133 

 NOTE ON FLOUR AND GRAIN BEETLES. 



\V. HAGUfi HARRIXGTON. 



(Bead lOlh FebrUay-y, 1887.) 



Among the m^e6ts wliich prove nnwelcoine visitors or (Jweflers xw 

 our lioiises are species of beet'es wliicli are almost universiilly distri- 

 buted over the world, and wbich cause, sometimes, immense toss 

 through their attacks on stored grain, or on its products. It is not mv 

 intention this evening to give any extended history of these obnoxious 

 insects, but merely to mention tho prtn ipil ones wliich occur h re, and 

 to call attention to the longevity of one spscies. The gru') which is so 

 frequently found in flour and meal is the larva of Tenebrio molitor, a 

 beetle belontjing to the Tenebrionidsx?, several membei-s of wluch occur 

 m, or abotit, houses, and aie known as " black beetles." The insect, 

 in its several stag6s, ig more abundant about bakeries, mills and flour 

 ware-loni5es, than! ih ordinary dwellings, and is also destructive on 

 .shipb'oard. The grhb is cylindrical in sliape and about an inch long, 

 barro\Ving and living in the floor. The beetle is of a blackish-brown 

 colonV, of mbfer;ito siz ^, flying abuhdafifcly at nJ^hfc, and coming in St 

 open windows. The grain beetles ai-e very much smaller and belong to 

 the Ualandrid.Te, a family of the Rhyncophora or "snout beetles." They 

 especially frequent granaries and flour mills, and in the former some- 

 times work great damage. Two species occur here, viz.: Colandra einj^oi 

 and C. granaria, but not so far as I am aware in Sufficient abundance 

 to be very destructive, as they are in more southerly portions of the 

 continent. The life history of these weevils is briefly as follows : The 

 females bores with her long beak a minute hole in a grain of wherat, 

 barley or rit;e, kc, in which sho deposits an egg, from which hatche's a 

 little stout footless grub, or maggot, which burrows into the grain, 

 feeding until fully grown on its substance, and thfein undergoiitg its trans- 

 formations in the cmjjty fchell, which is all that remains when it comes 

 forth as thfe perfect beetle. The mature insects, or beetles, also feed 

 upoh the grain, but do hot so rapidly consume it. As yon arfe aware, 

 the duration of the life of the majOiity of insects is v^i-y brief, 

 ^sp'eci^lly after they h.ive reached the imajgo, or perfect state. Laf-va; 

 mky live for several months, or evien ytiais, ijut their final ti-Ansfor- 

 mations undergone they letiter a brief exist'ehce, mesiiiHred by Xveeks, 

 days, Or even hours. 



Certain species, however, such as some bees and wasps live fur 

 almost a yeir, while some ants are said to live for several years. The 

 S[)ecimens of Calandra granaria which I exhibit this evening are, when 

 the average longevity of insects is considered, genuine patriarchs; their 

 days have been long in the land. They were given to me on 4th July, 

 ISST), by Mr. Litchford, who found a great number of them in a flour 



