Showing papers in "Coleopterists Bulletin in 1982"

Tropical forests: their richness in coleoptera and other arthropod species

Abstract: Extrapolation from data about canopy insects collected by fogging methods together with estimates of tropical plant host specificity indicate that one hectare of unrich seasonal forest in Panama may have in excess of 41,000 species of arthropods. Further extrapolation of available data based on known relative richness of insect Orders and canopy richness leads to the conclusion that current estimates of Arthropod species numbers are grossly underestimated; that there could be as many as 30 million species extant globally, not 1.5 million a, usually estimated. Since the early days of naturalists, there has been the question of how many species there were in the forests of the tropics. Bates (1892) wrote of collecting more than 700 species of butterflies within an hour's walk of his home in Para, Brazil. Many have guessed that the arthropod fauna of the world today contains between 1.5 to 10 million species. No hard data are available however, and these estimates are less than reliable and as a result misleading. In a recent paper, Erwin and Scott (1980) provided the first hard data with regard to the Coleoptera fauna of a single species of tree in the tropical seasonal forest of Panama. Also recently, Peter Raven of the Missouri Botanical Gardens wrote me with the same inquiry that Bates had pondered-"How many species are there in one acre of rich tropical forest?" With the hard data available from the Panama study, I set out to give as close an estimate as possible and was shocked by my conclusions. The tropical tree Luehea seemannii is a medium-sized seasonal forest evergreen tree with open canopy, large and wide-spaced leaves. The trees sampled (n = 19) had few epiphytes or lianas generally, certainly not the epiphytic load normally thought of as being rich. These 19 trees over a three season sampling regime produced 955+ species of beetles, excluding weevils. In other samples now being processed from Brazil, there are as many weevils as leaf-beetles, usually more, so I added 206 (weevils) to the Luehea count and rounded to 1,200 for convenience. There can be as many as 245 species of trees in one hectare of rich forest in the tropics, often some of these in the same genus. Usually there are between 40 to 100 species and/or genera, so I used 70 as an average number of genus-group trees where host-specificity might play a role with regard to arthropods. No data are available with which to judge the proportion of host-specific arthropods per trophic group anywhere, let alone the tropics. So conservatively, I allowed 20% of the Luehea herbivorous beetles to be host-specific (i.e., must use this tree species in some way for successful reproduction), 5% of the predators (i.e., are tied to one or more of the hostspecific herbivores), 10% of the fungivores (i.e., are tied to fungus associated only with this tree), and 5% of the scavengers (i.e., are associated in some way with only the tree or with the other three trophic groups) (Table 1).

Comparative Biology of the Goldenrod Leaf Beetles, Trirhabda virgata LeConte and T. borealis Blake (Coleoptera: Chrysomelidae)

Abstract: Life histories are presented for Trirhabda virgata and T. borealis, two closely related leaf beetles that co-occur on goldenrod (Solidago spp.) in central New York. Eggs and larvae of the two species were indistinguishable, although T. virgata larvae were significantly larger. Life cycles were similar except for a slight difference in phenology; all stages of T. borealis appeared 1 to 2 weeks earlier in the season than those of T. virgata. Females of T. virgata possess more ovarioles/ovary and laid more eggs/cluster than T. borealis females. Invertebrate natural enemies of Trirhabda included 18 species in 10 families; most common were the host-specific tachinid, Aplomyiopsis xylota (Curran), the generalist coccinellid, Hippodamia glacialis (F.), and the nabid, Nabicula subcoleoptrata (Kirby). Trirhabda distribution and abundance in central New York were determined by surveying 23 old field sites. Mean beetle density was 7.6 ? 1.4 individuals/sweep. Trirhabda virgata, present in all sites, was the dominant species, typically accounting for 90% of the beetles collected per field. Densities of the two species varied independently among sites. Spatial autocorrelation analysis did not detect any geographic pattern associated with either species' abundance. Possible explanations for the relative rarity of T. borealis are proposed.

Notes on the Weevils Tyloderma, Auleutes, and Onychylis That Feed on Ludwigia and Other Aquatic Plants in Southern South America

