Official name:
Synonyms:
Pamphredon inornata [Soortenregister]
Cemonus shuckardi (Morawitz)
Dineurus shuckardi (Westwood 1837)
Pemphredon inornatus (Say 1824)
Pemphredon shuckardi (Morawitz 1864)
Pemphredon tenax (Fox 1892)
see more on: www.gbif.org

CONTENTS
1. Distribution
2. Behaviour
3. Plant relations
4. Prey relations
5. Parasitic relations
6. Identification
1. DISTRIBUTION
Pemphredon inornata is a common wasp [waarneming.nl] that occurs throughout the Netherlands [Peeters et al. 2004].
Garden species
The species has been first observed in our garden in 2022.
2. BEHAVIOUR
2.1. ACTIVITY
The species is active from the beginning of May until half October [Peeters et al. 2004]. Normally there is one generation per year, but in advantageous years sometimes two [Blösch 2000].
2.2. DEVELOPMENT
Nest
The species uses marrow filled plant stems, abandoned corridors of xylophagous insects in dead wood, and galls of frit flies (Chloropidae) [Peeters et al. 2004],[Ruchin et al., 2019], Lipara [Klein 1999],[Ruchin et al. 2019]. Decayed wood, trunks and poles can also be used [Bohart 1976].
Corridors with a diameter of 2,5-3 mm are gnawed in wood [Tsuneki 1952 (als P. shuckardi)].
The nest may consist of branched corridors with some brood cells or a single brood cell, seldom are these constructed in a row in predominantly in tube-like structures [Tsuneki 1952 (als P. shuckardi)]. In the first case the prey is somewhat mixed with wood flour and no separating walls are constructed [Blösch 2000]. Brood cells arranged in a row are separated by such wall constructed from wood pulp [Tsuneki 1952]. Nest constructed in Lipara galls do not contain separating walls and are closed by a plug made of plant fibers [Blösch, 2000].
When the brood cell is filled the corridor leading to it is filled with wood flour. Pemphredon wasps often construct one or more spare corridor that is used to store the flour during construction [Tsuneki 1952].
Every brood cell contains up to 30-50 prey [Peeters et al. 2004],[Tsuneki 1952 (als P. shuckardi)].
Eggs develop in about three to five days [Cranshaw 2014]. The larva develops in about two weeks to pre-pupa [Cranshaw 2014]. The second generation will overwinter as pre-pupa, the first generation will developed in short period to pupa [Cranshaw 2014]. The pupal phase will will take about three weeks [Cranshaw 2014].
Pemphredon has clear potandry, the appearing male first and usually occupy the frontal cells, the females develop in the cell located in the back [Blösch 2000].
2.3. BEE HOTEL
Some Pemphredon females are known to be observed collecting nesting materials on bee hotels [Breugel 2014]. Whether this is true for P. inornata is not mentioned in the literature to me.
2.4. MATING
–
2.5. HUNTING
Caught prey is paralysed by stinging or killed by crushing it with the jaws [Ruchin et al. 2019], [Piek 2013], [Lomholdt 1984]. P. inornata has been observed stinging its prey in the ventral side while hovering in flight [Tsuneki 1952 (als P. shuckardi)]. Sometimes a caught prey is eaten by the wasp, which will not be stung [Tsuneki 1952 (als P. shuckardi)].
The prey is transported to the nest using the mandibles [Blösch 2000],[Tsuneki 1952 (als P. shuckardi)].
3. PLANT RELATIONS
3.1. WOOD TYPES
The following wood types are mentioned in literature as medium for the wasp to built her nests in:
Adoxaceae (Moschatel family) | Sambucus (Elder) [Peeters et al. 2004],[Danks 1974 (as Cemonus shuckardi)]] |
Anacardiaceae (Sumac family) | Rhus (Sumac) [Cranshaw 2014 (Pemphredon spp.)] |
Betulaceae (Birch family) | Betula (Birch) [Peeters et al. 2004] |
Oleaceae (Olive family) | Forsythia [Peeters et al. 2004] |
Poaceae (Grasses) | Phragmites (Reed) [Peeters et al. 2004] |
Rosaceae (Rose family) | Rosa (Rose) [Peeters et al. 2004] Rubus (Blackberry) [Peeters et al. 2004],[Danks 1971 (as Cemonus shuckardi)] Sorbus (Rowan) [Peeters et al. 2004] |
Salicaceae (Willow family) | Populus (Poplar) [Peeters et al. 2004] Salix (Willow) [Peeters et al. 2004] |
Galls of Lipara flies are used as well for nesting, Lipara lucens [Blösch 2000].
