Official name:
Synonyms:
Pamphredon inornata [Nederlands soortenregister]
Cemonus shuckardi (Morawitz)
Dineurus shuckardi (Westwood 1837)
Pemphredon inornatus (Say 1824)
Pemphredon shuckardi (Morawitz 1864)
Pemphredon tenax (Fox 1892)
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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, 1996],[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 [Nederlands 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 [Nederlands 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]
References
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Nederlands soortenregister Nederlands Soortenregister
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Piek, 2013 PIEK, Tom (ed.). Venoms of the Hymenoptera: biochemical, pharmacological and behavioural aspects. Elsevier, 2013.
Ruchin et al., 2019 Ruchin, Alexander & Antropov, Alexander. (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.
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