slide1
Download
Skip this Video
Download Presentation
Methods – temperature dependent development

Loading in 2 Seconds...

play fullscreen
1 / 13

Methods – temperature dependent development - PowerPoint PPT Presentation


  • 62 Views
  • Uploaded on

Temperature dependent development, cold tolerance, predicted numbers of generations/year and predicted areas of establishment. Methods – temperature dependent development. insects reared from egg to adult at 16, 20.5, 25.5, 29, 33, 34, and 36 o C at 14:10, 60-70% RH recorded days to molting

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Methods – temperature dependent development' - david-harvey


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Temperature dependent development, cold tolerance, predicted numbers of generations/year and predicted areas of establishment

methods temperature dependent development
Methods – temperature dependent development
  • insects reared from egg to adult at 16, 20.5, 25.5, 29, 33, 34, and 36oC at 14:10, 60-70% RH
  • recorded days to molting
  • analyses:
    • linear regression to calculate degree day requirement and lower development threshold.
    • non-linear regression to estimate upper lethal threshold
    • use of historical weather data to map predicted numbers of generations/year across North America
slide5

13.4

Linear model

DD = 1/slope = 355

slide6

0.07

All immature

0.06

0.05

0.04

Developmental Rate (Days

0.03

0.02

0.01

0.00

15

20

25

30

35

Temperature (

o

C)

34.8

Non-linear model

slide8
But.........
  • Map prediction assumes continual development throughout the year as long as temperatures are above the lower threshold
  • We know that this is not true due to reproductive diapause during the winter
  • Based on sampling data in Saint Lucie Co., we believe that diapause is initiated by mid November and ends in mid April. During this period, about 796 DD are accumulated.
  • Thus, the map overestimates the number of generations/year in St. Lucie Co. Florida by about 2.2 (796/355).
methods cold tolerance
Methods – cold tolerance
  • young adults held at 0, 5, and 10oC for 0.5, 1, 2, 4, and 8 days.
  • after chilling period, adults placed at room temperature and status (alive/dead) assessed after 24 hours
slide11

100

0oC

80

60

Percentage survival (%)

40

20

0

0

1

2

3

4

5

6

7

8

9

10

Days

slide12

Ltime90 ≥ 10 days at 0oC

Ltime50 ≥ 4 days at 0oC

Limitation of prediction:

- we used summer insects

- diapause insects may be

more cold tolerant

ad