The LifeHistory of Climaciaareolaris (Hagen), a Neuropterous'Parasite' of FreshWater Sponges* HarleyP. Brown Departmentof ZoologicalSciences, University of Oklahoma,Norman Climaciaareolaris is an insectbelonging to the FamilySisyridae, of the OrderNeuroptera. The larvaeof all knownmetmbers of this family occur as parasitesupon fresh water sponges of theFamily Spongillidae, Order Demo- spongiae,hence the common name applied to thesisyrids by Needham-"spon- gillaflies." (However,the larvae may be found,at times,upon bryozoans or algae.) Accordingto thepresent scheme of classificationand stateof knowl- edge, thereare but two representativesof the familywhich normally occur in temperateNorth America: Climacia areolaris (Hagen), and Sisyravicaria Walker. Bothof thesespecies are widelydistributed in the UnitedStates, occurringfrom the Gulf of Mexicoto Canada,and fromthe Atlantic coast at least as farwest as New Mexico (*Carpenter,1940). In the regionwhere the presentwork was carriedon bothspecies occur. Despite theirwide distribution,and the fact that severalinvesigators have becomeinterested in them.,the life history of neitherof theseAmerican sisyrids has been workedout. In fact,the only extensivelife historystudy of any memberof the family,so faras I have been able to discover,is thatof Withy- combe,upon a Britishspecies of Sisyra (Withycombe,1922). Mating,eggs, and firstinstar larvae of Climaciahave neverbeen described. The investigationsupon whichthis articleis based were initiatedin the summerof 1941, continuedduring parts of the summersof 1942, 1944, and 1945, and carriedon intensivelyfrom June 16 throughAugust, 1949. All significantwork was done at the Franz Theodore Stone Laboratory,which is located at Put-in-Bay,Ohio, on an island in the westernend of Lake Erie, withina fewmiles of the Canadian boundaryline. I wishto acknowledgemy indebtednessto: Prof.Nathan Banks foridentification of specimens;Prof. M. W. Boesel for advice and assistancethroughout the work; Profs. H. B. Hungerford,M. C. Old, and R. C. Smi"thfor helpful suggestions; Prof. T. H. Langloisfor the use of the facilitiesof the Franz Theodore Stone Laboratory; Mr. Bert Millen for the use and care of the tank at the Ohio State Fish Hatchery. HISTORICALREVIEW Adult sisyridswere first described by Degeer in 1771, as membersof the the Genus Hemerobius. In 1829, the Genus Sisyrawas createdby Burmeister for these European forms. In the same year,the late instarlarvae were de- scribedby Westwood. A quotationfrom Needhatn (1901) is of interest: * Contributionfrom the Franz TheodoreStone Laboratory,Put-in-Bay, Ohio. 130 1952 BROWN: LIFE HISTORY OF CLIMACIA AREOLARIS 131 "A discussionwas then raging in thelearned societies of theold worldas to whether spongesbelong to theplant or to theanimal kingdom, and the Sisyra larva was dragged, an innocentvictim, into this controversy. Dujardin, maintaining that sponges are animals, toldthe French academy that he foundin thesponge body numerous fine filaments that movedto and fro. JamesHogg, on theother hand, believing that sponges are plants, maintainedbefore the Linnaean society of Londonthat the filaments seen by Dujardin were thesetae on theback of these larvae, which had crawled,as is theirwont, into the spcnge throughthe open osteoles. "The larvapossessed two structures, also, so uniquein characterthat interest in them hassurvived the sponge controversy, andon accountof which the original figures of West- woodand Grubeare handed down in textbooksof thepresent day. Thesepeculiar parts are1) paired,jointed appendages beneath the abdominal segments, and 2) long,dezurved, piercingmouth parts, of a uniquesuctorial type. "Notwithstandingtheinterest attaching to thislarva, it seemsnot to havebeen reared." Needham rearedthe larvae of the specieshe found at Saranac Inn, New York--i.e.,he placed spinninglarvae in vials,obtaining from them both pupae and adults. He describedthis species as Sisyra umbrata. He also reared adults of Climacia frompupae withincocoons collectedfrom the hatchery supplytrough. These he describedas Climacia dictyona. Needham supplied one of his students,Miss Anthony,with preserved material, from which she workedout some details of the metamorphosisand anatomicalstructures of Sisyra,publishing her results in 1902. Banks (1906) relegatedboth of Needham'snew speciesto synonymy,with Sisyra vicariaWalker (1853), and Climacia areolaris (Hagen) (1861), re- spectively. The latterwas originallyplaced in the Genus Micromus,until the genericname Climaciawas introducedby MacLachian (1869). In 1906, Handlirsch createdthe Family Sisyridae,including therein the then-known speciesof Sisyra,Climacia, and Neurorthus. Priorto thattime (and, by some authors,after that time), these generahad been generallyassigned to