Endothenia daeckeana Krft. is an obligate associate of S. purpurea L. in Wisconsin. This paper presents a preliminary analysis of the ecological relationship between this moth and its host plant

Guntenspergen, Glenn R

Rupprecht, Charles R

English

University of Wisconsin-Milwaukee

University of Wisconsin MilwaukeeUWM Digital CommonsField Station Bulletins UWM Field StationSpring 1983The ecology of a moth associated with the northernpitcher plant (Sarracenia purpurea)Glenn R. GuntenspergenUniversity of Wisconsin - MilwaukeeCharles R. RupprechtUniversity of Wisconsin-MilwaukeeFollow this and additional works at: https://dc.uwm.edu/fieldstation_bulletinsPart of the Forest Biology Commons, and the Zoology CommonsThis Article is brought to you for free and open access by UWM Digital Commons. It has been accepted for inclusion in Field Station Bulletins by anauthorized administrator of UWM Digital Commons. For more information, please contact open-access@uwm.edu.Recommended CitationGuntenspergen, G.R. and C.R. Rupprecht. 1983. The ecology of a moth associated with the northern pitcher plant (Sarraceniapurpurea). Field Station Bulletin 16(1): 10-13.THE ECOLOGY OF A MOTH ASSOCIATEDWITH THE NORTHERN PITCHER PLANT,SARRACENIA PURPUREA L.ABSTRACTEndothenia daeckeana Krft. Is an obligate associate of ~. purpurea L. in Wis-consin. This paper presents a preliminary analysis of the ecological relationshipbetween this moth and its host plant.INTRODUCTIONThe insectivorous habit has evolved in seven plant families world wide (Lloyd1942. Schmucher and Linnemann 1959). Representatives of three families: theDroseracea. the Lentibulariaceae. and the Sarraceniaceae occur in North America.All but one of the eight species of the genus Sarracenia are confined to the south-eastern United States. Sarracenia purpurea L.• the northern pitcher plant, has thewidest distribution reaching northward into the Canadian Provinces (McDaniel 1966).In Wisconsin. this species is confined to wet acidic or alkaline organic soils.Much scientific and popular attention has focused on the insectivorous natureof this species (Lloyd 1942. Darwin 1900. Thompson 1981). ~. purpurea has acluster of specialized pitcher-shaped leaves that fill with liquid. Insects areattracted to these leaves. become trapped in the pitchers. die. and are digestedby enzymes secreted by the plant (Lloyd 1942).Much less is known about the insect associates which make use of the pitcherplants' other structures. A number of insect species use various parts of ~. ~­purea without being entrapped. Fish and Hall (1978) provide a detailed examina-tion of the growth and development of the pitcher plant leaves and their insectfauna. They described a unique community of insect larvae and microbial decomposersthat inhabit the modi fied leaves of the species. Jones (1907, 1908, 1921) describedthree groups of moths which also inhabit different portions of the plant: Papaipemaappasionata Harvey (making use of the leaf). Exyra rolandiana Grt. (the rhizome).and Endothenia daeckeana Krft. (the reproductive structures).Despite an early interest in the insect associates of ~. purpurea, few detailedecological studies exist. This preliminary study was designed to examine theecology of one of these insect associates. the moth, Endothenia daeckeana. In thenorthern portion of its range. f. daeckeana is an obligate associate of ~. purpureaand has been reported from plants in Maine and New Jersey (Heinrich 1926, Jones1907. and Brower and Brower 1971). Previous work suggests that the larvae over-winter in the flowering stalks but little else is known about its distribution orecology.METHODSPitcher plant flowering stalks from the previous year were randomly collectedfrom flarks within the Cedarburg Bog, Ozaukee Co .• Wisconsin. A different flarkany larvae orthe laboratory.Therea fter,- 11-was used for each sampling period. Each old stalk was opened andpupae found were collected and reared in closed culture dishes inPreliminary samples were collected in January and February 1981.sampling was at least monthly through July.In early July, we placed 1m. tall wooden dowels covered with Tanglefoot amongseveral patches of pitcher plants. These dowels were placed close to the plantsso that any emerging insects might be sampled. Traps were checked several timesduring the remainder of the summer.Flowering individuals were marked in late May and checked through the sun~erfor evidence of insect predation.RESULTSLarvae were found in all collections of old flowering stalks. These moth lar-vae were reared in the laboratory and adults sent to the Smithsonian Institutionfor identification. All Jdults were identified as 01ethreu~ (:Endothenialdaeckeana Krft., 01ethreutidae, Lepidoptera. About 20% of the flowering stalksexamined had larvae, pupae, or visible signs of their presence (Table 1). Eachinfected flowering stalk had only one larva or rarely two. Most of the larvaewere found in the hollow flowering stalk but a few were also found in the recepta-cle.