Slide 1

Tachinid Fly (Lespesia archippivora) Parasitism of Monarch Butterfly Larvae (Danaus plexippus) Kaitlyn Creasey February 14, 2007 Slide 2 University of Minnesota Dr. Karen Oberhauser Slide 3 Tachinid Fly (Lespesia archippivora) Photo by Author Slide 4 Armyworm Slide 5 Monarch Butterfly Larva (Danaus plexippus) Photo by Author Slide 6 Life Cycle of Tachinid Flies Photos by Author and Dr. Karen Oberhauser Slide 7 Life Cycle of Tachinid Flies Photos by Author and Dr. Karen Oberhauser Slide 8 Life Cycle of Tachinid Flies Photos by Author and Dr. Karen Oberhauser Slide 9 Life Cycle of Tachinid Flies Photos by Author and Dr. Karen Oberhauser Slide 10 Life Cycle of Tachinid Flies Photos by Author and Dr. Karen Oberhauser Slide 11 Life Cycle of Tachinid Flies Photos by Author and Dr. Karen Oberhauser Slide 12 Monarch Instars Photo used with permission of Dr. Karen Oberhauser Slide 13 Egg Photo used with permission of Dr. Karen Oberhauser Slide 14 First-instar Photo used with permission of Dr. Karen Oberhauser Slide 15 Second-instar Photo used with permission of Dr. Karen Oberhauser Slide 16 Third-instar Photo used with permission of Dr. Karen Oberhauser Slide 17 Fourth-instar Photo used with permission of Dr. Karen Oberhauser Slide 18 Fifth-instar Photo used with permission of Dr. Karen Oberhauser Slide 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 Slide 20 Slide 21 Slide 22 Slide 23 Slide 24 Slide 25 Slide 26 Slide 27 Photo by Author Slide 28 Background Goal 2: Find correlation between tachinid pupae sex, mass, and duration of pupal stage of tachinid flies Cardoza et al. (1997) Slide 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 Slide 30 Solutions for Problems Encountered After 24 hours, monarch larvae had died before any tachinid larvae could emerge Slide 31 Solutions for Problems Encountered After 24 hours, monarch larvae had died before any tachinid larvae could emerge Echegaray (1975) Slide 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 Slide 33 Superparasitized Monarch Larva Slide 34 Slide 35 Slide 36 Slide 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 Slide 38 Tachinid Fly Parasitized Wild Monarch Larvae Survey Percent healthy adults Percent parasitized by tachinid flies Percent died from other causes 70.9 (n=61)7.0 (n=6)22.1 (n=19) Slide 39 Tachinid Fly Parasitized Wild Monarch Larvae Survey Percent healthy adults Percent parasitized by tachinid flies Percent died from other causes 70.9 (n=61)7.0 (n=6)22.1 (n=19) Slide 40 Percent Parasitized Monarch Larvae at each Site Slide 41 Percent Monarch Larvae vs. Instar at Collection (chi square value=11.296, df=6, 0.10>p>0.05) Slide 42 Mean Tachinid Pupa Mass vs. Sex (p=0.0001; standard error for females =9.31 x 10 -4 ; standard error for males =1.97 x 10 -3 ) Slide 43 Tachinid Sex vs. Tachinid Duration of Pupal Stage (p=0.0001; standard error for females =0.31; standard error for males =0.18) Slide 44 Number of Tachinid Larvae per Monarch Larva Slide 45 Number of Tachinid Larvae per Monarch Larvae vs. Mean Tachinid Pupae Mass (p=4.29E-4, standard error for 1-4 = 3.77E-5; standard error for 5-8 = 1.60E-5) Slide 46 Monarch Parasitisms by Tachinid Flies Monarch instarNumber of tachinid larvae First2 Fourth3 Slide 47 Conclusion 7% wild monarch larvae parasitized Slide 48 Conclusion 7% wild monarch larvae parasitized Male tachinid pupae were statistically heavier than females and remained in the pupal stage longer than females Slide 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 Slide 50 Future Work Continuing the study of percent of parasitized monarch larvae Slide 51 Future Work Continuing the study of percent of parasitized monarch larvae Maintaining a population of tachinid flies in the laboratory Slide 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 Slide 53 Acknowledgements Dr. Karen Oberhauser Roger Moon Lois Fruen Research Class Slide 54 Tachinid Fly (Lespesia archippivora) Parasitism of Monarch Butterfly Larvae (Danaus plexippus) Kaitlyn Creasey February 14, 2007