242 flDtolano Counties Section. LIST OF OFFICERS. (1907.) Chairman: J. M, Lores. Vice-Chairman: W. R. Witsoy. Committee: T. Aksbll. W. H. Evass. Adbiak J. Bbown, M.Sc, F.I.C., H. L. Hind. F.C.8. R. L. Siau. W. W. Botxbb, F.C.S., F.R.M.S. F. L. Talbot. J. A. Evans. Hon. Treasurer: W. L. Hodokinson. Hon. Secretary: Abchibald S. Bbnnbtt, Liverpool Chambers, Cherry Street, Birmingham. MEETING HELD AT THE GRAND HOTEL, BIRMINGHAM, ON THURSDAY, DECEMBER 13th, 1906. Mr. J. M. Lones in the Chair. The following paper was read and discussed :— Some Insects Injurious to Barley and other Grain when in Store. By Walter E. Comjnge, M.Sc., F.E.S., Foreign Member of the Association of Economic Entomologists, Washington, U.S.A., and Special Lecturer on Economic Zoology in the University of Birmingham. Stored grain, and particularly barley, when attacked by insects is generally said to be " weevilled," and although two species of weevil do considerable damage to grain when in store, there are upwards of 30 other insects in this country which are the cause of serious damage and loss. Miss Ormerod (11/A Report of Observations of Injurious Insects, 1888, p. 75) records some observations from a correspondent who states, " in SOME INSECTS INJURIOUS TO BAULKY AND OTHER GUAIN. 243 the winter of 1884—85 wo lost between £1,000 and £2,000 on a single cargo of Russian wheat" by C'alandra gramria. Kirby and Spence also make frequent reference to individual losses, as do other writers. It may bo pointed out in passing that the number of species and of individuals which are found in stored grain in this country have for some years been steadily increasing, this is partly due, no doubt, to the apathy of certain millowners, maltsters, and others who will not take proper preventive and remedial measures, and also to the higher and more equal temperature maintained in modorn mills. Some account, therefore, of the life-histories of the commoner species met with, the problems encountered in endeavouring to reduce the loss they occasion, and the means now employed for exterminating, wherever possible, may not be without interest. List of Insects Destructive to Grain, etc., when in Store. Atropos divinuloria, Fabr The Grain Louse. Tenebriodes maxiritaniciis, L The Cadelle. Silvanus surinamictis, L The Saw-toothed Grain Beetle. Minus fur, L The Brown Grain Beetle. Niplus holokucus, Fald. Niplus crenatus, Fabr. Mezium affine, Boield. Gibbium scotias, Fabr. Tenebrio molitor, L The Yellow Meal-worm. Tenebrio obscurus, L The Dark Meal-worm. Alphiiobius diaperinus, Panz. Alphitobius piceus, 01. Gnafhocerus cornulus, Fabr The Broad-horned Flour Beetle. Gnalhocerus maxillosus, Fabr The Slender-horned Flour Beetle. Tribolium feirugineum, Fabr Tho Rust Red Flour Beetle. Tribolium confusum, Duv The Confused Flour Beetle. Palorus meiinus, Herbst. Lathdiais oryzce, Wat. Calandra (Silopkilus) granaria, L. The Grain Weevil. Calandra(Sitophilm) oryzm, L. ... The Rice Weevil. Plodia interpundella, Hbn The Indian Meal Moth. Epheslia kuehniclla, Zell Tho Mediterranean Flour Moth. Pyralis farinalis, L The Meal Moth. SUrotroga ccrealella, 01 The Angoumois Grain Moth. Tinea granella,L The Wolf Moth. 244 COLLINGE: SOME INSECTS INJURIOUS TO Atropos divinatoria, Fabr.—The Grain Louse. This insect is a small, wingless, louse-like creature, with well- developed mouth organs, and an omnivorous feeder. During the past fow years it has been forwarded to me in samples of malt, which literally swarmed with these minuto insects. Generally speaking, it seldom occurs in this country in sufficient numbers to constitute a pest. It is common in most houses, feeding on the starchy piste used by paperhangers and that used by bookbinders. Tenehriodes maurttaniais, L.—The Caddie. The name Cadellc was given lo the larva of this insect many years ago by the French, it was originally described, however, in 1758. It stands by itself amongst grain-feeding insects in that both the larva and beetle attack and destroy any othor grain insects they may meet with. For a long time it was claimed that this beetle was carnivorous, but later observations have shown that it is both herbivorous and pre- daceous. There is only one brood in the year. Kirkup (Trans. Entom. Soc., 1812, 1, 329) records that- one found in a Spanish almond lived in the larval stage for 15 months, and remained alive as a beetle for a year and nine months. They are omnivorous feeders, in the larval condition passing from grain to grain, upon all of which they feed. The larva is a soft, fleshy, almost white grub, with short, scattered hairs, and the head dark brown, and there are two dark patches on the first three segments. Those in the first segment being most con spicuous. Tho last segment terminates in two dark, horny points. The pupa is almost white. The adult beetle is nearly black in colour and about a third of an inch in length. Silvanus sunnumicus, L.