-able 1. The percentage of Sarracenia purpurea individuals inhabited byby larvae and pupae of Endothenia daeckeana during 1981 in the CedarburgBog, Wisconsin.early midMarch Apri 1 May June June JulyLarvae present 20 28 18 19 3 8Pupae present 0 0 2 0 0 0Evidence of pupae 0 0 0 11 17 16N 82 83 132 59 99 63Pupae first appeared in late May. However, evidence of pupae and larvae wasfound in old flowering stalks until the last collection date in early July. Mostold flowering stalks had deteriorated after the July date and fallen to the peatsurface. Sampling of old flowering stalks was discontinued after this date.We collected no adult Endothenia moths on our tangle foot traps. Adults hademerged from our laboratory reared larvae 10-21 days after they pupated, so wesuspect that we had put out our traps too late.In 1981, pitcher plants in the Cedarburg Bog flowered from the end of May tothe middle of June. This overlapped the suggested period of adult moth emergence(which apparently continued until early July). By the July sampling date, thedeveloping capsules showed evidence of larval damage. The larvae found were 1/2the size of the overwintering ones and were consuming unripened seeds.-12-Most of the moth larvae that pupated in the laboratory did not develop intoadults. An internal parasitoid developed in these individuals and emerged. Thesewere collected and identified as an Ascogaster spp. All Ascogaster are egg-larvalparasitoids of concealed feeding micro1epidoptera (Shaw pers. comm.).DISCUSSIONf. daeckeana adults emerge throughout the summer and lay their eggs on thedeveloping flower bud or seed capsule of S.: purpurea. It appears that only oneegg is laid on each flowering stalk. Larvae feed on the seeds, then burrow intothe receptacle and hollow out a chamber or continue through and develop a chamberin the hollow flowering stalk. The larvae oven;inter in the stem or receptacleand begin to pupate shortly before the flowering period. Adults emerge soon after.The larvae are vulnerable to attack by a parasitoid, Ascogaster spp. Ascogasterbelongs to the Braconidae subfamily Cheloninae. a large economically beneficialgroup of parasitic Hymenoptera. In the Cheloninae, an egg is laid in the hostand the parasitoid matures when the host reaches maturity (Borror et al. 1976).Ascogaster seems quite efficient at finding Endothenia larvae. Over BOI of thelarvae reared in the laboratory had Ascogaster developing within them.The ecology of f. daeckeana is the result of complex selective pressures exertedby the host plant and the parasitoid. In Wisconsin, f. daeckeana has an obligaterelationship with the pitcher plant, ~. purpurea. It utilizes safe portions ofthe plant and avoids contact with the pitchers. The flowering stalk and develop-ing capsule provide a source of food and a relatively safe site for development.On the other hand, the braconid. Ascogaster spp .• keeps the Endothenia populationin check and probably exerts other selective pressures.Endothenia adults may lay only one egg per capsule as a response to Ascogasterpredation. Endothenia larvae may be particularly vulnerable to the Ascogasterspp. in the flowering stalk. Individuals in the receptacle may be more protected.We have not been able to resolve whether Ascogaster spp. is an obligate para-sitoid of f. daeckeana or has an alternate host. Having an alternate host may beimportant in years when pitcher plant flowering is low or when population levelsof ~. daeckeana are low.ACKNOWLEDGMENTSWe thank J. Keough for assistance in the field and lab. S. R. Shaw of theSystematic Entomology Laboratory (U. S. National Museum of Natural History) pro-vided identification of the Ascogaster specimens. D. M. Weisman of the SystematicEntomology Laboratory of USDA identified the Endothenia material.LITERATURE CITEDBorror, D. J., D. M. Delong, and C. A. Triplehorn. 1976. An introduction tothe study of insects. 4th Edition. New York: Holt. Rinehart and Wilson.B52 pp.-13-Brower. J. H. and A. E. Brower. 1971. Notes on the biology and distribution ofmoths associated with the pitcher plant in Maine. Proc. Entomological Soc.of Ontario. 101: 79-83.Darwin, C. 1900. Insectivorous Plants. 2nd Edition. New York: Appleton.Fish, D. and D. W. Hall. 1978. Succession and stratification of aquaticinsects inhabiting the leaves of the insectivorous plant. Sarraceniapurpurea. Am. Midl. Natur. 99: 172-183.Heinrich, C. 1926. Revision of the N. American moths of the subfamiliesLaspeyresiinae and Olethreutinae. Bull. 132. U. S. National Museum(Smithsonian Institution).Jones, F. M. 1907. Pitcher-plant insects. II. Entomol. News 18:413-420.Jones. F. M. 1908. Pitcher-plant insects. III. Entomol. News 19:150-156.Jones, F. M. 1921. Pitcher-plants and their moths. Nat. Hist. 21: 296-316.Lloyd. L. E. 1942. Carnivorous plants. Chronica Botanica. Waltham, Mass.352 pp.McDaniel, S. 1966. A taxonomic revision of Sarracenia (Sarraceniaceae).Ph.D. thesis. Florida State University.Schmucker, Th. and G. Linneman 1959. Carnivorie. In: W. Ruhland (Ed.).Handbuch der Planzenphysiologie. Band XI. Heterotrophie: 193-283.Berlin: Springer-Verlag.Thompson. J. N. 1981. Reversed animal-plant interactions: the evolution ofinsectivorous and ant-fed plants. Biological Journal of the LinaeanSociety 16:147-155.G. R. Guntenspergen and C. R. RupprechtBiological Sciences Ph.D. ProgramUniversity of Wisconsin-MilwaukeeMilwaukee. WI 53201

The ecology of a moth associated with the northern pitcher plant (Sarracenia purpurea)

https://dc.uwm.edu/cgi/viewcontent.cgi?article=1094&amp;context=fieldstation_bulletins

The ecology of a moth associated with the northern pitcher plant (Sarracenia purpurea)

Abstract

Similar works

Full text

Available Versions

University of Wisconsin-Milwaukee