140 Bulletin 224. 



third of the buds were destroyed on many clusters. Thus the insect 

 is capable of making very ragged bunches of grapes, for all infested 

 blossom-buds soon appear blackened and blasted and fall from the 

 clusters. 



The life-history and habits of the insect.- — We have but little definite 

 knowledge of the life-history of this grape blossom-bud gnat. Prob- 

 ably the minute, two-winged gnats emerge from the soil in May and 

 lay their eggs on, or possibly stick them into, the growing blossom- 

 buds of the grape clusters. Hatching in a few days, the little mag- 

 gots live inside the blossom-buds, feeding on the pistil and causing 

 the buds to enlarge and take on a reddish color. Developing rapidly, 

 the maggots get full grown and are ready to leave before the blossoms 

 open. They emerge from the buds either by eating holes in the sides, 

 or through slits caused by the breaking of the bud-cap in an attempt 

 to open into the blossom. Dropping to the ground, the maggots soon 

 bury themselves. We have found as many as 18 maggots in a single 

 grape blossom-bud. None of the infested buds ever open into 

 blossoms, but soon shrivel and blacken or " blast " and drop off after 

 the maggots leave them. The maggots wriggle about actively, and 

 often bring the two ends of their body together, and by suddenly 

 straightening out, throw themselves nearly half an inch into the air 

 and about that distance over the ground. 



By June 23 all the maggots had gone into the ground and their 

 further life-history is still one of Nature's many mysteries. Possibly 

 they may transform into another brood of the gnats whose maggots 

 make galls on the grape foliage or live on some different plant ; or the 

 insect may remain in the soil as maggots or pupae until the next May. 

 We saw nothing more of the insect after the maggots went into the 

 soil late in June, and were unable to keep the maggots alive in our 

 cages. 



Remedial suggestions.— Ap-psiTently there is no practicable way to 

 get at this new grape enemy with a spray of any kind. It is out of 

 reach inside the little blossom-buds. But the fact that we found it 

 occurring in injurious numbers only in neglected vineyards or near 

 wood-lots or hedges, indicates that the progressive grape-grower who 

 properly cultivates and feeds his vines can always keep this new insect 

 under control. 



Mark Vernon Slingerland. 

 Fred Johnson. 



