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Douglas W Tallamy - One of the best experts on this subject based on the ideXlab platform.
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female choice by scent recognition in the spotted Cucumber Beetle
Ethology, 2006Co-Authors: Jeremy F Brodt, Douglas W TallamyAbstract:In species that demonstrate female choice, geographically distinct populations can vary in their signal-response behaviors as a result of environmental differences or genetic drift. Observing whether or not females discriminate against males from allopatric populations can establish such signal deviations. Here we compare mating success within and between populations of the spotted Cucumber Beetle (Diabrotica undecimpunctata howardi) collected from Delaware, Tennessee, Missouri, and New Mexico, USA. A no-choice cross-mating experiment was employed to measure female preference for sympatric and allopatric males. While only two of the populations (Tennessee and Missouri) demonstrated statistically significant female preference for sympatric males, this trend was observed in all populations tested. Further, we show that (i) males from Tennessee, Missouri, and New Mexico differ in their scent, (ii) females may use population-specific scents to discriminate among males, and (iii) females whose antennae have been surgically removed are unable to recognize acceptable mates. New Mexico males, which were never accepted by either Tennessee or Missouri females, became acceptable mates when crowded with Tennessee or Missouri males prior to copulation. We infer that male odor may be an important factor in determining Cucumber Beetle mating success.
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male traits under cryptic female choice in the spotted Cucumber Beetle coleoptera chrysomelidae
Behavioral Ecology, 2002Co-Authors: Douglas W Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted Cucumber Beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed musculature that, when contracted, folded the vaginal duct leading to the female's bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99% of the Beetles that came to cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered cucurbitacins did not stroke females faster than males with no cucurbitacins, and fast-stroking males were not more likely to find and sequester cucurbitacins than were males that stroked more slowly. Males with a cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Copyright 2002.
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male traits under cryptic female choice in the spotted Cucumber Beetle coleoptera chrysomelidae
Behavioral Ecology, 2002Co-Authors: Douglas W Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted Cucumber Beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed musculature that, when contracted, folded the vaginal duct leading to the female’s bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99% of the Beetles that came to cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered cucurbitacins did not stroke females faster than males with no cucurbitacins, and fast-stroking males were not more likely to find and sequester cucurbitacins than were males that stroked more slowly. Males with a cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Key words: copulatory courtship, cryptic female choice, Diabrotica undecimpunctata, sexual selection. [Behav Ecol 13:511–518 (2002)]
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Fate of Male-derived Cucurbitacins in Spotted Cucumber Beetle Females
Journal of Chemical Ecology, 2000Co-Authors: Douglas W Tallamy, Piotr M. Górski, Julia K. BurzonAbstract:Using the spotted Cucumber Beetle, Diabrotica undecimpunctata howardi , as a model species, we begin an examination of the role of dietary cucurbitacins, the bitter tetracyclic triterpenes produced by cucurbits, in the reproductive behavior of luperine chrysomelids that seek these compounds for purposes other than host-plant recognition or nutrition. By manipulating the cucurbitacin content of adult diets, we determine: (1) how males and females partition cucurbitacins between reproductive organs and other tissues, (2) the extent to which males pass cucurbitacins to females during copulation, and (3) if females increase their cucurbitacin stores via multiple matings. After two days of exposure to dietary cucurbitacins, 8.3 times more cucurbitacins per gram dry weight were sequestered in male spermatophores than in the aggregate of remaining male tissues. These cucurbitacin-rich spermatophores were passed to females during mating, and 78.8% of the transferred cucurbitacin was deposited in eggs, 11.8% was irreversibly sequestered in other female tissues, and 9.4% was apparently excreted. Females copulated with 0–15 males prior to accepting a complete spermatophere, but did not accept measurable amounts of cucurbitacin from rejected males. Regardless of when it was received, females lost subsequent receptivity to additional males after accepting a complete spermatophore. The implications of these data are discussed in terms of sexual selection hypotheses and mating behavior in Cucumber Beetles.
