Sceliphron assimile

(Dahlbom, 1843)

Clayman's Mud-dauber Wasp

Sceliphron assimile is a solitary thread-waisted wasp in the Sphecidae, commonly known as Clayman's Mud-dauber . It is a mud-nesting that constructs elongated clay provisioned with paralyzed spiders for its larvae. The species has been studied in Jamaica, where detailed and behavioral research has documented its nesting habits, daily activity patterns, and prey preferences. Like other Sceliphron species, it is a of spiders and exhibits solitary nesting .

Pronunciation

How to pronounce Sceliphron assimile: //sɛˈlɪfrɒn əˈsɪmɪli//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Habitat

Nests are built in sheltered locations such as beneath rock overhangs, under bridges, under building eaves, and inside old structures. per unit area positively correlates with nest cell number, while illuminance negatively correlates with cell number, suggesting preference for shaded protected sites.

Distribution

Caribbean (Jamaica), Middle America, and Oceania. GBIF records confirm presence in Caribbean and Middle America.

Seasonality

are active from sunrise until shortly before sunset. Nesting activity occurs during an 8.5-hour period beginning approximately 3 hours after sunrise, with individuals rarely spending more than 4 hours per day on nesting activities.

Diet

feed on nectar. Females provision nests with paralyzed spiders, primarily from Argiopidae, with Thomisidae, Salticidae, and Oxyopidae also represented.

Life Cycle

Females construct mud , provision each with multiple paralyzed spiders, lay a single , and seal the cell with a mud cap. Incompletely stored cells are closed with an externally concave mud at onset of rain or between 16:00–17:00 hours and are not reopened the same day. Larvae consume the cached spiders, pupate within a silken cocoon, and emerge as by chewing a round exit hole at the cell end.

Behavior

Solitary nesting; each female constructs her own nest. Females that build multiple nests locate them within a few meters of each other. Males seek females throughout the . spend non-nesting time resting and feeding. At sunset, adults settle in roosting groups. The number of mud pellets used to construct a is negatively correlated with the body length of the builder, though cell length is not.

Ecological Role

of spiders; contributes to spider . Parasitized by cuckoo wasps (Chrysididae), ichneumon wasps (Acroricnus, Osprynchotus), chalcid wasps (Melittobia), velvet ants (Sphaeropthalma), bee flies (Anthrax), and sarcophagid flies (Amobia).

Human Relevance

Nests may be considered aesthetic nuisances on buildings. Non-aggressive; sting is mild compared to social and is used primarily for prey paralysis rather than defense.

Similar Taxa

  • Sceliphron caementariumSimilar mud-nesting and ; S. caementarium is larger (24–28 mm vs. smaller S. assimile), more widespread in North America, and has more prominent yellow markings.
  • Sceliphron curvatumSmaller Asian (15–25 mm) with reduced yellow markings, dark coloration, and tendency to nest indoors on walls and furniture; distinguished from S. assimile by geographic origin and specific color pattern differences.
  • Chalybion californicumBlue Mud Dauber reuses or renovates Sceliphron nests rather than constructing original mud ; metallic blue-black coloration distinguishes it from black-and-yellow Sceliphron .

More Details

Population Biology

A mark-recapture study in Jamaica found mean levels of 281 males and 259 total females in an 18.2 ha area, with estimated daily survival rates of 0.903 for males, 0.924 for total females, and 0.945 for reproducing females. Mean was 9.6 per female, with achieved fecundity ranging 4.2–16.8 eggs depending on survival rates. Only an estimated 28% of females survived to nest.

Wing Wear and Age

Minimum age is linearly correlated with wing wear (r = +0.69), which is associated with progressive ovarian maturation. All surviving females become parous by middle age.

Sex Ratio

The proportion of females in the Jamaican was 0.48, compared to 0.55 expected at , suggesting differential mortality or protarrhenotoky and proterandry influencing sex ratios.

Sources and further reading