Pentatomid Bugs Research Articles

A PATH-ANALYTIC MODEL FOR THE MEASUREMENT OF SELECTION ON MORPHOLOGY.

This paper describes a path model for the analysis of phenotypic selection upon continuous morphological characters. The path-analysis model assumes that selection occurs on unmeasured general size and shape allometry factors that summarize linear relations among sets of ontogenetically, phylogenetically, or functionally related traits. An unmeasured factor for general size is considered the only aspect of morphometric covariance matrices for which there is an a priori biological explanation. Consequently, selection coefficients are derived for each measured character by holding constant only a general size factor, rather than by using multiple regression to adjust for the full covariance matrix. Fitness is treated as an unmeasured factor with loadings, representing directional selection coefficients, computed as the covariances of the size-adjusted characters with the measured fitness indicator. The magnitudes and signs of the selection coefficients, combined with biological insight, may suggest hypotheses of selection on one or more shape allometry factors. Hypotheses of selection on general size and shape allometry factors are evaluated through cycles of measurement, analysis, and experimentation, designed to refine the path diagram depicting the covariances among the measured characters, the measured indicator of fitness, and unmeasured factors for morphology and fitness. The path-analysis and multiple-regression models were applied to data from remeasurement of Lande and Arnold's (1983) pentatomid bugs and to Bumpus's (1899) data on house sparrows. The path analysis suggested the hypothesis that variation in bug survivorship was an expression of directional selection on wing loading. Bumpus's data are consistent with a hypothesis of stabilizing selection on general size in females and directional selection for small wing size relative to body size in males.

Pentatomid Bugs Reduce Rice Grain Quality in Farmers' Fields in Orissa

Pentatomid Bugs Reduce Rice Grain Quality in Farmers' Fields in Orissa

Relative Effectiveness of Insecticide Sprays on Insect Damage and Yield of Three Cowpea Cultivars in Swaziland

Field trials were carried out for two seasons on the effect of insecticides on insect pests, damage and yield of three cowpea cultivars.During the first season, the preflowering stage of crop growth was found to be infested by Aphis spp, Empoasca spp, Ootheca spp and Epilachna spp, the flowering stage by Megalurothrips sjostedti, Heliothis armigera, Astylus atromaculatus, Coryna kersteni and Mylabris amplectens and the postflowering stage by H. armigera and a number of coreid and pentatomid bugs. Fenthion gave the least protection against pod damage by H. armigera. There were significant increases in the number of harvestable pods per plant with insecticides. There were no significant differences in hull weight and shelling percentage. Grain yield was increased by 96.2 and 109.4% after treatment with dichlorvos and cypermethrin, respectively.In the second season, cypermethrin and monocrotophos were most effective. Cypermethrin reduced the number of pod-sucking bugs by 58%, H. armigera by 93%, while monocrotophos reduced Empoasca spp by 39% and M. sjostedti by 79%. Cypermethrin reduced damage by pod-sucking bugs by 28%, and by H. armigera by 95%. Monocrotophos reduced damage by pod-sucking bugs by 14%, and by H. armigera by 80%. Significant increases in the number of harvestable pods per plant were obtained with monocrotophos and cypermethrin treatments. There were no significant differences between the number of seeds per pod, and the weight of 1000 seed-grains. Grain yield was increased by 55.4% after both cypermethrin and monocrotophos treatment. The application of these insecticides were financially beneficial but the gain was reduced when six sprays were applied. Cypermethrin and monocrotophos are promising insecticides for controlling insect pests on cowpeas.

Pentatomid bugs (Hemiptera) that transmit a flagellate disease of cultivated palms in South America

AbstractDescriptions are given of two new species of pentatomid bug, one known to transmit the disease ‘marchitez’ (caused by Phytomonas staheli) of oil palm in Ecuador and the other associated with hartrot (caused by the same flagellate) in coconut palm in French Guiana. Notes are included on a third species also associated with hartrot in French Guiana. The species are Lincus lethifer sp.n., L. apollo sp.n. and L. croupius Rolston.

