Short Communication |
Corresponding author: Alfred Daniel Johnson ( danieljalfred@gmail.com ) Academic editor: Volker Lohrmann
© 2023 Alfred Daniel Johnson, Tamir Rozenberg, Michal Segoli.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Johnson AD, Rozenberg T, Segoli M (2023) Notes on the parasitoids found within the nests of Delta dimidiatipenne (Hymenoptera, Vespidae). Journal of Hymenoptera Research 96: 925-936. https://doi.org/10.3897/jhr.96.102336
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An examination of parasitoids that had completed their development but were trapped within Delta dimidiatipenne nests revealed 15 species of insect parasitoids, belonging to eight families under two orders. A new association of Miltogramminae (Diptera: Sarcophagidae) with this wasp is also reported.
Diptera, Miltogramminae, parasitoids, potter wasps, Sarcophagidae
Potter wasps (Eumeninae) are the largest vespid wasp subfamily in the world, comprising nearly 3800 species in more than 210 currently described genera (
Eumeninae’s main natural enemies are birds, ants, bats, and parasitoids (
Apart from these nest parasitoids, several studies have also reported the occurrence of parasitized prey and parasitoids of the prey insects trapped in the nests of solitary wasps. This may occur when the potter wasps collect and bring to the nest already parasitized prey (
We focused on the wasp species Delta dimidiatipenne de Saussure, 1852 (Hymenoptera, Vespidae, Eumeninae), which has been recorded in Afghanistan, Algeria, Chad, Djibouti, Egypt, Eritrea, Ethiopia, India, Iran, Israel, Jordan, Mauritania, Morocco, Nepal, Niger, Oman, Pakistan, Qatar, Saudi Arabia, Spain, Somalia, South Africa, Sudan, Syria, Tajikistan, Turkey, Turkmenistan, the United Arab Emirates, Uganda, and Yemen, mainly in desert habitats (
The current study was conducted in Israel’s Negev and Judean Deserts during 2021–22. The climate is characterized by hot, dry summers, with an average maximum daily temperature of around 36 °C (Judean Desert) and 27 °C (Negev Desert) in July–August, and cold winters, with an average minimum daily temperature of around 18 °C (Judean Desert) and 9 °C (Negev Desert) in January–February. Annual precipitation is ca. 100 mm (data retrieved from the Israel Meteorological Service, https://ims.gov.il/en). A total of 11 field sites were selected, especially ones in proximity to temporary water holes that are used by potter wasps for drinking and nest construction. Delta dimidiatipenne normally build nests under rock ledges and in concealed rock surfaces, presumably to avoid direct insolation by the sun, which may result in overheating of the brood cell, and also to avoid the nest from being washed away by the heavy rains that occasionally occur during the nesting season. In each of the field sites, we sampled from five to 10 nests. However, it was difficult to estimate the exact number of nests that were sampled because the nests sometimes partially overlapped. In each nest, we sampled between three to 18 cells. This is again a rough estimation as some cells were partially disintegrated or contained secondary residences such as spiders, beetles or bees. We located nests from previous years, which can easily be recognized by the presence of emergence holes. Some nests had emergence holes in each cell, suggesting complete successful emergence, while other nests had some emergence holes and some intact cells, suggesting partial emergence success. In a few cases, we also found nests that were completely sealed without any emergence holes, suggesting that neither parasitoids nor potter wasps emerged successfully. Wherever feasible, we opened the cells by carefully dampening them with water and gently breaking the cell walls open using forceps and collecting all the parasitoids within. Apart from the focal study species, D. dimidiatipenne, we also collected and documented other vespid potter wasps in the study area by sweeping with nets near the water hole. We identified all the collected insects to the lowest taxonomic level possible, using keys published by
Potter wasp species, other than D. dimidiatipenne, that were collected include the following: Delta asina mixtum (Giordani Soika, 1944), Delta hottentotum elegans (De Saussure, 1852), Katamenes niger (Brullé, 1839), Katamenes dimidiativentris (Giordani Soika, 1941), Katamenes jenjouristei (Kostylev, 1939), and Ancistrocerus biphaleratus (de Saussure, 1852). We identified D. dimidiatipenne nests based on their distinctive pot-shaped entrance with a size of approximately 1 cm in diameter. Moreover, D. dimidiatipenne adults are the largest (approximately 2.5 cm long) of all the above-mentioned potter wasp species, and they construct the largest nests, comprising ca. 20 cells. Also, whenever we collected fresh cells (e.g., as part of our other published studies), this species always emerged from them. We have also recorded 12 imagines of D. dimidiatipenne that were trapped within the cell. This reaffirms that we have sampled only the nests of D. dimidiatipenne.
