XXIII 



FIG-INSECTS 



547 



Eiley has called attention ^ to some facts in connection with 

 /. tritici and /. grande, that make it clear that these two supposed 

 species are really alternate generations, and that both generations 

 are probably in larger part, if not entirely, parthenogenetic. 

 Some species of the genus Megastigmus are known to be of 

 phytophagous habits.^ 



The most interesting of all the forms of Chalcididae are 

 perhaps those called fig- Insects, A considerable number of species 

 are now known, and amongst them we meet with the unusual 

 phenomenon of species with wingless males, the females possessing 

 the organs of flight normally developed. The wingless males 

 exhibit the strangest forms, and bear no resemblance whatever to 

 their more legitimately formed partners (Fig. 358, A, B). Many 

 of the fig-Insects belong to a special group called Agaonides. 

 Others belong to the group Torymides, which contains likewise 

 many Chalcididae of an ordinary kind ; possibly some of these 

 may be parasitic on the Agaonides. Some of these Torymid fig- 

 Insects have winged males, as is normal in the family, but in 

 other cases winged and wing- 

 less forms of the male of one 

 species may be present. 



The most notorious of these 

 fig- Insects is the one known 

 as Blasto][)lhagci grossorum (Fig. 

 358), this being the chief agent 

 in the custom known as capri- 

 fication of the cultivated fig- 

 tree. This process has been 

 practised from time immemorial, 

 and is at the present day still 

 carried on in Italy and the 

 Grecian archipelago. The Greek 



writers who describe it say that Fig. B5S.Blastophaga grossor^tm. A 



the wild fig-tree, though it does 

 not ripen its own fruit, is ab- 

 solutely essential for the perfection of the fruit of the cultivated 

 In accordance with this view, branches from the wild fig 



Male, X 22; B, female, x 15. (After 

 Mayer, Mitt. Stat. JVeapel, iii. 1882.) 



fig. 



^ Reijort of the Entomologist, Bci^. Agriculture, Washington, 1886, p. 542, 

 2 Wachtl, Wien. ent. Zeit. xii. 1893, p. 24, and Howard, P.U.S. Nat. Mus. xiv. 

 1892, p, 586. 



