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BULLETIN OF THE

Southern California Academy of Sciences

LOS ANGELES, CALIFORNIA

Vol. 55

January-April, 1956

PartI

CONTENTS

Pseudoscorpions, A Natural Control of Siphonaptera in

Neotoma Nests. Jens W. Knudsen 1

Four New Predaceous Mites. Philip Garman and E. A. McGregor 7 A Remarkable New Rhagovelia From the Dominican Republic.

C. /. Drake and J. Maldonado-Capriles 14

A New Cantacaderid From Brasil. Carl J. Drake and F. Plaumann.. 17 Notes on Metamorphoses of tlie Giant Skippers ( Megathyminae )

and the Life History of an Arizona Species.

John Adams Comstock 19

A New Species of Stegocephalus (Amphipoda) From California.

D. E. Hurley 28

Two Rare Ampliipods From California With Notes on the Genus

Atylus. /. Laurens Barnard 35

A New Species of AmnicoUd Snail From Chihuahua, Mexico.

Robert J. Drake 44

Fish Records From the Pleistocene of Southern California.

George P. Kanakoff 47

Laurena Moore Alliot 50

Scientific Notes 51

Academy Proceedings „. 54

Issued May 8, 1956

KB

Southern California Academy of Sciences

OFFICERS AND DIRECTORS

Mr. Kenneth E. Stager PreaidetU

Dr. Hildegarde Howard Sirst Vice-President

Dr. Fred S. TruiaL Second Vice-President

Miss Gretchen Sibley Secretary

Mr, Lloyd M. Martin Assistant to Secretary

Dr. W. Dwight Pierce Treasurer

Dr. John A. Comstock Editor

Dr. A. Weir Bell Miss Gretchen Sibley

Dr. John A. Comstock Miss Ruth D. Simpson

Dr. Theodore Downs Mr. Kenneth E. Stager

Dr. Hildegarde Howard Dr. Fred S. Truxal

Dr. W. Dwight Pierce Dr. Louis C. Wheeler Dr. Sherwin F. Wood

ADVISORY BOARD Mr. J. Stanley Brode Dr. Carroll L. Lang

Dr. Thomas Clements Mr. Lloyd M. Martin

Dt. Howard R. Hill Mr. Theodore Payne

Dr. Homer P. King Dr. R. H. Swift

Miss Bonnie Templeton

SCIENCE SECTIONS Section of Agricultural Sciences Section of Earth Sciences

Mr. Lloyd M. Martin, Chairman Dr. William H. Easton, Chairman

Anthropological Section Section of Health and Sanitation

Miss Ruth D. Simpson, Chairman Dr. Irving Rehman, Chairman

Botanical Section Section of Junior Scientists

Dr. Lyman Benson, Chairman Miss Bess Reed Peacock, Chairman

Section of Conservation Section of Physical Sciences

Dr. Sherwin F. Wood, Chairman Dr. Julius Sumner Miller, Chairmen

Section of Zoological Sciences Dr. William V. Mayer, Chairman

STANDING COMMITTEES

Finance Publication

Dr. W. Dwight Pierce, Chairman Dr. John A. Comstock, Chaimuin

Mr. Allen Steuart, Auditor Dr. A. W. Bell

Dr. John A. Comstock Dr. William H. Easton

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Membership Dr. William V. Mayer

Library Mrs. Lloyd M. Martin, Chairman

OFFICE OF THE ACADEMY Los Angeles County Museum, Exposition Park, Los Angeles 7, California

Program

Mr. Kenneth E. Stager, Chairman Hospitality

Mr. Donald Drake

Bulletin, Southern California Academy of Sciences

Volume 55 - - - - - - Part 1, 1956

PSEUDOSCORPIONS, A NATURAL CONTROL OF SIPHONAPTERA IN NEOTOMA NESTS*

Bij Jens W. Knudsen

Reasearch Fellow, Allan Hancock Foundation, University of Southern California

INTRODUCTION AND ACKNOWLEDGMENT

With the exception of Alphonsus' ( 1922 ) brief and unfinished work with pseudoscorpions in beehives, an investigation of pseu- doscorpion feeding habits with respect to possible economic vakie has not been made. Upon finding large numbers of pseudo- scorpions in Neotoma nests (Neotoina, Citellus, and Cijnomys are the important plague reservoirs in the United States, Eskey, 1940) the writer conducted research from June 1953, to Feb. 1954, to determine ( 1 ) if pseudoscorpions feed on plague fleas, thus controlling them, (2) the extent of the control, and (3) the per cent of Neotoma nests with pseudoscorpions, as well as (4) the range within which pseudoscorpions occur in rodent nests.

At this time the writer wishes to express his thanks to Dr. Clayton C. Hoff of the University of New Mexico for identifying the pseudoscorpions concerned in this problem.

Field observations. Wood rats are shown to be abundant in the south-west United States (Burt and Grossenheider 1952). A census taken in Lopez Canyon, which revealed a total of 151 wood rat nests along three-tenths of a mile of canyon road, gives an idea as to the possible magnitude of the Neotoma populations for this area. The wood rat, Neotoma fuscipes Baird, builds its nest in the low foothill regions, generally near an old creek bed where the vegetation offers a maximum of food and protection.

