Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae)
This study evaluated foraging effectiveness of Pacific cicada killers (Sphecius convallis) by comparing observed prey loads to that predicted by an optimality model. Female S. convallis preyed exclusively on the cicada Tibicen parallelus, resulting in a mean loaded flight muscle ratio (FMR) of 0.187...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2012-02-01
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| Series: | Insects |
| Subjects: | |
| Online Access: | http://www.mdpi.com/2075-4450/3/1/133/ |
| _version_ | 1818058832367058944 |
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| author | Joseph R. Coelho Charles W. Holliday Jon M. Hastings |
| author_facet | Joseph R. Coelho Charles W. Holliday Jon M. Hastings |
| author_sort | Joseph R. Coelho |
| collection | DOAJ |
| description | This study evaluated foraging effectiveness of Pacific cicada killers (Sphecius convallis) by comparing observed prey loads to that predicted by an optimality model. Female S. convallis preyed exclusively on the cicada Tibicen parallelus, resulting in a mean loaded flight muscle ratio (FMR) of 0.187 (N = 46). This value lies just above the marginal level, and only seven wasps (15%) were below 0.179. The low standard error (0.002) suggests that S. convallis is the most ideal flying predator so far examined in this respect. Preying on a single species may have allowed stabilizing selection to adjust the morphology of females to a nearly ideal size. That the loaded FMR is slightly above the marginal level may provide a small safety factor for wasps that do not have optimal thorax temperatures or that have to contend with attempted prey theft. Operational FMR was directly related to wasp body mass. Smaller wasps were overloaded in spite of provisioning with smaller cicadas, while larger wasps were underloaded despite provisioning with larger cicadas. Small wasps may have abandoned larger cicadas because of difficulty with carriage. |
| first_indexed | 2024-12-10T13:06:54Z |
| format | Article |
| id | doaj.art-32f134c157e443c4a6c368929f46e1f3 |
| institution | Directory Open Access Journal |
| issn | 2075-4450 |
| language | English |
| last_indexed | 2024-12-10T13:06:54Z |
| publishDate | 2012-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Insects |
| spelling | doaj.art-32f134c157e443c4a6c368929f46e1f32022-12-22T01:47:50ZengMDPI AGInsects2075-44502012-02-013113314010.3390/insects3010133Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae)Joseph R. CoelhoCharles W. HollidayJon M. HastingsThis study evaluated foraging effectiveness of Pacific cicada killers (Sphecius convallis) by comparing observed prey loads to that predicted by an optimality model. Female S. convallis preyed exclusively on the cicada Tibicen parallelus, resulting in a mean loaded flight muscle ratio (FMR) of 0.187 (N = 46). This value lies just above the marginal level, and only seven wasps (15%) were below 0.179. The low standard error (0.002) suggests that S. convallis is the most ideal flying predator so far examined in this respect. Preying on a single species may have allowed stabilizing selection to adjust the morphology of females to a nearly ideal size. That the loaded FMR is slightly above the marginal level may provide a small safety factor for wasps that do not have optimal thorax temperatures or that have to contend with attempted prey theft. Operational FMR was directly related to wasp body mass. Smaller wasps were overloaded in spite of provisioning with smaller cicadas, while larger wasps were underloaded despite provisioning with larger cicadas. Small wasps may have abandoned larger cicadas because of difficulty with carriage.http://www.mdpi.com/2075-4450/3/1/133/waspoptimal foragingcicadadesertinsectload carriageflightforce |
| spellingShingle | Joseph R. Coelho Charles W. Holliday Jon M. Hastings Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae) Insects wasp optimal foraging cicada desert insect load carriage flight force |
| title | Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae) |
| title_full | Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae) |
| title_fullStr | Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae) |
| title_full_unstemmed | Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae) |
| title_short | Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae) |
| title_sort | near optimal foraging in the pacific cicada killer sphecius convallis patton hymenoptera crabronidae |
| topic | wasp optimal foraging cicada desert insect load carriage flight force |
| url | http://www.mdpi.com/2075-4450/3/1/133/ |
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