PROC. ENT. SOC. WASH., VOL. 21, XO. 6, JUNE, IQIQ 125 



The winter of 1917-1918 was so mild that the 1917 leaves re- 

 mained on the trees until March i, when the new leaves of 1918 

 had unfolded. The young worms went from the old to the new 

 leaves without difficulty and completed their normal develop- 

 ment. During the first half of September, 1918, there was a 

 heavy three days rain. This was followed by a month or more 

 of warm weather. By November i many of the white oak leaves 

 were well grown and the Phryganidia eggs of the fall brood were 

 laid directly on these. Hatching took place normally and the 

 young worms passed the winter of 1918-1919 in good condition 

 and show every indication of reaching full development. 



The interesting question now arises as to whether, after feed- 

 ing for five generations (summer, winter, 1917; summer, winter, 

 1918; summer, 1919) on the white oak this particular strain of 

 the species will have lost its taste for the live oak and will be- 

 come exterminated the first winter the white oak leaves fall early. 

 On the other hand, it is possible that practically every winter 

 some of the white oak leaves remain on the trees until spring and 

 at least part of the brood laid on the white oak winters normally. 



The principal natural enemies of the oak worm besides this 

 peculiar habit of self destruction are a "wilt" disease which some- 

 times kills the worms by the thousands; the spined soldier bug 

 (Podisus maculiventris Say, 1 which punctures and sucks dry 

 the eggs, all stages of the worms and the chrysalids; a small 

 grayish fly (T'.ryptocera flavipes Coq. 2 ) which kills the larger 

 worms and the black and yellow chalcid (Chalcis abiesiae Girault 3 ) 

 and the oak worm ichneumonid (Itoplectis behrensi (Cress.) 4 ), 

 which parasitise the chrysalids. 



A MICROLEPIDOPTERON INJURIOUS TO AVOCADO. 



BY AUGUST BUSCK. 

 Stenoma catenifer Walsingham. 

 (Biol. Ccntr. Amer., iv., p. 168, 1912). 



This species feeds in the fruit and seed of Avocado (Aguacate) 

 Persea spp. and appears to be of considerable economic im- 

 portance by its destructiveness. It is the species mentioned as 

 Stenoma species, by Sasscer (Jour. Econ. Ent., vol. 2, p. 127, 1918), 

 Barber (Proc. Ent. Soc. Wash., vol. 2 1, p. 59, 1919), and by Popenoe 



1 Identified by E. H. Gibson. 



2 Identified by C. T. Greene. 



3 Identified by S. A. Rohwer. 



4 Identified by R. A. Cushman. 



