Analysis of Body Measurements and Wing Shape to DiscriminateRhagoletis pomonellaandRhagoletis zephyria(Diptera: Tephritidae) in Washington State

Abstract

Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) is a quarantine pest of apple (Malus sp.) in Washington state that is almost identical morphologically to Rhagoletis zephyria Snow, a nonpest of apple. Historically, the longer ovipositor in R. pomonella has been used to separate it from R. zephyria, despite overlap in ovipositor lengths. Here, the objectives were to determine whether use of multiple body measurements and wing shape can improve discrimination of the species. Ovipositor lengths allowed 94.6% correct identification of female R. pomonella but only 7.0% correct identification of R. zephyria. We found that multiple body measurements and wing shape can better separate these species. Canonical variates analysis (CVA) of nine body measurements in female flies largely separated the species. In contrast, CVA of nine body measurements poorly separated the males of these species. Discriminant analysis using nine body measurements classified female R. pomonella and R. zephyria with 95.4 and 100% accuracy, respectively. Geometric morphometrics and CVA separated wing shapes between species in both sexes. Bookstein shape coordinates indicated that the wing of R. pomonella is more tapered at the tip than that of R. zephyria. Use of wing shape in an assignments test identified female R. pomonella with 98.5% and female R. zephyria with 99.0% accuracy, and it correctly identified 100% of flies whose identities were questionable based on ovipositor lengths. Results indicate that use of multiple body measurements or wing shape is an improvement over the use of ovipositor length alone for identifying female R. pomonella and R. zephyria in Washington state.

New records ofRhagoletisLoew, 1862 (Diptera: Tephritidae) and their host plants in western Montana, U.S.A.

“…Traps were removed on 1 August. Flies with a wing pattern resembling that of R. pomonella (Bush 1966) were removed from the trap, cleaned with citrus solvent, and soaked in water for two days to soften the body parts so they could be manipulated for identifi cation based on morphological (Yee et al 2009(Yee et al , 2011a. Fruit was previously collected from the stand at Troy and from surrounding trees in 2012 and was resampled following trapping in 2013.…”

Comparative Body Size and Shape Analyses of F1 HybridRhagoletis pomonellaandRhagoletis zephyria(Diptera: Tephritidae)

“…For individual body size measure analysis, Fj hybrids from the reciprocal cross were also analyzed (Table 1). Aculeus length in females or genitalia (epandrium and surstylus) length in males, head width, inter-eye width, wing length, wing band B and A widths [terminology based on Bush (1966)], and hind femur, hind tibia, and hind tarsus lengths were measured (Yee et al 2009). One-way analysis of variance was used to determine differences of each measure among fly groups, followed by pair-wise comparisons using the least significant difference (LSD) test and Bonferroni adjustment.…”

“…Methods for wing analysis based on landmark measurements have been described (Yee et al 2009) and are only summarized here. Except for the camera used, methods and all 18 wing landmark (LM) positions chosen were the same.…”

“…various nonhybrid flies (Hoñrnan and Shirrifs 2001;Moraes et al 2004;Lxjh and Bitner-Mathé 2005;Carreira et al 2006;Chengpeng et al 2007;Yee et al 2009Yee et al , 2011aRichmond et al 2012), so both could also be useful for hybrids. Size may also help classify hybrids to a smaller degree, based on nonhybrids (Yee et al 2009).…”

Molecular and Morphometric Data Indicate a New Species of the Aphid GenusRhopalosiphum(Hemiptera: Aphididae)

“…Recent studies analyzing wing shapes and DNA sequences successfully discriminated morphologically cryptic insect species and populations (Camara et al 2006;Favret 2009;Marsteller et al 2009;Valenzuela et al 2009;Yee et al 2009). The geometric morphometric method based on landmarks can separate information concerning shape from size and scaling of morphological structures, therefore allowing these structural characters, which are often correlated, to be tested independently (Zelditch et al 2004;Slice 2007).…”