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Cucurbitacins: A Role in Cucumber Beetle Steroid Nutrition?
Journal of Chemical Ecology, 1999Co-Authors: Fathi T. Halaweish, Douglas W Tallamy, Eva SantanaAbstract:The conditional role of cucurbitacins as phytosteroid supplements, cholesterol precursors, or ecdysteroid antagonists in the spotted Cucumber Beetle, Diabrotica undecimpunctata howardi , was investigated in two ways: by comparing larval survival and growth rate on cucurbitacin-rich and cucurbitacin-poor squash cultivars of Cucurbita pepo and by manipulating the presence of cholesterol, phytosteroids, and cucurbitacins in an artificial diet and examining the effects on adult survival and fecundity. Larvae that developed on cucurbitacin-rich roots grew significantly faster and survived as well as larvae on cucurbitacin-poor roots. There was no evidence, however, that adults could substitute cucurbitacins in vital phytosteroid roles. Beetles reared on a cucurbitacin-rich, phytosteroid-poor diet laid significantly fewer eggs and died significantly younger than Beetles with a full complement of dietary phytosteroids and also laid fewer eggs than Beetles with no access to phytosteroids in their adult diet. The data are consistent with the hypothesis that, when the side chain of dietary cucurbitacins can be successfully hydrogenated, these compounds play a nutritional role as substitutes or precursors for structural steroids. In contrast, when the carbon–carbon double bond cannot be hydrogenated, cucurbitacins may become antagonists at ecdysteroid receptors, negatively affecting Beetle fitness.
Julie A Mcclafferty - One of the best experts on this subject based on the ideXlab platform.
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male traits under cryptic female choice in the spotted Cucumber Beetle coleoptera chrysomelidae
Behavioral Ecology, 2002Co-Authors: Douglas W Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted Cucumber Beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed musculature that, when contracted, folded the vaginal duct leading to the female's bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99% of the Beetles that came to cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered cucurbitacins did not stroke females faster than males with no cucurbitacins, and fast-stroking males were not more likely to find and sequester cucurbitacins than were males that stroked more slowly. Males with a cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Copyright 2002.
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male traits under cryptic female choice in the spotted Cucumber Beetle coleoptera chrysomelidae
Behavioral Ecology, 2002Co-Authors: Douglas W Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted Cucumber Beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed musculature that, when contracted, folded the vaginal duct leading to the female’s bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99% of the Beetles that came to cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered cucurbitacins did not stroke females faster than males with no cucurbitacins, and fast-stroking males were not more likely to find and sequester cucurbitacins than were males that stroked more slowly. Males with a cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Key words: copulatory courtship, cryptic female choice, Diabrotica undecimpunctata, sexual selection. [Behav Ecol 13:511–518 (2002)]
Michael P. Hoffmann - One of the best experts on this subject based on the ideXlab platform.
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Curcurbita pepo subspecies delineates striped Cucumber Beetle (Acalymma vittatum) preference.
Horticulture research, 2016Co-Authors: Lauren J. Brzozowski, Michael P. Hoffmann, B M Leckie, J Gardner, M MazourekAbstract:The striped Cucumber Beetle (Acalymma vittatum (F.)) is a destructive pest of cucurbit crops, and management could be improved by host plant resistance, especially in organic farming systems. However, despite the variation in striped Cucumber Beetle preference observed within the economically important species, Cucurbita pepo L., plant breeders and entomologists lacked a simple framework to classify and exploit these differences. This study used recent phylogenetic evidence and bioassays to organize striped Cucumber Beetle preference within C. pepo. Our results indicate preference contrasts between the two agriculturally relevant subspecies: C. pepo subsp. texana and C. pepo subsp. pepo. Plants of C. pepo subsp. pepo were more strongly preferred than C. pepo subsp. texana plants. This structure of Beetle preference in C. pepo will allow plant breeders and entomologists to better focus research efforts on host plant non-preference to control striped Cucumber Beetles.