Parasitoids of predaceous and phytophagous pentatomid bugs in soybean fields at two sites of Alachua County, Florid

AbstractInvestigation into the parasitoids of three predaceous and five phytophagous stink bugs in soybean fields yielded five species of parasitic Hymenoptera and two species of Diptera. Hymenopterous wasps (Telenomus pentatomus, T. podisi, Trissolcus basalis, T. eddessae, and Gryon sp.) emerged from egg masses. The scelionids, T. podisi and T. basalis were the most dominant oophagous wasps. Each attacked four different species of stink bugs. The phytophagous stink bug, Piezodorus guildinii was parasitized by three species of scelionids. More than 65% parasitism was recorded for P. guildinii and Euschistus servus in two different soybean fields. Dipterous parasitoids: one sarcophagid, Sarcodexia innota and one tachinid, Trichopoda pennipes were recorded from Nezara viridula adults only at the Honey Plant site. Their impact was minimal. No parasitoids were recorded for the four stink bugs, including N. viridula at the Green Acres site. Egg discoloration was generally more evident in parasitized phytophagous than in any predaceous bug eggs.ZusammenfassungParasitoide Hymenopteren und Dipteren aus zoo‐ und phytophagen Wanzen (Het., Pentatomidae) von Sojabohnen‐Feldern zweier Standorte in Alachua County, FloridaEs wurden aus 3 räuberischen und 5 phytophagen Pentatomiden zweier Sojabohnen‐Felder 5 Arten Hymenoptera und 2 Arten Diptera als Parasitoiden festgestellt. Als Eiparasiten traten auf: die Hymenopteren Telenomus pentatomus, T. podisi, Trissolcus basalis, T. eddessae and Gryon sp., wovon T. podisi and T. basalis dominierten. Die phytophage Wanze Piezodorus guildinii wurde von 3 Arten Scelionidae parasitiert. Von dieser Wanzenart sowie von Euschistus servus wurden jeweils mehr als 65% parasitiert. Als parasitoide Dipteren wurden festgestellt: Sarcodexia innota (Sarcophagidae) und Trichopoda pennipes (Tachinidae), beide nur an einem Standort und in geringer Zahl. Die Eiverfärbung war bei den parasitierten phytophagen Wanzen auffälliger als bei den zoophagen.

THE MEASUREMENT OF SELECTION ON CORRELATED CHARACTERS.

Natural selection acts on phenotypes, regardless of their genetic basis, and produces immediate phenotypic effects within a generation that can be measured without recourse to principles of heredity or evolution. In contrast, evolutionary response to selection, the genetic change that occurs from one generation to the next, does depend on genetic variation. Animal and plant breeders routinely distinguish phenotypic selection from evolutionary response to selection (Mayo, 1980; Falconer, 1981). Upon making this critical distinction, emphasized by Haldane (1954), precise methods can be formulated for the measurement of phenotypic natural selection. Correlations between characters seriously complicate the measurement of phenotypic selection, because selection on a particular trait produces not only a direct effect on the distribution of that trait in a population, but also produces indirect effects on the distribution of correlated characters. The problem of character correlations has been largely ignored in current methods for measuring natural selection on quantitative traits. Selection has usually been treated as if it acted only on single characters (e.g., Haldane, 1954; Van Valen, 1965a; O'Donald, 1968, 1970; reviewed by Johnson, 1976 Ch. 7). This is obviously a tremendous oversimplification, since natural selection acts on many characters simultaneously and phenotypic correlations between traits are ubiquitous. In an important but neglected paper, Pearson (1903) showed that multivariate statistics could be used to disentangle the direct and indirect effects of selection to determine which traits in a correlated ensemble are the focus of direct selection. Here we extend and generalize Pearson's major results. The purpose of this paper is to derive measures of directional and stabilizing (or disruptive) selection on each of a set of phenotypically correlated characters. The analysis is retrospective, based on observed changes in the multivariate distribution of characters within a generation, not on the evolutionary response to selection. Nevertheless, the measures we propose have a close connection with equations for evolutionary change. Many other commonly used measures of the intensity of selection (such as selective mortality, change in mean fitness, variance in fitness, or estimates of particular forms of fitness functions) have little predictive value in relation to evolutionary change in quantitative traits. To demonstrate the utility of our approach, we analyze selection on four morphological characters in a population of pentatomid bugs during a brief period of high mortality. We also summarize a multivariate selection analysis on nine morphological characters of house sparrows caught in a severe winter storm, using the classic data of Bumpus (1899). Direct observations and measurements of natural selection serve to clarify one of the major factors of evolution. Critiques of the adaptationist program (Lewontin, 1978; Gould and Lewontin, 1979) stress that adaptation and selection are often invoked without strong supporting evidence. We suggest quantitative measurements of selection as the best alternative to the fabrication of adaptive scenarios. Our optimism that measurement can replace rhetorical claims for adaptation and selection is founded in the growing success of field workers in their efforts to measure major components of fitness in natural populations (e.g., Thornhill, 1976; Howard, 1979; Downhower and Brown, 1980; Boag and Grant, 1981; Clutton-Brock et

