24 Farmers’ Bulletin 1260. 
grain that was harvested during rainy weather or so stored that the 
moisture content was unusually high. Attempts to rear the moth in 
dry, warm laboratories have failed. The larve cut through burlap 
sacking and can damage sacks greatly when heavy infestations de- 
velop in sacked material. Figure 33 shows the characteristic web- 
bing together of infested seeds—in this instance navy beans—and 
figure 32 shows the tendency for larve to spin their whitish silken 
cocoons on the outside of grain sacks 
where the sacks touch each other. 
MEALWORMS. 
There are two species of meal- 
worms in the United States. The 
adults are the largest of the beetles 
found in grain and their larve are 
conspicuous, for they attain a length 
of about one inch and are as large 
around as an earthworm. 
YELLOW MEALWORM.” 
The adult of the yellow mealworm 
polished dark-brown or black 
beetle, somewhat more than half an 
inch long, with its thorax finely 
punctured and with its wing covers 
Wid. UBLeaRGh cc eae gees longitudinally striated or grooved. 
Indian meal moth, crawling on ker- (See fig. 34, at right.) The females 
ae of fs ie These worms ee lay bean-shaped white egos covered 
white or greenish in color and fre- : é s 
quently eat out the germ end of | With a sticky secretion that causes 
wee re nm & Jepeth of the dlour,.\iwenl, or geen ease yan 
which thay are placer to adhere to 
them. The eggs hatch in about two weeks into slender white larve, 
which soon turn yellow and assume the form shown in figure 34. 
When full grown, the larve are about an inch long and yellowish, 
shading to yellowish-brown toward each end and at the articulation 
of each segment. The pupa into which the larva transforms before 
becoming an adult beetle is shown in figure 34, 
The ie mealworm is ideal over the world and is fre- 
quently found in stored grains. It belongs to a family of beetles ** 
known as the darkling beetles because of their preference for dark 
places. The adults fly only at night. During daylight they conceal 
themselves, with the larvee, beneath sacks of grain, under grain boxes, 
1 Tenebrio molitor I. 16 Tencbrionidae. 