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Striped Cucumber Beetle (Coleoptera: Chrysomelidae) Aggregation in Response to Cultivar and Flowering
Environmental entomology, 2015Co-Authors: J Gardner, Michael P. Hoffmann, M MazourekAbstract:The striped Cucumber Beetle [Acalymma vittatum (F.)] is a specialist pest of cucurbits throughout its range in the United States and Canada. Improved integrated pest management options are needed across the pest's range, especially on organic farms where there are few effective controls. Trap cropping in cucurbits is an option, but there are significant challenges to the technique. Because cucurbit flowers are highly attractive to the Beetles, four field experiments tested whether cultivar and phenology interact to preferentially aggregate Beetles. The first experiment tested the hypothesis that cucurbit flowers were more attractive to striped Cucumber Beetles than was foliage. The second experiment tested whether there were differences in Beetle aggregation between two relatively attractive cultivars. The third and fourth experiments were factorial designs with two plant cultivars and two levels of flowering to specifically test for an interaction of cultivar and flowering. Results indicated that flowers were more attractive than foliage, Beetle aggregation was affected by plant cultivar, and that there was an interaction of cultivar with flowering. We conclude that a single cultivar may be sufficient to serve as a generic trap crop to protect a wide variety of cucurbits.
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Effect of Striped Cucumber Beetle (Coleoptera: Chrysomelidae) Foliar Feeding on Pumpkin Yield
Journal of Entomological Science, 2003Co-Authors: Michael P. Hoffmann, Ramesh Ayyappath, J GardnerAbstract:Field and laboratory studies were conducted to examine the relationship between foliar feeding damage caused by striped Cucumber Beetle, Acalymma vittatum (F.) (Coleoptera: Chrysomelidae), and yiel...
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Effect of Striped Cucumber Beetle (Coleoptera: Chrysomelidae) Foliar Feeding on Winter Squash Injury and Yield
Journal of Entomological Science, 2002Co-Authors: Ramesh Ayyappath, Michael P. Hoffmann, J GardnerAbstract:The relationship between leaf feeding injury caused by striped Cucumber Beetle, Acalymma vittatum (F.), and yield of winter squash, Cucurbita moschata Duch., was examined under field and laboratory conditions. In a field trial in 1998, individually-caged plants were artificially infested with varying numbers of Beetles to create a range of injury levels. Treatments consisted of three levels of injury (1 to 25, 26 to 50, and >50%) and uninjured controls, each at the cotyledon-, first-, second-, and third-leaf stages of plant development. Under laboratory conditions, the leaf area consumed by known numbers of Beetles for varying durations was quantified on cotyledon-, first-, second-, and third-leaf plants. In the field trial, winter squash was relatively tolerant of foliar injury. Total fruit mass was influenced by injury level and growth stage, but not by their interaction. Number of fruit, mass per fruit and number of marketable fruit were influenced by the interaction of factors. Maturity rating was aff...
