Intraguild predation (IGP) is a ubiquitous, important and common interaction that occurs in aphidophagous guilds. The effects of extraguild prey (EGP, i.e., aphids) density, predator life stage combinations and duration of the interaction on the level, asymmetry and direction of intraguild predation between lacewing Chrysoperla carnea and ladybird Hippodamia variegata were examined in simple laboratory arena and more complex microcosm environment. Three initial densities of 50, 150 and 400 Aphis fabae third instar nymphs and a control without aphids were provided to six combinations of predator life stages (2nd and 3rd larval instars of lacewing and 3rd and 4th instars and adult females of ladybird). The remaining aphid density and occurrence of IGP were checked after 24, 48 and 72 h. The IGP intensity (IGP level, IL) was similar in the simple arena (reaching 0.6 between larvae in absence of EGP and 0.3 between lacewing larvae and ladybird females) and microcosm environment (0.3 without EGP). In both environments, increasing EGP density lowered IL according to negative exponential relationship. IGP was asymmetric (general average asymmetry was 0.82 in simple arena and 0.93 in microcosm, the difference was not significant) and mostly in favour of larvae of C. carnea, except in the combination of 2nd larvae of C. carnea with the 4th larvae and adults of H. variegata. The direction of IGP, but not other characteristics, partially changed during the duration of the experiment. The incidence of IGP interactions among aphid predators under real conditions and its consequences on aphid biological control are discussed.
- Klíčová slova
- black bean aphid, competition, green lacewing, lady beetle, predator-predator interaction,
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: This article summarized errors obtained by diverse techniques used for the derivation of cross-sectional contours in nonadult humeri and tibiae. MATERIALS AND METHODS: We analyzed cross-sectional contours in a total sample of 62 humeral and 75 tibial diaphyses in the age between birth and 12 years divided into three age groups. Long bone 35% (humeri) and midshaft (tibiae) cross-sections were taken on micro-CT images and analyzed by EPJMacro in FIJI. Properties were extracted from contours derived by manual, automatic, spline, and ellipse techniques. Agreement between techniques was assessed using manually extracted properties such as the true value using percent prediction error (%PE), reduced major axis regression, and ±95% limits of agreement. RESULTS: The lowest measurement errors were obtained for total areas, moderate errors for cortical areas and section moduli, and the highest errors for medullary areas for both bones. Derivation of humeral nonadult cross-sectional properties is less sensitive to the technique used for derivation of periosteal and endosteal contours, reaching mean %PEs below 5%. In contrast, tibial nonadult cross-sectional properties are more sensitive to the technique used and exceed 5% for some combinations. DISCUSSION: Automatic techniques provide reasonably high agreement with manually extracted contours for nonadult humeri but low agreement for tibiae. Semiautomatic approaches-spline and ellipse techniques-may reduce the error for all studied properties in tibiae, especially when combined with manually traced periosteal contours. The positive effect of the semiautomatic technique on measurement error is low for humeri.
- Klíčová slova
- EPJMacro, ImageJ, biomechanics, humerus, tibia,
- MeSH
- anatomie průřezová MeSH
- antropologie fyzická MeSH
- antropometrie MeSH
- dítě MeSH
- humerus * anatomie a histologie diagnostické zobrazování MeSH
- kojenec MeSH
- lidé MeSH
- novorozenec MeSH
- okostice * anatomie a histologie diagnostické zobrazování MeSH
- předškolní dítě MeSH
- rentgenová mikrotomografie MeSH
- reprodukovatelnost výsledků MeSH
- statistické modely MeSH
- tibie * anatomie a histologie diagnostické zobrazování MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- novorozenec MeSH
- předškolní dítě MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
