Circular No. 102. United States Department of urc, AU OF ENTOM WAfcl). KiitomologUt in: v^r vi; vi. i h i . ii. < in i n INTRODUCTORY ettlers \ -|>:l! :lL r ll> WBS i III l< M I Hit. 1 lllto tlll> < « H 1 1 1 1 I" \ \\ 1 1 from Euroj)e, and is credited with having been cultivated here for two hundred years before being troubled with insects. Several species of native American insects have been observed to feed upon this plant, but none, so far as we know, has become sufficiently attached to it to cause se- rious injur}'. I-Vw of our edible plant-, in short, down t.i the time of the civil war have enjoyed such immunity from the ravages of insects. In the ( )lil World two in- sects, called asparagus bee- tles, have been known as enemies of the asparagus since early times. In the \ ear 1862 one of these insects, the common asparagus beetle L.) was the occasion of considerable alarm on asparagus farms in Queens County. N. Y.. where it threatened to destroy this, one of the most valuable crops grown on Long Island. Subsequent Fio. 1 Spraj ol asparagus, with comm. I>nr:. . mpara Up at right, m.I Injury. ID). ier account* of these Insects have been published i» earlier yeai follows: Yearbook fj. 8, Dept. Agric. f. 1896 (1897), pp. 841 382; Bui. 10, Dir. Knt.. IT. s. Dept. Agrlc, pp. 54 69, 1898; Bui. 88, Pt I. Bur. Bat-, U. 8. Airri... pp. .". 1". ; (42 Car. 102 OS inquiry developed the fact thai the species had begun its destructive work at Astoria, near New York City, in I860, where, it is now conceded, it was introduced about 1856." In 1881 another European importation was detected on asparagus near Baltimore, Md. — the twelve-spotted asparagus beetle (CriocerU duodecimpunctata L.), sometimes called the "red'* asparagus beetle to distinguish it from the "blue" species. THE COMMON ASPARAGUS BEETLE. (Crioceris asparagi I., i From the seat of it- introduction at Astoria. X. Y.. the common asparagus beetle soon spread to the asparagus farms of Queens County. X. V.. and by 1S<'»2 was reported to have occasioned the lo- ot' over a third of the crops in certain localities, the loss being estimated at $50,000. Injury is due to the Avork of both adults and g-gf^ larva' upon the tender shoots, which they render P^VQP '' A P| unfit for market early in the season. Later they I^Rn . J destroy by defoliation the high-grown plants. ^m |( particularly seedlings, the roots of which are W U M J weakened by having their tops devoured. The larva? are sometimes so abundant that the black molasses-like fluid which they emit from their mouth- soils the hands of those engaged in bunch- ing the -talks for market : anil the ('ISil> are some- time- laid upon the stalks in such number- that the latter are rendered unsightly and even slip- pery by their presence. Larva', as well as beetle-. attack the tenderest portions of the plants, but the beetles gnaw with seemingly equal relish the epidermis, or rind, of the stem-. The beetle- are also accused of gnawing young shoots beneath the surface, causing them to become woody and crooked in growth. In some localities it is in establishing new beds that the greatest trouble and expense are incurred. The plants must grow a year as seedlings and two more in the beds before being cut for table use, and during these three year- they are constantly exposed to the attack- of this insect. The beetle is a beautiful creature, slender and graceful in form, blue-black in color, with red thorax, and with lemon-yellow and Fig. 2. — Common as- paragus beetle I Cri- oceris asparagi i : ". Dark form of bee- tle : b, light form. Enlarged (author's illustration). The rapture of this species was recorded early in the past century in Penn- sylvania — presumably near Hanover — and again in the vicinity of Chicago and Rock Island. III., about ten years after the discovery on Long Island: but. as the insect diil not obtain a permanent foothold, but died out in these localities, these importations can not be considered introductions. [Cir. 102] dark-blue wing covers having :i reddish border. A c mon form aboul the District of Columbia is illustrated in fig. •"•. a. Farther north the prevailing form i- darker, the lighter coloring 3ometimee showing onh as a reddish border and six small submarginal yellow spots (fig. 2, \.n extreme, light form nol uncommon in the south (in range "i the insect is shown (fig. 2, 6) for comparison. The length i- ;i trifle less than one fourth inch. ii rsTom "i bpri u>. From tin- -rciic of its firsl colonization in Queens County, the insecl migrated to the other truck growing portions of Long [sland. 