Abstract: Adults of the weevils Tyloderma spp. A and B and Auleutes bosqi (Hustache) fed on the leaves of Ludwigia peploides (H.B.K.) Raven (water primrose) and appear to have it as their only host plant. They fed only on L. peploides in laboratory tests and were collected only from this plant in the field. Onychylis sp. nr. nitrirostris (Boheman) was collected from L. peploides, Eichhornia crassipes (Mart.) Solms (waterhyacinth), and Pistia stratiotes L. (waterlettuce) in the field; in the laboratory it fed on L. peploides, P. stratiotes, and Limnobium stoloniferum (G.F.W. Meyer) Griseb. (frogbit), but not on E. crassipes. The larvae of Tyloderma sp. A and of 0. sp. nr. nigrirostris were probably stem borers, but the larvae of A. bosqi fed on the leaves. All 4 species of weevils could be candidates for biological control of these aquatic weeds in the United States and other countries. Several species of the aquatic plant genus, Ludwigia (water primrose) are aquatic weeds of economic importance in the southeastern United States (Weldon et al. 1969). Some of these pest species have been introduced from other countries and some are native in the U.S. The genus is also native in South America, and Cabrera (1965) recorded 7 species of Ludwigia (=Jussiaea) in Buenos Aires Province, Argentina. We found several species of weevils that fed on Ludwigia peploides (H.B.K.) Raven in Argentina, none of which occur in North America; they are Tyloderma spp. A and B,4 Auleutes bosqi Hustache, and Onychylis sp. nr. nigrirostris (Boheman). Cordo and DeLoach (1982) found a flea beetle, Lysathiaflavipes (Boheman), that heavily damaged Ludwigia in Argentina. These insects could be used in a biological control program if they prove sufficiently host specific to introduce. Wibmer (1981), in his revision named 30 species of Tyloderma north of Mexico. Little is known of their biologies and host ranges. Four species probably have Ludwigia as their host plant (Wibmer 1981). Blackwelder (1947) listed 25 species of Tyloderma south of the United States, 6 of them from Argentina, 2 from Brazil, 2 from the Caribbean, 1 from Venezuela, and the rest from Mexico and Central America. ' Coleoptera: Curculionidae. 2 Accepted for publication February 12, 1982. 3 Present address of the junior author: Grassland, Soil and Water Research Laboratory, ARS, USDA, P.O. Box 748, Temple TX 76503. 4Determined by C. W. O'Brien, Florida A&M University, Tallahassee, FL 32307.

False powderpost beetles of the genus Dinoderus in North American (Coleoptera, Bostrichidae).

Abstract: A key to the five species commonly intercepted at USA ports of entry is given. Only bifoveolatus, japonicus, and minutus are established in North America; distributions and synonymies are given. D. brevis and ocellaris are not established. Dinoderus is an important genus. One notorius species, minutus, the bamboo powderpost beetle, is cosmopolitan, common in stored bamboo, and is also a pest of dried stored foods. Several less well known species are serious pests of wood and stored food products. Identification of North American species, at first glance, seems simple because of the existence of a determination key by Fisher (1950:25). However, both length of tarsomeres and length of lateral pronotal margins as used in that key are seen only with difficulty and even then are not easily interpreted. In addition, variation in minutus causes identification problems. For these reasons a new key to the species of Dinoderus is here presented. Also included are catalogue changes, new distributions, and synonymies made since Fisher's revision of the Bostrichidae. However, Fisher's complete synonymies, references, distributions and host data are not repeated here.

Weevils Listronotus marginicollis and L. cinnamomeus that feed on Limnobium and Myriophyllum in Argentina.

Abstract: The weevil Listronotus (=Hyperodes) cinnamomeus (Hustache) appeared to be host specific on frogbit, Limnobium stoloniferum (G.F.W. Meyer) Griseb. In the field, we collected it only from L. stoloniferum. In the laboratory, adults fed only on L. stoloniferum and slightly on 4 other test plants, among 22 plant species tested. The adults fed on the leaves and the larvae mined the leaves and pupated in the petiole. Populations reached I adult per 3 or 4 plants during the summer. The weevil Listronotus marginicollis (Hustache) appeared to be host specific on parrotfeather, Myriophyllum aquaticum (Velloso) Verde (=M. brasiliense). In the field, we collected it only from M. aquaticum. In the laboratory, adults fed heavily on M. aquaticum, moderately on L. stoloniferum, and slightly on 12 other test plants among 43 plant species tested. The adults fed on the leaves of M. aquaticum and often killed the terminal bud. The larvae tunnelled in the stem, both above and below the waterline; 79% of the stems were damaged in one area. Some species of aquatic macrophytes of the genera Limnobium (frogbit) and Myriophyllum (watermilfoil, parrotfeather) are aquatic weeds of economic importance in the southeastern United States (Weldon et al. 1969). These genera have closely-related species native in southern South America. One of them, M. aquaticum (Velloso) Verde (=M. brasiliense Camb.), was introduced into the United States from South America. Cabrera (1965, 1968) recorded 1 species of Hydromystria (now =Limnobium stoloniferum (G.F.W. Meyer) Griseb.) and 2 species of Myriophyllum (M. aquaticum and M. elatinoides Gaudichaud) from Buenos Aires Province, Argentina. We report here our observations and tests on the biologies and host ranges of two weevils that we found attacking these plants in Argentina. These are the weevils Listronotus marginicollis (Hustache) on Myriophyllum and L. cinnamomeus (Hustache) on Limnobium. Neither of these weevils are known to occur outside of South America. We made observations and tests to determine if these weevils might be candidates for biological control of Myriophyllum and Limnobium in the United States. The tests were made from 1972 to 1975 during the course of our main project on biological control of waterhyacinth Eichhornia crassipes (Mart.) Solms (DeLoach and Cordo 1976; DeLoach et al. ' Coleoptera: Curculionidae. 2 Accepted for publication February 12, 1982. 3 Present address of thejunior author: Grassland, Soil and Water Research Laboratory, ARS, USDA, P.O. Box 748, Temple, TX 76503. 4 C. W. O'Brien, Florida A&M University, Tallahassee, FL 32307.

