Apr. 15, 1925 
Larvae Resembling the Corn Borer 
791 
black or a deep chestnut brown and 
is always black as the larva emerges 
from the egg. Just as the larvae of 
the corn borer group have only two 
setae, IV and V, on the prespiracular 
pinacula of the prothorax, so on this 
point the nod u ids are structurally 
identical, but on the third, fourth, fifth, 
and sixth abdominal segments the setal 
distribution differs with respect to IV 
and V; IV is removed quite a distance 
from V and is directly caudad of the 
spiracle (pi. 2, H). 
ACHATODES ZEAE HARRIS 
Gortyna zeae Harris, 1841, Ins. Mass. Inj. Veg., 
p. 319. 
Achatodes zeae Harris, Dyar, 1902, List N. Amer. 
Lepidop., No. 2158; Barnes and McDunnough, 
1917, Check List Lepidop. Bor. Amer., No. 
2642. 
Since Harris described Achatodes zeae 
(the spindleworm). and the injury to 
corn caused by its larva, infrequent 
references have been made to it in en¬ 
tomological literature. Forbes in his 
classical Twenty-third Report gives an 
account of it (#, p. 85) and character¬ 
izes it as the spindleworm, apparently 
from the fact that it has been found 
attacking corn in the so-called spindle 
stage of that plant. 
The species is very abundant every¬ 
where in Massachusetts in elderberry, 
but has only rarely been seen attack¬ 
ing corn. Dyar ( 6 , p. 174) gives its 
distribution as the North Atlantic 
States. On May 28, 1921, eight young 
larvae were found in an equal number 
of sweet corn plants, but this corn was 
not advanced to the spindle stage. The 
corn was in proximity to a large growth 
of elderberry. The larvae found in the 
stalks were in well-defined burrows and 
were headed upward in these tunnels. 
The latter are very similar in appear¬ 
ance to those of the European corn 
borer, but in the above case the sea¬ 
sonal occurrence of Achatodes larvae 
did not synchronize with the latter. 
The plants were badly wilted as if from 
Papaipema attack. 
The natural food plant of this species 
is elderberry in which the larvae have 
been found in large numbers. On May 
17, 1921, it was possible to cut out, 
from new elderberry shoots springing 
from the soil, quantities of the larvae. 
On June 10 they were found in all 
stages of development. The first pupae 
were taken in the burrows June 16 and 
subsequently some were found which 
pupated in the soil, but pupation occurs 
largely in the burrows where the larvae 
developed. The pupae are large, red¬ 
dish-brown and are supplied with two 
prominent processes on the cephalic 
end. 
The larva (pi. 1, G) is striking in ap¬ 
pearance. Head, thoracic and anal 
shields, and the pinacula are glossy 
black; the body of the larva is yellowish- 
white. On all the abdominal seg¬ 
ments, with the exception of the ninth, 
the two anterior median pinacula are 
larger than those of the caudal pair; 
the anterior pair are circular in contour, 
the caudal pair elliptical. On the ninth 
abdominal segment the anterior set 
equals the posterior pair in size. 
The larva of this species may be dis¬ 
tinguished from other larvae treated in 
this paper by an examination of the 
anal shield. This is strongly chitinized, 
black, rugose, and bears on its caudal 
margin three pairs or a row of promi¬ 
nent and strongly produced spines. 
KEY TO TIIE SEPARATION OF LARVAE TREATED HERETOFORE 
1. Larvae without strongly produced spines on the anal shield_ 2 
Larvae with strongly produced spines on the anal shield_ Achatodes zeae 
2. Larvae with three setae on prespiracular shield_ 3 
Larvae with two setae on prespiracular shield_ 4 
3. Setae III and V on prespiracular shield small, indistinct, much smaller 
than Seta IV_ Epiblema scudderiana 
Setae III and V on prespiracular shield prominent, well defined, equal to 
Seta IV in size_ Depressaria heracliana 
4. Crochets on planta of pseudopods arranged in an incomplete circle or 
penellipse_ 5 
Crochets arranged otherwise; in mesoseries_ Heliothis obsoleta 
5. Seta III of the eighth abdominal segment normal sized; pinacula bear¬ 
ing Setae VII and VIII, respectively, on the eighth abdominal segment 
wanting, poorly defined or only lightly chitinized_ 6 
Seta III of the eighth abdominal segment abnormally long, terminating 
short of the caudal border of the ninth abdominal segment; pinacula 
bearing Setae VII and VIII, respectively, on the eighth abdominal 
segment well defined, strongly chitinized_ Nomophila noctuella 
6. Pinacula on body segments pale and indefinite ( D . zeacolella, winter 
form)_ 7 
Pinacula on body segments strongly chitinized, well defined, and heavily 
pigmented_____ 8 
