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Factors Affecting The Spatial Distribution Of Oviposition Sites For Tandem Black Saddlebags Dragonflies (Odonata: Libellulidae), Jessica L. Thornton, Paul V. Switzer Jan 2015

Factors Affecting The Spatial Distribution Of Oviposition Sites For Tandem Black Saddlebags Dragonflies (Odonata: Libellulidae), Jessica L. Thornton, Paul V. Switzer

Paul V. Switzer

Oviposition site location may be affected by (1) factors influencing the costs and benefits to the offspring (e.g., resource availability, competition, predation risk) and (2) factors influencing the costs and benefits to the female (e.g., predation risk or mate ha- rassment). In cases in which both the male and female are involved in locating a site, costs and benefits may differ for each parent and the resulting oviposition site location may represent the outcome of selection pressures on one or both of them. We studied oviposi- tion behavior in the black saddlebags dragonfly (Tramea lacerata Hagen), a species in which …


Male-Male Mounting And The Unreliability Of Body Size As A Character For Mate Choice In Male Japanese Beetles (Popillia Japonica Newman), Paul V. Switzer, Patrick S. Forsythe, Kipp C. Kruse Jan 2014

Male-Male Mounting And The Unreliability Of Body Size As A Character For Mate Choice In Male Japanese Beetles (Popillia Japonica Newman), Paul V. Switzer, Patrick S. Forsythe, Kipp C. Kruse

Paul V. Switzer

Background: Same-sex pairing is common in many animal species. In many insects, same-sex pairing is often thought to be a result of poor sexual discrimination (i.e., a mistake), but few detailed studies of the mechanisms underlying the mistaken pairing have been conducted. Previous studies have found that in the field, a small proportion of Japanese beetle (Popillia japonica) mating pairs consist of two males instead of a male and a female. In the current study, we investigated the relationship between body size, the tendency to mount other males, and the duration of these mounts, in laboratory experiments on male Japanese …


Effectiveness Of Hand Removal For Small-Scale Management Of Japanese Beetles (Coleoptera: Scarabaeidae), Paul V. Switzer, Ryan M. Cumming Jan 2014

Effectiveness Of Hand Removal For Small-Scale Management Of Japanese Beetles (Coleoptera: Scarabaeidae), Paul V. Switzer, Ryan M. Cumming

Paul V. Switzer

Hand removal is often recommended as a method for small-scale control of Japanese beetles (Popillia japonica Newman). In this study, we investigated the effectiveness of daily hand removal for controlling damage by Japanese beetles on grape plants. We also investigated whether the timing of the removal (at 0800, 1400, or 1900 hours, or at all 3 periods) inßuenced the effectiveness of the technique. We found that hand removal signiÞcantly lowered the number of beetles on, and consequently the damage to, grape plants relative to nonremoval controls. Of the single removal treatments, removal of beetles at 1900 hours was most effective, …


Examining The Causes Of Rarity For The Odonata Of Illinois, Miranda R. White, Paul V. Switzer Jan 2013

Examining The Causes Of Rarity For The Odonata Of Illinois, Miranda R. White, Paul V. Switzer

Paul V. Switzer

Odonata (dragonflies and damselflies) play an important role in habitat management and conservation, but our understanding of the causes of commonness versus rarity in this group is limited. In this study we examined the causes of rarity for the Odonata of Illinois. Using S-ratings for conservation status and published habitat classifications for Illinois odonates, we investigated whether habitat type (lotic versus lentic) or habitat specificity (whether they were limited to a specific type of aquatic habitat) was related to commonness. We found that lotic species and habitat specialists were more likely to be rare than lentic and generalist species. More …


A New Species Of Saphonecrus (Hymenoptera, Cynipoidea) Associated With Plant Galls On Castanopsis (Fagaceae) In China, Zhiwei Liu, Xiao-Hui Yang, Dao-Hong Zhu, Yi-Yuan He Jul 2012

A New Species Of Saphonecrus (Hymenoptera, Cynipoidea) Associated With Plant Galls On Castanopsis (Fagaceae) In China, Zhiwei Liu, Xiao-Hui Yang, Dao-Hong Zhu, Yi-Yuan He

Zhiwei Liu

A new cynipid species, Saphonecrus hupingshanensis Liu, Yang, et Zhu, sp. nov. (Hymenoptera: Cynipidae: Synergini), is described from China. This is the first species of the inquilinous tribe Synergini ever known to have an association with chinquapins (Fagaceae: Castanopsis). The biology and implication to species diversity of Cynipidae in eastern and southeast Asia are discussed.


Physiological Status Of Male And Female Popillia Japonica (Coleoptera: Scarabaeidae) Affects Mating And Grouping Behavior, Natasha Tigreros, Rashmi Jadhav, Katelyn A. Kowles, Britto P. Nathan, Paul Switzer Jan 2010

Physiological Status Of Male And Female Popillia Japonica (Coleoptera: Scarabaeidae) Affects Mating And Grouping Behavior, Natasha Tigreros, Rashmi Jadhav, Katelyn A. Kowles, Britto P. Nathan, Paul Switzer

Paul V. Switzer

Because mating may be costly, sexually active males or females are predicted to be in relatively good physiological condition and may preferentially direct their mating behavior toward relatively high-quality mates. We tested this hypothesis in Japanese beetles (Popillia japonica Newman), a pest species in which males and females may be either isolated or in aggregations while feeding on host plants. We examined male size and lipid content and female size and egg load with respect to both their pairing status and whether they were isolated or in aggregations. Males that were paired had the highest lipid levels, and single, isolated …


