Post by nomad on Sept 3, 2016 6:59:27 GMT
Ectemnius Wasps.
Ectemnius species are smart wasps of the Crabronidae family that have large bulging eyes. Many of the British species are mainly Hoverfly (Syrphidae) hunters but take other Diptera. These wasps are very sensitive to any movement when they land on large leaves of various shrubs or plants to keep a sharp look out for prey but they never stay still in anyone place for very long.
I first spotted these wasps hunting along a hedgerow in an urban cemetery towards the end of July and I again found them visiting my Japanese anemone plants (Nemone hupehensis) in my garden during the last week of August. Although the wasps in both locations look very similar, it is not known if those seen in the cemetery are the same species that are now visiting my garden. As I watched a hoverfly on an anemone flower, an Ectemnius wasp moved in very quickly and grasped the feeding insect, then flying off at speed with its victim, before I could even raise my camera. There long legs are idea for carrying prey. Studying these visiting wasps they certainly sensed I was there and sometimes I wondered who was watching who. Alighting on a leaf they have a habit of lifting their heads when looking for prey above them, turning in a circle as they do. One day I noticed a hoverfly sawfly mimic Xylota segnis running about on the anemones leaves feeding on anemophilous (wind-dispersed) pollen, when it suddenly saw an Ectemnius wasp it gave chase, a strange observation, as that insect would be no match for the wasp hunter who can tackle prey larger than themselves.
Perhaps the wasps shown below may Ectemnius cavifrons but there are a number of similar species such as Ectemnius cephalotes and an expert with a microscope is needed I believe to tell them apart. Those Ectemnius species have nests in soft wood which of consist of several cells each containing up to a dozen prey items.
July 2016.
August 2016.
Ectemnius species are smart wasps of the Crabronidae family that have large bulging eyes. Many of the British species are mainly Hoverfly (Syrphidae) hunters but take other Diptera. These wasps are very sensitive to any movement when they land on large leaves of various shrubs or plants to keep a sharp look out for prey but they never stay still in anyone place for very long.
I first spotted these wasps hunting along a hedgerow in an urban cemetery towards the end of July and I again found them visiting my Japanese anemone plants (Nemone hupehensis) in my garden during the last week of August. Although the wasps in both locations look very similar, it is not known if those seen in the cemetery are the same species that are now visiting my garden. As I watched a hoverfly on an anemone flower, an Ectemnius wasp moved in very quickly and grasped the feeding insect, then flying off at speed with its victim, before I could even raise my camera. There long legs are idea for carrying prey. Studying these visiting wasps they certainly sensed I was there and sometimes I wondered who was watching who. Alighting on a leaf they have a habit of lifting their heads when looking for prey above them, turning in a circle as they do. One day I noticed a hoverfly sawfly mimic Xylota segnis running about on the anemones leaves feeding on anemophilous (wind-dispersed) pollen, when it suddenly saw an Ectemnius wasp it gave chase, a strange observation, as that insect would be no match for the wasp hunter who can tackle prey larger than themselves.
Perhaps the wasps shown below may Ectemnius cavifrons but there are a number of similar species such as Ectemnius cephalotes and an expert with a microscope is needed I believe to tell them apart. Those Ectemnius species have nests in soft wood which of consist of several cells each containing up to a dozen prey items.
July 2016.
August 2016.
