8 THE SPRING GRAIN-APHIS OR 
TEXT FIGURES. 
Pag-e. 
Fig. 1. The spring grain-aphis {Toxoptera graminum): Winged and wingless 
viviparous females and young on wheat plant 12 
2. Map showing the locality from which the spring grain-aphis was re- 
ceived in 1882 and the two additional localities where it is probable 
that it also occurred in injurious numbers in that year; also the two 
localities where it was found in 1884 14 
3. Map showing the distribution of the spring grain-aphis in both the east- 
ern and the western hemispheres 17 
4. Map showing the known distribution of the spring grain-aphis in the 
United States and Canada 19 
5. Maps showing areas covered by outbreaks of the spring grain-aphis dur- 
ing the years 1890, 1901, 1903, and 1907 20 
6. The spring grain-aphis : Male and antenna 45 
7. The spring grain-aphis: Winged viviparous female and antenna 46 
8. The spring grain-aphis : Wingless viviparous female 47 
9 . The spring grain-aphis : Oviparous female showing eggs within the abdo- 
men 50 
10. The spring grain-aphis: Hind tibia of oviparous female 50 
11. The spring grain-aphis: Eggs 51 
12. The spring grain-aphis : Young, first instar 59 
13. The spring grain-aphis: Young, second instar 59 
14. The spring grain-aphis: Pupa of winged viviparous female 60 
15. The spring grain-aphis: Shrunken and nearly spent oviparous female.. 79 
16. The spring grain-aphis: Aberrant female with both eggs and embryos in 
abdomen showing through the body wall 80 
17. The spring-grain-aphis: Aberrant female pupa which produced young. 81 
18. The spring grain-aphis: Shell of egg after young stem-mother has 
emerged 103 
19. Aphidius testaceipes, principal parasite of the spring grain-aphis: Adult 
female, antenna of male, egg ±04 
20. Aphidius testaceipes ovipositing in the body of the spring grain-aphis... 105 
21. Position of larva of Aphidius testaceipes in the body of wingless adult 
female of the spring grain-aphis, from 11 a. m. to 12.32^ p. m 110 
22. Position of larva of Aphidius testaceipes in the body of the spring grain- 
aphis at the beginning of the change to a yellowish color Ill 
23. Full-grown larva of Aphidius testaceipes taken from body of the spring 
grain-aphis as shown in figure 21 Ill 
24. Larva of Aphidius testaceipes spinning its cocoon in the dead body of the 
spring grain-aphis 112 
25. Larva of Aphidius testaceipes working its way prematurely from the body 
of the spring grain-aphis 112 
26. Full-grown larva of Aphidius testaceipes 112 
27. Pupa of Aphidius testaceipes immediately after pupation 113 
28. Dead "green bugs " ( Toxoptera graminum) showing exit holes of Aphidi- 
us testaceipes 113 
29. The spring grain-aphis: Winged female parasitized by Aphidius testa- 
ceipes 118 
30. Aphelinus mali: Adult and stigmal club 122 
31. Aphelinus nigritus: Adult and stigmal club 123 
32. Aphelinus semiflavus: Adult and stigmal club 124 
33. The spring grain-aphis: Dried remains from which adult Aphelinus 
nigritus has emerged 124 
34. Megorismus sp. : Male, female abdomen 126 