1 1 -i ><»ii reached southern Connecticut, and has no^ extended it - range northward through that State and Massachusetts to the State line of N ■• Hampshire, Southward ii has traveled through NeM Jersey, where ii was firsl noticed in l s, ''S. eastern Pennsylvania, Delaware, and Maryland to southern Virginia and North Carolina. It- distribution by natural means has been mainly by the flight of the beetles. Undoubtedly, also, the beetles have been transported from place to place by water, both up and down stream by rising and falling tide, as the fact that it has nol until recently deviated far from the immediate neighborhood of the seacoasl and of large water courses near the coast bears abundant testimony. Another reason for the prevalence of this species in these localities i- that asparagus was originally a maritime plant and has escaped from cultivation and grown most luxuriantly in the vicinity of bodies of water. It is well known thai it i- usually upon wild plant- that these insects first make their appearance in new localities. There is evidence also that their disseminat i < > 1 1 may be effected by what I >octor Howard has termed a "commercial jump," either by commerce in propagating root-, among which the insects may be present either as hibernating beetles or as pupa', or by the accidental carriage of the hectic- i>n railmad train- or boats. B) some such artificial mean- the asparagus beetle had round its way to northwestern New York, between Koine and Buffalo, and to Ohio, between Cleveland and the Pennsylvania State line. During 1896 it- course was trace. I along the Hudson River above Albany. [nquiry concerning the Ohi icurrence disclosed the fad that the plant- in one locality were brought from New York. The presence of this insecl in eastern Massachusetts at about the same time was in like manner probably due to direct shipments of root- from infested localities to Boston and vicinity. It i- noticeable that up to this time it- inland spread, except in the neighborhood of water, had been extremely limited. [Or. 102] DISTRIB1 llnN IN L908. This species is presenl now in what is known as the Upper Austral life zone, although in certain point- in New England it has Located in what is considered the Transition zone. Its course up the Hudson River lies within a rather narrow strip of Upper Austral. In all probability it is destined in time to overspread the entire Upper Austral zone and to make its way to some extent into neighboring areas in which it may find conditions for its continuance. Its distribution in Massachusetts, though wide, is local. In New Hampshire it has been recorded from Nashua and Portsmouth. It is possible that in a few years it may be able to encroach slightly upon the bordering States of Vermont, in the vicinity of the Connecticut River Valley, and Maine, near the New Hampshire seaboard. It is well established in Connecticut, occurs in Rhode Island, and is gen- erally distributed through New Jersey. Delaware, and Maryland, and in southeastern Pennsylvania near the Delaware River. It was predicted by the writer that, although this species in 189G was still local in New York and Ohio, we might expect within a few years to hear of its invading other portions of those States lying within the Upper Austral zone: Canada, of which there is a strip of Upper Austral bordering the northern shore of Lake Erie: and. later, Indiana, Illinois, Kentucky, and States farther west. By l!S!)7 the species had occupied the strip bordering the southern shore of Lake Erie, being recorded from nine counties of eastern Ohio. The following year it was noticed in western Virginia. In 1898 it was reported from Benton Harbor. Mich., where, however, it had been present since 1896. By 1899 it had appeared in Canada in the Niagara River region and was accompanied by the twelve-spotted species. The insect obviously received more or Less severe setbacks in succeeding years, but by 1904 the common form was observed about Toronto, Canada, and about 4 miles west of Chicago. 111. It has now become very generally distributed in the asparagus-growing sec- tions of New York State, having reached Glens Falls, its northern- most recorded limit in the United States. In Ohio the species has been established near Columbus since l ( .Hi:'>. and near Cincinnati since 1905. but has not been reported from Kentucky or Indiana, although it has probably invaded the latter State. In 1904 the occurrence of this insect at Bouldin Island. California, was reported, but the following year it could not be found. Its dis- appearance was attributed to the fact that the island had been flooded. causing the death of the pest. In 1906, however, the beetle was reported in abundance near Oakley. Cal. In North Carolina the species is well established in the east-central part, including portions of "Wake. Wayne. Warsaw, and Duplin coun- [Cir. 102] ties. The species has also been reported in Wisconsin, bul nothing has I'irii learned regarding ii- actual distribution in thai State. ii m'.i rs \ \i> i ii i ii i-ii >m . The common asparagus beetle passes the winter in the adull state under convenient shelter, such as piles of rubbish, sticks, or stones, or under the loose bark of trees and fence posts. Toward the end of April or in May, according i" locality, al about the season for immon as] newly batched i; •. pupa. All enlarged (author's Illustration). cutting til*- asparagus for market, the beetles issue from their hiber- nating quarters and lay the eggs for the firsl brood. The egg is very large in proportion to the beetle, being nearly a sixteenth of an inch in length, and of the elongate-oval form illus- trated ;ii b i fig. 3). 