'■%*> s / v . U.S. DEPARTMENT OF AGRICULTURE, BDREAU OF ENTOMOLOGY— CIRCULAR No. 149. L. O. HOWARD. Entomologi.1 ind Chirt of Bureau. THE COTTON STAINER. W. I). HUNTER, Til ' ' F ligations. • A.swiNGTON : OOVERNXCT PRIMING OFFICE : 1»1J B UREA U OF ENTOMOLOG Y. L. 0. Howard, Entomologist and Chief of Bureau. C. L. Marlatt, Entomologist and Acting Chief in Absence of Chief. R. S. Clifton, Executive Assistant. W. F. Tastet, Chief Clerk. F. H. Chittenden, in charge of truck crop and stored product insect investigations. A. D. Hopkins, in charge of forest insect investigations. W. D. Hunter, in charge of southern field crop insect investigations. F. M. Webster, in charge of cereal and forage insect investigations. A. L. Quaintance, in charge of deciduous fruit insect investigations. E. F. Phillips, in charge of bee culture. D. M. Rogers, in charge of preventing spread of moths, field work. Rolla P. Currie, in charge of editorial work. Mabel Colcord, in charge of library. Southern Field Crop Insect Investigations. W. D. Hunter, in charge. F. C. Bishopp, A. H. Jennings, H. P. Wood, W. V. King, engaged in tick life-history investigations. W. D. Pierce, G. D. Smith, J. D. Mitchell, Harry Pinkus. 15. R. Coad, R. W. Moreland, engaged in cotton-boll weevil investigations. A. C. Morgan, G. A. Runner, S. E. Crumb, D. C. Parman, engaged in tobacco insect investigations. T. E. Holloway, J. L. Webb, E. R. Barber, engaged in sugar cane and rice insect investigations. E. A. McGregor, W. A. Thomas, engaged in red spider and other cotton insect investi- gations. R A. Cooley, D. L. Van Dine, A. F. Conradi, C. C. Krumbhaar, collaborators. Circular No. 149. United States Department of Agriculture, BUREAU OF ENTOMOLOGY. L. O. HOWARD. Kntomologist »nd Chief of Bureau. THE COTTON STAINER, /< itdercut tuturelhu II -Si b By W. D. 11 1 mi i;, In < f Southern Field Crop Insect Investigations. i\ I EtODUOTION. The cotton stainer (Dysdercus suiureUua H.-Schf.) ia tin- only representative in the United States of a lar^e group of species which includes the mosl important enemies of cotton in tropical countries. Km. 1. — The cotton stainer (Dfiitrtut sututdlu*) a, Nymph, oi s. nymph, ■BOOB I ' mph, thir I Prom \i There are 28 species of the genus known in the Americas. The form which occur-- in the United State- is not of very great impor- tance, on account of it- local restriction, but in Florida it i- un- doubtedly the mosl important cotton inseci that exists at prc-ciit. It has been known a- an enemy to cotton in that State for many years, hut has never shown any tendency to spread to other regions. i THE COTTOX STAINEB. DISTKimTIOX. The cotton stainer of the United States is known only from Florida. Georgia, and portions of South Carolina and Alabama. Except in Florida it occurs in small numbers. Outside of the United States this insect is known from the upper West Indian Islands, namely, Bahamas, Cuba, and Porto Rico. There is a doubtful record of its occurrence in Brazil. The evidence available at this time seems to show rather conclusively, however, that it does not extend south of Porto Rico. In the lower islands of the West Indies it is replaced by other specie-. DESCRIPTION. The following description of the adult insect is taken from an account by Dr. L. O. Howard. 1 "The adult bug varies in length from 10 mm. to 15 mm. (0.4 to 0.6 inch). The hinder portion of the thorax and of the wing-covers varies from dark brown to black, the latter being crossed with narrow lines of light yellow, as shown in Figure 52, b [fig. 2, b]. The head and forepart of the thorax are red, varying from light to dark. The underside of the body is bright red, with the segments outlined by narrow light-yellow bands. The antenna? are black, as are also all tibia? and tarsi; the femora or thighs are red. The beak is red. except the last joint which is black. All of these colorational mark- ings vary considerably in intensity." The eggs are oval, light yellow in color, and when magnified show a finely reticulated surface. They are deposited loosely in the sand or earth or upon the food plants. Each female depo>it- about 100 eggs. The immature stages of this insect (fig. 1) resemble the adidt in form and coloration, although the general color of the body is some- what more reddish. FOOD PLAXTS. The cotton stainer has a number of food plants. The only ones of any special importance aside from cotton are the orange and the eggplant. The damage to cotton far surpasses that to the other plants. In the case of the orange the habit of the insect is to attack the fruit at about the time it is ripening. This is evidently a tem- porary habit, probably induced by the general scarcity of the normal food plants at the time the oranges are ripening. The injury to eggplants was recorded in 1896 by Prof. A. L. Quaintance, but does not seem to have been considerable. Among the wild plants upon which this insect feeds are Hibis- cus sp., as well as several others including guava, Spanish cocklebur • Insect Life, vol. 1, pp! 237-238, 18S9. PHE COTTON STAIN i i;. ,'j (f'rriifi lobata), and nightshade {Solarium nigrum). Observations made in the vicinity of Orlando, Fla., bj Dr. \ w Morrill, indicate thai the Spanish cocklebur i- probabh the most importanl of these plants. l> \\i IG1 