THE OREGON NATURALIST. 



T. ferrugineum have occasioned considerable 

 alarm among millers, flour and feed dealers, 

 grocers and dealers in patent foods. These 

 two species resemble each other so closely that 

 It is only with the aid of a magnifying glass 

 that a difference can he detected. Their liabits 

 are also very similar, 



« For many years these insects have been 

 known in Europe as enemies of meal, flour, 

 grain and other stored products, and even as 

 jiests in museums. Although they live in grain, 

 their chief damage probably is to flour and 

 patented articles of diet containing faiinaceous 

 matter. The eggs are dejiosited in the flour, 

 and these and the young larvne being miiiute 

 and pale in color are not noticed; but after the 

 flour has been barreled or sealed up in boxes 

 for some time, the adult beetles mike their 

 appearance and in due coarse of time the 

 product is ruined. A part of the trouble caused 

 to purchaser, dealer and manufacturer, is due 

 to the fact that the insects are highly offensive, 

 a few specimens being sufficient to impart a 

 disagreeable odor to the infested substance. 

 In addition to these two species of Triholium, 

 there is another similar beetle that attacks grain, 

 viz, the slender horned flour beetle {Echocems 

 maxillosus) which will be described further on. 

 The confused flour beetle {Ttibolium con- 



fnsum. Duv.) is a minute, reddish-brown 

 beetle, elongate and depressed. 



It can be separated fromy^z-rMc-zw^ww chiefly by 

 the structure of the antenna which is gradually 

 clavate. The head also differs somewhat. 

 Chittenden's experiments during the 

 years 1893-94, proved that this species 

 is an exceptionally high temperature, 

 is capable of undergoing its entire 

 round of transformation in thirty six days, but 

 in spring and autumn weather it requires a 

 much longer time. In well heated buildings, 

 at this rate, there are at least four and ]iossibly 

 five, broods during the yeai . 



The injuries reported of this species, as noted 

 down in the records of the U. S. Department 

 of Agriculture, far outnumber those of any 



other farnivorous insect. During the past year 

 the species has been found in patenttd food at a 

 local grocery, in wheat from New Mexico, in 

 flour from Massachusetts in oatmeal, flour and 

 meal from Indiana, and in corn, peanuts and 

 seeds. It has also been found upon snuff", 

 orris root, baking powder, rice chaff, graham 

 flour, red pepper, and upon dried insects. 



The rust-red flour beetle (Tribolium 

 ferrugineum) resembles in general a]ipearance 

 the preceding species, but may be distinguished 

 by the antenna having a distinct terminal 

 three jointed club The larva ami 

 pupa also resemble strongly, those oi conjusuni. 

 It has been found in cotton seed, and at the 

 Columbian Exposition it was present in injurious 

 numbers in most of the cereal exhibits from the 

 tropics; also in cakes, jams, nuts, and seeds of 

 many kinds. The species is common through- 

 out the United States, particula^rly through the 

 South. 



The slender horned flour bettle {Echocerus 

 maxillosus) has habits similar to those of the 

 preceding species, and is frequently found in 

 the Southern States, where it lives on grain in 

 the field as well as upon the stored product. 

 It has also been found under the b.irk of trees. 

 This species is probably a naave of tropical 

 America, and although not positively known to 

 have established itself north of Southern Ohio, 

 is gradually extending northward. Species 

 resembles Tribolium, but is of a lighter color 

 and is somewhat smaller, measuring a trifle over 

 an eighth of an inch in length. On the head 

 between the eyes are two pointed tubercles, 

 and the mandibles in the male are armed with 

 a pair of slender, incurved horns. 



A solution of gum arable, to which has been 

 added a very slight quantity of corrosive sub- 

 limate, may be used for fastening small insects 

 to mica or paper triangles. 



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