'Allan Hancock Foundation Contribution No. 174.

lUi.iiiiN. So. C'aiii. .\< \lll\l^ oi Scii-NCKs \'()1. 55. I'.iil I, h)5()

Tlic lints lire hir^c .stnic'ttircs iilkIc oI sticks ;iul hark ami arc* tliK'c t(i 1(1111 Irct lii^li. I'^acli linl liis iiian\ tiiiiiicls ai)(l rooms whifh contain stored food, a toilet area, leediiiu; eliamher, and nest Clips in which aehdt lleas. dexclopinti; lar\al fleas, and i)sen- doscorpions ; re loinid. I'Oi (ield chita nest cnps with snrronnding and nnderKiiiu material were collected in one-<j;aIIon hottles, processed in lleilesc hmncis, ;ni(l llie Sipiii )naplera and psendo- scorpions counted.

Rsondoscorpions were fonnd to occnr in Ncotoina nests from ()re<2;on to Baja (-'ahfornia. eastward to Texas, and sonthward to Sonora, Mexico. Of L53 Ni'olonui nests collected in the San Ga- hriel M( i iilains, Lns .'Xn^eles (bounty, .sevent)-()iie per cent con- tained psendoscorj^ions (mostly Dinoclicirus sicaritis ]. ('. (Jham- herlin and a possihle new s):)ecies of Hcspcrochcrnes) ranging from one to lort\-fonr per lint.

Dnriiig the snninici- months an a\erage of eight(X'n adnlt fleas {A)ioiniops\iUus luuhi/n.s (Haker), AnomiopmUiis faLsicdlifornictis C. Fox, Di(i)ii(iiins iiKniUnins (Baker), Hoplopmllus anotnalus (Baker), and Orchojxd.s s. scxdcntafiis Baker, in order of great- est ahnndance) was fonnd in nests without pseudoscorpions while nests with psendoscorpions a\'eraged twelve fleas, a re- duction of one-third. A ratio of five adult fleas to three pseudo- scorpions was also found. Favorable temperatures and humidi- ties allow great increases in the flea population during the winter and spring months in Southern California (over 1400 fleas were found on a single occasion); however, the pseudoscorpion pop- ulation within the rat nests also shows a marked increase at these times.

Feeding test observations. The examination of flea and pseudoscorpion populations in nature, though significant to this study, was not an accurate measurement of the pseudoscorpion's feeding habits. It was necessary, therefore, to determine by feeding tests what items of food would be eaten by the pseudo- scorpion, to measure its preference, if any, and to obtain some idea of the volume of food it would eat at a given time. For these experiments hundreds of pseudoscorpions were isolated in separate one-and-one-half dram, cotton-stoppered vials, and fed selected items of food. One feeding test consisted of one three- hour feeding period for one pseudoscoqjion with recorded obser- \ations every five minutes for one-half hour, and then everv ten minutes for two and one-half hours.

Of one hundred pseudoscorpions offered adult fleas, eighty- eight were observed to feed; in contrast to this ninety-four of one hundred pseudoscoipions fed when they were offered flea larvae; and again ninety of one hundred pseudoscorpions fed on mites offered to them. Pseudoscorpions also fed upon Collem-

Bulletin, So. Calif. Academy of Sciences

Vol. 55, Part 1, 1956

PLATE 1

A pseudoscorpion starting to feed upon an adult flea during a feeding experiment.

bola, beetle larvae, and small spiders but displayed little prefer- ence for these. When one hundred pseudoscorpions were offered adult and larval fleas simultaneously, sixty-six per cent chose larval fleas and thirty-four per cent chose adults. When offered adult fleas and mites simultaneously sixty-nine per cent chose the fleas and thirty-one per cent chose mites. In preference tests where larval fleas and mites were offered to the pseudoscorpions simultaneously, seventy per cent chose flea larvae while only thirty per cent chose mites. Compiled data of all preference tests show that 45.3 per cent of all pseudoscorpions chose larval fleas, 34.3 per cent chose adult fleas, and only 20.3 per cent chose mites.

Ten pseudoscorpions were fed continuously until they would no longer take any food. Fifty-three flea larvae were consumed by the ten in a matter of three-and-one-haff hours. During an- other experiment twenty-four adult fleas were eaten by five pseudoscorpions. The results demonstrate that an average of about five adult or larval fleas can be eaten at one feeding time by a single pseudoscorpion. After twenty-four hours these same pseudoscorpions fed in only a languorous manner, indicating that they were not in any great need of food.

lUiii UN. So, (Iaiii. .\( \i)i \n oi Scikncks

Vol. 55, I'.irt 1, l!)r>()

PLATE 2

A \oung pseudoscorpiun luis captured a flc-a lar\ a prior to feeding. The larva is coiled around the pseudoscorpiun' s chelae.

Since pseudoscorpions feed by sucking body fluids from their prey it is the opinion of the writer that the preference displayed by them is based on the quantity of body fluids of one food type as compared to another. There is a direct correlation between the amount of body fluid of the food items and the preference displayed. The sizes of the mites, fleas, and flea larvae were as closeh' alike as possible to make these tests fair. The walking speed of the mite or flea as compared to the flea larva was a hindrance to the individual in that it walked into or around the pseudoscorpion more frequently than did the slower forms. In spite of speed or slowness the pseudoscorpion displayed prefer- ence in that it picked up and set aside, numerous times, any food item that it did not prefer until a suitable type was located, at which time feeding was begun. All other known forms of possible error or chance reaction were ruled out by the high number of feeding tests conducted.