3.2. FOOD PLANTS
The following wood types are mentioned in literature as food sources:
Adoxaceae (Moschatel family) | Sambucus (Elder) [Tsuneki 1952] |
Apiaceae (Umbelliferae) | Angelica (Wild angelica) [Blösch 2000],[Woydak 1996] Daucus [Blösch, 2000],[Woydak 1996] Pastinaca (Parsnip) [Blösch 2000],[Woydak 1996] |
Asteraceae (Composite family) | Achillea (Yarrow) [Blösch 2000] Cirsium (Thistle) – Cirsium arvense (Creeping thistle) [Blösch 2000],[Woydak 1996] |
Rosaceae (Rose family) | Crataegus (Hawthorn) [Blösch 2000],[Woydak 1996] |
Pemphredon wasps have been observed licking honeydew [Blösch 2000] on leaves of Sambucus [Tsuneki 1952].
Garden species
In the garden some umbellifers are present but I have not observed the species on it.
Apicaceae (Umbelliferae) | Foeniculum – Foeniculum vulgare (Fennel) Pastinaca – Pastinaca sativa (Parsnip) |
Asteraceae (Composite family) | Anthemis – Anthemis tinctoria (Dyer’s chamomile) Cichorium – Cichorium intibus (Chicory) Solidago – Solidago gigantea (Giant goldenrod) Tanacetum – Tanacetum vulgare (Tansy) Taraxacum – Taraxacum officinale (Common dandelion) |
3.3. PROOI PLANTEN
Pemphredon finds her prey on their food plants. The following plants are mentioned in literature:
Adoxaceae (Moschatel family) | Sambucus (Elder) – Sambucus buergeriana [Tsuneki 1952] |
Garden species
The garden does not contain any of the mentioned prey plants.
4. PREY RELATIONS
The species uses aphids (Aphidoidea) for her brood [Peeters et al. 2004],[Blösch 2000],[Woydak 1996].
Sometimes a caught prey is eaten by the wasp without transporting it to the nest [Tsuneki 1952 (als P. shuckardi)].
The following species and group occurring in the Netherlands [Soortenregister] are mentioned in literature:
Aphididae (Aphids) | Amphorophora [Lomholdt 1984],[Woydak 1996] Anuraphis [Lomholdt 1984],[Woydak 1996] Aphis [Lomholdt 1984],[Woydak 1996],[Danks 1971 (as Cemonus shuckardi)] – Aphis salicariae [Danks 1971 (as Cemonus shuckardi)]] Chaitophorus [Lomholdt 1984],[Woydak 1996] Macrosiphoniella – Macrosiphoniella usquertensis [Danks 1971 (as Cemonus shuckardi)] Megoura viciae – Megoura viciae [Danks 1971 (as Cemonus shuckardi)] Myzus [Lomholdt 1984],[Woydak 1996] Phorodon [Lomholdt 1984],[Woydak 1996] Pterocomma [Lomholdt 1984],[Woydak 1996] Thelaxes [Lomholdt 1984],[Woydak 1996] Therioaphis subgen. Pterocallidium [Lomholdt 1984 (as Pterocallidium)] |
Prey species outside the Netherlands:
Aphididae (Aphids) | Callipterus [Lomholdt 1984],[Woydak 1996] Eterocallidium [Woydak 1996] Macroshiphum [Lomholdt 1984],[Woydak 1996] Callaphidinae [Blösch 2000 (as Callaphididae] Chaitophorinae [Blösch 2000 (as Chaitophoridae)] Thelaxinae [Blösch 2000 (as Thelaxidae] |
Garden species
None of the mentioned prey species have been observed yet in our garden.