American oryctini: strategus verrilli ratcliffe rediscovered and described, and new records and comments for other strategus and hispanioryctes (coleoptera: scarabaeidae: dynastinae)

Abstract: Strategus verrilli Ratcliffe was rediscovered on Dominica and is here redescribed, and a neotype is designated. A second specimen of Strategus craigi Ratcliffe (from the Huachuca mountains in Arizona) is reported and provides a new country record for this species. A female of S. ajax (Olivier) is reported from the Bahamas. Strategus monguilloni Voirin is reaffirmed as a synonym of S. mandibularis Sternberg, and the correct identification of the female allotype of S. gracilis Endrodi is questioned. Hispanioryctes wittmeri Howden and Endrodi is reported from Haiti.

A revision of the trimytini of america north of mexico (coleoptera: tenebrionidae).

Abstract: The tribe Trimytini of the subfamily Tentyriinae consists of two genera and seven species in America north of Mexico. Chilometopon castaneum Casey, C. brevipenne Casey, and C. ensifer Casey are synonymized under C. abnorme (Horn). The genus Prometopion Casey is synonymized with Chilometopon Horn, and the species P. amplipenne Casey is synonymized under C. helopioides Horn. Trimytis nympha Casey, T. tonsa Casey, T. ignava Casey, and T. trapezifera Casey are synonymized with T. pruinosa LeConte. One new species from southern California, Chilometopon microps, is described and illustrated, and a key to the United States species is provided. The tribe Trimytini is placed in the subfamily Tentyriinae. The following characters will separate the Tentyriinae from the rest of the Tenebrionidae. Mentum largest of all tenebrionids, usually concealing both ligula and maxillae; mesocoxae enclosed by mesoand metasternum; mesotrochantin hidden; usually apterous; no visible membrane between abdominal sterna five, six, and seven; and no defensive glands. Members of this subfamily are usually sand dwellers. The Nearctic tribes recognized in this subfamily are Nyctoporini, Cryptoglossini, Cnemodinini, Auchmobiini, Eurymetopini, Trimytini, Triorophini, Edrotini, Craniotini, Typhlusechini, Asidini, and Cnemeplantini. Watt (1974) erected the subfamily Pimeliinae to include the aforementioned tribes plus the Palearctic Pimeliini and Platyopini, and Doyen (1972) elevated the Tentyriinae to family status. The Trimytini are characterized as follows: epistomal lobe usually strongly prolonged and relatively flat; mandibles bifid with upper tooth clasping epistomal lobe or labrum, with basal swelling present or absent; elytra not inflexed; and winged or wingless. Genera displaying these characters include Chilometopon, Trimytis and Trientoma. The Trimytini appear to be most closely related to the Eurymetopini and Triorophini. The habitus of the Eurymetopini closely resembles that of Trimytis, but the lack of a strongly prolonged epistomal lobe separates these tribes. The habitus of Triorophini somewhat resembles that of Chilometopon, but the base of the elytra are pinched inward and coincide with the base of the pronotum contrasting with Chilometopon in which the base of the elytra is distinctly wider than the pronotal base. Triorophines have inflexed elytra which embrace the sides of the abdomen and when the epistomal lobe is prolonged it is also very convex, readily separating the two tribes. I This is Arizona Agricultural Experiment Station Manuscript No. 7022. 2 Current address: Athletic Department, Moby Gym, Colorado State University, Ft. Collins, CO 80523, U.S.A.

Two new species of the genus dirodes pascoe from india (coleoptera: curculionidae: hylobiinae)

Abstract: Two new species of genus Dirodes Pascoe are reported, the first records of this genus from India. The characters of Dirodes Pascoe are summarized, and a key to all three so far described species is given. We have studied 35 Indian species of subfamily Hylobiinae under a 5 year PL-480 Project on the family Curculionidae. Several of these species are new and belong to genera which are being reported for the first time from this country (Pajni and Sood 1980a, b, c). The present communication includes our observations on two new species of the oriental genus Dirodes Pascoe, previously represented by one species from Sumatra. The characterization of the genus Dirodes as given by Pascoe (1887) has been elaborated, and a key to the 3 species now known is given. The genus Dirodes Pascoe has been placed under the tribe Sternechini by Dalla Torre et al. (1932), following the tribal division of the subfamily Hylobiinae by Marshall (1932). This tribe differs from the other tribes in that the claws are basally connate. Present genus shares important features with subfamily Hylobiinae but also has some resemblance with Cleoninae. With Hylobiinae, it agrees in general body form, chaetotaxy of metepimeron, and presence of short parameres on the phallobase. However, the connate claws and the short aedeagal and phallobasic apodemes in the male genitalia place the genus close to Cleoninae. As such the study of genitalia in other genera of this tribe will throw important light on the correct rank of this and other genera of the tribe Sternechini.