Bulletin, So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

Controlled hut observations. The controlled rat nests, de- signed to simulate natural nests, were used in the laboratory to check the results obtained in the field; in this way a strict con- trol of the number of insects and pseudoscorpions was possible. The nests were constructed in large, flea-proofed battery jars that were furnished with straw and stocked with set numbers of fleas, pseudoscorpions, mites, Collembola, Thysanura, and other insects, and maintained for thirty-eight days, which gave ample time for the completion of an adult-to-adult life cycle of the flea. Fourteen controlled huts were set up, of which ten were carried to completion, the other four being eliminated when neighborhood boys released the wood rats. Results were based on the number of adult fleas present at the time of termi- nation of the controlled experiments. At termination, huts con- taining pseudoscorpions averaged 19.4 fleas while huts without pseudoscorpions averaged 34.7 fleas. This reduction of fleas is roughly one third and closely matches the reduction found in nature.

Other observations. During the months of May and Sep- tember it was common to find that the wood rat had removed its current nest cups, either intact or in part, and discarded them near the hut. It is possible that flea larvae may also be removed with the nest and left exposed to the killing rays of the sun.

Discussion. Locally pseudoscorpions were demonstrated in seventy-one per cent of the Neotoma nests, and were found to occur in rodent nests from Oregon to Baja California, eastward to Texas, and southward to Sonora, Mexico, which, according to the U. S. Public Health survey (Eskey) of 1935 is the same critical desert region in which the wood rat serves as the most important reservoir of syl vatic plague.

It was demonstrated that pseudoscoi-pions will and do eat adult and larval fleas as well as mites and other arthropods, and that they display a strong preference for the larvae, due perhaps to the higher body fluid content of this stage. The reduction of the flea population in nature by roughly one-third in the nests containing pseudoscorpions, as compared to nests without pseu- doscorpions, would tend to substantiate this. Little doubt was left that pseudoscorpions do control Siphonaptera when test huts in the laboratory also demonstrated a one-third reduction as compared to control huts without pseudoscorpions. It is not the belief of the investigator that pseudoscorpions enter the nests for the sole purpose of obtaining Siphonaptera, but rather to obtain food in general. Once in the Neotoma nest pseudoscor- pions are in a situation where it is possible for them to elminate tremendous numbers of Siphonaptera. Thus the pseudoscorpion may be considered important as a natural control for fleas and

lUiitiiN Sci (Mil \c Mil \n (II S( II \( |.s \'()l. 55, I'art I, IU5{)

tluT('!)N .1 loiilrolliiisz; laitni ol the s\l\;itic i)la,mu'. The iiilorma- (ioii hroiiiihl out in tin's in\ cstiuat ion in ^tMioral gives a greater nndcislandinu ol the s\ Katie plague problem, and when all data au' eonsidered. i'\idenec warrants tlic iccounition ol the ]rsen(l()- scoqiion as a lorni ol natnral eontro! ol tlie plagiif Ilea in ScotoiiKi nests.

sr\i\i \i;v

1. Tsendoseorpions are present in wood rat nests from Oregon to Baja Clalifonna. and eastward to Texas and Sonora, Mexico. In this range the wood lat is the important plagne reservoir animal.

2. Psendoscorpions iire jiresent in o\er seventy per cent of the Ncotonui nests in niiinhrrs ranging from one to forty-fonr.

3. There is a reduction in the flea population ol about one- third in nests with psendoscorpions as compared to nests without them. The nuniber of H(>as is in\'ersel\' ]')roportional to the num- ber of pseudoscoipions.

4. Pseudoscoqiions enter the Ncotoina nests to ol)tain all forms of food, and not solely for Siphonaptera.

5. Feeding experiments proved that psendoscorpions will eat adult and lar\'al fleas as well as other anthropods, and that they prefer flea lanae to other forms of food.

6. The controlled hut experiments demonstrated a one-third re- duction of the flea population identical witli that found in nature.

7. Such domestic habits of the wood rat as nest rebuilding may be a minor controlling factor.

8. Pseudoscoqjions in the Neotoina nests are reducing the flea population which in turn retards plague transmission.

9. Evidence warrants the recognition of psendoscorpions as a form of natural control of plague fleas in Neotoma nests.

LITERATURE CITED Alfonsus, A.

1922. "An Enemy of the Mites in the Bee Hive," Bee World, 4:2-3. Burt, W. H., and Grossenlieider, R. P.

1952. "A field guide to the Mammals," Houghton Mifflin Company, Boston. Eskey, C. R., and Haas, V. H.

1940. "Tlague in the Western Part of the United States," U. S. Puhlir lleolth Bulletin Nn. 245. Hubbard, Clarence Andresen

1947. Flea.s of Western Nortit America, Iowa State College Press, Ames, Iowa. Knudsen, Jens W.

1954. Psendoscorpions, a Natural Control of Siphonaptera in Neotoma Xests, Uni\'ersity of Southern California Library, Masters Thesis, Zoolog\'.

6

Bulletin, So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

FOUR NEW PREDACEOUS MITES (ACARINA, PHYTOSEIIDAE)

By Philip Gaeman and E. A. McGregor

In a study by McGregor of the mites found to occur on citrus in southern Cahfornia, four species received special attention by Garman in the matter of identification. Accordingly the present paper has been prepared to appear in advance of the principal publication, so that established species names may be had for reference.

These phytoseiid mites are predaceous, and many of them are important enemies of the phytophagous tetranychid mites, or "spider mites," and hence are of economic importance.

Garmania lewisi new species Plate 3, figs. 1, 2, 3.

