Lygaeidae Research Articles

RESPONSES TO SELECTION ON FLIGHT BEHAVIOR IN A MIGRATORY POPULATION OF MILKWEED BUG (ONCOPELTUS FASCIATUS).

EvolutionVolume 43, Issue 8 p. 1805-1808 Note and CommentFree Access RESPONSES TO SELECTION ON FLIGHT BEHAVIOR IN A MIGRATORY POPULATION OF MILKWEED BUG (ONCOPELTUS FASCIATUS) James O. Palmer, James O. Palmer Department of Biology, Program in Evolutionary Ecology and Behavior, University of Iowa, Iowa City, IA, 52242Present address: Department of Entomology, Texas A&M University, College Station, TX 77843.Search for more papers by this authorHugh Dingle, Hugh Dingle Department of Entomology, University of California, Davis, CA, 95616Search for more papers by this author James O. Palmer, James O. Palmer Department of Biology, Program in Evolutionary Ecology and Behavior, University of Iowa, Iowa City, IA, 52242Present address: Department of Entomology, Texas A&M University, College Station, TX 77843.Search for more papers by this authorHugh Dingle, Hugh Dingle Department of Entomology, University of California, Davis, CA, 95616Search for more papers by this author First published: December 1989 https://doi.org/10.1111/j.1558-5646.1989.tb02629.xCitations: 13 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume43, Issue8December 1989Pages 1805-1808 ReferencesRelatedInformation

Predators of Fig Wasps

Predators inflict high mortality on the four species of wasps associated with the fig Ficus pertusa L. in Monteverde, Costa Rica. Because one of these wasps is the obligate pollinator of the fig, predation may have a strong impact on successful pollen donation by the plant. The natural histories of several predators are described: an ant that feeds on wasps arriving to oviposit, moth and weevil larvae that destroy wasps as they develop within the fruits, a staphylinid beetle that feeds on mature wasps before they leave the fruits, and a group of birds that gleans wasps as they leave. The synchrony of arrival and departure of pollinators from the fig trees probably make them the species least vulnerable to predation. FIGS (Ficus SPP.) AND THEIR POLLINATOR WASPS form a keystone (Gilbert 1980), an interaction upon which other species depend and around which they accumulate. The dependence of frugivorous birds (Snow 1981, Beehler 1985), bats (Heithaus et al. 1975, Morrison 1978), and primates (Raemaekers 1979, Milton 1980, Terborgh 1983) on ripe figs is well known. Several insects (Smilanick & Ehler 1976, Janzen 1979, Frank 1983) and birds (Janzen 1981) are major seed predators when fruits are still on the tree, and a large group of lygaeid bugs feeds exclusively on seeds of fallen figs (Slater 1972). Such interactions have a major impact on the female reproductive function of seed production in figs. Less well known are species that interact with the mutualism via their impact on the pollinator wasps (Hymenoptera: Chalcidoidea: Agaonidae), and thus potentially limit the figs' male reproductive function of pollen donation. The larvae of certain chalcidoid wasps are known to kill developing agaonid larvae (Kuttamathiathu 1955, Galil & Eisikowitch 1968), and ants (Frank 1983), dragonflies, and birds (Janzen 1979) have been observed to prey upon adults. Here I describe the suite of insects and birds that are major predators of four wasp species associated with one Costa Rican fig, and speculate on the extent to which they specialize on fig wasps. I then consider how great an impact predation has on the pollinator species, and thus indirectly on the fig itself. STUDY SITE AND NATURAL HISTORY Ficus pertusa, a small (5-12 m), hemiepiphytic or freestanding tree, is one of the two most common Ficus species in Central America (Condit 1969). It is found from 0 to 2000 m in moist highland to lowland forests and savannas and in both disturbed and undisturbed habitats (Burger 1977). F. pertusa grows abundantly in pastures and remnant patches of primary and secondary forest throughout the community of Monteverde, Costa Rica, located just below the Continental Divide on the Pacific slope of the Cordillera de Tilaran (10?12'N, 84?42'W, elevation 13501450 m). Undisturbed forest in the area is transitional between lower montane wet and moist forest (Holdridge

Effects of Gamma Radiation and a Chemosterilant Applied to Late Nymphal Instars of the Large Milkweed Bug (Hemiptera: Lygaeidae)

