ZOB 



A BIOLOGICAL JOUR 



Vol. II. JANUARY, 1892. No. 4. 



SOME BIOLOGICAL PECULIARITIES OF THE PHYL- 

 LOXERA AND A METHOD OF UTILIZING THEM 

 FOR THE PROTECTION OF VINEYARDS. 



BY H. H. BEHR. 



Almost every investigator of the biological phenomena in Phyl- 

 loxera, and its different forms of existence, has been struck by the 

 comparatively and unexpected ease with which the winged gen- 

 eration of the insect pest may be developed. 



This experience has left an 'impression that under ordinary cir- 

 cumstances, that is in our vineyards, the winged generation of the 

 insect develops as regularly and frequently as in the glass jars, where, 

 together with some grape roots, the wingless insects are kept pris- 

 oners by the entomologist. The scarcity of the winged insect— in 

 fact I do not know any case o{ its being observed except in the 

 glass jar — has always been imputed to its minuteness, nocturnal 

 habits, shortness of existence, etc. Still if the insect would develop 

 as regularly out of the glass jar as it does within it, it would not so 

 successfully have escaped notice. 



As to its nocturnal habits, I am not so certain that they arc ex- 

 clusively so. At least, in the glass jar, they seem lively enough 

 during day time. But, even supposing that they are exclusively 

 nocturnal, there is not much probability that they would escape our 

 notice if they kept regular seasons. Water tanks that reflect the 

 sun in day time and either the moon or artificial lights at night, and 

 which especially to the minute insect world prove such an attractive 

 trap, would have yielded at least some Phylloxera amongst the many 

 winged Aphidians, Coccides, Tipulides, Microptera, Noctuides, and 

 even Sphinges, which become victims to the deceptive reflection, 

 or if wise enough to escape that illusion are wafted into the water 

 by some untimely breeze, whose power their weak wings cannot 

 counteract. There is just a trace of voHtion in the flight of Aphid- 



