812 Popular Editions of Station Bulletins of the 



The eggs hatch within a week after laying, and 

 Larva. produce small, white, soft-bodied larvae with two 

 pronounced reddish eye spots. These larvae are 

 provided with mouth parts like those of the adult, but are some- 

 what less active and destructive. On the pear they feed mainly 

 on the young leaves and emphasize the injury done by the adults, 

 since they are naturally most abundant on trees that have fed the 

 parent insects in largest numbers. This additional shock to the 

 tree greatly retards its return to a normal condition, as the leaves 

 are often destroyed or deformed to such an extent that the young 

 pears that have set cannot be nourished and, therefore, drop ; nor 

 can new fruit spurs for the next year be developed. Later, the 

 larvae feed to some extent on the tips and edges of the growing 

 terminal leaves', which may be blackened. A secretion similar to 

 that produced on the buds by the adult thrips may also be caused 

 by the work of the larvae. 



After feeding for about two weeks the larvae drop from the trees, 

 may feed for a time on weeds and grass, and then enter the soil 

 to form the resting cells. They remain unchanged in these until 

 late October, then change to pupae and pass the winter in that 

 stage or as hibernating adults. 



While commonly called " pear " thrips, this pest 

 Food plants, may feed or work on quite a range of plants. It 



was found in ISTew York during 1911 on apple, 

 apricot, cherry, peach, plum and quince as well as on pear; and 

 in California it also attacks almond, fig, grape and English walnut. 

 If it becomes established in the East it may have to be fought on 

 the above fruits and probably others. 



As a sucking insect, the thrips cannot be reached 

 Control. by internal poisons, but must be destroyed by 



contact insecticides. It is not difficult to kill, if 

 reached, as the spraying experiments of 1911 proved that it would 

 be destroyed by a good wetting with any of the insecticides used. 

 The difiiculty is, however, that the adults very soon get into the 

 buds where spray mixtures cannot reach them directly. Early 

 recognition of their presence and prompt, thorough, qiiickly 

 repeated applications are necessary for success. 