5. PARASITIC RELATIONS
The following species and group occurring in the Netherlands [Soortenregister] are mentioned in literature:
Hymenoptera (Wasps) | Chrysididae (Cuckoo wasps) Pseudomalus * – Pseudomalus auratus [Peeters et al. 2004],[Ruchin et al. 2019],[Woydak 1996],[Paukkunen 2015],[Blösch, 2000 (as Omalus auratus] ➡︎ brood idiobiont ectoparasitoid (eats food stock and larva) [Tsuneki 1952] Ichneumonidae (Ichneumon wasps) Perithous – Perithous divinator [Blösch 2000],[Peeters et al. 2004] |
*cuckoo wasp female does not enter the nest, but parasitizes a living aphid that then is caught by P. inornata [Paukkunen 2015]
6. IDENTIFICATION
Length males: 6 – 7,5 mm
Length females: 5 – 8 mm
Genus
The genus Pemphredon can be identified using the following characters:
1. Forewing: with two submarginal cells [Bitsch 2022],[Jacobs 2007]
2. Forewing: with two discoidal cells [Bitsch 2022],[Jacobs 2007]
3. Forewing: pterostigma smaller than marginal cell [Bitsch 2022],[Jacobs 2007]
4. Thorax: pronotum not enlarged, sides do not reach tegula [Bitsch 2022],[Jacobs 2007]
5. Thorax: notauli do not reach back edge mesonotum [Bitsch 2022],[Jacobs 2007]
6. Abdomen: front first abdominal segment petiolate [Bitsch 2022],[Jacobs 2007]

specimen caught for photo identification on 22-v-2022, length ±7,5 mm

1. Antenna with 12 segments [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
2. Abdomen with 6 segments [Bitsch, 2022],[Jacobs, 2007],[Smissen 2003]
3. Clypeus with few silver hairs [Bitsch 2022],[Smissen 2003]
4. Tergite 6 with pygidium [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
HEAD
1. Clypeus: apical edge flat with three teeth [Bitsch 2022],[Jacobs 2007], in the middle obtuse-angled protruding [Bitsch 2022],[Jacobs 2007],[Smissen 2003]. Seen from below the tooth resembles a tubercle in a semi-circle [Bitsch 2022].

Jacobs/Bitsch (red line) use a different clypeus depiction than Smissen (blue dotted line, frontal view looking down).
Clypeus characteristically domed and simultaneously sharply protruding [Smissen 2003]
2. Without horn between the antennal implants [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
3. Antennal segment 3 about 2x longer than wide [Jacobs 2007],[Smissen 2003]
THORAX
1. Forewing: first [Smissen 2003] and second discoidal transverse veins join submarginal cell [Bitsch 2022],[Jacobs 2007],[Smissen 2003], second vein predominantly antefurcal (here antefurcal) [Smissen 2003].

2. Forewing: second submarginal cell higher than wide [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
3. Foreleg: outer side member 1 (metatarsus) with very long hairs [Smissen 2003]
4. Hindleg: outer side shin (tibia) with distinct thorns on bumps [Smissen 2003]
5. Hindleg: inner side thigh (femur) chagrined.
6. Pronotum: wide and glossy [Smissen 2003]
7. Occiput, mesonotum, scutellum and metanotum finely, coarsely punctured, glossy to polished [Smissen 2003]

8. Mesoscutum usually with oil-like shine [Smissen 2003]
9. Scutum glossy, the spaces between the punctures is 3-4x the puncture diameter [Smissen 2003]
10. Ventrally (mesosternum) and side (mesopleuron) thorax in front middle hip (coxa) almost structureless, smooth and glossy [Bitsch 2022],[Smissen 2003]

11. Propodeum: boundary predominantly wide, glossy and polished [Smissen 2003]
12. Boundary without stair-like structure [Smissen 2003]
A stair-like structure has two clear vertical rails (green dotted line) with horizontal rungs (red lines) in between, the entire structure lies deeper in the boundary causing this to be interrupted.