Male.— Dorsal setae in number and arrangement that of Garmania hulhicola (Oudemans), as figured by Nesbitt for the female, but the length of these setae is distinctly longer in the present species. The outline of the stemi-genital scutum is rather ill-defined in our species, but it has 5 pairs of setae and 4 anglu- lations each side. The posterior boundary of the genital poition of this scutum is somewhat indistinct. The anal plate is expan- sive, occupying most of the area behind coxae IV; it is sub- cordate in outline, and distinctly sculptured; it bears 14 longish setae, 3 transverse rows of 4 each, and one each side marginally opposite anterior face of anus; one pair of setae on anus. An- terior appendages of hypostome with each external mala basally bearing internally two somewhat separated spines. The median hypostomal structure, between the malae, bearing laterally along its midregion a fringe of fine setae. Anterior pair of ventral hypostomal setae not stronger than others. Hypostomal teeth either lacking or extremely minute.

Hl'l.l.KTIN, So. Cm II . \i \l>l Nn OF SCIENCES

Vol. 55, Part 1, 1956

PLATE 3

Garmania letcisi n. sp.: fig. 1, ventral view of hypo.stome; fig. 2, sternal- genital plate and co.xal bases; fig. 3, posterior venter and associated setae.

HoLOTYPE MALE.— No. 8-21-54. on orange, Irvine, Calif., Aug. 16, 1954, collected by H. Lewis. Deposited in the collection of the Los Angeles County Museum. Also on slide 9-8-54, on orange, Ir\'ine, Calif., Aug. 24, 1954, collected by Lewis.

Typhlodromus citri new species Plate 4, figs. 1, 2, 3, 4, 5, 6

Female.— Resembling T. compicuus (Carman), but differing in several particulars, as confirmed by E. W. Baker. With 8 pairs of marginal setae on dorsal shied, mostly short; seta M-2 and L-8 the longest; seta M-2 not paired with any other seta, nearly equidistant from D-5 and L-8. An interscutal seta laterad of seta

Bulletin, So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

PLATE 4

Typhlodromus citri n. sp.: fig. 1, dorsum showing setal details; fig. 2, peritremal plate; fig. 3, setae on base of tarsus IV; fig. 4, sternal plate; fig. 5, genital and metapodal plates; fig. 6, ventrianal plate.

L-4, and one well behind L-6. Sternal scutum roughly rectangu- lar, with 2 pairs of setae, and with humeral angles prominently pointed. Two pairs of metapodal plates, each with a seta. Genital plate thimble-shaped, gently convex behind, with a pair of setae. Anal plate sagittate, broadest anteriorly, somewhat wider than genital scutum, with 4 pairs of pre-anal setae; a fine pore behind each second inner seta. Peritreme reaching anteriorly to seta D-1, recurved posteriorly like the head and neck of a bird. Tarsus IV with a rather long seta.

lUiiiiiN. So Cm II. \( Ai)iM\ OK Sciences \()I. 55. V.ni I, 1956

PLATE 5

Amhlyseius limonicus n. sp.; fig. 1, dorsum showing setal details; fig. 2, palpus; fig. 3, tritostemum; fig. 4, posterior venter, showing ventrianal scutum and associated setae and parapodal plates; fig. 5, sternal scutum and metapodal plates; fig. 6, hypostome.

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Bulletin^ So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

HoLOTYE FEMALE No. 4-18-52, On lemon, N. Whittier Heights, Calif., April 18, 1952, collected by F. Mimger. Deposited in the collection of the Los Angeles County Museum. Also No. 9-27-53, on lemon, Whittier, Calif., Sept. 27, 1953, collected by Munger; also No. 54-2-1, on lemon, Camarillo, Calif., Dec. 17, 1953, col- lected by H. Lewis- and No. 4-23-54, lemon, N. Whittier Heights, Calif., May 1953, collected by F. Munger.

Amblyseius limonicus new species

Plate 5, figs. 1, 2, 3, 4, 5, 6.

Female. Dorsum with lateral setae 1, 4 and 9 longer than others, though not as long as in other members of the genus. Dorsals very minute, two small scapulars; pores as in figure 1. Integument smooth. Chelicerae with 7 to 9 teeth on fixed arm. Palpi each with a spatulate seta on the inside of segment 3. Epi- stome of usual form— the cornicles slender, somewhat approxi- mate. Leg IV with longer setae on genual, tibia and first tarsal segment. Anal plate (fig. 4) expanded anteriorly, with forward setae grouped somewhat as in T. finlandiciis, but the spacing be- tween the setae more unequal and the middle pair nearer the anterior margin. Two lunate pores as in fig. 4. Sternal plate with two setae each side and an almost circular metapodal plate be- hind caudo-lateral angle on each side. Parapodal plates consist- ing of a slender, almost needle-like pair each side, the smaller about 1/5 as long as the larger. Peritreme plate blunt at posterior end, but not as squarely truncate as in some members of the genus. Tracheae each side extending forward to coxa I or almost in line with seta D\ Genital armatiu'e semicircular in appearance, with lines radiating from the anterior margin.

Male not available.

Female, Measurements. Length .198-. 240 mm., width .135 mm., leg IV .255-.285 mm., seta L" .048-.056 mm.

Habitat. Found on orange and lemon, California, presum- ably feeding on Tetranychidae. Santa Ana, Sept. 20, 1940, Mc- Burnie Coll.; Carpinteria, Nov. 11, 1954, Lewis Coll.; Goleta, Oct. 4, 1953, Hall Coll.; Chula Vista, Aug. 5, 1935, Jones Coll.