1 1 is nearly three times as long ;i- wide and of a dark-brown color. The eggs are deposited endwise upon the stem or foliage and in early spring on the developing (stalks, usually in rows of •_' to 7 or more i fig. t ). In from three to eight day- the eggs hatch, the young larva?, commonly called "grubs" or u worms," presenting the appearance indicated in fig. 3, - . The head of the newly hatched larva is large, black, and bead-like; its body is gray; and its three pair- of legs, Marl,. Ii al once be- gins to feed, and is from ten day- to a fortnight, according to Fitch and others, in attaining full size. When full grown the larva appears as in fig. 3, d. Ii is soft and fleshy, much wrinkled, and of a dark grav or olive color, some! imes light, • Km not infrequently very dark. The head is shining black, as are also the six legs. Each segment is proi ided with a pair of foot-like tuber- cles, which, with the anal proleg, assist it in crawling and in clinging to th«' plant. The mature larva enter- the earth, ami here, within a little rounded, dirt -covered COCOOn which it form-, the pupa -tate i- Li'ir. 102] - -• rial). assumed. The pupa is yellowish in color, and its appearance is suffi- ciently shown by the illustration (fig. '■'>. e). In five to eight or more days the adult beetle is produced, which in due time issues from the ground. THE LIFE CYCLE. Of the duration of the life cycle Fitch has remarked that it is about thirty days from the time the egg is laid until the insect grows to maturity and comes out in its perfect form, but that the time will be shorter in the hottest part of the season than in the cooler days of May and June. These periods are for Long Island. During a hot spell in midsummer the minimum period of ovulation and of the pupa stage was observed at Washington, D. C. Eggs that were laid on the 5th of A.UgUSt hatched on the 8th, or in three days. A larva transformed to pupa on August 4 and to adult August 9. or in five days. Allowing ten days as the minimum credited period of the larval stage, a day or two for the larva to enter the ground and form its cocoon, and two or three days more for the beetle to mature and leave the earth, the insect i- again ready to attack it- food plant and to continue the reproduction of its kind in about three weeks from the time that the egg is laid. This may be fairly taken to represent the minimum midsummer life-cycle period of the species in the District of Columbia and south- ward. In the colder climate of Xew England, ami elsewhere in spring and autumn weather, the development from cg larva' and assist very materially in preventing its increase. One of the most efficient of these is the spotted ladybird, Megitta n>(ti lead, learning that nol re than ■•" per cent of tin' insects were killed when Paris green and lime were used, while 90 per cent were killed with arsenate of lead. In a third experiment, in winch resin — « »: » | » \\:i- added to make the latter in cide adhere more » l< >-•• 1 \ ti> the plants, all of the insects were killed <»ii 50 plant- treated. In tin- case the arsenate <>!' lead was used at the rate of 1 pound to _l gallons of water, ami 2j pounds of resin soap was added t" render the mixture more adhesive. In the North, where these experiments were made, they were begun the first <>f June. Arsenate of lead has been used with satisfactory results "ii asparagus at the rate of l pound in IC gallons of water, Inn some additional experiments arc necessary i<> ascertain the exact amount of the poison thai can In- used economically to produce the required result. In ordinary weather a second spraying of arsenate of lead with a resin soap added i- desirable, especially if rainfall intervenes. Moic specific information in regard to the method of preparing and applying arsenate of lead i- given in Circular No. s ~. winch maj be obtained gratis on application. Everything considered, injury by tin- species is most noticeable when the beetles are working on the asparagus tips at the time they ate being cut for f 1 or market, a- more fully described on paj It i-. of course, impossible t<> apply arsenicals to the edible product owing to the danger of poisoning human beings. About all that can he done ai this time i- to cut a- frequently a- possible, but after the cutting season is over the arsenicals may be freely used in accordance with the direction- already given. The brushing method. A simple ami inexpensive method of kill- ing the larva' in hot weather i- to heat or brush them from the plants with a -tick so that they will drop to the hare ground.. The larvae are delicate creature-, and. a- they crawl \er\ -lowly. |V\\ arc able to regain shelter of the plants, bul die when exposed to the heated earth. The same method is in use against the pea aphis. THE TWELVE-SPOTTED ASPARAGUS BEETLE. [Crioceris duodceim punctata L.) A rarer, and consequently less injurious species than the pre- ceding i- the twelve-spotted asparagus hectic. It i- generally dis- tributed in Europe, where it i- apparently native and. although common, not especially destructive. Like the preceding, it lives ex- clusively on asparagus, and the chief damage it doe- i- due to the [Cir. 102] 10 depredations of the hibernated beetles in early spring upon the young and edible asparagus shoots. Later generations attack the foliage, living, for at least a considerable portion of the larval stage, within the ripening berries. • INTRODl CTION AM) SPREAD IN THE UNITED STATES. The presence of this bisect in America, as lias been stated, was first discovered in 1881. and in the vicinity of Baltimore, Md. This beetle was noticed in considerable numbers from the first, showing that it had probably been introduced several years earlier. At that time it was quite local, occurring- only