Moths | Birders on the Road

Moths of the Lower Rio Grande Valley

Less Common, but Regular Moths (Tortrids, Pyralids, & Button Moths)

Tortrids

A moth is sitting on a black mesh screen

A small moth is sitting on a white surface

Cotton Tipworm Moth (Crocidosema plebejana of authors)

Sexually dimorphic and variable: the female (left) has a dark brown back and is buffy on the sides. The male (center and right) is dark brown with a bold creamy patch in the distal half, crossed by a brownish band. The "racing stripes" along the costa is typical of most Olethreutine tortrids. The unusual scientific name is used by BugGuide (and probably other sources) because this bug may represent more than one species! Recorded March - September.

A drawing of the state of texas with a green border.

Javelin Moth (Bactra verutana)

Variable, but usually shows two strong dark blotches on the forewing. The dead giveaway is the checkered inner edge of the forewing, giving the illusion of a black-and-white string going down the back (when visible)! Beware of other Bactra species that have the same "string" but are plainer; these could also possibly show up in the LRGV. Recorded July - March.

A brown moth is sitting on a white wall.

Sculptured Moth (Eumarozia malachitana)

The large, colorful median patch (ranging from chestnut to green) that blends smoothly from darker to paler towards the costa contrasts sharply with the brindled appearance of the rest of the bug! The white line outlining the patch curves sinuously and outlines another dark, crescent-shaped patch in the distal part of the forewing. Recorded October - February.

Knudson's Leafroller (Pseudexentera knudsoni)

This highly variable tortrix can be similar to the Salaciana Pelochrista (Pelochrista salaciana), but the head is usually either ochre-colored or blackish. Generally the forewings are pale with wide blackish or brownish AM and PM bands, but some bugs can look dark overall with pale bands. Recorded February to April, with records in July and November.

A close up of a moth on a wooden surface.

Omnivorous Leafroller (Platynota stultana)

Not to be confused with the Omnivorous Platynota (Platynota rostrana), the platynotas as a whole can be extremely varied and confusing, so much so that many experts are reluctant to ID a particular bug to species without DNA analysis or dissection! One useful field mark for the Omnivorous Leafroller is the gray head and palps which both sexes show. Both also tend to be orange in the basal half and bright yellow in the distal half (although there are some melanistic individuals), with a black patch that runs down diagonally from the costa to the inner margin. Recorded July - October.

A green and white drawing of the state of texas.

Pyralids

A small green moth is sitting on a piece of paper.

A green and white moth is sitting on a sandy surface.

Flex-lined Cacotherapia (Cacotherapia flexilinealis)

A Texas specialty, this little moth is easily identified by its overall green coloration and the black zig-zaggy PM and ST lines. Recorded March - May, with records in January, August, and November.

Maple Webworm (Pococera asperatella)

The most prominent field mark on this little gray moth is the wide white basal portion of the median band. Above this is a double AM line filled white, and the somewhat straight black PM line makes a dip before reaching the costa. If you can see it, the banded abdomen is also a good clue. Recorded May to October, with records in March.

A close up of a moth on a metal surface.

A small brown moth is sitting on a white surface.

Dusky Raisin Moth (Ephestiodes gilvescentella)

Very similar to the related Reddish Ephestiodes, but the bugs I feel more comfortable calling Dusky Raisins are the ones with a more strongly marked AM and PM line (sometimes the AM line appears spotted) and better match other Dusky Raisin images on the MPG and BugGuide than the Reddish, but honestly, some may not be identifiable without DNA analysis. iNaturalist will often jump on one species over the other when submitted, so I tend to trust their judgment! Recorded January to May, July to August, and October to November.

A green map of texas with a black outline on a white background.

Gold-banded Etiella (Etiella zinckenella)

This distinctive brownish-gray moth has a thin band of chestnut-colored scales bordered distally by a wide ochre band. Beware that the long palps can sometimes be broken off! Recorded February and March.

Button Moths

A close up of a moth sitting on a brick wall.

Southern Flannel Moth (Megalopyge opercularis)

This furry yellow moth has orchre-colored forewings with a yellow ST area. The pattern can be variable, but most bugs in the LRGV show the white rays bordering the darker costa, as in the bug on the right. Some will show more squiggly lines in the costal area. Recorded February - August.

A small brown moth is sitting on a piece of wood.

A small brown bug is sitting on a brick wall.

Twin Slug Moth (Adoneta gemina)

A Texas specialty, with most records being in the south. This small brown button moth usually shows a sinuous white line running from the inner margin of the forewing to the ST area, but this line can be partially broken or totally absent. In that case, look for the darker brown smudges that would border this line, along with small brown spots in the ST area. Some individuals (like the bug on the far right) can be quite golden. Recorded February - March and June - November.

Yellow-shouldered Slug Moth (Lithacodes fasciola)

Even though these bugs look more like the illustration of Graceful Slug Moth (Lithacodes gracea) in the excellent Leckie & Beadle guide, I was assured that at least the bug on the far right was indeed a Yellow-shouldered, so that's what I've been calling these. They do show the strong diagonal line across the ST area that Yellow-shouldered is supposed to show, but the white median line isn't as "toothed" as in other images of Yellow-shouldered, so in reality I suppose these bugs could be either. For now I'm going with the experts and leaving these labeled as Yellow-shouldered. Recorded March - October.