Biological effects of gamma radiation and apholate, a chemosterilant, were evaluated when fifth-instar nymphs of Oncopeltus fasciatus (Dallas) were treated. Irradiation of older fifth instars revealed less sensitivity than younger ones. Dosages 2 and 1.2 times greater were necessary on older nymphs for mortality and wing deformities, respectively, in 50% of the insects. Compared with mortality, fecundity and fertility were affected at lower dosages of radiation. When both sexes were treated and mated, fecundity was reduced by 75% at 2.2 krad; 75% reduction in fertility occurred at about two-thirds of that dose, or 1.4 krad. When males alone were treated and mated, ED75 values were higher (3.5 krad for fecundity and 3.0 for fertility). Thus, males were less sensitive with respect to these two criteria. Adult longevity of nonirradiated females and males was 32.0 to 33.5 d, respectively. Longevity was reduced by 14% in females and 18% in males after treatment of late fifth Instars with 6 krad. Topical applications of apholate resulted in wing deformities and mortality similar to the pattern described for radiation. Compared with late fifth instars, greater sensitivity occurred in fifth instars treated early. Lethal effects occurred at lower doses than wing deformities. This result contrasted with radiation treatments in which doses were similar with respect to lethality and wing deformities. Weight losses also occurred following treatment with apholate but were not significant. Treatments of early or late fifth instars with gamma radiation or apholate showed no differences between sexes in mortality or wing deformities.

Toxic responses of developing fifth instar milkweed bugs, Oncopeltus fasciatus (Hemiptera), to aflatoxin B1.

Although studies on the aflatoxins have involved test systems ranging from cell cultures to laboratory animals, there appears to be a general lack of information on the ecological and economic effects of aflatoxins on insects. However, this situation is gradually changing. These studies involved the toxic responses of fifth instar milkweed bugs (Oncopeltus fasciatus) to AFB/sub 1/. Milkweed bugs pass through five distinct nymphal instars. In the fifth instar stage, the insect is marked with lateral spots on all of the abdominal pleurites and median spots on the fifth, sixth, seventh, eighth, and ninth dorsal abdominal tergites. The apex of the ventral abdominal surface is black and the remainder of the body is reddish-orange. Also, the adult is elongate to oval, and it is black and red in color. Because of this insect's ability to live and reproduce normally when provided dried sunflower seeds and water, it is a very desirable model to study through out the year. It is thought that juvenile insect stages are more sensitive to AFT than are adults, thus the instar and its developmental and sexual responses to aflatoxins are of interest.

Responses to Selection among Life-History Traits in a Nonmigratory Population of Milkweed Bugs (Oncopeltus fasciatus)

Responses to Selection among Life-History Traits in a Nonmigratory Population of Milkweed Bugs (Oncopeltus fasciatus)

Responses in flight to selection on wing length in non‐migratory milkweed bugs, Oncopeltus fasciatus

AbstractA sample of nonmigratory Oncopeltus fasciatus (Dallas) (Hemiptera: Lygaeidae) from Puerto Rico was subjected to bi‐directional selection for wing length for 20 generations. Response to selection was strong in both directions. In the 8th and 14th generations samples were drawn from the selected lines and tested for tethered flight. There was little flight observed and no correlation between wing length and flight duration. There was also no correlation between wing length and fecundity. These results contrast with results from a migratory population from Iowa, U.S.A. where there were positive genetic correlations between wing length and both flight and fecundity. A migration‐life history syndrome was thus apparent in the migratory Iowa population, but was not present in the non‐migratory population from Puerto Rico.RésuméRelations de la sélection en fonction de la longueur de l'aile et le vol chez Oncopeltus fasciatusL'étude de la relation entre la longueur de l'aile, le vol et la fécondité a été faite sur une population sédentaire d'O. fasciatus de Porto Rico; les résultat ont été comparés à ceux d'une population migratrice de L'Iowa, U.S.A. Les punaises de Porto Rico ont été sélectionnées pour leurs ailes longues ou countes pendant 20 générations, en utilisant des lignées répétitives. Une forte réponse a été obtenue par rapport aux témoines des lignées non sélectionnées. Aux 8ème et 14ème generations de selection, des punaises ont été prélevées pour examen de leur vol entravé. Très peu de vols ont été obtenus et il n'y avait aucune corrélation entre la durée du vol et la longueur de l'aile. Parallèlement, la fé***c̀ondité pendant les 5 premiers jours de reproduction a été mesurée, et aucune corrélation n'a été mise en évidence, mais il n'y avait pas non plus de corrélation entre longueur de l'aile et fécondité. Ces résultats différent de ceux de la population migratrice de l'Iowa, pout laquelle il y avait une corrélation génétique positive entre longueur de l'aile, vol et fécondité. Chez les punaises de l'Iowa, il y aurait ainsi un syndrome biologique de migration avec des ailes longues, une fécondité élevée précoce et des vols de longue durée. Il n'y avait pas de manifestation de ce syndrome chez les populations sédentaires de Porto Rico. Les O. fasciatus migrateurs et sédentaires différent évidemment par la base génétique de leur biologie.

