BULLETIN OF THE ILLINOIS STATE LABORATORY OF Natural History. VOLUME III. Akticle I. — Notes on Some Illinois Microgasters: with De- scriptio7is of New Species. By Clarence M. Weed, M. Sc. [In working over the material by which the interesting group of Mierogasters is represented in the collections of the Laboratory, so much of interest was found that it was thought worth while to record at this time some of the more important facts. The writer desires to express his thanks to Prof. S. A. Forbes for permission to study the collections and use the notes, as well as for many other favors; to Dr. C. V. Riley, who has very kindly verified the determinations; and to Dr. A. S. Packard, Prof. H. Garman, and Mr. Chas. W. Woodworth for favors received.] MiCROPLiTis CERATOMi^, Riley. This species was bred by Dr. Riley from Ceratomia quad- ricornis^ in Missouri.* During the summer of 1885, from a larva of the sphinx just mentioned, confined in a breeding cage at Champaign, there emerged eighty-four of the Microplitis grubs, which spun parallel, leathery, ribbed cocoons upon the back of their host. The cocoons were formed in two longitud- inal series, one on each side of the dorso-median line of the larva, which were connected with a posterior transverse series. On the 25th of May, 1886, the adults began to emerge, and con- tinued to issue until June 5. They agree with Riley's descrip- tion (1. c), except that they are larger, the majority of them being 3 mm. long, and some even reaching 3.5 mra. The *Notes on North American Mierogasters, Trans. St. Louis Acad. Sci., Vol. IV., p. 303 [8]. 2 Illinois State Laboratory of Natural History. depth of coloring of the costa and stigma varies considerably in the same lot of specimens, in the majority of them being of the normal piceous, but in occasional specimens becoming lighter. From another lot of Ceratomia larvie, there were ob- tained August 1 of the same season, similar cocoons, the adults from which began to emerge August 12, and all had issued within a few days thereafter. Dr. Riley mentions (1. c.) hav- ing bred this large variety from inasses of cocoons spun regu- ularly side by side, as were our specimens, but having no rib« as ours have. MiCROPLITIS MAMESTR^, Sp. n. Under this name I describe a well-marked species bred from the larvae of Mamestra picta, at Normal, in 1884, In a breeding cage containing a large lot of Mamestra larvae there were noticed July 2, two specimens, each having a peculiar ribbed cocoon fastened transversely between the anal prolegs. These cocoons were isolated, and August 23 there had emerged from them the two Microplitis females here described. Cocoon.—5 mm. long, 2 mm. wide. Reddish brown, cylin- drical, with a pointed cap at each end, and about ten slightly oblique ribs running longitudinally. Tough and without loose threads. The cap forms a perfect circle, and in the specimens at hand one on each cocoon had been entirely separated by the insect before emerging. The corners are well developed, so that a longitudinal section, without the caps, would be of the form of a rectangular parallelogram. Described from two specimens found attached, singly, be- tween the anal prolegs of larvae of Mamestra pida, Harr. Imago, ?.—Length, 3 mm. Black; antennae, mandibles, and labrum, reddish brown; palpi, and legs, including whole of coxae, and more or less of the under side of abdomen, together with a portion of the margins of terga of first and second ab- dominal segments ferruginous; claws blackish. Wings hyaline; tegulae, with inner portions of costa and nervures, approaching ferruginous (being slightly more yellowish than legs), and outer portion testaceous. Inner half of stigma same color as inner portions of costa, nearly transparent; outer portions darker, clouded. Antennae not quite as long as body; joints 3-15, Some Illinois Microgasters. 3 slightly constricted at middle, the terminal joint appearing flattened when seen from above, and enlarged at the middle and tapering to a point when seen from the side. Mesonotum confluently punctured. Metanotum coarsely reticulated, the posterior margin of the metascutum being raised, and the metascutellum having a prominent longitudinal median carina. Abdomen shorter than thorax; basal segment vertical, the ter- gum finely reticulated, with a median groove extending from anterior margin two thirds of its length, and a slight tubercle on middle of posterior margin; tergum of second and following segments smooth and shining, with sparse pubescence. Radial vein arising from middle of stigma, nearly forming a right angle with basal nervure of the quadrate areolet; a white spot on cubital vein at base of areolet, and a7iother on the vein clos- ing the areolet exteriorly, just before its juncture with the cubital vein. Side of stigma bordering first cubital cell very slightly swollen; that bordering radial cell straight. Apical nervures slender, but easily seen. Described from two females bred from Mamestra 2>icta, Harr. This species is very distinct from M. ceratomke^ Riley, and