Posts Tagged ‘Hylogomphus adelphus’

MYN – Hylogomphus adelphus exuvia (dorsal)

May 4, 2020

The following Anisoptera exuvia — collected by Freda van den Broek on 10 June 2019 along the St. Croix River in Polk County, Wisconsin USA — is definitely a member of Family Gomphidae (Clubtails), probably Mustached Clubtail (Hylogomphus adelphus).

Dorsal view

The abdomen is wider than the head. Vestigial mid-dorsal hooks are noticeable along several abdominal segments, especially segment nine (S9). A “median groove” is apparent along part of the abdomen. The lateral spine on S9 is spinulose-serrate along the outer edge.

10 JUN 2019 | Polk County, WI | H. adelphus exuvia (dorsal)

Related Resources

Tech Tips

This subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

15 photos of the specimen were taken using an aperture of f/16; in-camera focus peaking was used to highlight select areas in each photo. Adobe Photoshop CC 2017 was used to create- and annotate the focus-stacked composite image shown above.

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Hylogomphus adelphus exuvia (ventral)

May 1, 2020

The following Anisoptera exuvia — collected by Freda van den Broek on 10 June 2019 along the St. Croix River in Polk County, Wisconsin USA — is definitely a member of Family Gomphidae (Clubtails), probably Mustached Clubtail (Hylogomphus adelphus).

Ventral view

Notice the exuvia has a flat labium (prementum). There are lateral spines located on abdominal segments six through nine (S6-S9); the lateral spine on S9 is spinulose-serrate along the outer edge. Also notice the well-developed tibial burrowing hooks on its legs.

10 JUN 2019 | Polk County, WI | H. adelphus exuvia (ventral)

Male (vestigial genitalia)

Male odonates have two sets of sex organs: primary genitalia located on abdominal segment nine (S9); and secondary genitalia located on abdominal segments two-to-three (S2-3).

Both sets of vestigial genitalia are clearly visible on the ventral side of some (but not all) specimens, such as the H. adelphus exuvia shown above.

Related Resources

Tech Tips

This subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

12 photos of the specimen were taken using an aperture of f/16; in-camera focus peaking was used to highlight select areas in each photo. A subset of six (6) photos and Adobe Photoshop CC 2017 were used to create- and annotate the focus-stacked composite image shown above.

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Hylogomphus adelphus exuvia

April 29, 2020

An Anisoptera exuvia was collected by Freda van den Broek on 10 June 2019 along the St. Croix River in Polk County, Wisconsin USA.

This specimen is definitely a member of Family Gomphidae (Clubtails), probably Mustached Clubtail (Hylogomphus adelphus).

10 JUN 2019 | Polk County, WI | Anisoptera exuvia (face-head-dorsal)

Related Resources

Tech Tips

This subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. This photo is a “one-off,” that is, not a composite image.

Eight (8) photos of the specimen were taken using an aperture of f/16; in-camera focus peaking was used to highlight select areas in each photo. Adobe Photoshop CC 2017 will be used to create a focus-stacked composite image of the exuvia.

Copyright © 2020 Walter Sanford. All rights reserved.


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