INSTITUTE, PUSA, FOR 1916-17 83 



mon, but they are always found in company with C aland m 

 oryzce and Rhizopertha dominion. 



Tribolium has been observed to occur with Rhizopertha 

 more than with Calandra and some experiments have been 

 undertaken to find out its status definitely. 



This year there was an opportunity of following Tene- 

 broides mauritanicus throughout the year and of finding 

 out its true status. Tt is found commonly with Calandra 

 oryzce. It takes about a year to complete the life-cycle, the 

 adult beetles appearing and laying eggs in July- August 

 and the rest of the year being passed in larval stage. The 

 adult beetles live for several months and prey upon Calan- 

 dra oryzce weevils. The grubs do not attack the weevils 

 .but bore wheat and rice grains. 



In the report for the year 1914-15, it was stated that 

 Tenebroides mauritanicus on the whole played a beneficial 

 part and its presence in affected wheat and rice would be 

 beneficial. Further study has shown that the good the 

 adult beetles do by preying upon the weevils is practically 

 of no "help. The real damage to wheat is done by the 

 weevils from July onwards and Tenebroides mauritanicus 

 is present at this time only in the larval stage and does not 

 attain the adult stage till the next year. Also the beetles 

 do not appear in sufficiently large numbers to be of use in 

 checking the weevils. 



8. Insecticides. Two insecticides were received for 

 trial, (1) Orrs Wood Preservative against termites and (2) 

 Incosopol, a preparation from cotton seed oil, manufac- 

 tured by the Indian Cotton Oil Company of Navsari, Bom- 

 bay Presidency, for trial against plant lice and such other 

 insects. The trials have been undertaken. 



Bagrada picta appeared in an experimental plot of 

 mustard and spraying with Fishoil Eesin soap at a strength 

 of 1 lb. in 4 gallons of water checked it entirely, killing even 

 the adults. 



9. Lantana work. This work was taken up on 

 instructions from Government and has for its object the 

 collection of information regarding the occurrence within 