Here the vertical rails are missing, and the horizontal rungs lie on top of the boundary.
ABDOMEN
1. Petiolus: longer than half the length of tergite 1 [Jacobs 2007], longer then half the length of the postpetiolus [Bitsch 2022]
2. Tergites and sternites almost without punctations [Smissen 2003]
3. Pygidium: short and wide [Jacobs 2007],[Smissen 2003]
The edges of the pygidium often diverge slightly upwards, the ratio upper space : apical space is ±1,4 in this specimen.

–
1. Antenna with 13 segments [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
2. Clypeus: with silver hairs [Bitsch 2022],[Smissen, 2003]
3. Tergite 7 without pygidium [Bitsch, 2022],[Jacobs 2007],[Smissen 2003]
HEAD
1. Clypeus: apical edge with triangular cut out [Bitsch 2022]
2. Without a thorn between the antennal implants [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
3. Antennal segments 5-8 with small, stump, matt reddish swellings [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
4. Antennal member 3: 1,6-2,1x longer than wide [Bitsch 2022]
THORAX
1. Forewing: first [Smissen, 2003] and second discoidal transverse veins join submarginal cell [Bitsch 2022],[Jacobs 2007],[Smissen 2003], second vein predominantly antefurcal (here antefurcal) [Smissen 2003].
2. Forewing: second submarginal cell higher than wide [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
3. Foreleg: outer side tarsal member 1 (metatarsus) with a few longer hairs [Smissen 2003]
4. Middle tarsal member 1 almost straight [jacobs 2007]
5. Hind leg: outer side shins (tibia) with some hairs and clear thorns [Smissen 2003]
6. Pronotum: wide and glossy [Smissen 2003]
7. Mesonotum frontally glossy, ± back half punctured or wrinkly punctured [Smissen 2003]
7. Scutellum: finely punctured, with large spaces between the punctures, glossy [Bitsch 2022],[Jacobs 2007],[Smissen 2003], space between punctures 1-4x thee puncture diameter [Bitsch 2022].
8. Metanotum: with sharp edges, very finely structured, semi-gloss or glossy [jacobs 2007],[Smissen 2003]
9. Ventrally (mesosternum) and side (mesopleuron) thorax in front middle hip (coxa) almost structureless, smooth and glossy [Jacobs 2007],[Smissen 2003]
10. Propodeum: boundary predominantly wide, glossy and polished [Smissen 2003]
11. Boundary without stair-like structure [Smissen 2003]
A stair-like structure has two clear vertical rails with horizontal rungs in between, the entire structure lies deeper in the boundary causing this to be interupted.
ABDOMEN
1. Petiolus: longer than half the length of tergite 1 [Jacobs 2007], longer then half the length of the postpetiolus [Bitsch 2022]
2. Tergiet VI glossy and finely and coarsely punctated [Smissen 2003]
3. Sternites IV-VI, seen in profile, with short more or less dense backwards pointing bristle hairs [Bitsch 2022],[Jacobs 2007]
4. Sternites III-VI mat, almost without punctures, apical seams narrow and not or slightly depressed [Bitsch 2022],[Jacobs 2007],[Smissen 2003]
Literature
Bitsch 2022 Bitsch, J., 2022. Hyménoptères sphéciformes d'Europe: Systématique (3e partie) : Pemphredoninae et Philanthinae. France: Fédération française des sociétés de sciences naturelles.Blösch 2000 Blösch, M. (2000). Die Grabwespen Deutschlands – Lebens‐weise, Verhalten, Verbreitung. 71. Teil. In Dahl, F.: Die Tierwelt Deutschlands. Begr.: 1925. – Keltern (Goecke & Evers). – 480 S. 341 Farbfotos. ISBN 3‐931374‐26‐2 (hardcover). DM 98,–. Zool. Reihe, 78: 353-353. https://doi.org/10.1002/mmnz.20020780208
Bohart & Menke 1976 Bohart, R.M. & Menke A.S., 1976. Sphecid wasps of the world: a generic revision. - University of California Press, 695 p.