HoLOTYPE Santa Ana slide; Carman Lot 40-21386. Deposited in the Connecticut Agricultural Experiment Station collection. Also a slide, McGregor Lot 11-9-54.

Notes. The anal plate of this species strongly resembles that of Typhlodromus finlandiciis, but there is a noticeable difference in the spacing of the setae in relation to one another. There is also an importance difference in the length of the tracheae, which extend much farther forward than those of finlandictis. In addi-

11

Hi'i 1.1 UN. So. ('.Mil-. A( API An ok Sciences \'()1. 55, I'ait 1, li)5()

PLATE 6

Ameroseius californicus n. sp.: fig. 1, seta D"', fig. 2, ventral view of right side of hypostome; fig. 3, forked seta on palp-tarsus; fig. 4, dorsal view of mite; fig. 5, sternal plate; fig. 6, one of the leaffike setae at front apex of body; fig. 7, posterior venter, showing ventrianal scutum, parapodal plates, and associated setae.

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Bulletin, So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

tion, the chelicerae bear a conspicuous row of teeth, not seen in ftnlandicus. The greater length of the lateral setae, as men- tioned above, and the small size of the dorsals, places it in Ajnblyseius .

Ameroseius califomicus new species

Plate 6, figs. 1, 2, 3, 4, 5, 6, 7.

The senior author examined this mite and concluded that it probably belongs in the genus Ameroseius, and is probably un- described.

Female.— Dorsum evidently with 11 pairs of lateral setae; L- and L^ are shorter than L^". There appear to be 7 pairs of interscutal (?) setae anterior to setae L^. The median dorsal setae ( or spines ) increase gradually in length from front to rear. Most of the body setae are thick-lanceolate, with weak secondary pectinations. A pair of plumate setae borne at front tip of body. Dorsal integument mosaic. Sternal scutum sub-rectangular, bear- ing 2 pairs of setae, with humeral angles rather prominent. Meta- podal plates ovate, rather acutely pointed mesad. Parapodal plates one each side, banana-shaped. Ventri-anal scutum ovate, much wider than long, posterior margin scalloped, bearing one pair of paraanal setae, and a post-anal seta. A row of 4 setae immediately in front of anterior margin of ventri-anal scutum. One seta mesad of each parapodal plate. Forked sensory' seta of pedipalp with a small secondary spur on inner spine. Cheli- cera with 3 rounded teeth on the fixed arm. All legs with only short setae. Peritreme extending anteriorly to seta D\

This species differs from Berlese's hirsutus in the chaetotaxy of the posterior venter, outline of the anal plate, shape of the metapodal and parapodal plates, and in the length of the various dorsal and lateral setae.

HoLOTYPE FEMALE No. 3-31-55, citrus, near Stanton, Calif., March 31, 1955, Collected McGregor. Deposited in the collection of the Los Angeles County Museum. Four mites ( Typhlodromus sp. ) also on this slide.

13

Mil. 1. 1- I IN. So. (Iaiii. \i \i)i \n oi S( ii ncks \'()1. 55, I'ait I, 195()

A lUvMAKKABLi: XKW Kl lACOX'KLIA FROM THE DOMINICAN KEFUBLIC

( H(Miiii)t('rii:\'cliichie)

BfJ C J. DltAkl, AM) J. .\lALI;().\AiX)-C>'AJ'lULES"

DiiriiiL:; tlir latter part ot last Dccciiihcr (1955), the junior author spent ten days collecting Hemiptera in the Dominican lU'puhlie of the West Indies. Among the aquatic Hemiptera netted, there are sexcral specimens of an undescribed ripple- strider belonging to the genus Rliagovelia Mayr. This peculiar \\ ater-treader differs from all its congeners of the Americas in having the third segment of the antennae in the male very strongK' dorso-\entrally compressed so as to make it very inroad, thin, nearly flat and nearly elongate-ovate in outline. In female specimens this segment is not modified, is cylindical and similar in general aspect to that found in other members of the genus. As almost all of described species of Rhagovelia are represented in the collection of the authors, we feel that the strongly modified third antennal segment should be treated as a specific character peculiar to the inale sex of the new species characterized below.

Rhagovelia secluda, n. sp.

Plate 7 figs. 1-4

Apterous form: Moderately large, black, with the transverse, subapical, orange band divided at the middle; anterior third of pronotum and entire body beneath heavily coated with bluish pruinose; all acetabula stramineous. Head with median longitu- dinal line and V-shaped basal mark impressed, black, shining; beset with the usual long bristly hairs; anterior part of frons brown, lightly frosted; rostnmi testaceous, with terminal seg- ment and inferior side blackish; eyes blackish; width across eyes, 0.80 mm. Antennae blackish fuscous with base of proximal seg- ment testaceous or stramineous, clothed with short dark brown pubescence, the first two segments with the usual long bristly hairs; segment III (male; fig. 1) very strongly dorso-ventrally flattened, thin, elongate-ovate, or (female) cylindrical and not modified, measurements— (male) I, 90; II, 30; III, 55; IV, 45 and (female) I, 86; II, 30; III, 55; IV, 18.

1 Iowa State College, Ames, Iowa

- University of Puerto Rico, Mayagues, P. R.

