Transcript Tachinid Fly (Lespesia archippivora) Parasitism of Monarch

Tachinid Fly (Lespesia archippivora)
Parasitism of Monarch Butterfly
Larvae (Danaus plexippus)
Kaitlyn Creasey
February 14, 2007
University of Minnesota
Dr. Karen Oberhauser
Tachinid Fly (Lespesia archippivora)
Photo by Author
Armyworm
Monarch Butterfly Larva
(Danaus plexippus)
Photo by Author
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
Monarch Instars
Photo used with permission of Dr. Karen Oberhauser
Egg
Photo used with permission of Dr. Karen Oberhauser
First-instar
Photo used with permission of Dr. Karen Oberhauser
Second-instar
Photo used with permission of Dr. Karen Oberhauser
Third-instar
Photo used with permission of Dr. Karen Oberhauser
Fourth-instar
Photo used with permission of Dr. Karen Oberhauser
Fifth-instar
Photo used with permission of Dr. Karen Oberhauser
Focus of Project
• Continue Oberhauser study (20002005) on wild monarch tachinid
parasitism
• Study correlations of sex, mass, and
length of pupation of tachinid pupae
• Successfully parasitize monarch larvae
with laboratory-raised tachinid flies
Photo by Author
Background
• Goal 2: Find correlation between tachinid pupae
sex, mass, and duration of pupal stage of
tachinid flies
• Cardoza et al. (1997)
Hypotheses
• Female tachinid pupae would be larger
than male tachinid pupae and duration
of pupal stage would be longer for
females
• Number of tachinid larvae laid on a
monarch larva would affect the mass of
tachinid pupae
Solutions for Problems
Encountered
• After 24 hours, monarch larvae had died
before any tachinid larvae could emerge
Solutions for Problems
Encountered
• After 24 hours, monarch larvae had died
before any tachinid larvae could emerge
• Echegaray (1975)
Solutions for Problems
Encountered
• After 24 hours, monarch larvae had died
before any tachinid larvae could emerge
• Echegaray (1975)
• Dissection showed an average of 20
tachinid fly larvae in a single dead
monarch larvae
Superparasitized Monarch Larva
Superparasitized Monarch Larva
Superparasitized Monarch Larva
Superparasitized Monarch Larva
Solutions for Problems
Encountered
• Larvae exposure time to the flies was
shortened in order to avoid super parasitism
and allow tachinid larvae to fully develop
Tachinid Fly Parasitized Wild
Monarch Larvae Survey
Percent healthy
adults
70.9 (n=61)
Percent
parasitized by
tachinid flies
Percent died from
other causes
7.0 (n=6)
22.1 (n=19)
Tachinid Fly Parasitized Wild
Monarch Larvae Survey
Percent healthy
adults
70.9 (n=61)
Percent
parasitized by
tachinid flies
Percent died from
other causes
7.0 (n=6)
22.1 (n=19)
Percent Parasitized Monarch Larvae at
each Site
Percent of Monarch Larvae
100
90
80
P erc et
healthy
adults
70
60
50
P erc ent
paras itized
40
30
P erc ent died
from other
c aus es
20
10
0
Falcon Heights
Park (n=18)
Cumberland,
WI (n=10)
Site
Air Reserve
Station
(n=20)
Amery, WI
(n=28)
Percent Monarch Larvae vs.
Instar at Collection
Percent of Monarch Larvae
90
80
70
Percent healthy
adults
60
Percent
parasitized
50
40
Percent died
from other
causes
30
20
10
0
First and
Second
(n=13)
Third (n=26)
Fourth
(n=25)
Fifth (n=18)
Instar at Collection
(chi square value=11.296, df=6, 0.10>p>0.05)
Mean Tachinid Pupa Mass vs. Sex
0.05
0.045
0.04
Mass (g)
0.035
0.03
A verage
mas s (g)
0.025
0.02
0.015
0.01
0.005
0
Females
Males
Sex
(p=0.0001; standard error for females =9.31 x 10-4; standard error
for males =1.97 x 10-3)
Tachinid Sex vs. Tachinid
Duration of Pupal Stage
Duration of Pupal Stage (days)
16
14
12
10
A verage
duration of
pupal s tage
8
6
4
2
0
Female
Male
Sex
(p=0.0001; standard error for females =0.31; standard error for
males =0.18)
Number of Tachinid Larvae per
Monarch Larva
Number of Times Value Occured
8
7
6
5
T ac hinid
L a rvae pe r
M ona rc h
4
3
2
1
0
1
2
3
4
5
6
7
Number of Tachinid Larvae per Monarch Larva
8
Number of Tachinid Larvae per
Monarch Larvae vs. Mean Tachinid
Pupae Mass
0.04
0.035
Mass (g)
0.03
0.025
0.02
A verage
mas s (g)
0.015
0.01
0.005
0
1-4
5-8
Number of Tachinid Larv ae
(p=4.29E-4, standard error for 1-4 = 3.77E-5; standard error
for 5-8 = 1.60E-5)
Monarch Parasitisms by Tachinid Flies
Monarch instar
First
Fourth
Number of tachinid
larvae
2
3
Conclusion
• 7% wild monarch larvae parasitized
Conclusion
• 7% wild monarch larvae parasitized
• Male tachinid pupae were statistically heavier than
females and remained in the pupal stage longer than
females
Conclusion
• 7% wild monarch larvae parasitized
• Male tachinid pupae were statistically heavier than
females and remained in the pupal stage longer than
females
• When a larger number of tachinid larvae emerged
from host monarch larvae, the average mass of the
tachinid pupae was significantly less
Future Work
• Continuing the study of percent of
parasitized monarch larvae
Future Work
• Continuing the study of percent of
parasitized monarch larvae
• Maintaining a population of tachinid flies
in the laboratory
Future Work
• Continuing the study of percent of
parasitized monarch larvae
• Maintaining a population of tachinid flies
in the laboratory
• Continuing the study of the relationships
between tachinid flies and monarch
larvae
Acknowledgements
•
•
•
•
Dr. Karen Oberhauser
Roger Moon
Lois Fruen
Research Class
Tachinid Fly (Lespesia archippivora)
Parasitism of Monarch Butterfly
Larvae (Danaus plexippus)
Kaitlyn Creasey
February 14, 2007