Dianthidium texanum

Resin bees in the genus Dianthidium are distinguished from other megachilids by their use of plant resins for nest construction and their characteristic pebbled body texture. D. texanum can be separated from other Dianthidium species by geographic distribution and subtle morphological features including details of facial markings and abdominal sculpture. The species is most reliably identified by examination of collected specimens under magnification, though presence in Texas and surrounding regions provides strong contextual support.

Medium-sized megachilid bee with robust, compact body typical of the genus Dianthidium. Integument dark with pale or yellowish markings. Females carry pollen on a dense scopa of hairs located on the underside of the abdomen rather than on the hind legs. Body surface often appears somewhat pebbled or sculptured, contributing to the common name. Wings with typical hymenopteran venation, folded longitudinally at rest.

Occurs in diverse habitats including woodlands, chaparral, and grassland-edge environments where suitable nesting substrates and floral resources are available. Requires access to pre-existing cavities in dead wood or hollow stems for nesting, and sources of plant resin for cell construction. Documented from pinyon-juniper woodland and other semi-arid habitats in the southwestern United States.

Native to North America and Middle America. Recorded from the southwestern United States, particularly Texas and surrounding states, with range extending into northern Mexico. Documented observations span from the southern Great Plains through the Chihuahuan Desert and into the Colorado Plateau region.

Adult activity period spans late spring through summer, with peak activity in June and July. Nesting activity observed in late June. Generation time appears to be univoltine or partially bivoltine depending on latitude and local climate conditions.

Adults feed on nectar from diverse flowering plants. Females provision nest cells with pollen mixed with nectar to form "bee bread" for larval consumption. Specific floral associations documented include milkweed (Asclepias) and various wildflowers in the Asteraceae and other families.

Solitary bee with complete metamorphosis. Females establish nests in pre-existing cavities, creating a series of cells separated by resin partitions. Each cell receives a pollen-nectar provision and a single egg. Larvae develop within sealed cells, pupate, and emerge as adults. Development time from egg to adult approximately 3-4 weeks under favorable conditions. Overwintering stage likely as prepupa or pupa in completed nests.

Females are solitary nesters that demonstrate strong site fidelity once a suitable cavity is located. Nesting involves collecting resin from plants, transporting it to the nest, and fashioning it into cell partitions and entrance plugs. Resin plugs may include one empty cell at the entrance as a defensive measure against parasites. Adults are diurnal foragers, with females making repeated trips between nest and flowers to provision cells.

Primary pollinator of diverse flowering plants in its range. As a cavity-nesting bee, contributes to pollination services in both natural and anthropogenic habitats. Serves as host for parasitic wasps including leucospids (family Leucospidae), forming part of complex food webs involving native bees and their natural enemies. Nest architecture using resin may influence secondary cavity users.

Occasionally documented in bee block and bee hotel monitoring programs, contributing to citizen science datasets on native bee diversity. Potential pollinator of native plants and crops in its range. Not known to be aggressive or of medical importance. Provides educational value for understanding solitary bee biology and conservation needs.

• Heriades spp.Other small megachilid bees that also nest in pre-existing cavities and use resin for nest construction; distinguished by different body proportions and facial morphology
• Osmia spp.Mason bees in same family that use mud or chewed leaf material rather than resin for nest partitions; generally more robust with different abdominal scopa structure
• Megachile spp.Leafcutter bees that use cut leaf pieces for nest cell lining; larger size and distinctive leaf-cutting behavior separate them from Dianthidium

• native bee
• solitary bee
• resin bee
• pollinator
• cavity nester
• Megachilidae
• Anthidiini
• parasite host
• bee block species

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• Meloidae Holdings | Entomology Research Museum
• Bug Eric: Wasp Wednesday: Leucospis
• Bug Eric: More Drama at the Bee Block
• Eumastacidae | Beetles In The Bush