Indirect-parasitism
Guides
Holopyga
cuckoo wasps
Holopyga is a genus of cuckoo wasps in the family Chrysididae. Species in this genus exhibit a distinctive cleptoparasitic life history: females oviposit into aphids, and when crabronid wasps such as Pemphredon collect these aphids as prey for their nests, the Holopyga larva emerges first and consumes the food stores intended for the host larva. This indirect parasitism of wasp nests via aphid intermediates has been documented for Holopyga by Veenendaal (2012). The genus contains approximately 35 described species distributed across Europe and other regions.
Holopyga horus
Holopyga horus is a species of cuckoo wasp in the family Chrysididae. Like other members of the genus Holopyga, it is a cleptoparasite that exploits the nests of other wasps. Research indicates that females may lay eggs directly into aphids, which are then captured by crabronid wasps such as Pemphredon and carried to their nests. The cuckoo wasp larva emerges before the host larva and consumes the provisions intended for the host offspring. This indirect parasitic strategy has been documented in related Holopyga species and is suspected to occur in H. horus.
Holopyga ventralis
Holopyga ventralis is a species of cuckoo wasp in the family Chrysididae. The genus Holopyga comprises small, brilliantly metallic-colored wasps that are cleptoparasites of other wasps. Based on observations of related species in the genus, H. ventralis likely exhibits the distinctive parasitic behavior of laying eggs into aphids, which are then carried as prey by crabronid wasps into their nests where the Holopyga larva develops at the expense of the host wasp's offspring.
Omalus aeneus
Cuckoo Wasp
Omalus aeneus is a small, metallic cuckoo wasp in the family Chrysididae. Females reach 4.5–5.4 mm in body length, males 4.4–5 mm. The species exhibits striking metallic coloration ranging from blue, green, and purple to nearly black or golden, with greenish-blue abdomen and legs. This cleptoparasitic wasp has two or more generations annually in southern Europe and exploits a remarkable indirect parasitism strategy: females oviposit into living aphids, which are subsequently captured by aphid-hunting crabronid wasps and transported to their nests, where the cuckoo wasp larva develops.
Omalus downeyi
Downey's Cuckoo Wasp
Omalus downeyi is a species of cuckoo wasp in the family Chrysididae. Like other members of the genus Omalus, it is a kleptoparasite that targets the nests of solitary wasps, particularly aphid-hunting wasps in the family Crabronidae such as Pemphredon and Passaloecus. The species exhibits an indirect parasitic strategy: females oviposit into aphids, which are then captured by host wasps and transported to their nests, where the cuckoo wasp larva develops by consuming the host's provisions.
Omalus glomeratus
Omalus glomeratus is a species of cuckoo wasp (family Chrysididae) known for its kleptoparasitic lifestyle. Like other members of the genus Omalus, females oviposit directly into aphids, exploiting the hunting behavior of aphid wasps in the family Crabronidae (such as Pemphredon and Passaloecus). When a crabronid wasp captures and carries the parasitized aphid to its nest, the Omalus larva hatches and consumes the food provisions intended for the host larva. This indirect parasitic strategy avoids the risks of direct nest entry. The species has been observed in Europe and represents part of a broader behavioral pattern documented across Omalus, Pseudomalus, and Holopyga.
Omalus iridescens
Omalus iridescens is a species of cuckoo wasp in the family Chrysididae. Like other members of the genus Omalus, it is a cleptoparasite that exploits the nesting behavior of solitary wasps. The species exhibits the characteristic metallic coloration typical of chrysidid wasps. Based on documented behaviors of closely related Omalus species, females likely oviposit into aphids that are subsequently captured by crabronid wasps and transported to their nests, where the cuckoo wasp larva develops at the expense of the host's offspring.
Omalus variatus
Omalus variatus is a species of cuckoo wasp in the family Chrysididae. Like other members of its genus, it is a kleptoparasite that targets the nests of solitary wasps, particularly aphid-hunting wasps in the family Crabronidae. The species exhibits a distinctive indirect parasitism strategy: females oviposit into aphids, which are then captured by host wasps and transported to their nests, where the cuckoo wasp larva develops by consuming the host's provisions.
Pseudomalus auratus
cuckoo wasp, jewel wasp
Pseudomalus auratus is a small cuckoo wasp in the family Chrysididae, notable for its striking metallic coloration with emerald green head and thorax contrasting with a ruby red abdomen. Native to the Palearctic region, it has been accidentally introduced to North America, likely before 1828. The species exhibits an unusual indirect parasitic strategy: females oviposit into aphids, which are then captured by crabronid wasps and carried to their nests, where the cuckoo wasp larva emerges to kill the host larva and consume the stored provisions.