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Yield Response of Pumpkin and Winter Squash to Simulated Cucumber Beetle (Coleoptera: Chrysomelidae) Feeding Injury
Journal of economic entomology, 2000Co-Authors: Michael P. Hoffmann, Ramesh Ayyappath, Jonathan J. KirkwylandAbstract:Field studies were conducted to characterize the yield responses of pumpkin, Cucurbita pepo L., and winter squash, Cucurbita maxima Duch., to simulated striped Cucumber Beetle, Acalymma vittatum (F.), feeding damage. Preliminary studies in pumpkin (‘Spookie’) were conducted in 1993, and more complete studies in 1994 and 1995 in pumpkin (Spookie), and in 1995 and 1996 in winter squash (‘Waltham’). Plants were artificially injured 1 time at the cotyledon, 1st, 2nd, or 3rd true leaf stages by clipping specified percentages of leaf area from all leaves on the plant. Treatments consisted of a control treatment with no simulated injury and 4 levels of simulated injury. Pumpkin treatments were 10, 20, 40, and 80% leaf area removal in 1993 and 1994 and 20, 40, 60, and 80% in 1995. Winter squash treatments were 20, 40, 60, and 80% leaf area removal in 1995, and 10, 20, 40, and 80% in 1996. In 1993, 5 wk after planting, mean leaf, stem, and total dry weight were significantly lower on pumpkin plants subjected to ≥20% simulated leaf injury regardless of the growth stage when the injury occurred. Injury at the 3rd leaf stage resulted in a significant reduction in the mean leaf and total dry weight of plant, across all levels of injury. At 2–3 wk before crop maturity, fruit weight and number of fruit per plant were significantly lower with 80% leaf area removal. In 1994 and 1995, and when pumpkins were grown to full maturity and apparently able to compensate for the simulated damage, neither number nor weight of marketable fruit per plant were affected significantly by simulated injury at any stage of development nor level of simulated injury. In contrast, ≥20% and 80% leaf area removal to winter squash resulted in significant reductions in the weight of marketable fruit and/or number of marketable fruit, in 1995 and 1996, respectively. The results of this study indicate that pumpkins can tolerate relatively high levels of simulated defoliation, whereas winter squash is less tolerant. Variable results across years in winter squash may indicate an interaction between injury and plant stress caused by abiotic factors such as soil moisture availability.
Julia K. Burzon - One of the best experts on this subject based on the ideXlab platform.
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Fate of Male-derived Cucurbitacins in Spotted Cucumber Beetle Females
Journal of Chemical Ecology, 2000Co-Authors: Douglas W Tallamy, Piotr M. Górski, Julia K. BurzonAbstract:Using the spotted Cucumber Beetle, Diabrotica undecimpunctata howardi , as a model species, we begin an examination of the role of dietary cucurbitacins, the bitter tetracyclic triterpenes produced by cucurbits, in the reproductive behavior of luperine chrysomelids that seek these compounds for purposes other than host-plant recognition or nutrition. By manipulating the cucurbitacin content of adult diets, we determine: (1) how males and females partition cucurbitacins between reproductive organs and other tissues, (2) the extent to which males pass cucurbitacins to females during copulation, and (3) if females increase their cucurbitacin stores via multiple matings. After two days of exposure to dietary cucurbitacins, 8.3 times more cucurbitacins per gram dry weight were sequestered in male spermatophores than in the aggregate of remaining male tissues. These cucurbitacin-rich spermatophores were passed to females during mating, and 78.8% of the transferred cucurbitacin was deposited in eggs, 11.8% was irreversibly sequestered in other female tissues, and 9.4% was apparently excreted. Females copulated with 0–15 males prior to accepting a complete spermatophere, but did not accept measurable amounts of cucurbitacin from rejected males. Regardless of when it was received, females lost subsequent receptivity to additional males after accepting a complete spermatophore. The implications of these data are discussed in terms of sexual selection hypotheses and mating behavior in Cucumber Beetles.
Rose C. Gergerich - One of the best experts on this subject based on the ideXlab platform.
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Entry of ingested plant viruses into the hemocoel of the Beetle vector Diabrotica undecimpunctata howardi
Phytopathology, 1994Co-Authors: R Y Wang, Rose C. GergerichAbstract:Southern bean mosaic sobemovirus (SBMV) and the cowpea strain of tobacco mosaic tobamovirus (CP-TMV) are found in the hemocoel of some Beetle vectors after they have fed on infected plants. The location in the alimentary canal through which ingested plant viruses enter the hemocoel of the spotted Cucumber Beetle Diabrotica undecimpunctata howardi was studied. Immunofluorescent and electron microscopy were used to detect the presence of ingested viruses in the gut lumen and the epithelial cells lining the midgut of the spotted Cucumber Beetle. Virusspecific immunofluorescent microscopy detected bean pod mottle virus and tobacco ringspot virus only in the lumen of the gut; these two viruses cannot be detected in the hemocoel [...]