158 MISCELLANEOUS FOREST INSECTS. 



the larva feeding within the seed until it reaches maturity, passing 

 the winter within the seed as a prepupal larva, transforming into 

 a pupa early in the spring, and emerging as an adult in time to 

 oviposit in the rather young seeds of the trees. The egg-laying 

 habit of some of the chalcidids which attack the seeds of shrubs or 

 vines differs in a measure from that of those attacking the seeds of 

 trees; for instance, the grape-seed chalcidid (Evoxysorna vitis Saund.) 

 oviposits in the seeds that are quite hard, and the only way that 

 the female is able to deposit eggs within the seed of the grape is by 

 finding a soft portion of the shell which is known as the chalaza. 

 This is also the case with the seed chalcidid of Virginia creeper 

 (Prodecatoma pTiytophaga Crosby). The oviposition of species of 

 Megastigmus which live within the seeds of coniferous trees has never 

 been observed, but owing to the heavy, leathery texture of the cones 

 it is possible that oviposition occurs when the cones are very small. 

 Species of chalcidids feeding within the seeds of various plants 

 have proven in some cases to be of much economic importance. A 

 few examples will suffice to show this. Forty pounds of apple seed 

 planted at Budapest failed to give even a good standing of apple 

 seedlings, the seeds having been destroyed by the apple-seed chalcidid 

 (SyntoTnaspis druparum). The seeds of the Douglas fir usually gath- 

 ered in Aberdeenshire, Scotland, and amounting to over 300 bushels 

 were, according to a letter from Mr. John Crosier published by Mac- 

 Dougall in 1906, not worth gathering, owing to the attack of the Doug- 

 las fir seed chalcidid ( Megastigmus spermotropJius) . According to a 

 letter published by Riley in 1893, the seeds of the silver fir (Ahies 

 pectinata) in the forests of Denmark were so completely destroyed 

 during the years 1886 and 1888 by species of the genus Megastigmus 

 that not a single healthy seed could be found. As a great many of the 

 species of Megastigmus which are troublesome in Europe come from 

 the seed of the American conifers it is very likely that difficulty will 

 be found in North America on account of the attacks of these insects. 

 No parasite of the species of the genus Megastigmus is as yet known. 



SYNTOMASPIS DBTJPARUM (Boheman). 



This species, which normally attacks the apple but is known to 

 attack the seeds of mountain ash (Sorhu^ scandica, and probably 

 Sorhus latifolia) and hawthorn (Cratsegus), is very elaborately treated 

 by Crosby in his paper entitled "Certain seed-infesting chalcid fhes," 

 where an account is given of practically the entire life history of this 

 insect. The egg is deposited by the female within the seed of an 

 apple when the apple is about thi-ee-fourths of an inch in diameter. 

 The young larva feeds within the seed and develops untU it hibernates 

 as a larva within the seed, pupatmg early in the spring and emerging 

 as an adult in June. As this species is not of any economic importance 