is easily distinguished from M. gortynce, Riley, by its larger size, quadrate areolet, red posterior coxae, etc. Apanteles congeegatus. Say. A long series of this abundant and variable species is to be found in the Laboratory collections. Adult specimens' have been taken with the sweep-net at Normal, McLean County, July 1, 1882, and June 27, 1883; at Anna, Union County, September 13, 1883; and at Urbana, Champaign County, June 15, 1885. Some were also collected in woods near Pekin, Tazewell County, August 14, 1883, and still others were found among some col- lections made by beating the foliage of Ampelopsis quinqiiefo- lia at Urbana, May 23, 1885. Large numbers of specimens of this Apanteles have also been bred at various times from the larvae of our two common species of tomato-worms, — Phlegethontius Carolina^ and P. celeus. Cocoons obtained from the former species were received from Swanwick. 111., Sept. 1, 1884, and within five days 4 Illinois State Laboratory of Natural History. the flies had all emerged. Another lot was bred at Normal dur- ing the same season, the dates of emergence from the cocoons being almost the same as for those just mentioned. In 1879, another series whs bred from larvae of this sphinx in August. During August, 1882, and September, 1884, these parasites were also bred from P. celeus^ one lot being collected at Normal, and the other at Godfrey. The cocoons of all these specimens were of the usual white kind, with little loose silk. The variety of A. congregatus bred by Mr. Scudder front Pieris rapce., described by Dr. Packard* as Microgaster pieridis, and referred by Dr. Rileyf to the species mentioned (the variety name pieridivora being substituted for pieridis, because the latter was preoccupied), was frequently bred during the summer of 1886 from larvae of Pieris rapce, brought to the Laboratory because they showed signs of disease. Especial mention may be made of three lots of the parasites bred by Prof. Garman, the cocoons of one lot being of a lemon-yellow color; those of another being of about the same shade, excepting a slight green- ish tinge in some specimens; and those of the third being creamy white, with scarcely a trace of yellow. Yet there is no men- tionable difference in the adults of the different lots. There were, on an average, about thirty cocoons obtained from each Pieris larva. The Apanteles larvae of one set emerged from the skin of their host August 11, and came forth from the cocoons as adults August 29. Another lot formed cocoons September 2, and the adults were found dead in the breeding box September 22. On page 104 of the Twelfth Report of the State Entomo- logist of Illinois, Prof. Forbes has described an Apanteles bred from the larvae of Mesographe (Orohena) rimosalis, Guenee, under the name Apanteles orobenoe. A critical examination of a larger series of specimens than was then at hand, shows that this is but a variety of Apanteles congregatus, distinguished by the dark anterior and intermediate coxae and trochanters. In some specimens these parts of the front and middle legs are almost as light-colored as in the normal specimens from sphinx *Proc. Bost. See. Nat. Hist., Vol. XXI., p. 26. jAm. Nat., Yol. XVI., p. 680. Some Illinois Microgasters. 5 larvae. Hence these insects should be known as A. cottgregdtus, Say, var. orobence, Forbes. Apanteles militaris, Walsh. This well-known species, as would be expected from a knowledge of its habits, was found in especial abundance dur- ing the years when the army worm was destructive. In 1882 specimens were sent to the office by Mr. D. S. Harris, of Cuba, 111., with the statement that he had bred them from the army worm, which was then very abundant in that vicinity. Bur- ring the same season, this notorious pest was destructively abundant in certain portions of McLean County, but its opera- tions were rapidly checked by A. niilifaris, which is the species referred to by Prof. Forbes on page 102 of his First Report (the twelfth of the series). Describing the history of a brood of worms observed in a certain field, he writes: "When first no- ticed, on the 24th of June, these worms were doing serious damage to a heavy growth of timothy on high ground, march- ing from one side of the lawn to the other. By the 3d of July, the season for the transformation to pupse had been reached, but apparently not over twenty-five per cent, of the worms suc- ceeded in effecting the change, the remainder dying in such numbers that the ground was reeking with a sickening stench. At the same time clusters of the cocoons of one of the common parasites of the army worm were found everywhere abundant on the surface of the ground, and in some cases on the dried remains of the army worm itself. Of seventy-six pupa? of the worm, collected in this field at this time, but one reached maturity." From cocoons collected in this field July 2, the adult Apanteles continued to emerge until July 20. The only specimens bred in 1886 were from a mass of thirty-nine white cocoons loosely fastened togther, parallel