﻿INTRODUCTORY REMARKS ON THE MYArARTDAE 



The Mymaridae are a family of excessively minute insects, 

 and authorities are not agreed as to the position that it should 

 occupy in the great groups of Hymenoptera. Almost all the 

 known species are parasitic in the eggs of other insects. Those 

 species with which I am personally accjuainted always emerge 

 singly from the egg that they have destroyed, but others arc 

 lired in some numbers from a single egg. Probably they at- 

 tack the eggs of almost all orders of insects, as I have bred them 

 from those of Lepidoptera, of Rhynchota. Homopterous and 

 Hemipterous, and also of Neuroptera, and they likewise destroy 

 those of Coleoptera. Some are recorded as having been bred 

 from scale-insects and plant-lice. Of the species hitherto describ- 

 ed, in comparatively few cases, are the hosts known, and it is safe 

 to say that all the species hitherto collected by Entomologists do 

 not amount to one in hundreds, that exist. Some of the larger 

 species may be obtained in numbers with the sweeping ne't by 

 anyone with good eyesight, and others are frequently seen in 

 ]jlenty running on glass windows, especially those of hot-houses 

 ill cold countries, as the English collectors observed three-quar- 

 ters of a century ago. The majority of the species that exist, 

 however, are not likely to be met with, except by breeding them, 

 for many are so minute, that except by chance they cannot be 

 collected in the field. Some species do not exceed one-third of 

 a millimeter in length and others are said to be even smaller, 

 while the pallid color of many of the minute species renders them 

 almost invisible to the naked eye. 



The long and very slender wings, fringed with long hairs, are 

 one of the most striking characteristics of the family, and with 

 these delicate organs of flight some even of the smallest species 

 can fly better than might have been expected. Many of them 

 have a frequent habit of rising slowly and vertically upwards on 

 tlie wing, and as they cannot withstand a moderately strong cur- 

 r( nt of air, this habit must lead to a much quicker and wider dis- 

 tribution of the species than could ever be attained by their 

 own unaided powers of flight. The leg's of most species are 



