606 



Journal of Agriculture, Victoria. [10 Oct., 1916. 



instances, they die before the fruit is formed. Thrips are minute insects, 

 seldom exceeding a line in length. The eggs are extremely small, 

 cylindrical, and round at one end. From them issue little larvae quite 

 as active as their parents. When the insects are fully grown, their 

 wings are long, narrow, and lie flat on their back when at rest. They 

 are surrounded with ciliae, or hairs, giving them the appearance oi 

 tassels. The species under notice is an introduction from Europe, ana 

 has long been known in England and elsewhere as one of the gardener's 

 worst enemies. The life cycle of these insects is as follows: — Develop- 

 ment of egg, 10 days; de- 

 velopment of larva, 30 

 days; development of 

 nymph, 7 days; total, 47 

 days. During the past few 

 years these troublesome in- 

 sects have been very severe 

 on potato crops in many 

 parts of the State, and 

 Mr. G. Seymour, the 

 former potato expert of the 

 Department, estimated one 

 season's loss at several thou- 

 sand pounds. The thrips 

 question is even now a very 

 serious one, as so large a 

 number of plants are sub- 

 ject to its attack, and no 

 one knows where the trouble 

 is goiner to end. It behoves 

 all growers to look this 

 trouble square in the face, 

 and, if possible, to keep it 

 within reasonable bounds. 

 When the fruit trees are in 

 bud is the time for an occa- 

 sional spraying. Various 

 remedies have been tried, 

 the best of which is as fol- 

 lows : — Benzole emulsion . 

 This is a patent prepara- 

 tion, which can be obtained 

 fro.ii any seedsman in Mel- 

 bourne. The cost per tin is 



only a few pence. One tinful (1 lb.), when diluted, makes 5 gallons of 

 spray. If this is sprayed on the flowers it acts as a deterrent. Fruit-growers 

 in the Beaconsfield District, on my suggestion, used this material, and they 

 report good results. As a deterrent, spraying with tar-impregnated 

 water, or a weak kerosene emulsion, is recommended. The following is 

 the formula for coal-tar water. — Boil 1 lb. coal tar in 2 gallons of rain 

 water, and while hot add from 50 to' 100 gallons of water. Nicotine, 

 lime sulphur, hellebore, and quassia sprays have also given good results. 

 Pine Spray, a patent preparation, has also been used with success 

 against these pests. I would suggest that, when an orchard is badly 



Fig. 22. — Common Thrips (Tliriiift f abaci. 

 Liiulemaiin) . 



