32 DESTRUCTIVE INSECTS OF VICTORIA : 



larva, 30 days ; development of nymph, 7 days ; total 

 development, 47 days. In Florida, Professor Quaintance 

 found it to be as follows : Development of eggs, 3J to 4 

 days ; development of larva, 7 to 9 days ; development of 

 nymph, 4 days ; total, 10| to 13 days. Experiments will 

 be made by the Entomological Branch to ascertain, if 

 possible, the difference in time of development as compared 

 with the above results. 



During the past few years, in Victoria, these troublesome 

 insects have been very severe on potato crops in many 

 parts of the State, and for the benefit of growers I have 

 included the report of the Assistant Entomologist, Mr. 

 French, jun., who, with Mr. G. Seymour, Potato Expert, 

 has been conducting some important experiments in the 

 Romsey and Lancefield district. He writes "In com- 

 pany with Mr. Seymour, Potato Expert, I paid a visit to 

 Romsey and Lancefield, and inspected the potato crops, 

 and was surprised at the damage to them done by the 

 thrips. Mr. Seymour estimates this season's loss at several 

 thousand pounds at least. Last year the loss was about 

 eight thousand pounds. The thrips are simply in millions, 

 not only affecting potatoes, but also the pea crops, grasses, 

 hawthorn and African box-thorn hedges, and, in fact, 

 nearly every kind of plant. There is thus great difficulty 

 in effectively dealing with the pest. The lower leaves of 

 the potato plant are generally attacked first, and, after 

 these are destroyed, the top ones are affected, and in a short 

 time the whole plant shrivels up, and the potatoes are 

 often only the size of a small marble. I may mention that 

 on one pea leaf no less than 23 larvae of the thrips were 

 counted. This will give some idea of the enormous number 

 of these insects. 



Messrs. Robb Brothers very kindly placed part of their 

 potato crop at our disposal for experiments, and I desire 

 to tender them my best thanks for their assistance. Mr. 

 Seymour procured the loan of a Strawsonizer spraying 

 outfit from a firm in Melbourne. This was fixed up in a dray. 