Genetic and Maternal Influences on Life History Plasticity in Response to Photoperiod by Milkweed Bugs (Oncopeltus fasciatus)

Using two geographically adjacent, temperate-zone populations of the milkweed bug Oncopeltus fasciatus, we employed a split-family experimental design to estimate genotype-environment interaction (g-e) and across-environment genetic correlations for two female life history characters, age at first reproduction and fecundity over the first 5 days of reproduction. For each of a number of families, some sisters were reared in a short-day environment (LD 11:13, 23$^\circ$C) and others in a long-day environment (LD 14:10, 23$^\circ$C); the environments were chosen to simulate the temporal environmental heterogeneity experienced by lineages of temperate-zone bugs. Bugs normally exhibit a plastic response to such heterogeneity by delaying the onset of reproduction in short days relative to that in long days, the delay providing time for migration to occur. In one population, there is significant variation caused by g-e for the age at first reproduction, indicating the existence of genetic variance for plasticity in this character. This result suggests that there is potential for the evolution of phenotypic plasticity in the timing of reproduction. In each population, however, there is a positive genetic correlation between the timing of reproduction in the long- and short-day environments, implying that the evolution of life history in one environment can influence evolution in the alternative environment. In particular, the potential rate of evolution toward a joint optimum of early reproduction in long days and delayed reproduction in short days will be less than if the across-environment correlation were zero or negative. During the attainment of equilibrium at the joint optimum, selection can prevent optimization of the age at first reproduction and maintain genetic variation for this character within environments. However, a maternal effect that prevents long delays in the onset of reproduction from occurring in two successive generations of bugs provides a means for lessening the influence of selection in the alternative environment. This maternal effect also ensures that a spring generation of bugs does not exhibit an inappropriate diapause. For fecundity, one population has a positive across-environment genetic correlation, indicating that performance generalizes across environments for this fitness component. In the other population, primarily because of the performance of one sibship, a negative across-environment correlation implies that performance is specialized. The populations also differ in life history. The basis for such microgeographic differentiation, the first recorded for migratory temperate-zone populations of this species, may be sampling, differential migration, or adaptation. More work is necessary to distinguish among these hypotheses. Consistent with previous studies, we found high levels of genetic variation for life history characters within populations and, in general, a lack of genetic correlation between the age at first reproduction and fecundity.

Wing and flight muscle polymorphism in a lygaeid bug, Horvathiolus gibbicollis: determinants and life history consequences

ABSTRACT. Horvathiolus gibbicollis (Costa), a ground‐living seed‐feeding bug of the mediterranean region, has two wing morphs. In macrop‐terous bugs both pairs of wings are fully developed. In brachypterous ones forewings are reduced to about two‐thirds and hindwings to less than a third of their length in macropters. Each morph bred true with regard to wing length when reared under variable density, food and temperature conditions for several generations. All F1 offspring between crosses of the two morphs were brachypterous. In F2 approximately 25% were macropters and 75% brachypters implying monogenic control of wingform. Flight muscles in macropters vary from fully developed to totally reduced. This variation is determined by environmental conditions during adult life. Most young adult bugs have flight muscles, and totally starved or unmated bugs retain their flight muscles. Fed and mated females histolyse flight muscles as they start laying eggs, while most males of the same group retain their muscles. Brachypterous bugs have a smaller thorax and larger abdomen than macropterous ones. Brachypterous bugs reach adulthood slightly before macropterous ones, and they have a distinctly shorter adult preoviposition period. Lifetime egg production does not differ significantly between the two wing morphs. However, the temporal pattern of egg laying is different in the two morphs. The mx‐curve of macropters starts later, then attains a higher peak and finally decreases faster than that of brachypters. Initially, macropters lay smaller eggs than brachypters, but egg volume increases with age in macropters and eventually approaches that of brachypters. The initial increase in reproductive effort (egg volumexegg number) of macropters is concomitant with wing muscle histolysis and the mobilization of thorax space for reproduction. Adult survival rate does not differ between the morphs.