Mortality factors of satin moth,Leucoma salicis [Lep.: Lymantriidae], in aspen forests in Maine

Natural control agents of the satin moth,Leucoma salicis (L.) were examined in 2Populus grandidentataMichaux stands. Highest mortality occurred in overwintering larvae, with the causal agents 2 fungi,Paecilomyces sp. andHirsutella giganteaPetch, a factor causing death symptomatic of a pathogen, the parasiteEupteromalis hemipterus (Walker) and death from unknown causes. Mortality fromPaecilomyces sp. andE. hemipterus was reduced where overwintering sites were covered with burlap cloth. Parasites recovered from larvae and pupae included the braconidsApanteles melanoscelus (Ratzeburg) andMeteorus versicolor (Wesmeal), the ichneumonidCoccygomimus pedalis (Cresson), the tachinidsCompsilura concinnata (Meigen),Carcelia laxifronsVilleneuve,Tachinomyia variataCurran, and the sarcophagidsSarcophaga aldrichiParker andAgria houseiShewell. Larval and pupal predators included the carabidCalosoma frigidumKirby, pentatomids, and birds, particularly black-billed cuckoos,Coccyzus erythrophthaimus (Wilson). Eggs were parasitized by the scelionidTelenomus prob.californicusAshmead and the trichogrammidTrichogramma minutum (Riley). Predators of adult satin moths included the hermit thrush,Hylocichla guttata (Pallas), and pentatomid bugs.

Bacteria Isolated from Black Rot of Rice Grains

In black rot of rice grains a black spot develops on a part of the rice grain, which is formed at the middle or apical part of the grains and rarely at the basal part. Recently, its occurrence has gradually increased in Hokkaido and has been causing serious damage.From both the affected and healthy rice grains, many bacteria and some fungi were isolated. Among them, yellow bacteria were most frequently isolated.Sixty five isolates of bacteria, obtained from both kinds of grains collected from various paddy areas in Hokkaido, were classified into four groups according to some major characteristics. Moreover, group I was divided into three strains on the bases of some minor characteristics. Group II consisting of fluorescent, achromogenic and chromogenic groups named by Iizuka et al.The bacterial isolates of each group were identified as follows;I. A; Enterobacter cloacae, B and C; Erwinia herbicola.II. Fluorescent group; Pseudomonas schulkilliensis and allied species.Achromogenic group; p. sp. (non-fluorescent).Chromogenic group; p. cerealis, p. melanogenum and p. lacunogenes.III. Brevibacterium spp.IV. uncertain.Rice grains did not show any symptom on the surface of them when they were inoculated with E. herbicola through the seed-coat by the injection method before their milky ripe stage. The black rot occurred on the wounded part of grains, whenever they were inoculated with E. herbicola or not, by the needle inoculation method in the milky ripe stage and E. herbicola were re-isolated from both the blackening part of the inoculated and non-inoculated grains. The causal agent of the black rot of rice grains was recoginized as due to the sucking of rice grains by the pentatomid bugs and allied species. Moreover, it was proved that Xanthomonas itoana was synonymous with E. herbicola.

