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Spanish Moss, the Unfinished Chigger Story
John O. Whitaker, Jr. and Carol Ruckdeschel

Southeastern Naturalist, Volume 9, Issue 1 (2010): 85–94

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2010 SOUTHEASTERN NATURALIST 9(1):85–94 Spanish Moss, the Unfinished Chigger Story John O. Whitaker, Jr.1,* and Carol Ruckdeschel2 Abstract - There is a widespread belief in the southern parts of the United States that Trombiculidae (Chiggers) are common in Tillandsia usneoides (Spanish Moss) (Bromeliaceae). However, no chiggers were found among the 3297 organisms collected from T. usneoides and T. recurvata (Ball Moss) in trees and from the ground on Cumberland Island, GA. The organisms included 1721 Acari (mites), and in order of decreasing abundance were Psocoptera (barklice), Collembola (springtails), Araneae (spiders), Coccidae (scales), Thysanoptera (thrips), Formicidae (ants), Isopoda (sowbugs), Diplopoda (millipedes), Coleoptera, and Lepidoptera larvae. The millipede Polyxenus fascicularis (Polyxenidae) and the ensign scale insect Orthezia tillandsia (Ortheziidae) were of particular interest because of their rarity and host specificity, respectively. Introduction There is apparently a widespread belief in the southeastern United States that there are numerous chiggers in Tillandsia usneoides (L.) L. (Bromeliaceae) (Spanish Moss). Several Spanish Moss websites make statements such as “chiggers are noteworthy” (http://everything2.com/index. pl?node=Spanish%20moss), “contains hundreds of chiggers in each bunch, and so should be handled with care” (http://en.wikipedia.org/wiki/Spanish_ moss), “the prevalence of ‘red bugs’ or chiggers is legendary” (http:// edis.ifas.ufl .edu/FR005), and “redbugs, or chiggers, are also common residents in Spanish-moss on the ground and may cause an unpleasant, itching rash on the skin if the plants are handled” (http://www.sfrc.ufl .edu/4h/Spanish_ moss/spanmoss.htm). However, Benson (2004) had this to say: “Chiggers In Spanish Moss? ... I’ve never found any credible supporting evidence for this supposed fact. Even though chiggers that attach to humans (there are several species) are common on lizards and skinks, including those that can climb trees, it is not likely that the mites would be living in the hanging moss as part of their life cycle. The adult mites would have to live in the moss and deposit their eggs there for the larvae (chiggers) to be present and attach to passing vertebrates. And if a chigger were attached to a lizard that climbed a tree and the chigger fell off, it would molt into the next non-biting stage of the life cycle. It would be interesting to find Spanish Moss with chiggers actually living in it, and not just stories from what adults were told when they were growing up.” There is little literature on the inhabitants of Spanish moss. Rosenfeld (1911, 1912) presented information on insects and 1Department of Ecology and Organismal Biology, Indiana State University, Terre Haute, IN 47809. 2Cumberland Island Museum, PO Box 7080, St. Marys, GA 31558. *Corresponding author - John.Whitaker@indstate.edu. 86 Southeastern Naturalist Vol. 9, No. 1 spiders in Spanish Moss from swamps in the vicinity of Mansura, Avoyelles Parish, central Louisiana, probably from trees although this was not specifi- cally stated. Rosenfeld examined the Spanish Moss by placing unspecified but weighed amounts onto white paper or oilcloth on a table. He collected the inhabitants directly from the table and then (any hidden organisms) by tearing the moss into fine shreds and holding them up to a window for light. He examined 6 samples of