THE PEAR THRIPS IN CALIFORNIA. 19 



torted somewhat in the same manner as does peaeh leaf-curl. Some- 

 times the larvae feed on the young fruit, but rarely to the extent of 

 causing any great loss. 



INJURY TO APRICOTS. 



Apricots have not, as a rule, been injured commercially except 

 in cases where there are a few young trees around home grounds or 

 near an infested pear or prune orchard. They are sometimes injured 

 to about the same degree as peaches, and in some cases isolated trees 

 have been observed which failed to bloom as a result of the work of 

 the thrips. Larval injury to the young fruit is usually more exten- 

 sive than is the case with peaches and may at times be serious. How- 

 ever, apricots are apparently not favorite breeding places for thrips. 



INJURY TO ALMONDS. 



Almonds are injured less by the thrips than any ot the foregoing 

 fruits. On account of the early blossoming of the trees and the rela- 

 tively greater amount of exposed leaf surface at the time the thrips 

 are out in numbers, together with the character of the blossom, which 

 is similar to that of the peach, feeding by the thrips very rarely causes 

 much commercial loss in almond orchards. 



DESCRIPTION. 



EGG. 



The egg when first deposited is bean-shaped, translucent white, measuring on the 

 average about 0.416 mm. in length and about 0.166 mm. at its widest part in the 

 middle. (PL I, fig. 2.) 



Just before hatching it decreases in length, appears swollen, has a slight brownish 

 tint, and is faintly striated longitudinally where the antennae and legs are folded to- 

 gether. The dark brown spots, the eyes of the young larva, are apparent at one end. 



LARVA. 



FIRST STAGE (LARVA 1 DAY OLD). 



Length 0.646 mm.; width of head 0.166 mm.; width of mesothorax 0.183 mm.; 

 width of abdomen 0.15 mm. ; lengtn of antennas 0.2 mm. ; length of antennal segments: 

 I 20//, II 40/i, III 45/*, IV 100/i. General color translucent white. General shape fusi- 

 form. Antennae, head, and legs large in proportion to the rest of the body, and unwieldy. 

 Antennae distinctly four-segmented, first segment short, cylindrical; second segment 

 about twice as long as first, oval cylindrical; third segment slightly longer than second, 

 urn-shaped ; fourth about as long as rest of joints together, acutely conical . A few very 

 fine inconspicuous hairs present on all joints, more prominent on segment 4; Head 

 subquadrate; eyes reddisn brown. Thorax about as long as abdomen, slightly wider. 

 Abdomen gradually tapering, 10-segmented, first eight segments subequal, IX and X 

 longer and more abruptly tapering, with a fringe of long, white, nearly inconspicuous 

 hairs. Legs stout; femora and tibiae nearly equal in length; tarsi one-jointed, ending 

 in a single black claw. (PL I, fig. 3.) 