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Bulletin, So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

PLATE 7

Rhagovelia secluda, n. sp. (male). Fig. 1. Antenna. Fig. 2. Left fore leg (inferior side). Fig. 3. Right hind leg (anterior side showing ventral spines. Fig. 4. Right male paramere.

Pronotum produced posteriorly, covering about two-fifths of mesonotum in both male and female, broadly rounded behind, the width across orange band less than twice median length (90:50); mesonotum with uncovered part shorter than pronotum (38:50), sharply obliquely narrowed posteriorly on both sides, with apex fairly wide and feebly rounded, the width across apex much narrower than its width just behind pronotum (54:105); metanotum not visible behind mesonotum but uncovered on each side of posteriorly narrowed sides of mesonotum.

Legs (male; figs. 2 & 3) black-fuscous, with basal part of anterior femora, all coxae and all trochanters stramineous or testaceous, pubescent, with the usual long, black, bristly hairs. Anterior legs ( fig. 2 ) with femora subcylindrical, with a thin row of long black hairs on median line of inferior surface, subequal to tibiae in length (98:97); tibiae strongly dilated beyond the basal two-fifths, widest in front of middle, with superior surface

15

JiLLLLiiN, So. Cm II . Ai Ai>i \n oi Sc iincks \'o1. 55, l';irt 1, H)5(i

slightly coinox. with iiilnior side hroadK lonuitndiiialK' scooped out on the apical three-fit tlis ( fiu- -'. the anterior edji;e beset with a long hnish ol inoderateK lonu. dense, stiff, brownish hairs; tarsi with first two seunients \cr\ short, th(> third moderately lonij; incasurtMnents— femora, 9(S; tibiae, 96; tarsi I, 4; II, 3; III, -1\. Middle legs \-er\- lonti, slender; t;irsi HI with a deep apical (.Kit ( .diont fi\-e-se\(Miths of the length of the segment), with the usual f;nilike, ]-)lnmose h;iirs ;uising from the bottom of the cleft; me;isuix'ments— femora, ISO; tibiae, 150; tarsi 1, 3; II, 80; III, 70. Hind legs (fig. 3t with femora moderately swollen, thickest at b;isal two-fifths, then- provided with a long, stout spines (all spines slightly bent outward), which is preceded by four or five very short spines and then followed by nine or ten short spines (each decreasing in size apically), also provided \\ith ;uiother row of five to seven spines in front of and parallel to median row (first spine placed opposite long spines— spines short and a little difficult to find); tibiae straight, feebly tapered apically, without a distinct spur at apex, armed beneath with a median longitudinal row of fifteen to eighteen, short, stout spines;— tarsi I, 5; II, 16; III, 31. Male parameres as in fig. 4.

Legs ( female ) : Color and bristly hairs as in male; anterior tibiae scarcely widened apically; hind femora very little swollen, sometimes with a short spine near apical fifth of inferior surface. All coxae and trochanters unanned in both sexes. Measurements (middle legs) -femora 160; tibiae, 140; tarsi I, 4; IT, 80; III, 70 and (hind legs)— femora, 140; tibiae, 160;— tarsi I, 5; II, 16; III, 30.

Abdomen (male) slightly tapered posteriorly, with last ter- gite nearly one-half longer than preceding segment; connexiva reflexed obliquely upwards, slowly narrowed posteriorly, not produced at apex, terminating at end of last tergite in a narrow, acute angle. NIale parameres fairly large, shaped as in fig. 4. Abdomen in female more tapering posteriorly than in male; last tergite much longer than preceding segment, the last ven- trite deeply roundly excavated on hind margin (slightly more so at middle); connexiva strongly reflexed, with last three seg- ments resting on surface of abdomen but with outer margins not meeting within; last tergite and ends of connexiva provided with dense patches of long black hairs; exposed basal tergites (not concealed by reflexed connexiva ) provided with pubescence, the other tergites almost nude. Macropterous form of both sexes unknown.

Length, 3.90 mm. (male) and 4.15 mm. (female); width, 1.33 mm.

Type (male) and allotype (female), on the road from Con- tanza to Valle Nuevo, Province de la Vega, Dominican Republic,

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Bulletin, So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

altitude 6,000 feet, along the margin of a small stream, Dec. 27, 1955. Paratypes; 7 specimens, taken in same school as type, also 3 nymphs. Type in Drake Collection.

The antennal and leg characters distinguish this insect at once from other members of the genus; it belongs to the group of Rhogovelia, which have the pronotum (apterous form) pro- duced posteriorly so as to cover around half of the mesonotum. The flattened third antennal segment of the male is peculiar to this species.

A NEW CANTACADERID FROM BRASIL

( Hemiptera : Tingidae )

By Carl J. Drake' and F. Plaumann"

Up to the present time, the genus Zetekella Drake ( 1938 ) has been known only from the genotype ( Z. zeteki Drake ) collected in Panama. The present paper describes a second species of the genus from southern Brasil. The following notes are intended to supplement the original generic description;—

Head moderately long to long, subquadrate, armed with five stout spines— three anterior spines and a pair between these and eyes; no spines between or behind eyes. Bucculae long, parallel- sided, open in front, the ends slightly surpassing apex of head. Rostrum extremely long, extending on venter. Antennae moder- ately long( slender, pubescent; segments I and II very short, with tip of latter barely surpassing apex of head; III longest, straight, very little thinner than others; IV moderately long, pro- vided with longer pubescence. Macropterous form unknown.