insects from December (n = 2) and January (n = 4) and found 2539 insects and 255 spiders. He examined 5 samples from June and found only 54 insects and 12 spiders. A total of 65 species of insects in 60 genera and 40 species of spiders in 28 genera were collected. He concluded that both insects and spiders were more abundant in winter than in summer because they were using this habitat for hibernation. Because of the methods used, most of Rosenfeld’s information was on larger insects and on spiders. He presented no information on other invertebrates, such as millipedes, sowbugs, mites, etc., nor much on smaller organisms of any kind. Rainwater (1941) also presented information on insects in Spanish Moss from Louisiana, including numbers of species as follows: Thysanura (1), Orthoptera (4), Neuroptera (1), Homoptera (5), Hemiptera (40), Coleoptera (70), Lepidoptera (5), Diptera (3), and Hymenoptera (17). Rainwater reported no Acarina, Collembola, Psocoptera, or Thysanoptera, even though we found them to be fairly common. Rainwater did, however, report them from other habitats. Young and Lockley (1989) collected monthly samples of Spanish Moss from Mississippi over a 13-month period from 3 Quercus nigra L. (Water Oak) trees (Fagaceae). They found spiders (approx. 600), beetles (600), chalcidoid wasps (500), and miscellaneous insects (300). The original purpose of this paper was to determine the numbers and species of chiggers (larvae of mites of the family Trombiculidae) in Spanish Moss from Cumberland Island, a barrier island in Camden County off the coast of southern Georgia. The second objective was to determine the various invertebrates associated with Spanish Moss from that locality. This paper will include information on chiggers, or lack thereof, and a general summary of the results. Data on other mites, ants, spiders, and other invertebrates will be published at a later date. Materials and Methods Description of study area Cumberland Island is a barrier island along the Georgia coast separated from the mainland by 3 to 5 km of salt marsh and tidal rivers. The island is approximately 27 km long and 5 km wide at its widest point, and supports much upland maritime forest. The Spanish Moss samples were collected from within and under Quercus virginiana P. Mill. (Live Oak) trees, adjacent to open, developed areas. Storms frequently dislodge these epiphytes causing them to fall to the ground where they would normally provide a specialized habitat, but on 2010 J.O. Whitaker, Jr. and C. Ruckdeschel 87 the island they are usually quickly consumed, especially by feral horses. We covered fallen samples with a wire exclosure to prevent them from being eaten. The arboreal samples were taken from above the feral-horse browse line, i.e., above 2 m. Similar amounts were collected from the ground below the trees during each collection. Four samples of Spanish Moss and 1 sample of T. recurvata (L.) L. (Ball Moss) were collected each month for one year from the northern end of Cumberland Island. These included an arboreal sample of Spanish Moss and one from below the same tree from each of two sites. The sample of Ball Moss was from one of these same trees. The samples consisted of approximately 1 liter, were placed in plastic bags, and as soon as possible were run through Berlese funnels to collect the invertebrates. The invertebrate samples were then placed in alcohol until they could be sorted, counted, and identifited. Results A total of 3297 invertebrates was taken during these studies (Table 1): 2878 from Spanish Moss and 419 from Ball Moss. These included 1614 mites from Spanish Moss, and 107 from Ball Moss. No chiggers (Trombiculidae) were collected. Chiggers may be found in Spanish Moss elsewhere, but they are absent or at least very uncommon in Spanish Moss on the north end of Cumberland Island. Total numbers of individual invertebrates over the seasons ranged from 493 (fall) to 1134 (spring) (Table 1). The range of invertebrates collected was greater for Spanish Moss (457 [autumn] to 924 [spring]) than it was for Ball Moss (34 [winter] to 210 [spring]). More organisms were found in Spanish Moss on the ground (1754) than in trees (1124), and more were found in Spanish Moss in trees than in Ball Moss in trees (419). Acarina Mites formed the single largest category of organisms from the Spanish Moss samples. A number of species are involved, and these should form the basis for a later paper. Ten ticks were found, but have not been identified as yet. There was no major difference between numbers of mites by season, except that there were slightly fewer in autumn (winter = 476, spring = 501, summer = 532, and autumn = 212). There were always more mites in Spanish Moss on the ground than in the trees (Table 1). Araneae (spiders) Unlike Rosenfeld (1911), we found the fewest spiders in Spanish Moss in the winter (n = 11) as compared to the other seasons (spring = 36, summer = 42, autumn = 50). There were more spiders in the samples from the tree than on the ground in every month. Collembola Springtails were much more common in the Spanish Moss on the ground (167) than in the trees (Table 1), with only 10 being found in the moss in the 88 Southeastern Naturalist Vol. 9, No. 1 Table 1. Invertebrates of Tillandsia usneoides (Spanish Moss) and T. recurvata (Ball Moss), collected over a period of one year on Cumberland Island, Camden County, GA. T.u. = T. usneoides, T.r. = T. recurvata Winter (Dec.–Feb.) Spring (Mar.–May) Summer (June–Aug.) Autumn (Sept.–Nov.) T.u. T.r. T.u. T.r. T.u. T.r. T.u. T.r. Tree Ground Tree Tree Ground Tree Tree Ground Tree Tree Ground Tree Acarina: mites 45 418 13 99 330 72 156 358 18 81 127 4 Ixodidae: ticks 0 0 0 0 2 0 0 0 0 0 8 0 Aranea: spiders 8 3 8 29 7 27 29 13 10 30 20 10 Diplopoda, Polyxenus fascicularis 7 0 0 1 0 0 2 0 0 8 4 0 Isopoda: sowbugs 0 1 0 0 0 12 1 34 26 0 8 2 Collembola: springtails 0 27 4 2 78 10 7 54 9 1 8 1 Thysanoptera: thrips 11 13 2 59 15 15 16 4 2 11 15 6 Coleoptera: beetles Coleopteran larvae 1 0 0 1 0 1 17 1 3 27 18 1 Elaterid (click beetle) larvae 0 0 0 0 1 0 0 0 0 0 0 0 Cucujidae: Oryzaephilus sp.: 0 1 1 0 0 0 0 0 0 0 2 0 Sawtooth Grain Beetle Curculionidae: snout beetles 0 0 0 2 0 1 1 0 0 0 1 0 Elateridae: click beetles 0 0 0 0 0 0 0 3 0 0 0 0 Chrysomelidae: leaf beetles 0 0 0 0 0 0 0 0 0 1 0 0 Coleoptera, unidentified small 3 0 0 0 0 2 0 0 0 2 0 0 Homoptera Ortheziidae: Orthezia tillandsiae 41 4 4 58 10 2 5 15 9 27 18 0 Cicadellidae: leafhoppers 0 0 0 0 0 1 0 0 0 0 1 0 Juvenile leafhopper 0 0 0 0 0 0 0 1 Coccidae: scale insect #2 0 0 0 0 0 0 0 1 Psocoptera: barklice 11 19 1 175 19 62 41 13 1 12 8 8 Orthoptera: crickets, roaches, and allies Gryllidae: crickets 0 0 0 0 0 0 1 1 0 0 0 0 Blattidae: roaches 0 1 0 0 0 2 0 1 0 0 0 0 Unidentified Orthoptera 0 0 0 0 0 1 0 0 2010 J.O. Whitaker, Jr. and C. Ruckdeschel 89 Table 1, continued Winter (Dec.–Feb.) Spring (Mar.–May) Summer (June–Aug.) Autumn (Sept.