to each other, found on a leaf of Indian corn in the field, August 2. The fliies emerged August 11. Apanteles ga.g(ecije, Riley. A single specimen (?) of this species was bred during May, 1886, from a larva of Teras minnia^ Robinson (inaUvorana, Le B.; Cinderella^ Riley). The cocoon was attached to a leaf. It is thin and white, 6 mm. long and about one third as wide. 6 Illinois State Laboratory of Natural History. Apanteles sakrothrip^, sp. n. On June 30, 1884, there was noticed in a breeding cage, at Normal, containing larvae of Sarrothripa lintneriana^ a dead larva in an imperfect cocoon, surrounded by cocoons of some hymenopterous parasite. A few days later there emerged from the latter six specimens of a well-marked Apanteles, for which I propose the above name. Unfortunately the cocoons were not saved, so that I am unable to describe them at this time.* Imago.—Length 2.5 mm. 5, ?. Black; palpi white; labrum and mandibles testaceous; antenuEB ferruginous; legs light red except posterior coxae, which are black. Wings hyaline; tegulae whitish; veins pale yellow except apical portion of costa which, with the stigma, is testaceous. Lateral membranous margins of terga of the three anterior segments, posterior portion of ter- gum of third segment, and sides and ventrum of abdomen, testaceous, lighter anteriorly. Dorsal portion of abdomen, ex- cept the two anterior terga, piceo- testaceous. Mesonotum shining, with distant, very shallow, punctures, many specimens having a slightly depressed area on the posterior portion of the mesoscutum, each side of the dorso- median line. Scutellum of nietathorax with punctures on its anterior portion, and finely reticulated posteriorly; without median carina. Tergum of first abdominal segment longer than wide, finely rugose, narrowing behind. Tergum of second segment also finely ru- gose, the wrinkles diverging obliquely from the anterior mar- gin: sides membranous. Terga of remaining segments smooth and shining. Ovipositor concealed. Radial vein arising slightly beyond the middle of the stigma. Described from six specimens (5 ?, 1 $) bred from a larva of Sarrothripa Untneriana. Much resembling A. congregatus and A. smerinthi, but easily distinguished from former by its shining mesonotum, and from latter by the rugose abdominal terga. Apanteles ornigis, sp. n. In the mines made by the larvas of the apple Ornix (0. geminatella, Pack. ) in apple leaves, at Normal, there were found March 21, 1886, many peculiar white, banded, cocoons of some hymenopterous parasite. Between April 27 and May 10 there Some Illinois Microgasters. 7 emerged specimens of a new species of Apanteles, for which the ahove name is proposed. When the cocoons were collected, the Apanteles larvae had not yet changed to pupse. This seems to be a common parasite of the Ornix named, as it was very abundant in the Normal nursery; and I have^ found it almost everywhere in the State where its host has been observed. Cocoon.—Length, 3 mm. Width, 1 mm. Oblong cy- lindrical; smooth, white, with a darker appearing central band about .5 mm. wide. The darker appearance of this band is caused, not by any difference in the color of the silk, but because the cocoon is there very much thinner than at the ends. To each end is attached a cord of fine silken threads, which are also fastened to the sides of the leaf-mine, thus suspending the cocoon after the manner of a hammock. Imago.—Length 2 to 2.5 mm. 3, ?. Black; palpi white; labrum and mandibles piceo-testaceous. Legs of female light red except base of posterior coxse, apical half of posterior tibiae, and posterior tarsi, which are dusky. First pair of legs of male light red, except coxas and apical joint, which are black- ish; second pair with more or less black on coxae, femora, and tibiae; posterior pair fuscous, with proximal portions of femora and tibiae lighter, and coxae black. Sides and ventral portions of anterior segments of the abdomen with more or less testa- ceous coloring, especially in the males. Wings hyaline; tegu- lae piceous; veins testaceous; stigma darker. Antennae pice- ous; slightly longer than the body. Scutum of mesothorax with rather distant shallow punctures, shining; scutellum also shining, with a few very shallow punctures. Scutellum of me- tathorax large, quadrate, reticulated, without median carina. Terga of first two abdominal segments and base of tergum of third segment finely reticulate; remainder smooth and shining. Tergum of basal segment narrowing posteriorly, with mem- branous testaceous borders. Ovipositor one third as long as abdomen. Radial vein arising beyond the middle of the stigma. Described from twelve specimens (8 5, 4 ?), bred from Ornix geminatella, Pack. 8 Illinois State Laboratory of Natural History. Apanteles crambi, sp. n. On the 13th of June, 1886, 1 found in a breeding cage con- taining larvEe of the root web worm, Crambus zeellus, Fernald, collected in the vicinity of Champaign, a Crambus cocoon con- taining a dead larva and several Microgaster cocoons. From the latter there emerged between June 19 and 22 several speci- mens of a well-marked species of Apanteles, for which the above name is proposed. Specimens exactly similar were bred during July from larvae of Crambus exsiccatus infesting lawns at Champaign. Doubtless this insect will aid materially in check- ing the ravages of these species of Crambus which are so dif- ficult to subdue by artificial means. Cocoon.