In size, form and general aspect, the two described species of Zatekella resemble members of the genus Acahjpta Westwood (1840). However, the subfamily characters of Cantacaderinae Stal (1873) separate at once Zetekella from Acahjpta and other genera of Tinginae.

Zetekella pulla, n. sp.

Brachypterous form: Small, ovate, brown with head and pronotum black and collar white, slightly shining, especially pronotum. Female broader than male. Long-winged form un- known. Length, 1.75-2.00 mm.; width, 1.00 mm.

^lowa State College, Ames, Iowa. ^Santa Catarina, Novateutonia, Brasil.

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Bulletin, Su. Calu-. Ac.Aut,M\ ut Sc.ie.nci.s NOl. 55, I'ail 1, l(J5(i

Head iiimilosc, l;iiil\ loiiU, coiisidciahK produced in Iroiit ol eyes, with .ipcx cxtcndinu; sli'j;litl\ hcNond lip ol sct'oiid aiilcniial segment, .Mined with fi\c. rathei- shoil stout spines (all spines in front oi cm'S; median directed lorward, the two ]iairs snberect). Antennae brown, rather short, fairly slender, rather densely pn- hescent, measurements- I "v II I; III, ol; IV, 16. Antennal tubercles short, stout, rounded at a[)e\, blackduseous. Rostrum \er)- stout, white-testaceous. \rvy lonii;, with tip reachinii; second ventrite: laminae blackduseous, ar('olat(\ open behind.

I'rouotum ncarK Hat. ()l)li(|ucl\ narrowed on sides anteriorly, almost trapezoidal in ontnn(\ with front margin truncate, imi- carinate. tlu^ median carina distinctly elevated, nniseriate, with a few extra aieolae nt'ar middle; collar biseriate, mostly whitish; paranota not \c'r\ wide, slightK" refle.xed, biseriate, the areolae small; ealli small, impressed, impunctate; posterior margins sub- truncate (slighth' obtuseh' angulate at middle). Scutcllum small, black, exposed. Areolae of collar, paranota and pronotum nearly equal in size, slightly smaller in median carina. Outer margins of pronotiun and superior margin of median carina beset with numerous, very short, pale spinulae. Ostiolar orifice with a cir- cular opening. Dorsal surface of pronotum sparsely provided with erect, pale, seta-like pubescence. Legs rather short, moder- ately slender, brown, clothed with short, pale pubescence.

Ehtra rounded, much wider than pronotum, widest near basal fourth, there distincth" wider than widest part of pronotum (90:55), with inner margins meeting in a straight line down the middle of the abdomen, with outer margins beset with numerous, short, setalike hairs; boundary veins separating subcostal, dis- coidal and sutural ares provided with erect, setalike hairs; dorsal surface with setalike hairs more numerous than on pronotum; costal area moderately wide, the areolae moderately large, hya- line and arranged in regular rows; subcostal area wider than costal, quadriseriate, the areolae nearly as large as in costal area; clavus fused and not distinctly set-off; discoidal area elongate-ovate with apex extending beyond middle of elytra, four areolae deep at middle; sutural area small ( short- winged form). Abdomen beneath brown, the sternum black.

Length, 1.85-2.00 mm.; wddth. 0.90-1.05 mm.

Type ( male ) and allotype ( female ) , Nova Teutonia, Brasil, June, 1955. Paratypes: 2 specimens, same data as type. Type in Drake Collection.

Separated from Z. zeteki Drake by cephalic spines and ely- tra! areas as discussed above.

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Bulletin, So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

NOTES ON METAMORPHOSES OF THE GIANT

SKIPPERS (LEPIDOPTERA; MEGATHYMINAE)

AND THE LIFE HISTORY OF AN

ARIZONA SPECIES

By John Adams Comstock

The "Giant Skippers," or "Yucca Borers" are a group of butter- flies that occur in the southern states, particularly in areas where yuccas and agaves are abundant. They are also found in Mexico.

Two genera are represented in the subfamily. The first is the genus Aegiale, with a single species,— /lespemrw Walker, occurring in Mexico. The larvae of this species feed within the fleshy leaves of certain century plants (Agaves), called Maguey by the natives, particularly the species from which pulque and tequila are made. These large, fat 'grubs' are highly prized as food by the natives. The choicest bottle of tequila, put up for home consumption, con- tains one of these delicious caterpillars, floating directly under the cork.

The second genus of the group is Megathymus, with numerous species recorded from California, Arizona, Texas, Florida and adjacent states, with a few from Mexico.

The first species to receive a name was Megathymus yuccae (Boisduval & LeConte). This was published in 1833 as Eiidamiis yuccae, and with it appeared the first life history record.^

One hundred years later the number of new species or varie- ties in this genus which had been described for boreal America stood at only 13, and the references to early stages and foodplants totaled only 17.

In a group that is as intriguing as this, it seems strange that forty-three years had to pass ( 1833 to 1876 ) before any addi- tional information was published on life histories. It was not until 1876 that C. V. Riley published his first two papers on Megathymus yuccae,- and laid the groundwork for an under- standing of the developmental phenomena of that large group within the genus which are yucca borers.

The past twenty-one years have added 10 or more species or races, and the references in the literature to life histories, food-

1 Lep. Am. Sept. pi. 70. 18.33

2 Trans. Acad. Sci. St. Louis, pp. 323-344. 1876, and Eighth Missouri Rep. pp. 168-183. 1876.

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luMiiiN, So. (^.M.ir. A( \i)i \n oi- Sciknces Vol. 55, I'ail I, l()5()

|)laiit.s and liahils 1ki\c totaled 27, a.s ma\- he noted in the hibli- ograpiu siippleniciit iiiij; this pajx-r. I'ossihK' this list may he in- creiused h\ some ohscmc rch'iciKcs that ha\c cseaped our notice.