Prom observations made in the Bahamas in 1878, Mi. E. A. Schwarz concluded thai this Bpecies is an enemy of cotton of very greal importance in those islands. In Florida the damage is scat- tered and naturally difficult to estimate. In one instance, pointed <>ut by Dr. Morrill, the complete destruction of 25 acres of long-staple cotton was attributed to this insect. Generally . however, the injury dot'-, doI extend further than tin- staining of a portion of the crop Pro. a n (Fr produced on the plantation. A case referred to by Dr. Morrill' is undoubtedly typical. In this instance at Hawthorn, Fla., in 1902, about 1,000 bales of long-staple cotton were ginned at a certain establishment. ( hit of this number 200 bales were classed as stained. Staining reduces the value of the cotton in varying degrees, running from 50 per cent in - ases down to 5 or 10 per cent. It has generally been supposed thai the staining of the fiber was due to tlic excremenl of the insect, bul Dr. Morrill's observations in Florida seem to indicate that this is nol the true explanation, From studies in the fields and experiments in rearing cages he came to the conclusion thai the staining of the lint is the resull of the attack of the insects upon immature bolls, and especially on the seed - ! siir. Em., I 4 THE COTTON STAINER. at about the time of the opening of the bolls. The brownish color appears to arise from the injured seed. At any rate the examination of considerable seed cotton showed practically invariably that the stain was most dense immediately surrounding the seed. Another reason for the conclusion at which Dr. Morrill arrived was that the amount of staining found was generally entirely too great to be accounted for by the excrement of the insect, although there is no doubt that a portion of this stain is due to that cause. 1 REPRESSION. One habit of the insect makes it amenable to simple control meas- ures. This is its tendency to develop in close colonies restricted for a long time to one or at most to a very few plants. At such times the red color of the bugs makes them conspicuous objects. When they are found, it is an easy matter to destroy them by jarring them into buckets containing a little water and a few drops of kerosene. This will be found perfectly satisfactory and an economical method of control. In special cases the purchase of spraying machinery and the application of kerosene emulsion may be justified. By practicing the destruction of the colonies scrupulously through the season practically all can be destroyed before they have an opportunity to injure cultivated plants. As has been noted, the weed known as Spanish cocklebur should be watched especially. Of course the planter will realize that preventing the growing of this useless plant and others that support the bug will have the effect of an insurance against injury to his crops. At certain seasons, especially in the fall and early spring, the cotton stainer can be attracted to baits. Cottonseed or sugar cane are very suitable for this purpose, more especially the former. If small heaps of cottonseed are placed in the cotton fields or in their imme- diate vicinity, it will be found that they soon become densely cov- ered by the stainers. At such times they may easily be destroyed by the use of hot water or kerosene. Mr. P. L. Guppy has published an account (C'ir. Xo. 6, Board of Agriculture of Trinidad and Tobago, Dec. 17, 1911) of experiments in using baits formed of seed cotton for attracting the stainers. Small balls of seed cotton were hung on the cotton plants. These balls consisted of a large handful of seed cotton wrapped with twine. It was found that large numbers of the stainers were attracted to these balls. At intervals of several days the balls were carefully removed from the plants and shaken over receptacles containing oil. It is i Recently Mr. P. L. Gappy (Cir. No. G, Board of Agriculture of Trinidad and Tobago, p. 131, Dec. 17, 1911) verified Dr. Morrill's finding as to the origin of the slain. Hestates: " The damage is done before the bolls open by the insect piercing the walls in order to obtain the Juices and the cell sap exudes through the punctures thus made to the cotton lint which is being formed inside the boll." This statement refers to Dysdcrcus howardi Ballon. I 1 1 1 i t > I 1 1 ' \ .- I \ I M I ; . f> very doubtful whether this method will be found of practical use in the United States, bul i( Beems worth} of trial. \\ e maj summarize the feasible means of control in their order "I importance as follows: l. The prevention of the growth of the weeds upon which the cotton stainei breeds in great numbers. _'. The destruction, by means of kerosene and water, of the cole- Dies of young bugs as Boon as thej make their appearance during (he gnw ing season. 3. The attracting of the insects to Bmall piles of cotton seed and their destruction when congregated in large numbers by means of hot w ater or kerosene. Apl>m\ ed : .1 \M ES W li. >< >V St cretary of AgrieuUun . \\ isaaxortox, 1>. ( ., January 18, 191B. ADDITION A I. COPIES of this j.iiMlcatlon ■ may be procured from the Sitf.rintf.xi>- k\i OF DixiiiKNT.f, (io\. nimrtit I'rintln.: Office, Washington, D. C. ,at J Mats pn copy UNIVERSITY OF FLORIDA linn ii ii ii 3 1262 09216 5819