Story and photos by Anita Westervelt, Texas Master Naturalist
National Moth Week 2020 saw people around the Valley putting together moth-attracting set-ups to see what flies our nightly skies. https://www.stbctmn.org/post/mothing
While some moths that were attracted to a blacklight and moth sheet set-up were as tiny as a grain of rice, most had a wingspan of about one inch.
A couple of larger moths were regular visitors, like the indomitable graphic moth, Melipotis indomita, and the cellar graphic, Melipotis cellaris, both of which have a wing span of about one and one-half inches. The caterpillars of M. indomita feed on mesquite tree leaves; M. cellaris caterpillars feed on leaves of plants in the acacia genus, like the Valley’s native huisache, blackbrush and catclaw.
A Melipotis agrotoides, with a wingspan of a little more than one and three-quarters of an inch was observed during moth week — not at a moth sheet, but on the pavement under a security light. M. agrotoides is confined to the Lower Rio Grande Valley and south to South America, according to bugguide.net.
During the threat of rain on three nights of the event, I set up the blacklights and moth sheet in the shelter of the front porch. As expected, results weren’t successful and instead, I hoped to glimpse moths resting just after daybreak, before sunlight chased them off to more secure venues. I checked shrubs, utility poles and the ground and pavement beneath the security lights.
Midway through moth week, I found an interesting moth hanging on a blade of bamboo under a security light. Identified on www.iNaturalist.org as Apotolype blanchardi, it is a member of Lappet moths, in the Lasiocampidae family. An identifier on iNaturalist noted, “The tuft of black scales on the thorax and overall appearance suggest A. blanchardi, which is limited to south Texas and somewhat rare.” Bugguide.net suggests the larval host for A. blanchardi caterpillars is Pithecellobium dulce, known as monkeypod, and locally as guamuchil, a member of the legume family (Fabaceae), and possibly Delonix regia, the royal Poinciana tree, also in the Fabaceae family.
Other colorful moths attracted to the moth sheet set-up were those with interesting names like the Victorian lamplighter moth, Lamprosema victoriae, which has two bright white triangular markings on the forward edge of each forewing. The magician moth, Hileithia magualis, is a patchwork of camouflage in brown, tan, violet and gold and edged with white fringe at the bottom of the forewings. The snowy urola moth, Urola nivalis, is a satiny-white moth edged with a bright gold rim at the tips of the wings.
The largest moth to show up during the moth week event is a regular visitor to porches and garages in the Valley: the black witch, Ascalapha odorata. It is the largest moth north of Mexico and has a seven-inch wing span. Its caterpillars eat legumes, and favor acacia and mesquite trees. Although quite large, the black witch is harmless and often associated with good luck. The adult black witch moth feeds on nectar and is attracted to soft, overripe fruit, if you want to be hospitable.