secretion. The incubation period lasts 

 from 4 to 5 days. 



The freshly hatched larva bears the egg shell on its dorsum during the 

 first day. After having lost this covering it becomes covered with a thick layer 

 of its own faeces. The anal aperture is situated on the upperside of last segment 

 and by contracting of the body the excrements are pushed out and by the same 

 movement spread over the dorsal surface of the body. Digestion takes place 

 rapidly, the faeces becoming purplish after 15 to 20 minutes when a larva was 

 fed with purple flowers, having eaten white ones before. 



9 or 10 days after hatching the larva is full grown, it looses the excrement 

 layer and constructs a curious cocoon. The latter is attached to some part of 

 the plant and consists of a white frothy substance which flows from the 

 mouth aperture under convulsive contractions of the fore body. The froth has 

 the consistance of beaten white of an egg but the interior wall is more resistant 

 and somewhat horny. 



Before changing into a pupa the larva remains 4 — 6 days inactive in the 

 cocoon. The pupal stage lasts 6 — 7 days; the beetle remains 2 — 3 days in 

 the cocoon before emerging. 



The whole development thus lasts from 25 to 31 days. 