Breugel 2014 Breugel, P. van., 2014. Gasten van bijenhotels. – EIS Kenniscentrum Insecten en andere ongewervelden & Naturalis Biodiversity Center, Leiden.
Cranshaw 2014 Cranshaw, W., 2014. Colorado Insects of Interest Fact Sheets authored by Whitney Cranshaw - Pemphredon Wasps. Colorado State University.
Danks 1971 Danks, H.V., 1971. Biology of some stem‐nesting aculeate Hymenoptera. Transactions of the Royal Entomological Society of London, 122.11: 323-395.
Jacobs 2007 Jacobs, H.J., 2007. Die Grabwespen Deutschlands Ampulicidae. Sphecidae, Crabronidae–Bestimmungsschlüssel in Blank, SM & Taeger, A (Hrsg): Die Tierwelt Deutschlands und der angrenzenden Meeresteile nach ihren Merkmalen und nach ihrer Lebensweise, Hymenoptera III–Keltern, Goecke & Evers, 79: 1-207.
Klein 1999 Klein, W., 1999 De graafwespen van de Benelux: supplement. Jeugdbondsuitgeverij, 1-37. + Klein, W., 1996. De graafwespen van de Benelux. Jeugdbondsuitgeverij, 1-130.
Lomholdt 1984 Lomholdt, O., 1984. The Sphecidae (Hymenoptera) of Fennoscandia and Denmark. Fauna Entomologica Scandinavica, 4.1: 2.
Paukkunen et al. 2015 Paukkunen, J., Berg, A., Soon, V., Ødegaard, F., & Rosa, P., 2015. An illustrated key to the cuckoo wasps (Hymenoptera, Chrysididae) of the Nordic and Baltic countries, with description of a new species. ZooKeys, (548), 1.
Peeters et al. 2004 Peeters, T.M.J., C. van Achterberg, W.R.B. Heitmans, W.F. Klein, V. Lefeber, A.J. van Loon, A.A. Mabelis, H. Nieuwen-huijsen, M. Reemer, J. de Rond, J. Smit, H.H.W. Velthuis, 2004. De wespen en mieren van Nederland (Hymenoptera: Aculeata). – Nederlandse Fauna 6. Nationaal Natuurhistorisch Museum Naturalis, Leiden, knnv Uitgeverij, Utrecht & European Invertebrate Survey – Nederland, Leiden.
Piek 2013 Piek, T. (Ed.), 2013. Venoms of the Hymenoptera: biochemical, pharmacological and behavioural aspects. Elsevier.
Ruchin & Antropov 2019 Ruchin, A. & Antropov, A., 2019. Wasp fauna (Hymenoptera: Bethylidae, Chrysididae, Dryinidae, Tiphiidae, Mutillidae, Scoliidae, Pompilidae, Vespidae, Sphecidae, Crabronidae & Trigonalyidae) of Mordovia State Nature Reserve and its surroundings in Russia. Journal of Threatened Taxa. 11. 13195-13250. 10.11609/jott.4216.11.2.13195-13250.
Smissen 2003 Smissen, Jvd., 2003. Zur Kenntnis der Untergattung Cemonus Jurine 1807 (Hymenoptera: Sphecidae, Pemphredon) mit Schlüssel zur Determination und Hinweis auf ein gemeinsames Merkmal untersuchter Schilfbewohner (Hymenoptera: Sphecidae, Pompilidae). Not Faun Gembloux, 52: 53-101.
Soortenregister Nederlands Soortenregister
Tsuneki 1952 Tsuneki, K., 1952. Ethological studies on the Japanese species of Pemphredon (Hymenoptera, Sphecidae), with notes on their parasites, Ellampus spp.(Hym., Chrysididae)(With 5 Text-figures). 北海道大學理學部紀要, 11.1: 57-75.
Waarneming.nl Waarneming.nl
Woydak 1996 Woydak, H., 1996. Hymenoptera Aculeata Westfalica Familia: Sphecidae (Grabwespen), 3-135.
Citation
Krischan, O.R., 2025. Pemphredon inornata. Kerfdier, www.kerfdier.nl. Accessed on [date month year].