—Length, 3 mm. White, thin, loosely fastened together within the cocoon of the host. Imago.—Length, 2 mm. 5, ?. Black; palpi white; man- dibles testaceous; ventrum of abdomen, together with the ter- gum of the third abdominal segment testaceous, lighter anteri- orly. Terga of segments posterior to third, piceo-testaceous. Legs light red, except claws of front and middle pair, and tips of femora, together with the tarsi of posterior pair, which are piceo-testaceous, and posterior coxge, which are black, tipped with red. Wings hyaline; tegulae and proximal portion of costa testaceous; stigma and apical portion of costa darker, nearly piceous; veins whitish. Antenna? piceous; those of female shorter than the body, of male slightly longer. Mesothorax closely punctured, shining. Scutellum of raeta- thorax reticulate. Terga of two first abdominal segments lon- gitudinally rugulose, remainder smooth and shining. Ovipositor concealed. Radius arises slightly beyond the middle of the stigma. Described from many specimens, bred from larva? of Cram- bus zeellus, Fernald, and C. exsiccatus^ Zeller.. ADDENDA AND ERRATA. To coiiiplete the list of species recogiii/.cil by St«•-)) 480 Illinois iState Laboratory of Natural History. Page 400, between lines IJ and 10 insert as follows: 1851. Cyphonia redispina. Walk. List Horn. B. M. 597, 6; line 19, for postfaciata read posffasciata. Page 401, line 4, for huhalus read diceros. Page 402, at bottom of page add as follows: 1891. Ceresa huhalus. Fletcher, Rep. Ent. and Bot. Can. 191. 1892. Ceresa huhalus. Osb. Trans. la. Hort. Soc. 119, fig. 30. 1893. Ceresa biihalus. Osb. Fruit and Forest Tree Ins. 24, fig. 80. Page 403, line 21, for the interrogation point substitute a period; between lines 2 and 3 from bottom insert as follows: 1892. Ceresa taurina. Osb, Trans. la. Hort. Soc. 119. 1893. Ceresa taurina. Osb. Fruit and Forest Tree Ins. 24. Page 409, between lines 4 and 5 from bottom insert as fol- lows: Stictocephala gillettei, $. Godg. Ent. News, iii, 200. Page 411, line 2, for nigripes, Stal, read numda, Walk.; be- tween lines 2 and 3 insert as follows : 1858. Parmula munda. Walk. List Hom. B. M. Suppl. 152; line 4, for Mex. {Stdl), read Mex. and Guatemala ( Walk.). Page 412, between lines 11 and 12 from bottom insert as follows : 1892. Thelia cratwgi. Osb. Trans. la. Hort. Soc. 119. 1893. Thelia cratcegi. Osb. Fruit and Forest Tree Ins. 24. Page 413, line 12 from bottom, and page 414, line 1, for acuminata read acuminatus. Page 414, line 11, for Hyphina read Hyphinoe. Page 416, line 8 from bottom, for Telamona read Mem- bracis. Page 417, line 1, for 1841 read 1851. Page 422, between lines 8 and 9 insert as follows : 1892. Telamona niexicana? Godg. Ent. News, iii, 108. Page 424, line 9, for toj) read tips. Described Memhracidce of North America. 481 Page 425, line 6, dele " fig." ; line 2 from bottom, for galata read gahata. Page 427, line 4 from bottom, ior Membracis read Acutalis. Page 429, line 15, after '' lower " insert edge. Pages 435 and 436. Note.— An examination of the types shows that numbers 122 to 126 belong to Cyrtolobus. Page 437. After the numbers 128, 129, and 130, for A. read E. * Page 441, line 17 from bottom, for V. read Ama&tris'\; line 4 from bottom, insert (?) before V. Page 442, between lines 8 and 9 insert as follows : 1851. Thelia exjjansa. Walk. List. Hom. B. M. 563, 26; between lines 14 and 15 from bottom, insert as follows: Thelia mar- morata. Walk. List. Hom. B. M. 555, 4. Page 444, line 15 from bottom, after "scar" insert as fol- lows: Apical cell much longer than in marmorata, the length ex- ceeding the breadth more than twice, while in marmorata the cell is but a little longer than broad; line 14 from bottom, after '' fuliginous" and '"yellow" substitute semicolons for commas; line 7 from bottom, after " process," add as follows: in not being suddenly depressed a short distance before apex, in not having the median carina flat from this depression, and in being much more depressed anteriorly. Page 445, line 8. Note.—Through the kindness of Rev. W. W. Fowler, of Lincoln, England, I have had the opportunity to examine St3,rs type of the genus Optilete, and, as surmised, it proves to be a typical marmorata, Say. Between lines 16 and 17 from bottom insert as follows: 1851. Hemij)tycha longicor- nis. Walk. List Hom. B. M. 569, 7. Page 449, line 10 from bottom. Note.— Walker's Darnis lineola belongs to Phacusa {Fide Fowler). Page 452, No. 181, for prunitia, Butler, read hastata, St4l (A*c?e Fowler). * Ashmeadea being preoccupied, the name was changed to Ev- ashmeadea. t A more careful study of the species places it in Amaatris.