Behavioral Explanations Underlying The Lack Of Trap Effectiveness For Small-Scale Management Of Japanese Beetles (Coleoptera: Scarabaeidae), Paul V. Switzer, Patrick C. Enstrom, Carissa A. Schoenick Jan 2009

Behavioral Explanations Underlying The Lack Of Trap Effectiveness For Small-Scale Management Of Japanese Beetles (Coleoptera: Scarabaeidae), Paul V. Switzer, Patrick C. Enstrom, Carissa A. Schoenick

Paul V. Switzer

Traps containing a combination floral and synthetic pheromone lure are used to monitor and manage Japanese beetles, Popillia japonica Newman (Coleoptera: Scarabaeidae). One key factor limiting trap effectiveness for beetle control is the "trap spillover" phenomenon, in which the trap attracts beetles without capturing them, resulting in increased damage to surrounding host plants. We investigated the mechanisms underlying trap spillover by conducting two studies in a soybean field in east central Illinois. In the first study, we set up trap stations for 1 d and compared the sex, size, and egg load (for females) of beetles caught in the traps …


Environmental Conditions Affect Sperm Competition Risk In Japanese Beetles (Coleoptera: Scarabaeidae), Paul V. Switzer, Carissa A. Schoenick, Patrick C. Enstrom Jan 2008

Environmental Conditions Affect Sperm Competition Risk In Japanese Beetles (Coleoptera: Scarabaeidae), Paul V. Switzer, Carissa A. Schoenick, Patrick C. Enstrom

Paul V. Switzer

Males of many species guard their mates to prevent rivals from usurping paternity of the potential offspring. Environmental conditions, such as temperature, may affect a male’s ability to guard a female effectively and consequently the amount of sperm competition that occurs. We tested whether temperature and light affected mating behavior in laboratory experiments on the Japanese beetle, Popillia japonica Newman, a species in which males guard females for minutes to many hours after mating. When tested in groups, under conditions of high temperature and high light, males guarded females for shorter periods of time and males and females both mated …


Using Dragonflies As Common, Flexible, And Charismatic Subjects For Teaching The Scientific Process, Paul Switzer Jan 2007

Using Dragonflies As Common, Flexible, And Charismatic Subjects For Teaching The Scientific Process, Paul Switzer

Paul V. Switzer

No abstract provided.


The Cynipoid Genus Paramblynotus: Revision, Phylogeny, And Historical Biogeography (Hymenoptera, Liopteridae), Zhiwei Liu, Fredrik Ronquist, Goeran Nordlander Jan 2007

The Cynipoid Genus Paramblynotus: Revision, Phylogeny, And Historical Biogeography (Hymenoptera, Liopteridae), Zhiwei Liu, Fredrik Ronquist, Goeran Nordlander

Zhiwei Liu

The genus Paramblynotus is the most species-rich genus of the so-called macrocynipoids, the large cynipoid parasitoids of wood-boring and cone-boring insect larvae. The species range in size from some of the largest to the smallest macrocynipoids, comparable in size to microcynipoids. Paramblynotus members occur on all continents except Europe and Australia, with most species being tropical or subtropical. The biology is poorly known but a few observations indicate that the species are parasitoids of beetle larvae. In this monographic revision of the genus, we present a species-level cladistic analysis based on qualitative and quantitative features of the external morphology. For …


Spatial Learning In Dragonflies, Perri K. Eason, Paul Switzer Jan 2006

Spatial Learning In Dragonflies, Perri K. Eason, Paul Switzer

Paul V. Switzer

No abstract provided.


Individual Variation In The Duration Of Territory Occupation By Males Of The Dragonfly Perithemis Tenera (Odonata: Libellulidae), Paul V. Switzer Jan 2002

Individual Variation In The Duration Of Territory Occupation By Males Of The Dragonfly Perithemis Tenera (Odonata: Libellulidae), Paul V. Switzer

Paul V. Switzer

In the dragonfly Perithemis tenera Say, males defend territories around oviposition sites and defense of a site is critical for reproductive success. This study first demonstrated that individual males varied consistently in how long they defended a particular territory within a day (their “tenure”) and in the quality of the sites they defended. I then investigated a number of factors that may have affected territory tenure and may have led to the observed variation among males. Territory occupations that ended “voluntarily” were significantly longer than those that ended because the male was evicted from his territory. For voluntary desertions, tenure …


The Male-Male Tandem: A Novel Form Of Mate Guarding In Perithemis Tenera, Paul V. Switzer, Jaime K. Schultz Jan 2000

The Male-Male Tandem: A Novel Form Of Mate Guarding In Perithemis Tenera, Paul V. Switzer, Jaime K. Schultz

Paul V. Switzer

No abstract provided.


Proximate Constraints On Intruder Detection In The Dragonfly Perithemis Tenera (Odonata: Libellulidae): Effects Of Angle Of Approach And Background, Paul V. Switzer, Perri K. Eason Jan 2000

Proximate Constraints On Intruder Detection In The Dragonfly Perithemis Tenera (Odonata: Libellulidae): Effects Of Angle Of Approach And Background, Paul V. Switzer, Perri K. Eason

Paul V. Switzer

The implications of insects’ vision for territorial defense have been relatively little studied in the field. In the dragonfly Perithemis tenera Say we investigated whether either the angle at which an intruder was viewed by a territorial resident or the background against which it was viewed affected the detection of that intruder. Residents detected intruders at a greater distance if the intruders were directly in front of them; they also detected more intruders in front of them than from other angles. Intruders viewed against distant vegetation were detected more readily than were intruders against near vegetation. Residents detected more intruders …