56 AMERICAN HYMENOPTERA. 



Economic importance. — Not much is known of the life his- 

 tories of the tropical species, but the northern members are 

 recognized as beneficial parasites. Records indicate that E. 

 purgatus is one of the most valuable members of the tribe 

 since it preys upon several injurious insects of considerable 

 importance. It has been frequently noticed as a parasite of 

 the destructive army worm, Heliophila unipuncta Haw., on 

 which it " serves as a very efficient check." Professor Lug- 

 gar's report of 1896 gives the best evidence of its value as a 

 parasite. I have before me one specimen bred from the 

 cotton worm {Aletia) Alabama argillacea, but can find no 

 record of this host, and can not say whether or not it is fre- 

 quently attacked. It has also been reared from the zebra 

 caterpillar, Mamestra picta Haw., another injurious species, 

 and preys upon several of less importance. 



Life history and habits. — Little is known of the life history 

 or habits of the members of this genus aside from those of 

 E. purgatus^ but so far as known they do not differ from 

 those of other members of the tribe. 



Table op Species. 



1. Antennae black or dark fuscous 2. 



Antennae flavous or fulvoferruginous 9. 



2. Abdomen entirely black beyond the first segment 3. 



Abdomen not entirely black beyond the first segment 4. 



3. Larger macula appendiculate. 



fuscipennis flavostigma n. subsp. 

 Larger macula not appendiculate fuscipennis Szep. 



4. Wings fulvo-hyaline bicolor Tasch. 



Wings hyaline 5. 



5. Head with distinct longish tubercle below the antennae. 



fuscicornis Cam. 

 Head without distinct longish tubercle below the antennae 6. 



6. Discocubital cell with one macula 7. 



Discocubital cell with two maculae 8. 



7. Discocubital cell with a linear, arcuate macula... nigricornis Br. 

 Discocubital cell with a triangular macula cressoni n. sp. 



8. Abdomen beyond the fourth segment black fernaldi n. sp. 



Abdomen with segments 3 to 8 black monticola Cam. 



9. Discocubital cell with only one macula or a macula and one or 



more lines 10. 



Discocubital cell with more than one macula 19. 