A revision of the species of Australian and New Guinea shield bugs fromerly placed in the generaPoecilometisDallas andEumecopusDallas (Heteroptera : Pentatomidae), with description of new species and selection of lectotypes

The status of two genera of Australian Pentatomidae, Poecilometis Dallas and Eumecopus Dallas, is discussed, and the two genera provisionally amalgamated on evidence from external morphology and the structure of the aedeagus of the male. The name Poecilometis is adopted for the taxon. The species of Poecilometis as it is now understood are keyed and a complete description or redescription given of each, with figures of the dorsal aspect and male and female external genitalia (where both sexes were available). The genus is considered to contain 38 species and seven subspecies. Twelve new species (extraneus, papuensis, callosus, monteithi, cooki, griseicolor, mellicolor, parilis, lungloensis, politus, macromaculatus, and darwini), and three new subspecies (borealis obesus, darwini plenicolor, and nigriventris decoratus), are described. The following names are shown to be previously unrecognized junior synonyms of earlier names at specific and subspecific level: binotatus Walker (of alienus Walker); stigmaticus Van Duzee 1905, edwardsi Van Duzee, and elligticus Bergroth (of strigntus Westwood); rufescens Westwood (of lineatus Westwood); uniformis Schouteden (of gravis Fabricius); mundus Walker (of eximius Stal); cognatus Walker and vittiventris Stal (of apicalis Westwood); moseleyi Distant (of punctiventris Stal); eyrei Distant (of fuscescens Stal); adversidens Bergroth (of acanthopygius Stal). The following specific names are junior synonyms of earlier names but represent a different subspecies from that of the nominate form: conspersus Walker and abdominalis Distant (of apicalis Westwood); ynigrum Bergroth (of patruelis Stal); superbus Distant (of nigriventris Dallas). The following misidentifications in literature have been corrected: gravis Van Duzee, 1905, non Westwood (= strigatus Westwood); strigatus Van Duzee, 1905, non Westwood (= cooki, sp.nov); rufescens Van Duzee, 1905, non Westwood (= gravis Fabricius); australasiae Distant, 1899, non Donovan (= patruelis Stal); armatus Distant, 1899, in part non Fabricius (= calidus Walker). Lectotypes are selected for Poecilometis elligticus Bergroth, Poecilometis spenceri Bergroth, Eumecopus ynigrum Bergroth, Eumecopus acanthopygius Stal, and Eumecopus horni Bergroth. Poecilometis scutellatus Distant is a synonym of Theseus modestus (Stal 1865), and Theseus distanti is proposed as a new name for Theseus scutellatus Distant, 1910, now a secondary junior homonym of Theseus scutellatus (Distant 1899). Finally a discussion, with figures, is presented of the structure of the aedeagus in those species of which there were sufficient specimens available to risk dissection. These are compared with the aedeagus of one species of each of two related genera, Alcaeus varicornis (Westwood) and Theseus modestus (Stal). It is shown that all three genera are distinctive in that the sperm duct is not elongated into a terminal vesica, a character reminiscent of pentatomid bugs of the subfamily Asopinae. The species in Poecilometis appear to belong to several series, each perhaps a distinct genus, but the division indicated would differ from the traditional one. It is not considered practicable to adopt any new division of the genus until the aedeagi of a greater number of species of Poecilometis can be examined.

NATURAL AND SYNTHETIC MATERIALS WITH INSECT HORMONE ACTIVITY. 5. SPECIFIC JUVENILE HORMONE EFFECTS IN ALIPHATIC SESQUITERPENES.

