Tachinid Fly (Lespesia archippivora) Parasitism of Monarch Butterfly Larvae (Danaus plexippus)

1
Tachinid Fly (Lespesia archippivora) Parasitism
of Monarch Butterfly Larvae (Danaus plexippus)

• Kaitlyn Creasey
• February 14, 2007

2
University of Minnesota
Dr. Karen Oberhauser
3
Tachinid Fly (Lespesia archippivora)
Photo by Author
4
Armyworm
5
Monarch Butterfly Larva (Danaus plexippus)
Photo by Author
6
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
7
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
8
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
9
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
10
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
11
Life Cycle of Tachinid Flies
Photos by Author and Dr. Karen Oberhauser
12
Monarch Instars
Photo used with permission of Dr. Karen Oberhauser
13
Egg
Photo used with permission of Dr. Karen Oberhauser
14
First-instar
Photo used with permission of Dr. Karen Oberhauser
15
Second-instar
Photo used with permission of Dr. Karen Oberhauser
16
Third-instar
Photo used with permission of Dr. Karen Oberhauser
17
Fourth-instar
Photo used with permission of Dr. Karen Oberhauser
18
Fifth-instar
Photo used with permission of Dr. Karen Oberhauser
19
Focus of Project

• Continue Oberhauser study (2000-2005) 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

20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27
Photo by Author
28
Background

• Goal 2 Find correlation between tachinid pupae
  sex, mass, and duration of pupal stage of
  tachinid flies
• Cardoza et al. (1997)

29
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

30
Solutions for Problems Encountered

• After 24 hours, monarch larvae had died before
  any tachinid larvae could emerge

31
Solutions for Problems Encountered

• After 24 hours, monarch larvae had died before
  any tachinid larvae could emerge
• Echegaray (1975)

32
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

33
Superparasitized Monarch Larva
34
Superparasitized Monarch Larva
35
Superparasitized Monarch Larva
36
Superparasitized Monarch Larva
37
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

38
Tachinid Fly Parasitized Wild Monarch Larvae
Survey
Percent healthy adults Percent parasitized by tachinid flies Percent died from other causes
70.9 (n61) 7.0 (n6) 22.1 (n19)
39
Tachinid Fly Parasitized Wild Monarch Larvae
Survey
Percent healthy adults Percent parasitized by tachinid flies Percent died from other causes
70.9 (n61) 7.0 (n6) 22.1 (n19)
40
Percent Parasitized Monarch Larvae at each Site
41
Percent Monarch Larvae vs. Instar at Collection
(chi square value11.296, df6, 0.10gtpgt0.05)
42
Mean Tachinid Pupa Mass vs. Sex
(p0.0001 standard error for females 9.31 x
10-4 standard error for males 1.97 x 10-3)
43
Tachinid Sex vs. Tachinid Duration of Pupal Stage
(p0.0001 standard error for females 0.31
standard error for males 0.18)
44
Number of Tachinid Larvae per Monarch Larva
45
Number of Tachinid Larvae per Monarch Larvae vs.
Mean Tachinid Pupae Mass
(p4.29E-4, standard error for 1-4 3.77E-5
standard error for 5-8 1.60E-5)
46
Monarch Parasitisms by Tachinid Flies
Monarch instar Number of tachinid larvae
First 2
Fourth 3
47
Conclusion

• 7 wild monarch larvae parasitized

48
Conclusion

• 7 wild monarch larvae parasitized
• Male tachinid pupae were statistically heavier
  than females and remained in the pupal stage
  longer than females

49
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

50
Future Work

• Continuing the study of percent of parasitized
  monarch larvae

51
Future Work

• Continuing the study of percent of parasitized
  monarch larvae
• Maintaining a population of tachinid flies in the
  laboratory

52
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

53
Acknowledgements

• Dr. Karen Oberhauser
• Roger Moon
• Lois Fruen
• Research Class

54
Tachinid Fly (Lespesia archippivora) Parasitism
of Monarch Butterfly Larvae (Danaus plexippus)

• Kaitlyn Creasey
• February 14, 2007