Current status of the prairie cicada, Okanagana balli, in northeastern Illinois Dennis Nyberg and Sheryl Breedlove James Woodworth Prairie University of Illinois at Chicago
Okanagana balli dorsal view A small cicada (0.4g) emerging near solstice and restricted to prairie. 29Oct05 Okanagana balli 2
Marked for mark/recapture Okanagana balli are about 1 inch long as adults. 29Oct05 Okanagana balli 3
MOVIE 29Oct05 Okanagana balli 4
Woodworth Prairie in urban environment From Terraserver, date 10 April 2002 29Oct05 Okanagana balli 5
James Woodworth Prairie, A small (2.1 ha) original prairie Studied since 1926 Mesic site which could have been farmed Two small (0.1 ha) wetlands Conservation purchase by UIC in 1968 Regularly burned since 1972 Known for the prairie cicada as well as other flora and fauna 29Oct05 Okanagana balli 6
Woodworth Prairie Close-up 10 April 2002 Terraserver Most of the prairie was burned in 2001-02 dormant season 29Oct05 Okanagana balli 7
Research Questions What time of year are males singing? What time of day do males sing? What is the population size at JWP? How does copulation proceed? What types of plants are used for oviposition? What IL sites have the prairie cicada? 29Oct05 Okanagana balli 8
Cicada detection Singing males can be heard calling from about 20 m away. While one may hear 2 at the same time, it is rare to hear more than 2 at the same time. If they stop singing before one has location to <1 m 2, normally they are not found. When they fly they stay airborne for at least 10m and often fly out of visual contact. 29Oct05 Okanagana balli 9
Time of Year The earliest the cicada has been heard at the Woodworth prairie is 13 June (2000-05). The latest the prairie cicada has been heard at Woodworth is 14 July. The most reliable time of year is the last week of June. 29Oct05 Okanagana balli 10
Male sings at top of vegetation, but not on stalks rising above it. 29Oct05 Okanagana balli 11
Time of Day High temperature increase the probability of hearing the cicada. Sunny days increases the probability of hearing the cicada. Midday (11:30-2) is the best time of day. Cicadas have been heard calling as early as 8:30 and as late as 16:00. 29Oct05 Okanagana balli 12
Are cicadas found in all parts of the Woodworth site? The cicadas are usually not found singing within the wetlands Typically dry in late June. The cicadas are uncommon in the partly degraded northwest corner for reasons unknown. The larger dog day cicada (Tibicen) sings in August from the trees in backyards north of the prairie. 29Oct05 Okanagana balli 13
Predation A fight between a cicada and a wasp was witnessed. The cicada escaped from the wasp. Redwing blackbirds and mourning doves are regularly present and nesting at the time the cicada males are singing. 29Oct05 Okanagana balli 14
How many cicadas are there? Mark/recapture studies have been done at the Woodworth Prairie Singing males were caught in net. Each male received a unique mark using multicolored enamel fine tip marking pens (from art supply store). Males were photographed and then released at location caught. 29Oct05 Okanagana balli 15
A marked cicada Bright marks allowed identifying marked individuals without recapture 29Oct05 Okanagana balli 16
Mark/recapture Information 2001 Total marked = 54 Total resighted = 17 Most persistent: A12, marked 6/19 & last resighted 7 days later, 6/26 Fisher-Ford model yielded an estimated mortality of between 40% and 50% per day (for singing males). 29Oct05 Okanagana balli 17
Mark/Recapture Data 2001 Day M Mt C R ~ N ~2N R/C 1 3 3 0 2 0 3 0 0 3 8 11 8 0 0 4 2 13 3 1 39 78 0.333 5 5 18 5 0 0 6 0 18 0 0 7 9 27 11 2 148 297 0.182 8 8 35 14 6 81 163 0.429 9 0 35 0 0 10 11 46 16 5 147 294 0.313 11 8 54 11 3 198 396 0.272 29Oct05 Okanagana balli 18
Woodworth (JWP) Population Estimate in 2001 was 200 singing males at the prairie. Assuming an equal number of females the total was 400 cicadas. The estimate for 2002 was 400 males or 800 adult cicadas. The Okanagana balli population at JWP is estimated to be 100 400 per hectare. 29Oct05 Okanagana balli 19
Cicada life cycle Though they appear every year, based on literature, the cicada do not complete the egg to adult period in a single year. The egg to adult period is probably 3 to 5 years based on the literature. Ideas for ways to establish the length of the life cycle would be appreciated. 29Oct05 Okanagana balli 20
Male 29Oct05 Okanagana balli 21
Male, side view 29Oct05 Okanagana balli 22
female 29Oct05 Okanagana balli 23
Observations of mating 29Oct05 Okanagana balli 24
Copulation 29Oct05 Okanagana balli 25
More Mating 29Oct05 Okanagana balli 26
Mating 29Oct05 Okanagana balli 27
Mating Female flies to singing male Mating begins within a couple minutes of her arrival Copulation lasts 10 minutes Shortly after mating females flies off 29Oct05 Okanagana balli 28
Observation of oviposition 29Oct05 Okanagana balli 29
Oviposition scars on rose 29Oct05 Okanagana balli 30
Oviposition Plants Oviposition has been observed twice. The plant species were: Rosa carolina Solidago graminifolia The Rosa has a woody stem, the Solidago does not. Neither species is restricted to original prairie. 29Oct05 Okanagana balli 31
Six Eggs in rose stem 29Oct05 Okanagana balli 32
Eggs at an insertion point 29Oct05 Okanagana balli 33
Where in Illinois are cicadas found? POSITIVE SITES Cook County Woodworth Chicago Ridge NP Santa Fe Prairie Champaign Co. IC RR ROW Rantoul Iroquois Co. KBS RR ROW Kankakee County IC RR ROW north McLean County Weston NP Will County Raccoon Grove Vermont Cem. NP IC RR ROW Manteno IC RR ROW Offner Rd 29Oct05 Okanagana balli 34
Which Illinois prairie sites were assayed and cicadas NOT found? Cary Jr High NP GBNHS NP EJ & E RR ROW IC RR ROW S of Paxton IL54 Roberts Liberty Pr NP Loda NP Prospect Cem. NP Shoe Factory Rd NP Somme NP Ted Stone FPDCC US24 Iroquois Co US24 Kentland IN 29Oct05 Okanagana balli 35
Why is the prairie cicada restricted to prairies? As the adults can fly, As the oviposition sites does not seem particularly rare, it seems logical that there are necessary underground components present in prairies that are not present in old fields. Suggestions for how to identify such features would be appreciated. 29Oct05 Okanagana balli 36
Conservation of prairie cicadas A site RR ROW in Mt Prospect that Dr. Robert Hamilton told us had cicadas in 1970 no longer has them. The historical IC RR ROW at Raccoon Grove still has cicadas. Only Woodworth and Chicago Ridge had populations with more than a dozen seen. 29Oct05 Okanagana balli 37
Restoration of Okanagana balli The biggest populations are not large, so the notion they survive by saturating predators should be rejected. We know little about causes population increases or declines. At Woodworth populations fluctuate by less than order of magnitude from year to year. Oviposition occurs soon after mating so transport of mated female seems problematical. 29Oct05 Okanagana balli 38
Acknowledgements Many individuals helped in diverse ways: Assistance from Max Palmer and Gus Nyberg, should be singled out. The research was financially supported by the Woodworth Prairie of the University of Illinois at Chicago. 29Oct05 Okanagana balli 39