UNIVERSITY OF CALIFORNIA. AGRICULTURAL aP£fiMNT STATION. BULLETIN NO. *«• Tbe Hessian Fly and Resistant Grains. The Hessian fly {Cecidomyia destructor) ap- peared in the grain growing on the Experi- mental Grounds of the University of California in the spring of 1885. The visitation was so serious that it vitiated a number of experiments which were under way to ascertain the compar- ative values of different methods of culture and the application of different fertilizers. At the same time it was noticed that the work of the pest was much more destructive on some varie- ties of wheat than others, and it was decided to make the best possible use of the infested fields by a careful experiment in the season of 1886 to ascertain if any varieties could be found to be practically resistant. The experiment, owing to the peculiar character of the season, was conducted in such a way as to give the fullest advantage to the insect and the greatest disadvantage to the grain. The plots were sown late (February 25) and no doubt some of the varieties experimented with were ruined which would have only been partially destroy- ed had they been earlier sown and thus have eached a more advanced condition when the fly appeared. It is, however, quite as well, perhaps, because it made the test very severe, and the more useful, since, in the counties most atttioted by this pest, it is very often necessary to sow grain late because of the danger of water* billing during heavy winters. Seed was taken from the collection whioh has been secured with muoh care from different grain-growing countries of the world. There were in all 170 plots sown, with upward of 100 varieties of wheat, 25 barleys, 35 oats and the balanoe ryes. The grain was sown in drills, was well cultivated and given every chance to make a good growth. The soil is the upland idobe, somewhat ameliorated by application of ime and other fertilisers during previous years. Careful notes were taken of the behavior of each variety, and frequent examinations made to ssoertain the presence of the tly both in the Larval and tbe ** flaxseed " stages. A full so count of these observations will be given in the report of the College of Agriculture, for 1886, whioh will be issued during the coming winter. At this time it is merely in- tended to present the results of the ex peri* ment in condensed form. Of the 100 varieties of wheat sown, about 25 were destroyed. The plant was so weakened that no effort was made to throw out heads, and the stems were found to harbor in some cases as many as 30 larva* and " flaxseeds/' About 35 other varieties made a little better struggle and bore a few heads of grain, although in all oases the stems were found to be infested. About 20 varieties bore a fair crop of grain, although in all oates there were insects found on the stems; sometimes but few, and they in the upper joints (as high as the fourth); and in others quite a number were found. Of the I whole collection there were but »ix varieties in which no larva nor pupa of the fly were found, and they were as follows: 1. Bearded wheat from Missojtu. 2. Pales tine. 3. Peteli. 4. Volo. 5. Greek wheat from Atlanti. 6. Forelle. These wheats all have solid stems, the straw being filled with pith. They all belong to the hard wheat type {Tritkum durum), having rather long pointed grains, almost translucent, md a horny consistency, owing to their rich- ness In gluten — though when grown in this State they rapidly ohange in this respeot and become starchy. These wheats are chiefly grown in the countries bordering upon the Med* iterranean aud the Blaok ses. They do not succeed in the north of Europe* nor are they of muoh aooount even in the middle of France, They are, however, quite hardy and productive in California, and with the ohange in their char- acter noted above, promise to be of considerable value. Besides the experiment in whioh the large grain collection was used, as described above, there were larger areas sown on January 8th, with those varieties whioh had been observed as resisting the fly during the experiments of 1885, with the following result: Variety. Rate of yield per acre. Volo 31X bush. Bearded Missojeu 39K M Greek Atlanti 9K M The seed of the last variety, Greek At- lanti, was very old, being taken from the museum specimen, and it was therefore slow in germination, weak in growth, and deficient in yield. It showed, however, its immunity from the, fly as none oould be dis- covered by repeated examination. Now that fresh seed has been secured, it may be expect- ed to yield as well as the others named above, whioh it olosely resembles. These three wheati are of Greek origin, Samples of the grain were tubmitted to experts in milling and ship- ping wheats and pronoun oed good, merchantable wheat, and salable in the market at about 2J cents per oental less than No, 1 shipping wheat. As they are naturally of strong growth and productive, it is expected that they will be found valuable in those localities where other varieties are