Direct and Correlated Responses to Selection Among Life-History Traits in Milkweed Bugs (Oncopeltus fasciatus)

Direct and Correlated Responses to Selection Among Life-History Traits in Milkweed Bugs (Oncopeltus fasciatus)

Geographic variation in the effects of temperature on life-history traits in the large milkweed bug Oncopeltus fasciatus.

Complete sets of life-history data (sufficient to construct life-tables and calculate intrinsic rates of increase) were collected at each of three constant temperatures for descendants of two tropical populations of the Large Milkweed Bug, Oncopeltus fasciatus. Although the two populations occur only about 60 km apart, they experience quite different thermal regimes, with little variation in mean monthly temperature at either site. In addition to the pronounced effect of ambient temperature on life-history traits, significant population-by-temperature interactions were observed for six of the eight traits examined. The data and the recent history of the species' distribution are consistent with the hypothesis that natural selection in the cool habitat has favored improved survival and increased reproduction at cool temperatures, with some trade-offs with respect to performance at higher (but ecologically relevant) temperatures.

Rates of seed removal by ants at heath and woodland sites in southeastern Australia

AbstractAnts often appear to be important post‐dispersal seed predators, particularly in Australia where they are exceptionally abundant and apparently can remove large quantities of seeds from the ground. Rates of seed removal by ants usually are measured by recording removal from artificial seed baits, but the reliability of this approach has not been tested, nor have there been many attempts to integrate the results with the activity of seed‐eating ants. This paper describes the rates of seed removal, estimated using a baiting technique that is tested for its reliability, by the seed‐eating ants in adjacent heath and woodland sites at Wilson's Promontory, Victoria. Ants removed up to 100% of seeds, but rates varied according to seed species, size of seed clumps, season, time of exposure, and other aspects of the baiting technique. Methodological guidelines are provided to make baiting conditions approximately those likely to occur in nature.Seed‐eating ants, particularly species ofRhytidoponera, Chelaner and Pheidole, were by far the most important post‐dispersal seed predators, and patterns of seed removal were directly related to their composition, abundance and foraging behaviour. Lygaeid bugs were also observed eating seeds, but there was no evidence of seed predation by rodents or birds.The results suggest that seed predation by ants can substantially deplete seed reserves: however, its actual effect on seedling recruitment is likely to depend on many factors including seed size, crop size, weather, timing and location of seed fall, availability of alternative food sources, patterns of seedling mortality, and fire, none of which have been adequately investigated.

A new species of Laticlerada (Hemiptera: Lygaeidae) from Malaysia

Abstract Laticlerada muluensis, sp. nov. (Hemiptera: Lygaeidae) is described from Sarawak, Malaysia.

Heteropterous insects collected by light traps in Edirne (Turkey).

This study deals with Heteropterous insects collected by light traps settled in the experimental fields of Plant Production Institute, Edirne, during 1978-1981. By this method, 128 species of 12 families of Heteroptera have been encountered. Sigara nigrolineata (Fieb.) (Corixidae); Perithrecus gracilicornis (Put.), P. angus­ ticoIlis (R.Sb.) (Lygaeidae); Exolygus pratensis (L.), E. rugulspennis (Popp.) , Adel­ phocoris lineolatus (Gz.) and Trigonotylus ruficornis (G.) (Miridae) have been found as the most abundant species.