at the mouth of the Furnace Branch of the Patapsco River at a point a few miles south of Balti- more. It was then seen only on volunteer asparagus growing on the salty margin of this river, although beds of cultivated asparagus were plentiful in the immediate vicinity. Two years later it had proved even more troublesome than the common asparagus beetle. Assuming Baltimore to have been the original center of distribu- tion, the twelve-spotted asparagus beetle has been traced southward through Anne Arundel and Prince George counties to the District of Columbia, where it was detected live years from the time of it- first discovery. In 1892 it was reported to have appeared in considerable numbers on asparagus stalk- that had been cut down upon a farm in Carroll County. Md. The same year its appearance was announced in Glou- cester County, in southern New Jersey, and the following year in Cumberland and Camden counties of the same State. To have reached these points the insect, obviously, had traversed the inter- vening territory in Maryland, the northern half of Delaware, and Salem County. X. J. It was also found to have reached Virginia, near Washington. In 189-1 it had extended northward to Burlington County. X. J., and westward to Philadelphia County, in Pennsyl- vania. The same year it was detected in Queen Anne County. Md.. and near Rochester, X. Y. Two years later it established it -elf in Charles County. Md.. and had penetrated as far south in Virginia a- Westmoreland County. In May. 1896, a serious invasion was reported in Prince George County. Md.. where the beetles attacked the young shoots, gnawing ell the heads as soon as they showed above ground, thus entirely unfit- ting the crop for market. Nearly every year since, it has been reported in new localities in the United States and Canada until now it is well distributed westward and northward. In 1898 it had become generally distributed in New •Jersey " south of the shale from the Atlantic coast to the Delaware." Next year it was recorded in twelve counties in New York as far west [Clr. 102] II .i- Buffalo and in the following years generally throng] t N'\\ York State, as also in the Niagara district in Canada. An interesting fact in the occurrence of the asparagus beetles in the ira peninsula was that the two species arrived almost simulta- neously and that the twelve-spotted form was the dominant one. By 1902 the latter had ap peared in Connecticut, ii Ni'u I ln\ en, ami later in oilier port inn- uf i hat State, \ rill / h ^ 4 hi S< RIP] ION . 1 .11 I lll<- roai . wi> ii \ ui rs. The mature beetle ri- vals the common species in beauty, Init iiki\ be distinguished by it- much broader elytra and i''< 8 rweive-spotti 1 ,| ,. |.'. .1 tluodt larva orange -red color. ■ in of larva d ond o, ''. Knl. i Author's illu-i- vring cover is marked with six black dots, and the knees and a portion of iln 1 under surface of the thorax are also marked with black (fig. 6, a). The beetle, as ii occurs on the plant when in fruit, very closely resembles at a little distance the ripening asparagus berry. The common asparagus beetle, as is well known, dodges around a stem like a squirrel when disturbed, but the twelve- spotted form appears to trust to ili:_ r lit. taking wing more readily. Both species make a loud creaking sound when handled, by what is called stridulation, produced in the present species by rubbing the tip of the abdomen against the elytra. The full-grown larva i- shown at b (fig. 6). It measures, when extended, three-tenths of an inch i s nun. i. being of aboul the same proportions as the larva of the common species, but is readily separable by it- orange color. The ground color is lii_ r ht yellowish cream with an overlap of ochra- ceous orange which is most pronounced on the ex- terior portion- of the abdominal segments. The head, with the exception of the mouth-part's, is also ochraceous, the thoracic plate is prominent, divided into two parts, and is of a dark-brown color. Enlarged figures of the second abdominal seg- ment of both species are presented at < and d (fig. 6) for comparison. [Cir. 102] I'll - .. 7 mpunctaia. Egg, on as ignt leavi risiit : same, en- - .1. at loft. iAu- - - Illustration, i 12 In Europe, where this species is native, it is common, but not especially destructive* The chief damage is from the work of the hibernated beetles in early spring upon the young and edible asparagus shoots. Later beetles as well as larvae appear to feed exclusively on the berries. The eggs are deposited singly, and apparently by preference, upon old plants, toward the end- of shoots, which, lower down, bear ripen- ing berries, and they are attached along their sides I fig. 7), instead of at one end as with the common species. Soon after the larva hatches it finds its way to an asparagus berry, enters it. ami feeds upon the pulp. In due time it leaves this first berry for another one. and when full growth is attained it deserts its last larval habitation and enter- the earth, where it transforms to pupa and afterwards to the beetle. The life cycle does not differ materially from that of the common species, and there is probably the same number of genera- tions developed, or nearly as many. REMEDIES. The remedies are those indicated for the common asparagus beetle, with the possible exception of caustic lime and