The juvenile hormone activity of ethyl or methyl esters of aliphatic sesquiterpenic acids with 0 to 4 double bonds was tested on 8 species of insects belonging to 5 families of Hemiptera and Coleoptera. Special attention was paid to the addition of hydrogen chloride or epoxide groups on or across the double bonds. Certain chemical changes in the molecule appear to cause a general increase of the activity in all species studied. These are: the presence of 2,3 unsaturation conjugated with the carboxyl group; the trans stereochemical position of the C-3 methyl; an introduction of 10,11 epoxide or hydrochloride; and esterification with ethyl rather than with methyl. There are also chemical changes which lead to genus- or family-specific variations in juvenile hormone activity. With increasing amount of unsaturation the activity either remains almost unaffected (pyrrhocorid bugs) or increases (pentatomid bugs) or decreases considerably (tenebrionid and dermestid beetles). The addition of hydrogen chloride or epoxide to the 6,7 double bond causes enormous increase in the activity in the Pyrrhocoridae and Lygaeidae, no considerable change in the Pentatomidae, and great decreases in the beetles and Lepidoptera.

Nematospora coryli . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Nematospora coryli . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On seeds of Gossypium hirsutum . Also on Anacardium occidentale, Citrus spp., Coffea spp., Corylus avellana, Crotalaria juncea, C. striata, Cajanus cajan, Dolichos lablab, Phaseolus atropurpureus, P. acutifolius, P. lunatus, P. vulgaris, Tephrosia wegelii and Vigna sinensis [Vigna unguiculata] (5: 390; Leach, 1940; Pearson & Maxwell Darling, 1958). DISEASE: Yeast spot of bean and a large number of other seeds, Internal Boll Rot or Cotton staining or Stigmatomycosis. Cotton lint becomes dirty yellow and seeds are shrivelled. Spots mostly on the fruit and other fleshy parts or on the seed. On Lima bean cotyledons the lesions are a dark brown, sunken, wrinkled areas. After infection, beans cease developing and later become dwarfed or die. The earlier the attack, the more injury the bean sustains (Chupp & Sherf, 1960). Infection occurs only when the fruits are young and the atmosphere humid. GEOGRAPHICAL DISTRIBUTION: Mostly in Africa and Asia but has been reported from U.S.A. and Europe (4: 90; 26: 93; CMI Map 163, ed. 3, 1959). TRANSMISSION: Mechanically transmitted from plant to plant by pentatomid bugs of the genera Antestiopsis, Nezara and Dysdercus nigrofasciatus . The yeast always enters through insect punctures (5: 390; 14: 507; 23: 207). Its dissemination is favoured by bright sunny days which facilitate the movement of the carrier from one plant to another (Chupp & Sherf, 1960).

The adult scent glands and scent of nine bugs of the superfamily Coreoidea

In most of the six coreoid genera examined there are differences in the scent gland complex. This comprises a median, ventral, metathoracic reservoir with either one, two, or three pairs of accessory glands. The nine adult bugs examined all produced a colourless, single-phase scent, the components of which were similar although the relative proportions varied. Either n-hexanal or n-hexyl acetate, or both, were usually the major constituents (about 90 per cent of the total) and n-hexanol and acetic acid were also present in amounts varying from traces to about 10 per cent. In one species n-butanal was detected and in two species n-butyl butyrate and (probably) butyric acid were present. The characteristic, ester odour of these coreoid bugs is quite unlike that of pentatomid bugs examined so far and the two groups do not possess a single component in common; nevertheless there are interesting analogies between the scent components of both groups.

Characteristic odour components of the scent of stink bugs

The characteristic stink of three pentatomid bugs was shown to be largely due to a mixture of hex-2-enal, a dicarbonyl compound, and either oct-2-enal or dec-2-enal. In two coreid bugs n-hexanal was a major odour component. These or similar compounds occur in plants on which the bugs feed, but it is possible that the bugs may also produce them metabolically. The odours almost certainly have a defensive role.