rendered unprofitable because of the Hessian fly, and there will be small lots of the seed furnished by the College of Agricul- ture to those who desire to experiment with them in fields known to be infested with the fly. Their success both when sown on Janu- ary 8th and on February 25th shows that their immunity from the fly was in some peculiarity of their own and not in the time of sow- ing. The soil on which they were grown during the experiment here is quite poor and intractable, and better yields may be expected in more favorable situations. It is a matter of some importance to deter- mine whether a time for sowing oan be selected so as to successfully circumvent the fly. Iu our own experiments it appears that Pringle-s Defiance wheat sown on January 8th made a good growth, and bore at the rate of lij bush* els per acre although attacked by the fly, while the tame variety sown February 25th was praotioallv a failure. The same was true of Nepaul barley, whioh, sown January 8th, yielded at the rate of 20 bushels to the acre, while that sown on February 25th was destroy- ed. On some lands now infested by Hessian fly it is impracticable to sow grain until the heavy water of winter has disappeared from the soil, and it is, therefore, of more importance to have a variety whioh will succeed at any time of sowing than to have a safe time of sow- ing determined upon, whioh will oome when the land is seldom in condition to receive the We expect during the coming season to re* peat some parts, at least, of our experiments, to determine the fly resisting ability of different wheat varieties, and also to secure testimony from our correspondents who will conduct ex- periments in other distriots infested by the flv. We have a deoided advantage in this work in California, because we oan grow wheats from all latitudes sa . The barleys grown beside the wheats seemed muoh less vulnerable to the attacks of the fly, Of the 25 varieties sown, about 20 bore from fair to good orops, although in most oases the larvae and pupv of the fly were found on the sterna— sometimes few, sometimes many. Some escaped the fly entirely: the Guymalaya, a dark naked grain; the Manohurian, a small white train: the Four rowed black and the bix-rowed Elaok had no traces of the fly. The Large Naked Two-rowed had a few flaxseeds in the upper nodes. On the other hand, other varie- ties were nearly destroyed. Full details will be given in the forthcoming report The ryes were generally a failure in this year's sowings-in some oatet traceable to the fl^ but generally the result of other unfavor- aoie conditions. There was no trace of the ny found in the oats. During the last spring and summer many samples of grain supposed to be infested with the He«sian fly were received from wheat- growers in different parts of the State, extend - ing as far south as Tulare and Ventura counties. In every case the pest was found to be the grain louse or aphis (aphis aven**) % a muoh less serious enemy than the Hessian fly. A distinction be- tween these pests can be coarsely made in this way : The Hessian fly does not appear oongre- gated in great numbers upon the growing grain. When it Is abundant it may be seen, especially in the morning and evening, hovering over the wheat fields in vast numbers. The fly merely descends upon the plant to deposit its eggs. It is exoeedingly small, its whole length being but about one-tenth of an inoh. On the other hand, the grain aphis is found oolleoted in vast numbers on the grain, generally near the base of the stem, some individuals having wings, but the greater number wingless. The Hessian fly always has wings except in the larval state, when it is a white, semi -translucent maggot, rather spindle-shaped and about one-sixth of an inoh in length. Under its transparent skin may be seen greenish stripes extending around the body. This maggot changes when mature into a bright ohestnut color. When in this state it muoh resembles a flaxseed, and the rec- ognition of these "flaxseeds" wedged in be- tween the leaf and the stem, near the joints, it demonstration that the grain is infested with the Hessian fly. There are other whitish maggots infesting the stems of grain, but they do not assume a likeness to a flaxseed. The Hessian fly has but recently been dem- onstrated to have secured a lodgment in Cali- fornia, and its ravages have thus far been con- fined to valleys adjaoent to the San Francisco bay and its tributaries. It is a question how far its area ma> extend, but it Is highly doubt- ful if it oan thrive in the dry and hot interior valleys. It has been claimed that the praotioe of burning off the stubble is to be credited with the long freedom of California from the pest. Such praotioe is oertsinly to be oommended as at least likely to reduce the infllotion. In badly-infested localities this will not, however accomplish the dislodgment of the inseot, and it may be that the growing of resistant varieties will be of great advantage, Berkeky t Oct, ,9, 138$. E. J. Wiokson.