—The Saw-toothed Grain Beetle. A widely-distributed species, and common wherever grain is stored. Generally speaking, there are four broods in a year, but as in warm climates the whole life-cycle is completed in about 24 days, there may be as many as six or seven. In colder regions tho life-cycle occupies from six to ten weeks. The larva is somowhat flattonod, almost white, with slighter, darker BAULEY AND 0T1IEK CHAIN WHEN IN STOKE. 245 markings on each HOgmont. It has throo well-dovelopcd pairs of legs mid an abdominal prolcg, and is very active. When full fed it forms a covering consisting of small grains, etc., which it joins together by a sticky secretion, within this tho pupa is formed. The adult is about one-tenth of an inch in length, flattened, and of a chocolato-brown colour. Tho thorax is marked by two shallow, longitudinal grooves on the dorsal side, lateral to which are six saw-like teeth on each side. Minus fin; L.—Tho Brown Grain Beetle. This species haa frequently been recorded as damaging stored grain, although it is a general foedor upon decaying animal and vegetable matter. Xijrtus hololeucus, Fald. Like the preceding species, this and X. crenatus, Fabr., are general feeders. Both have frequently been forwarded to mo damaging seeds. Aiplus crcnatus, Fabr. This is another beetle often found in old granaries. Although feeding mainly on wood, to which it does great damage, it has been clearly proved that it feeds on flour, which it damages to a large extent. Mezium ajjine, Boield. Gilibium seolias, Fabr. Occasionally found in grain. Tenebrio moliior, L.—The Yellow Meal-worm. This and the next species, and their larvae, the latter commonly termed " meal-worms," are amongst the largest of the beetles attacking grain. The eggs are white and bean-shaped and about one-twentieth of an inch in length. They are deposited in flour, meal, and bran, particularly in bins. The larva looks not unlike a wire-worm; it is long, slender, and cylindrical, and about 1 inch in length. It is yellow in colour, becoming darker towards each joint, and there are two small anal spines. Tho pupa is pale ochreous. Tho adult beetle is a pitchy black above, ferruginous beneath, and a little over one-half of an inch 246 collinge: some insects injurious to in length. The eggs hatch in about 14 days. The lame appear in May and feed voraciously. They attain approximate growth in about three months and continue to feed until the following spring, when they change into pupae, in which condition they remain for about 14 days. There is a single brood only. The beetles are nocturnal in habit and strong fliers. Tcnebrio obsairus, L.—The Dark Meal-worm. Very similar in form and habits to the preceding species. The larva, is pale brown and unlike T. moliloi; which prefers damp or damaged flour, meal, etc., this species exhibits a decided preference for dry, sound flour. Alphitobius diaperintts, Panz. Alphitdbhts piceus, 01. Two very small beetles which have probably been introduced into this country with grain. Gnalhoccrus cormdus, Fabr.—The Broad-horned Flour Beetle. Gnulhocems maxillosius, Fabr.—The Slender-horned Flour Beetle. In prepared grain these two beetles are both very common. Trihciium fcrrugineum, Fabr.—The Rust Red Flour Beetle. Tribolium confusum, Duv.—The Confused Flour Beetle. Next to the weevils these two insects are perhaps the most injurious we have to stored grain. They prefer prepared cereals, such as flour, oatmeal, malt, nuts, beans, peas, and almost any seeds. They are very similar in form and habits. The eggs, which are small white bodies, are attached to the sides of, or in cracks in, bins, barrels, etc. The larvae hatch out in from 6— 12 days and remain as such for from 24—36 days, they then change- to naked pupae and 6—12 days later the mature insects appear. In a high temperature, the life-cycle has been completed in 36 days and I have frequently seen it gone through in 56 days. There arc usually four broods in a year. Palorus melinus, Herbst. Latheticus oryza?, Wat. Two very small beetles, measuring about 2i mm. in length. They occur in rice, flour, etc. BARLEY AND OTHER GRAIN WHEN IN STORE. 247 Calandra (Sitophilus) grunaria, L.—The Grain Weevil. This is, perhaps, the commonest of grain bootlos, and it is annually becoming more and more troublesome. It is a very prolific species and, given suitable conditions, a single pair will produce many thousands of descendants in a year. The female deposits her eggs one in each grain, first puncturing the grain with the long, snout-like proboscis. Most recent authors state that tho grain is punctured by the proboscis of the female, who then deposits an egg and seals up the puncture.