Poecilopompilus interruptus cressoni

(Banks, 1944)

Poecilopompilus interruptus cressoni is a of spider wasp in the Pompilidae. The nominate P. interruptus is a widespread member of a mostly tropical with three species reaching the United States. This subspecies was described by Nathan Banks in 1944. Spider wasps in this genus are known for their Müllerian mimicry of paper wasps (Polistes), sharing bold aposematic coloration despite being capable of delivering painful stings themselves.

Pronunciation

How to pronounce Poecilopompilus interruptus cressoni: //ˌpɛkɪloʊˈpɒmpɪləs ɪnˌtɛrəpˈtʊs ˈkrɛsənaɪ//

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Identification

Females of Poecilopompilus interruptus can be distinguished from the similar P. algidus by examining the spines on the front and the inner margin of the : P. interruptus has 4 weak spines on the front tarsi and parallel inner eye margins at the top, whereas P. algidus has 3 strong spines and strongly convergent inner eye margins. Color patterns are not reliable for separating these two . The cressoni would require examination of additional morphological characters not specified in available sources.

Distribution

The nominate Poecilopompilus interruptus occurs across much of the United States. The cressoni was described from material collected in the western United States, though specific type locality details are not provided in available sources. The broader species ranges from California to Texas and northward.

Diet

have been observed visiting flowers and extrafloral of sunflower (Helianthus spp.) for nectar. Larvae are provisioned with paralyzed orbweaver spiders ( Araneidae) as food.

Host Associations

Life Cycle

Females sting orbweaver spiders into weak paralysis, then transport them backwards overland to nesting sites in bare soil. Nests are shallow burrows 2.5–11 cm deep, angling 45–90 degrees, with a spherical terminal chamber where the prey is placed and a single laid upon it. The female carefully conceals the burrow entrance upon completion.

Behavior

Females hunt actively for spiders, then haul prey backwards to nesting sites. They excavate burrows in soil, sometimes biting through hard substrate and kicking debris with their front legs. are conspicuous and frequently observed on flowers.

Ecological Role

As a of orbweaver spiders, this helps regulate spider . The participates in Müllerian mimicry complexes with other aposematically colored wasps, potentially reducing pressure on all participants.

Human Relevance

The nominate P. interruptus has been documented delivering a painful sting when handled. One collector described a sting from P. interruptus as memorable and comparable to that of paper wasps (Polistes).

Similar Taxa

  • Poecilopompilus algidusOverlapping distribution and highly variable color patterns that can appear nearly identical; requires examination of tarsal spine number and margin shape for reliable separation
  • PolistesMimicry target for Müllerian mimicry; similar coloration and pattern but different (Vespidae), body shape, and

More Details

Mimicry

Poecilopompilus exhibit Müllerian mimicry of paper wasps (Polistes), with both groups sharing bold warning coloration. The mimicry is 'plastic' in P. algidus, with southern resembling paper wasps and northern populations resembling black spider wasps (Anoplius) with red abdominal bands. Whether P. interruptus cressoni shows similar geographic variation in mimicry expression is unknown.

Nomenclature

The epithet 'cressoni' likely honors Charles H. Tyler Cresson (1840–1916), an American entomologist who worked extensively on Hymenoptera, particularly bees and . Nathan Banks, who described this subspecies in 1944, frequently used patronyms honoring fellow entomologists.

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Sources and further reading