either the Osmylidae or the Hemerobiidae. Since then, a fourthgenus, Sisyrella (= Nopia), has been describedand includedin the family (Kruger, 1923; Navas, 1935). Kruger(1923) considersthe Balticgenus Rhophalis as belong- ing to the Sisyridae. Navas (1935) outlinesthe systematicsof the family,and presentsa table indicatingbroadly the geographicdistribution of the variousspecies. He lists fivespecies of Ncurorthus:two in Europe,two in Asia, and one in the islands of the PacificOcean. Of the threespecies of Climacia,two occur in South (and Central ?) America,the other in North America. Of the nineteen speciesof Sisyra,four are European,eight Asiatic, one African,three from the Pacificislands, anid three "American." Of the last three,I gatherthat only one occursnorth of the tropicsand Caribbeanislands. The two species of Sisyrellaare Asiatic. His supplement,listing species of Spongillidaewhich serveas food for sisyrids,appears, rather, to be a fragmentarycompilation of data on the distributionof freshwater sponges. His materialon Climacia is taken fromthe publicationsof Needham and Banks. His sectionson larval sisyridsand on the biologyof sisyridsare drawnentirely from Withycombe 132 THE AMERICAN MIDLAND NATURALIST 47 (1) (1922), althoughhe misinlterpretedan item or so. Thus,he mistookWithy- combe'sfigure of an egg-breaker,although it is so labeledeven in hisreproduc- tionof it, for a pupalstructure, and states that it is a heavilychitinized mandi- blewhich serves in themanner of a sawin liberatingthe pupa from the cocoon. Botharticles by Withycombe(1922, 1924) presentexcellent descriptions of the lifehistory of Sisyrafuscata in England,with pertinent information uponrelated groups. As previouslymentioned, they represent the most exten- sivelife history study upon members of theSisyridae. In theUnited States, the only investigation relating to thelife history of sisyrids,other than that of Needhain,was reported by Old (1932b). Work- ingat DouglasLake, Michigan, he collectedfrom sponges 38 larvae,placed themin-"finger bowls containing water, a thinlayer of sand,and a pebble largeenough to extendabove the water. Piecesof freshsponge replaced old piecesevcry day. The larvaesometimes fed on the sponge,sometimes not. Oftenthey showed no evidenceof even being aware of itspresence.... About 60 percent of them died within two to tendays. Of theremaining 40 percent whichpupated, 80 percent emerged in fromeleven to fifteendays. At pupa- tionthe larvae had a lengthof 3.5 to 4.0 mm." He foundabundant cocoons ofboth Sisyra and Climacia,and speculated thus: "The purposeof thisloosely wovennet (on Climaciacocoon) is notknown. It mightserve as a protection fromcertain parasitic insects. It doesnot, however, protect the pupa from be- comingwiet during submergence, as was shown by experiment." He describedthe swimmingmovements of sisyridlarvae as follows:"A larvaswims about by a peculiarbody movement. It holdsitself in a verticalposition, head up, arches tlhebody, and then,by slnappingback into the verticalposition, produces a forwardmovement." His attemptsat breedingsisyrids were as fruitlessas mostof myown: "Pupae broughtinto the laboratoryemerged and affordedmaterial for experimentson life-history. Twenty-five cocoons were placed in a naturalposi- tionover an aquariumcontaining sponges and waterplants, the latter project- ingabove the surface of thewater. A cageof clothnetting was adjustedover the aquarium.As the imagoesemerged, they flew to the top of the cage, soughta secludedcorner, and remainedthere, rarely flying about. Fromthree to fivedays later the flies could be pickedfrom the surface of thewater, where theyhad fallen. Theyappeared very weak in flight,and theslightest wetting renderedthem unable to extricatethemselves. Examination of thewater and plantsrevealed no evidenceof eggs. Repeatedobservations yielded no results. Flashinga lighton imagoesat nightcaused them to flyabout toward the light andexhibit positive phototropism." The onlyother significant point made by Old was thatnot all sponges seemto serveas hosts,since he had foundno sisyridlarvae upon Ephydatia fluviatilis,Heteromeyenia repens, or H. argyrosperma,although he had col- lectedniumerous specimens of at leastthe first of these. Both Comstock(1940) and Ward & Whipple(1918) presenta brief accountof theAmerican sisyrids, based solely upon Needham's work. The 1952 BROWN: LIFE HISTORY OF CLIMACIA AREOLARIS 133 sectionin Ward & Whipple on aquatic insects(written by Needham) includes a key to both adults and larvae,and is more readilyavailable than the paper by Needham & Betten (1901), in whichkeys are includedfor larvae,pupae, and adults. Both books also summarizeMiss Anthony'sdescripticn of the anatomyof thelarval Sisyra, so I need not recountany detailshere.