–Nov.) T.u. T.r. T.u. T.r. T.u. T.r. T.u. T.r. Tree Ground Tree Tree Ground Tree Tree Ground Tree Tree Ground Tree Diptera: true fl ies Cerapogonidae: biting midges 0 0 0 10 5 0 4 4 1 1 4 1 Chironomidae pupae: midges 0 0 0 2 3 0 0 0 0 0 0 0 Sciaridae: dark-winged fungus fl ies 0 0 0 0 1 0 0 0 0 0 0 0 Dipteran larva 0 0 0 0 0 0 1 9 0 0 1 0 Unidentified Diptera 0 0 1 0 0 0 1 3 0 0 2 0 Hemiptera: true bugs Unidentified Hemiptera 0 0 0 1 0 1 0 0 0 1 0 0 Miridae: plant bugs 0 0 0 1 0 0 5 0 0 0 0 0 Reduviidae: assassin bugs 0 0 0 0 0 0 5 3 0 0 0 0 Neuroptera: nerve-winged Insects Hemerobiidae: brown lacewings 0 0 0 0 0 1 1 0 0 0 0 0 Neuropteran larvae 0 0 0 0 0 0 0 0 0 0 1 0 Hymenoptera: bees, wasps, and ants Unidentified Hymenoptera 0 0 0 9 1 0 3 2 0 4 1 0 Formicidae: ants 0 0 0 0 0 1 36 23 56 0 0 2 Thysanura/Diplura: bristletails, etc. 0 0 0 1 0 0 0 0 0 0 0 0 Lepidoptera: moths Lepidopteran larvae 0 0 0 2 0 0 4 4 4 2 0 1 Lepidopteran adults 0 0 0 0 0 0 1 0 0 0 0 0 Totals 127 487 34 452 472 210 337 546 139 208 249 36 Overall summary Winter Spring Summer Fall Total T. usneoides Tree 127 452 337 208 1124 Ground 487 472 546 249 1754 Subtotal 614 924 883 457 2878 T. recurvata Tree 34 210 139 36 419 Total 648 1134 1022 493 3297 90 Southeastern Naturalist Vol. 9, No. 1 trees. However, they appeared at a greater rate in the Ball Moss in trees than they did in the Spanish Moss. There were 2 samples of Spanish Moss in the trees per month and these yielded 10 springtails, whereas the single sample of Ball Moss in the trees per month yielded 24 springtails. Diplopoda (millipedes) One of the most interesting organisms found was the tiny millipede, Polyxenus fasciculatus Say (Fig. 1), which is in a suborder of its own, Pselaphognatha. It looks more like a caterpillar than a millipede. This species was always in low numbers, but it was most abundant in Spanish Moss in trees in autumn (n = 8) and winter (n = 7) (Table 1). These organisms are not common (listed as “rare” by Pratt [1935]) but are found under stones and bark in the southern states and on Long Island. They are very small (about 2.5 mm) with 13 pairs of legs. They cannot roll into a ball, and do not have odor glands. There is one genus in the family, with 1 American species. Twentytwo individuals were found during the present study, all in Spanish Moss, 18 from the trees and 4 from the ground. Isopoda (sowbugs) A total of 44 sowbugs of two species was found in the Spanish Moss, mostly in summer and fall, and all but 1 were on the ground. Coleoptera Many beetles were found as follows: (a) various unidentified larvae (n = 70) mostly in the Spanish Moss from the trees in summer and autumn and on the ground in autumn; (b) elaterid larvae (n = 1) and elaterid adults (n = 3); (c) Curculionidae (5); (d) Cucujidae, Oryzaephilus sp. (Sawtoothed Grass Beetle) (4), and (e) Chrysomelidae (1). Figure 1. Polysenus fasciculatus (Diplopoda) from, Tillandsia usneoides (Spanish Moss) from Cumberland Island, GA. 2010 J.O. Whitaker, Jr. and C. Ruckdeschel 91 Orthoptera Few orthopterans were found, but included 4 blattids and 2 gryllids. Diptera The few dipterans included 30 cecidomyiids, 5 chironomid pupae, 1 sciarid, 7 other unidentified dipterans, and 11 dipteran larvae. Hemiptera There were relatively few true bugs found during this study, and many of them were nymphs. Eight reduviids, 6 mirids, and 2 unidentified hemipterans made up the hemipteran fauna (Table 1). Among the organisms from Spanish Moss from the trees were 3 anthocorids, Cardiastethus assimilis (Reuter) adult, Phytocoris Fallén sp. (1 nymph), and 5 corimelaenid nymphs. Homoptera Scale insects: Ortheziidae and Coccidae. Another particularly interesting organism was the ensign scale insect, Orthezia tillandsiae Morrison (Ortheziidae) (Fig. 2). There were 178 in the Spanish Moss and 15 in the Ball Moss. They occurred throughout the year, 47 individuals in Spanish Moss on the ground, 131 in the trees. These insects were found in all samples from the tree except 1 (July) and in all samples from the ground except 2 (January, February). Most were nymphs, but a few adult females were found, the first in April. The adults were about 6 mm long with 2 long (4 mm), waxy fl aps. Figure 2. Orthezia tillandsiae (Ortheziidae, Homoptera) from Tillandsia usneoides (Spanish Moss) from Cumberland Island, GA. 92 Southeastern Naturalist Vol. 9, No. 1 The eggs and also the nymphs occur between the fl aps. There was 1 other scale insect in Spanish Moss in autumn on the ground.One cicadellid was found on Spanish Moss from the ground, probably subfamily Gyponinae. One cicadellid was found from Ball Moss, Agalliopsis novella (Say). Neuroptera Two brown lacewings (Hemerobiidae) and 1 neuropteran larva were found: one lacewing and the larva in the Spanish Moss and one hemerobiid in the Ball Moss. Lepidoptera A total of 17 lepidopteran larvae, and 1 adult lepidopteran were found during this study. Hymenoptera The majority of hymenopterans found were small wasps (chalcoids, etc.) and ants (Formicidae). The wasps occurred in spring, summer, and fall, and the ants nearly all occurred in summer in both Spanish Moss and Ball Moss. Thysanura/Diplura Only 1 individual of these groups was found. Thysanoptera (thrips) A total of 169 thrips was found during this study, 144 in Spanish Moss and 25 on Ball Moss. Seventy-four were found in spring, 20 in winter, 26 in fall, and 24 in summer in Spanish moss. Discussion Very little study has occurred on the faunal community in Spanish Moss, except that of Rosenfeld (1911, 1912), Rainwater (1941), and Young and Lockley (1989). The purpose of Rosenfeld’s study was to determine if Anthonomus grandis Boheman (Boll Weevil) spent the winter in this material, but he then decided to report all insects and spiders, as this material provides an excellent place for many species of insects and spiders to hibernate. Most of the insects taken in Spanish Moss by Rosenfeld were adults. He found about 60 genera with 65 species in Spanish moss, 53 genera and 58 species in winter, but only about 15 species in summer. He presented his data in estimated numbers of organisms per ton of Spanish Moss. Among spiders, Rosenfeld found a total of 28 genera and 40 species. Of these, 27 genera and 38 species occurred in winter, whereas only 3 genera and species were found in summer. As for the question of summer versus winter use of the Spanish Moss, which Rosenfeld had reported, we found that different groups of organisms behaved in different ways. We did not find the greatest numbers of organisms or of species in winter (Table 1). Many of the species have not been identified yet, but the greatest numbers of organisms were taken in spring (924) and summer 2010 J.O. Whitaker, Jr. and C. Ruckdeschel 93 (883), and the least in winter (614) and autumn (457). A similar pattern was found in Ball Moss (spring [210], summer [139], fall [36], and winter [34]). The greatest number of spiders was taken in the warm season, May through November. Thrips were most abundant in April through June, scale insects in January through April and in September, and the psocopterans from November through July. Springtails (Collembola) had their greatest abundance on Spanish Moss under the trees, and they were most abundant in the spring and summer periods. The six mirid bugs found were all from the trees. Groups taken only from the ground were Cicadellidae (n = 1), 1 species of tiny elongate mite (n = 39, all taken in January and February), elaterid larvae (n = 1), adult elaterids (n = 3), sawtoothed grain beetles (Oryzaephilus surinamensis (L.), n = 3), ticks (n = 10), and blattids (n = 2). All but 1 of the sowbugs from Spanish Moss (total n = 44) were from the ground. All