There was another .segment of tiiis genvis, feeders in the fleshy leaves of ai^axcs, that had to wait a much lonsiier time before the secrets ol their c liildhood were disclosed.

A liiiit had been given in 1912, wlien Henry Skinner i:)ul)lislied Mc!j,(illiyiini.s st('))lirnsi:' and cpioted Hicksecker that "it feeds on Agave dcscrti."

However, no actual account of tlie life cycle of any agave feeder saw the light of day until the writer, in association with Comiuander Charles M. Dammers of Riverside, California, pub- lished and illustrated the metamorpliosis of M. stephensi in 1934,' just one hundred and one years after the first megathymid was described.

The circumstances associated with the first finding of the larva of stephensi may be of some interest to California lepidopterists.

It had long been surmised by local collectors that some inti- mate association must exist between Agave deserti and Mega- thijmus stephensi, since the two were always found in the same territory.

Early in October of 1932 I decided to make an attempt to soKe the problem, and, taking advantage of a short vacation period, my wife and I left for the desert on October 8.

Our planned destination was "La Puerta" in the lower end of Nhison Valley, San Diego County, a region that had been named by the veteran naturaHst, Frank Stephens, who had made it famous in zoological circles by the many records of mammals, birds, reptiles and insects which he had collected there.

Our route led by way of Julian, down the Banner grade to the San Felipe junction of the old Butterfield stage road leading toward Box Canyon. On reaching Julian we ran into rain, which increased to the point where the Banner grade, then unsurfaced, became a mud toboggan.

About a third of the way down we skidded into an upcoming car, which ripped off our left fender and upset our equanimity. Then back to Julian for an analysis of damage, which proved to be slight in comparison with the jolt to our nervous systems.

Our ardor was not unduly damaged. We were urged on by the tradition that "it ne\er really rains in Mason Valley."

3 Ent. News. XXIII: (3) pp. 126-127. 1912.

< Bull. So. Calif. Acad. Sci. 33: (2) pp. 79-86. 1934.

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Bulletin, So. Calif. Academy of Sciences Vol. 55, Part 1, 1956

Down the grade our progress was smooth, as would be ex- pected on a mud toboggan. In the lower altitude of the junction we expected a let-up in the downpour, but no; still came the rain, and the old Butterfield wagon tracks looked the consistency of liquid butter.

There was no turning back here. The vision of a sunny Mason Valley lured us on. The windshield-wiper groaned along in its effort to maintain visibility. After topping the ridge at the south- eastern end of San Felipe Valley, we noted a small dry lake bed, with surrounding hills that were well covered with agave. Here was a good place to begin operations, rather than risk the Box Canyon.

Rain or no rain, we must make a dissection of an agave, from crown to root. That is no easy task, with water trickling and tickling down one's back, and serrated century-plant leaves saw- ing at one's knees. The stalk took time, with no results. The fleshy leaves were tough, and hard to remove,— but what was that dark stain at the base of one of them! A cavity within, and Eureka! at last, a plump and luscious grub; a chamber, and an antechamber with an opaque window. Now we knew how to search for the hidden treasure.

The elemental forces now opened a bombardment of thunder and lightning, and research was over for the day. A soaked and sloshing return was made to camp, and it became evident that we would have to make the best of it that night, holed up in cramped positions in the car.

But, what mattered the deluge! I had what was presumably the larva of stephensi, and soon its secrets could be published the story poured forth for the benefit of the many thirsty lepi- dopterists, so eager to soak up information, and so desirous of seeing their cabinets brimming over with beautiful reared series of megathymids.

It takes a lot to dampen the enthusiasm of an entomologist, but that lot fell that night, to the accompaniment of vivid flashes, and the almost continuous roll of thunder. Seven inches of rain poured down on one of the most arid spots in California. We bedded down in a car, located on the edge of a dry lake bed. The morning light found us, an island in an inland sea, with waters lapping at the running boards.

We waded ashore to cut creosote bush, and crammed it under the wheels, in an effort to obtain traction, but to no avail. Start- ing the car succeeded only in grinding deeper into the mud.

"The rain was over and gone." The only thing to do was walk back over the way we came. Normal California desert sunshine

21

BULLLllN, St). C^VLir. ACAUL-MV Ul- Scili.NCKS \ ol. "5. I'uil 1, 1956

liiul it'tiinicd. tlic "fiiiic of (lie siii}j;iiij2; of birds had come," and till' six or .si\ cii-iiiilc walk aloiiu; tlu' wash that had been a road was not a haidship. In tlic first ranch house we encountered, a lu)spital)lc cldcrlN gentleman lielped to raise the morale of Mrs. Ciomstock, while I trudged on to a not \ery distant telephone.

A call to Julian l)i()uu;ht a well equipped truck, with power winch and stei-l cable, which pulled us out of the mud instanter.

Thus ended the adNcnture phase of our expedition.

All that remained to complete the pictvne was for our team, (Comstock and Dammers) to work out the details, take the neces- sar\- photographs, make the paintings, develop certain refine- ments in collecting and rearing methods, and finally to publish the account which I ha\e previously cited.