1916] Weiss — Monarthropalpus buxi Lab. 155 



Infested plants obtained during the middle of April and kept 

 in the laboratory were examined daily and the pupal stage found 

 to last from fourteen to eighteen days. As it was several degrees 

 warmer there than in the open, gro\\i;h was undoubtedly acceler- 

 ated. In the open this stage lasted an average of three weeks. In 

 the laboratory, the first adults emerged April 30 and every day 

 following for two weeks, while in the open, the first emergence was 

 on May 20. Inasmuch as the weather varies in different years, 

 it can be safely said that, in New Jersey, the adults appear as a 

 rule during the latter part of May. 



According to Professor Chaine who studied the insects at 

 Bordeaux, France, oviposition lasts from two to three weeks, the 

 female depositing the eggs singly in a slit cut by the ovipositor. 

 Young leaves are selected and the eggs deposited at a distance 

 from each other. In the laboratory, oviposition started a couple 

 of days after emergence, the adult females selecting the under 

 surfaces of tender green leaves. Each female would insert the 

 tip of her abdomen in the tissue and sway the body from side to 

 side during the act. The eggs are tiny, oval and translucent, 

 wide at the middle and tapering uniformly toward each rounded 

 end, being about one one-hundred and twentieth of an inch long 

 and twice as long as broad. To the naked eye, they are visible 

 only as white specks. They appear to be laid on their sides in 

 the tissue and the only outward indication of their presence is a 

 slight elevation of the tissue immediately over. them, these swel- 

 lings sometimes being a darker green than the remainder of the 

 leaf. The exact location of each egg can easily be seen by hold- 

 ing the leaf up to the light and examining it with a hand lens. 

 Each light oval spot surrounded by a dark ring means an egg. 

 Several leaves examined in this way were found to contain as many 

 as thirty-three and thirty-five eggs, which were later dissected 

 out. This condition however would prevail only in a cage where 

 many females were forced to oviposit in a few leaves as it was under 

 such conditions that the above numbers were found. 



After hatching, which required from two to three weeks in the 

 laboratory, the yellowish white maggots mine the leaves all sum- 

 mer, making small oval pockets which sometimes run together on 

 one side of a midrib if many larvae are present. The winter is 

 passed in these pockets, the larvae transforming to pupae in the 



