Observações de arnel

Cursed Crowfoot (Ranunculus sceleratus), photographed at a shallow seasonal pond along the Black Swan Trail in Elk Grove, CA. According to Jepson's eFlora, R. sceleratus is the only aquatic Ranunculus species that can be found in the Sacramento Valley, so I am running with this identification. Consistent with R. sceleratus are the following characteristics, which can be seen in the accompanying photographs:

1) The flowers contain 5 yellow petals, each of which is relatively small, measuring ~5 mm in radial length and ~ 3 mm in width.
2) The fruit is an aggregation of small, lenticular achenes, measuring ~ 1 mm in length. Each achene has a small, deltate beak measuring ~0.1 mm in length.
3) Cauline leaves closest to the plant's roots are lobed; more distal leaves are reduced and simple in shape. Unfortunately, I was not able to find any basal leaves to photograph, as these leaves have a distinctive reniform to semicircular shape with rounded lobes. I'm not sure if these basal leaves were simply lost in the tangle of vegetation at the bottom of the shallow pond where these Ranunculus plants were growing, or if they had already withered away.

References:
[1] Alan T. Whittemore 2012, Ranunculus sceleratus, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=40971, accessed on May 08, 2024.

An insect that I think is some sort of Plant Bug (Miridae sp.), which I photographed on the trunk of a non-native, ornamental tree at Jeanne and Jerry Strong Park in Elk Grove, CA. This was a fairly small individual, measuring around 8mm or 9mm in length. It was a bit skittish and could move surprisingly fast whenever it got nervous.

My tentative identification of this insect is based on the following observations:

1) At rest, the insect’s wings are folded flat over its back, forming an ‘X’ pattern there. The forewings (the pair of wings that are visible when the insect is at rest) are partly protective, and partly membranous, with the membranous portions overlapping. The scutellum is also prominent (or as prominent as can be on this rather cryptically colored insect). Finally, the insect’s antennae consists of 5 segments. Together, all of these traits place the insect in the Infraorder Heteroptera, within the Order Hemiptera.
2) Each wing has a cuneus – a thickened, triangular segment of the forewing that is located at the posterior tip of the protective portion of the forewing, and that is separated from the rest of the forewing by a suture. There are also two closed cells along the anterior edge of the membranous portion (most visible in the profile view of the insect). Finally, the appendages are long and thin. Together, all of these traits place the insect in Miridae, a family of Plant Bugs.
3) The family Miridae is a huge family consisting of around 2000 species, with multiple tribes. I have little familiarity with this family of Plant Bugs, so I’m leaving it identified to family only.

Given how little experience I have with the family Miridae, it’s entirely possible that I might have this identification wrong. Corrections and suggestions are welcome!

References:
[1] McLeod, Robin (2007, January 30). Suborder Heteroptera – True Bugs. Bug Guide. Retrieved on 5/7/24 from https://bugguide.net/node/view/94266
[2] Bartlett, Troy (2004, February 16). Family Miridae – Plant Bugs. Bug Guide. Retrieved on 5/7/24 from https://bugguide.net/node/view/94
[3] Miridae. (2005, July 29). In Wikipedia. Retrieved on 5/7/24 from https://en.wikipedia.org/w/index.php?title=Miridae&action=history&dir=prev

A Broad-headed Marsh Fly (Helophilus latifrons), photographed along the Black Swan Trail near Jeanne and Jerry Strong Park in Elk Grove, CA. Identified this fly as being H. latifrons based on the following observed characteristics (based on the treatment given in Field/Photo ID for Flies [1]:

1) The fly’s antennae consists of three segments, with one of them being a thin, hair-like arista. It also has a “spurious wing vein” running roughly parallel to the M3 vein. Finally, none of its veins fully terminate on the wing’s posterior margin, except for its CuA vein. Together, all of these characteristics place this fly in Syrphidae, the Hover Fly family.
2) The fly bears a certain resemblance to wasps and bees, which is typical of the Eristalini tribe (Drone Flies and kin).

3) The fly has solid black eyes, eliminating a few species within the Erstalini tribe which have patterned eyes, such as Eristalinus aeneus.

4) The fly lacks spots on its thorax, eliminating hover flies within the genus Meromacrus, as well as Myathropa florea. Its thorax also lacks hairs that would give its thorax a velvety appearance, eliminating hover flied within the genus Palpada.
5) The fly does have unbroken black stripes running the full length of its scutum, with a diffuse pterostigma and a broken orange band running across its second abdominal segment. This places the fly within the genus Helophilus.
6) The fly also has an unbroken orange band across its fourth abdominal segment. This narrows down our choices to two species – the Narrow-headed Marsh Fly (Helophilus fasciatus) and the Broad-headed Marsh Fly (Helophilus latifrons).
7) The orange patches of the broken band on the second abdominal segment have relatively sharp posterior corners and a straight posterior margin. This narrows down our choice to the Broad-headed Marsh Fly (Helophilus latifrons).

Note that I have no prior experience with H. latifrons, so it’s possible that my identification is incorrect. Suggestions and corrections are welcome!

References:
[1] Dankowicz, Z. R. & Dankowicz, E. (2023). Field/Photo ID for Flies. Retrieved on 5/6/24 from https://sites.google.com/view/flyguide.