Mantids and Milkweed Bugs: Efficacy of Aposematic Coloration Against Invertebrate Predators

Mantids and Milkweed Bugs: Efficacy of Aposematic Coloration Against Invertebrate Predators

Interspecific Hybridization and Genetic Divergence in Milkweed Bugs (Oncopeltus: Hemiptera: Lygaeidae)

Interspecific Hybridization and Genetic Divergence in Milkweed Bugs (Oncopeltus: Hemiptera: Lygaeidae)

Responses of the large milkweed bug,Oncopeltus fasciatus(hemiptera: lygaeidae) to high levels of air pollutants

Milkweed bugs were exposed to either 300 ppm CO, 5–10 ppm SO2, 5–10 ppm NO2, or compressed air (controls) for two hours a day throughout their life cycle and until 50 percent of the adults had died. The apparent stimulation of growth and reproduction by gaseous pollutants is difficult to explain.

Transmission of the Trypanosomatid Flagellate Phytomonas davidi, a Symbiont of the Euphorbiaceae, by the Hemipteran Bug Pachybrachius bilobata scutellatus1

ABSTRACT. Phytomonas davidi is found in the latex of species of the plant family Euphorbiaceae, including Chamaesyce hirta and C. hyssopifolia, to latitude 32°N in the southeastern United States. The hemipteran Pachybrachius bilobata scutellatus (family Lygaeidae) serves as an agent of transmission from plant to plant. Heavy infections of flagellates in the salivary glands were observed; trypanosomatids were less than one‐half the size seen in the plants and in the gut of the bug.

Effect of precocene II on acid phosphatase activity in the large milkweed bug,Oncopeltus fasciatus (Hemiptera: Lygaeidae)

When precocene II was applied to the fourth instar milkweed bug, there was a significant decrease in acid phosphatase activity in the hemolymph at the 40%, 50%, 60%, and 70% time periods in the stadium.

Relationship between metabolic rate, aging, lipid peroxidation, and fluorescent age pigment in milkweed bug, Oncopeltus fasciatus (Hemiptera).

The purpose of this investigation was to further elucidate the relationship between metabolic rate and life span by studying the effect of experimentally varied metabolic rate on in vitro lipid peroxidation, fluorescent age pigment accumulation, and aging in the adult milkweed bug. The metabolic rate was altered by housing the insects at 18 degrees, 25 degrees, and 30 degrees C. The life span of insects was inversely related to the ambient temperature. Metabolic rates, before the period of 10% mortality, were greater at the elevated temperatures, but in the last trimester of life the rates were higher at 25 degrees C than at 30 degrees C. The total average amount of oxygen consumption during the entire life span of the insects raised at different temperatures was statistically similar. Lipid peroxidation potential of the tissues and concentration of fluorescent age pigment increased with age at significantly faster rates in organisms raised at relatively higher temperatures. The results suggest a positive correlation between metabolic rate, aging, lipid peroxidation potential, and fluorescent age pigment concentration and are interpreted to support the concept that aging may be modulated by the rate of oxygen consumption.

SELECTIVE PREDATION IN A EURYPHAGOUS INVERTEBRATE PREDATOR, PARDOSA VANCOUVERI (ARACHNIDA: ARANEAE)

AbstractSelective predation (i.e., non-random feeding) was studied in a laboratory system that allowed individual lycosid spiders, Pardosa vancouveri, to feed on prey populations consisting of one or two kinds of insects. Various combinations of male and female fruit flies (Drosophila melanogaster), “small” and “large” beetle larvae (Tenebrio molitor), and nymphal milkweed bugs (Oncopeltus fasciatus) were used as prey. Female adult and subadult spiders were used as predators. Generally, fruit flies were selected by the spiders over mealworms or milkweed bugs, and small mealworms over large ones. No selection occurred between male and female flies. Very weak or no selection occurred between small beetle larvae and milkweed bugs. Spiders of both age classes showed similar selective tendencies. Prior feeding experiences did not alter feeding selections, but minor changes in the physical complexity of the environment did. Twelve criteria related to development, survival, growth, and fecundity were monitored for 12 groups of spiders fed either single or two-prey combinations of the five kinds of prey. The hierarchy of benefits conferred by the five kinds of prey was the same as that for selection. Male and female fruit flies equally benefited the spiders. The fruit flies yielded the most and large beetle larvae the least number of statistically superior benefits. Small beetle larvae and milkweed bugs were intermediate and about equal. There was no evidence that a mixed (i.e., two) prey diet is better than a single prey diet. It is hypothesized that selective predation by P. vancouveri involves prey sampling, memory of prey attributes, and selection of prey that possess attributes that are associated with high fitness.