ASPARAGUS-BEETLE EGG PARASITE 



By F. A. Johnston, 



Entomological Assistant, Truck-Crop and Stored-Product Insect Investigations, 



Bureau of Entomology 



INTRODUCTION 



On May 23, 1909, a minute chalcidid parasite was reported from Con- 

 cord, Mass., by Messrs. C. W. Prescott and J. B. Norton, of the Bureau 

 of Plant Industry, where, according to information received from Mr. 

 Prescott, the insect was observed devouring the contents of the eggs of 

 the asparagus beetle (Crioceris asparagi L.). Later, on June 2, Dr. H. T. 

 Femald found the same parasite at Amherst, Mass. The species was 

 referred to the Bureau of Entomology and was determined by Mr. J. C. 

 Crawford, of the United States National Museum, as being new to science, 

 and was accordingly described as Tetrastichus asparagi Cwfd. (i).^ In 

 July of that year and later, in August, Dr. Femald published short articles 

 on this species. Since the asparagus beetles have never been carefully 

 studied throughout their life history, the fact that the parasite had been 

 recorded was overlooked. In an earlier article, however, published in 

 1869, Riley and Walsh (6) referred to a notice of the occurrence of a para- 

 sitic fly as follows : 



But in the year 1863, as we learn from Isaac Hicks, of Long Island, a deliverer 

 appeared in the form of a small shining black parasitic fly, probably belonging either 

 to the Chalcis or to the Proctotrupes family. Whether this fly lays its eggs in the 

 eggs of the asparagus beetle or in the lar\-a of that insect does not seem to be at present 

 clearly ascertained ; but if the accounts that we have received of it be correct it must 

 do either one or the other. In the former case the larva that hatches out from the 

 parasitic egg will consume the egg of the asparagus beetle and entirely prevent it 

 from hatching; in the latter case it will destroy the larva before it has time to pass 

 into the perfect state. The result in either event will be equally destructive to the 

 bug and beneficial to the gardener. 



Later, in 1882, Lintner (4) made notes on the same species, referring to 

 the publication in the American Entomologist just quoted. Again in 

 1893 (5) he called attention to a parasite, stating that it was undescribed 

 and that it might have disappeared before it could receive scientific 

 attention, because nothing seemed to be known of it at that time. 



From the descriptions given it seems almost certain that the parasite 

 mentioned by Riley and Walsh and Tetrastichus asparagi C^^•fd. are the 

 same. If so, it is hard to explain why this insect, which was reported 

 in considerable numbers in 1863, should have escaped further observation 

 until 1909. 



' Reference is made by number to " Literature cited," p. 312. 



Journal of Agricultural Research, Vol. IV, No. 4 



Department of Agriculture, Washington, D. C, July 15, 1915 



K— 19 

 (303) 