sowbugs from Ball Moss were, of course, from trees. The monthly collections from Ball Moss from trees yielded many fewer organisms and much less biodiversity than did those from Spanish Moss in trees (Table 2). For purposes of comparison, if one assumed the two habitats to harbor the same fauna, one would expect the community from the Ball Moss to yield 91.7% as many individuals of each species as the Spanish Moss from the trees, since only 11 months (not January) were sampled for this species, yet there were only 36% as many. There were far fewer individuals of thrips, mites, spiders, coccids, psocopterans, unidentified hymenopterans, and beetle larvae. This result was probably because of the difference in growth forms between Spanish Moss and Ball Moss. Spanish Moss has many small parts in the same amount of material providing many more hiding places for organisms, probably leading to greater numbers of resident fauna. There were three groups in which more individuals were in the Ball Moss than in the Spanish Moss: springtails, sowbugs, and ants. It will be Table 2. Organisms in Spanish Moss compared to Ball Moss from Cumberland Island, GA, collected over a period of one year. No collections were made from Ball Moss in January. Spanish Moss Ball Moss Trees Ground Trees Total Acarina: mites 381 1233 107 1721 Psocoptidae: barklice 239 59 72 370 Collembola: springtails 10 167 24 201 Aranea: spiders 96 43 55 194 Ortheziidae: ensign scales 131 47 15 193 Thysanoptera: thrips 97 47 25 169 Formicidae: ants 36 23 59 118 Isopoda: sowbugs 1 43 40 84 Coleopteran (beetle) larvae 46 19 5 70 Diplopoda: millipedes 18 4 0 22 Hymenoptera: wasps 16 4 0 20 Lepidopteran larvae: caterpillars 8 4 5 17 Coleoptera: beetles 5 0 2 7 94 Southeastern Naturalist Vol. 9, No. 1 interesting to see if the springtails and ants differ in species between the two species of plants. The sowbugs seem particularly interesting since only one was taken in the Spanish Moss in the trees, which made it appear that the sowbugs did not generally go into trees. However, they were relatively aboundant on Ball Moss in the trees. The peculiar and rare millipedes that were found in the Spanish Moss did not occur at all in the Ball Moss. The coccids found so commonly in the Spanish Moss occurred also in the Ball Moss, but with no evidence of reproduction, i.e., no adult females. Acknowledgments Thanks go to Susan Halbert of the Florida Department of Agriculture and Consumer Services for identification of the hemipterans and homopterans, and to Greg Hodges (Taxonomic Entomologist, FDACS-DPI, Gainesville, FL) for verifying our identification of Orthezia tillandsiae. We also thank Laura Bakken for typing the manuscript and Linda Castor for helping with the literature and the photographs. Literature Cited Benson, E.P. 2004. Palmetto Pestalk, July 2004 Newsletter. Clemson University Urban Entomology Extension and Research. Available online at http://entweb. clemson.edu/urban/pesttalk/2004/julyaug04.pdf. Pratt, H.S. 1935. A Manual of the Common Invertebrate Animals Exclusive of Insects, Blakiston. Philadelphia, PA. 854 pp. Rainwater, C.F. 1941. Insects and spiders found in Spanish Moss, gin trash, and woods trash, and on Wild Cotton. US Department of Agriculture. Bureau of Entomology and Plant Quarantine. Bulletin E-528. 20 pp. Rosenfeld, A.H. 1911. Insects and spiders in Spanish moss. Journal of Economic Entomology 4:398–409. Rosenfeld, A.H. 1912. Insects and spiders in Spanish Moss (some additional data). Journal of Economic Entomology 5:338–339. Young, O.P., and T.C. Lockley. 1989. Spiders of Spanish Moss in the delta of Mississippi. Journal of Arachnology 17:143–148.