TWENTY-EIGHTH REPORT OF THE STATE ENTOMOLOGIST 15 



Mealworms (Tenebrio molitor L. and Tenebrio obscurus F.) . — 

 Of these two large grain insects, the yellow mealworm (T. molitor) 

 appears to be more common than the dark mealworm (T. obscurus) 

 in Montana. The adults are over one-half of an inch long, ellipti- 

 cal in shape, without the strong body constriction which is notice- 

 able in the cadelle. The yellow mealworm adult is shiny and dark 

 brown to black. The adult of the dark mealworm is similar in size 

 and shape but is dull pitchy black in color. The larvae are elongate, 

 cylindrical, shiny, about an inch long, yellowish in the yellow meal- 

 worm and darker in the other species. They breed in refuse grain 

 and coarse cereal and mill products, and are partial to moist situa- 

 tions. There is but one generation a year and, as they feed exter- 

 nally upon grains, they may be easily removed from grain by fan- 

 ning and screening. The j'ellow meal worm has been reported from 

 Bozeman, Culbertson, Darby, Dillon, Florence, Great Falls, Ham- 

 ilton, Hardin, Helena, Joliet, Kalispell, Malta, Miles City, Missoula, 

 and Wibaux. The dark mealworm is known from Bozeman, Great 

 Falls, Hardin, and Hill County. 



Cadelle (Tenebroides m,auritanicus (L)). — One of the larger 

 grain pests, the Cadelle is about one-third of an inch long, oblong, 

 flattened, and black with a conspicuous constriction between the 

 thorax and the abdomen. The larva is chalky white, fleshy, and 

 three-quarters of an inch long when full grown. The tip of the abdo- 

 men ends in two dark horns. Both the larva and the adult feed on 

 grain and grain products, and often devour only the germ from the 

 kernel. In Montana there are records of its occurrence in Great 

 Falls and Hardin. 



Meal moth (Pyralis farinalis L.). — The adult of this pest is a 

 rather fragile looking moth with a wing spread of approximately an 

 inch. The forewings are characteristically marked with deep brown 

 bases and tips, these areas being separated from the irregular inter- 

 mediate straw-colored stripe by white lines. The underwings are 

 brownish gray, which coloration may be broken into spots toward 

 the hind margin. The whitish larva becomes about an inch long 

 when full grown. It spins a tube as it develops, and trails a silken 

 thread behind it wherever it goes. This webbing is conspicuous in 

 grain which is heavily infested or which has supported this pest 

 for some time. It is a general feeder in grains, cereals, and is 

 sometimes found in hay or other dried vegetable material. It pre- 

 fers damp materials and is often abundant where grain or grain 

 products are allowed to accumulate. The larvae, which may be 

 tinged with orange at both ends, may gnaw through sacking and 

 cause such materials to spill. There are records in the Montana 

 Insect Pest Survey of its occurrence near Culbertson, Forsyth, 

 Hardin, Kremlin, and in Garfield County. 



Mediterranean Flour Moth (Ephestia kuehniella Zell.). — The 

 larvae of this small greyish moth may be found infesting accumu- 

 lations of flour, meal, or waste grain, webbing the material to- 



