32 Journal New York Entomological Society. [Vol. xvi. 



NOTES ON ONCIDERES QUERCUS SKINNER. 



By G. Beyer, 

 New York City. 



In 1905 I collected in the Huachuca Mountains, where I took 

 Oncideres quercus Skinner. The beetle was not plentiful as I captured 

 only 8 specimens during July and August. I was therefore surprised 

 to see during the latter part of September the amount of work the 

 insect had done and how many had been engaged in this work. 

 Oncideres girdles an oak twig about half an inch in diameter at the base 

 and fourteen to twenty-four inches long, gnaws the branch through to 

 near its center, so that it has a very slight hold on the tree, then gnaws 

 as many as six holes about three inches apart in the portion beyond 

 the girdle and deposits an egg in each hole. The girdled twig soon 

 dries up and the wind brings it to the ground. During September 

 there were hundreds of these twigs to be seen all over the mountains. 

 This proved that the beetle was very plentiful. The dry twigs also 

 induce other beetles to make their breeding place in them. I took 

 some of the infested twigs home and awaited results. In 1906 the 

 little Scolytid Chramesus icorice Lee, came out in great numbers and 

 during the summer there were certainly two broods of this beetle. It 

 seemed to me that there could not be much nourishment left in the 

 twigs for the larval Oncideres, which require two years for their devel- 

 opment, but, to my surprise, during 1907 about 100 specimens 

 emerged, also 4 specimens of Pogonoderus negundo SchaefF., and one 

 Liopus sp. nov. The development of the two latter species also 

 required two years. Last October I examined some of the twigs and 

 found quite a number of Oncideres larvae in good condition. This 

 shows that the beetle can stay over even another year if circumstances 

 are unfavorable. I expect to have another crop of this insect this year. 

 How little nourishment the larva? need is shown by the fact that a 

 single twig half an inch in diameter at the base and twenty inches long 

 contained 80 specimens of Chramesus icorice and 5 specimens of Onci- 

 deres quercus. 



