Joseph Spencer
@talkingrootworm.bsky.social
PhD entomologist & insect photographer. Scientist & Program Leader in Insect Behavior in the Illinois Natural History Survey/Prairie Research Institute at University of Illinois. I like & share images & stories about insects, rootworms, agriculture & more!
Thanks to ESA for making my photo the "Arthropod of the week"!
Entomological Society of America@entsocamerica.bsky.social · last mo.Arthropod Photo of the Week: September 2, 2026 Crab spider and black swallowtail caterpillar Xysticus sp. / Papilio polyxenes Araneae: Thomisidae / Lepidoptera: Papilionidae Observed in Illinois, USA By Joseph Spencer (@talkingrootworm.bsky.social), Illinois, USA #arthropodPOTW
Arthropod Photo of the Week: September 2, 2026 Crab spider and black swallowtail caterpillar Xysticus sp. / Papilio polyxenes Araneae: Thomisidae / Lepidoptera: Papilionidae Observed in Illinois, USA By Joseph Spencer (@talkingrootworm.bsky.social), Illinois, USA #arthropodPOTW
This is male #Polyphemus #moth, #Antheraea polyphemus (Family #Saturniidae). The feathery "plumose" #antennae are adapted for the detection of female #pheromone at low concentrations. If detected, males engage in upwind flight following the concentration gradient to the waiting female. #Lepidoptera
“Spy vs. Spy, Assassin #bug vs. Soldier bug" I didn’t see how one stealthy #predator caught the other, but the outcome was photogenic. Perhaps declining Autumn numbers of #caterpillars & other small prey make this inevitable? #Reduviidae #Podisus #Hemiptera [Champaign Co., Ill. USA. 14 Oct 2025]
“Spy vs. Spy, Assassin #bug vs. Soldier bug" I didn’t see how one stealthy #predator caught the other, but the outcome was photogenic. Perhaps declining Autumn numbers of #caterpillars & other small prey make this inevitable? #Reduviidae #Podisus #Hemiptera [Champaign Co., Ill. USA. 14 Oct 2025]
“Girl with kaleidoscope eyes” #Coelioxys sp. #Cuckoo #leafcutter #bees parasitize the nests of leafcutter bees by invading & laying their eggs inside that will kill the leafcutter larvae & then eat their store of nectar & pollen. This female was chilling on an aster in my garden.
“Girl with kaleidoscope eyes” #Coelioxys sp. #Cuckoo #leafcutter #bees parasitize the nests of leafcutter bees by invading & laying their eggs inside that will kill the leafcutter larvae & then eat their store of nectar & pollen. This female was chilling on an aster in my garden.
“Who’s in charge now?” If asked, I’d affirm the wheel bug, #Arilus cristatus, as the top predator in my yard. A recent encounter w/ one of the many cross #orbweavers, #Neoscona crucifera, in my yard reminded me that the tables can, and do, turn. #Arachtober #spider #Reduviidae #Araneidae #arachnid
“Who’s in charge now?” If asked, I’d affirm the wheel bug, #Arilus cristatus, as the top predator in my yard. A recent encounter w/ one of the many cross #orbweavers, #Neoscona crucifera, in my yard reminded me that the tables can, and do, turn. #Arachtober #spider #Reduviidae #Araneidae #arachnid
I've been following the "progress" of this little (<1 cm) #inchworm #caterpillar for a couple of days. It is wearing a trio of #ectoparasitic wasp larvae (in Family #Chalcididae). They're siphoning the caterpillar's blood & bodily fluids. It'll die soon & they will form pupae near the cadaver.
I've been following the "progress" of this little (<1 cm) #inchworm #caterpillar for a couple of days. It is wearing a trio of #ectoparasitic wasp larvae (in Family #Chalcididae). They're siphoning the caterpillar's blood & bodily fluids. It'll die soon & they will form pupae near the cadaver.
Three’s a crowd! The wheel bugs (#Arilus cristatus) in my garden seem confused about how many individuals are needed to start a family. They worked it out about an hour after my photos and the “third wheel” hit the road. #Reduviidae #AssassinBug [Champaign County, Illinois. USA. 19 September 2025]
Three’s a crowd! The wheel bugs (#Arilus cristatus) in my garden seem confused about how many individuals are needed to start a family. They worked it out about an hour after my photos and the “third wheel” hit the road. #Reduviidae #AssassinBug [Champaign County, Illinois. USA. 19 September 2025]
This afternoon, a group of #migrants on their way to Mexico stopped in my yard to grab a bite and rest. They are staying the night. I count 64 lodgers tonight. On Saturday evening, I had 142! #butterflies #monarchseason #monarch.
Days like today, when the yard is full of butterflies, remind me why I planted and tend my gardens of prairie plants. [Champaign County, IL. 13 September 2025]
Though they were vastly out-numbered by #monarchs, painted lady #butterflies, were still showing off as they completed for opportunities to sample the floral delights offered up by the Liatris blossoms. #Colias.
Though they were vastly out-numbered by #monarchs, painted lady #butterflies, were still showing off as they completed for opportunities to sample the floral delights offered up by the Liatris blossoms. #Colias.
Days like today, when the yard is full of butterflies, remind me why I planted and tend my gardens of prairie plants. [Champaign County, IL. 13 September 2025]
"I'm an #inchworm caterpillar, but I identify as stick." When disturbed, some #Geometridae family #caterpillars will straighten out in a stick-like posture to avoid detection. It's an effective form of #crypsis even the color/texture doesn't match well. [Champaign County, IL. USA. 5 September 2025]
Have you ever seen a #pelecinid #wasp? Well, you have now! Say "Hello" to #Pelecinus polyturator. Their larvae live as internal parasites of wood or ground dwelling scarab beetle larvae. Until 3 weeks ago, I'd only ever seen 1 individual. Since then, I've seen a dozen females.
Hanging around or hanging on! A nightwalk revealed #insects exploited by other #arthropods. Doomed big & little Paw Paw #sphinx #caterpillars parasitized by #braconid wasps, an #inchworm bearing more #wasp #cocoons, & a crane fly #Über allowing 2 #pseudoscorpions to hitch a ride (called #phoresy)
Have you ever seen a #pelecinid #wasp? Well, you have now! Say "Hello" to #Pelecinus polyturator. Their larvae live as internal parasites of wood or ground dwelling scarab beetle larvae. Until 3 weeks ago, I'd only ever seen 1 individual. Since then, I've seen a dozen females.
Hanging around or hanging on! A nightwalk revealed #insects exploited by other #arthropods. Doomed big & little Paw Paw #sphinx #caterpillars parasitized by #braconid wasps, an #inchworm bearing more #wasp #cocoons, & a crane fly #Über allowing 2 #pseudoscorpions to hitch a ride (called #phoresy)
Singularly fantastic & uncommon #arachnid. #Orsima ichneumon, the kaleidoscope #ant #mimic #spider #Salticidae, is found in SE Asia. This female was shadowing an ant while patrolling a leaf @ Trus Madi Jungle Girl Entomology Camp. #Sabah #Borneo. It has fewer than 50 records at #iNaturalist