Our collections from the nests resulted in a total of 15 parasitoid species, belonging to two orders and eight families of insects. Based on the literature, most of them are probably parasitoids of species that the potter wasps collect as prey, while some are nest parasitoids of the potter wasps themselves. The details are presented in Table
Order | Family | Taxon/ Species | No. of individuals | Place of collection | Potential host |
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Diptera | Sarcophagidae | Miltogramminae | 1 | Nahal Peres (31°00'31.52"N, 35°28'39.95"E) | Wasp larva ( |
Tachindae | Undetermined | 1 | Mamshit (31°02'31.47"N, 35°06'70.13"E) | Could be prey or wasp larva ( |
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Hymenoptera | Ichneumonidae | Netelia fuscicornis (Holmgren, 1860) | 1 | Ein Bokek (31°19'86.72"N, 35°35'03.57"E) | Prey ( |
Barylypa rufa (Holmgren, 1857) | 1 | Nahal Shoalim (30°95'29.57"N, 34°91'39.78"E) | Prey ( |
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Ophion similis (Szépligeti, 1905) | 1 | Nahal Daroch (30°86'09.39"N, 34°85'96.41"E) | Prey ( |
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Braconidae | Cotesia vanessae (Reinhard, 1880) | 17 individuals from three nests | Nahal Gov (30°90'38.30"N, 35°12'77.89"E) & Nahal Shoalim (30°95'29.57"N, 34°91'39.78"E) & Ein Zik (30°80'36.54"N, 34°85'10.00"E) | Prey (a gregarious parasitoid) ( |
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Microplistis sp. | 9 | Nahal Gov (30°90'38.30"N, 35°12'77.89"E) & Nahal Afran (30°86'38.14"N, 34°92'71.31"E) | Prey ( |
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Schoenlandella deserta (Telenga, 1955) | 1 | Nahal Mador (30°86'99.66"N, 34°96'40.56"E) | Prey ( |
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Chelonus sp. | 4 | Mamshit (31°02'31.47"N, 35°06'70.13"E), Nahal Afran (30°86'38.14"N, 34°92'71.31"E) | Prey ( |
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Rogas sp. | 1 | Nahal Shoalim (30°95'29.57"N, 34°91'39.78"E) | Prey ( |
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Phanerotoma sp. | 11 | Ein Bokek (31°19'86.72"N, 35°35'03.57"E) | Prey ( |
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Encyrtidae | Copidosoma primulum (Mercet, 1921) | Hundreds emerging out of 28 mummified caterpillars | In all the collection sites | Prey (Gregarious parasitoid) ( |
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Hymenoptera | Torymidae | Monodontomerus sp. | 3 | Nahal Afran (30°86'38.14"N, 34°92'71.31"E) | Could be prey or wasp larva ( |
Eulophidae | Melittobia acasta (Walker, 1839) | 4 | Nahal Zafit (30°97'21.47"N, 35°29'69.26"E) | Wasp larva (a gregarious parasitoid) ( |
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Chrysididae | Stilbum sp. | 1 | Saraf (30°78'72.25"N, 35°02'99.82"E) | Wasp larva ( |
Though Bombyliidae is one of the most commonly occurring parasitoids in potter wasp nests (
Based on their known ecology, all the ichneumonids, braconids, and the encyrtid that were documented in this study, i.e., 10 out of 15 recorded species, are parasitoids of the prey caterpillars brought by the potter wasps to the nests. In this sense, it is perhaps not surprising to find them trapped within potter wasp nests, as they are not likely to have adaptations that enable them to emerge successfully through the hardened mud cell walls. Moreover, the occurrence of most of these prey parasitoids seems to be rare. Such low occurrence could perhaps represent a generally low parasitism rate on the prey by these parasitoid species in the field. In addition, some predatory insects are known to discriminate against parasitized prey, which are often of lower quality (e.g.,
An exception was the high occurrence of Copidosoma primulum, which was found in all 11 study sites and was the most abundant of all the parasitoids that we documented. This accords with previous studies conducted on these species (
Out of the eight families that were collected, five families, viz., Sarcophagidae, Tachindae, Torymidae, Eulophidae, and Chrysididae, were most likely to be nest parasitoids, each represented by one species. These species and, more importantly, the potter wasp adults are all presumably well adapted to complete their development inside a potter wasp nest, and hence, it may be surprising that they were trapped within the nest. One possible explanation is that the occurrence of prey parasitized by Copidosoma, or other low-quality prey, led to the development of malnourished potter wasps, which were too small or not strong enough to break open the nest cell. This could potentially also be true for some of the other trapped nest parasitoids. Another possibility could be that the extreme desert conditions, such as exceptionally high temperatures or extremely dry conditions, occurring in this region, caused insect death inside the nests.
Miltogramminae (Diptera, Sarcophagidae) are primarly kleptoparasites of wasps and bees (
Usually, Miltogramminae are termed “satellite flies” as they wait on perching sites close to the entrance of a host’s nest for a nest-returning host female and then follow it, in flight, at a fixed distance behind. Some Miltogramminae are termed “hole searchers” as they patrol the host’s nesting site and enter the host’s nest, and some are dubbed “stalkers” as they enter the host’s nest after having detected the female host entering it (
Future research based on host-parasitoid rearing can shed more light on factors causing different parasitoid species’ emergence failure, their developmental nutritional requirements, and their ability to break open the nest successfully.
We thank Ofir Altstein, Ishai Hoffman, and Tamar Sinai, the enthusiastic technicians from the Mitrani Department of Desert Ecology, for their help during the field trips. We also thank the taxonomists from the Steinhardt Museum of Natural History for all their assistance in identifying/confirming the identity of the specimens: Gideon Pisanty (for Braconidae), Wolf Kuslitzky (for Ichneumonidae), Ariel Leib Friedman (for Sarcophagidae and Tachinidae), Sergei Zonstein (for Chrysididae), Miriam Kishinevsky (for Encyrtidae and Torymidae), and Zoya Yefremova (for Eulophidae). Our thanks are due to Prof. Yael Lubin, Dr. Efrat Gavish-Regev, Dr. Monica Mowery, and Valeria Arabesky for their moral support and comments on this manuscript.