Thermal Tolerance of

Red Flour Beetle

USDA-ARS, Parlier, CA

Judy Johnson and Karen Valero

RFB Life Stages

Adult

Larva

Pupa

0.0

0.2

0.4

0.6

0.8

1.0 48C

20

30

40

0.0

0.2

0.4

0.6

0.8

1.0 50C

4

8

12

0.0

0.2

0.4

0.6

0.8

1.0

Adults Pupae Late Larvae Early Larvae Eggs

52C

0.5

1

2

Mor

talit

y

Thermal Tolerance of RFB Life Stages

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 20 40 60 80 100

Time (min)

(N/N

0)0.

5

52C50C48CLinear (48C)Linear (50C)Linear (52C)

Thermal mortality curves for late instar RFB

Temp (°C) R2 LT95

(min)LT99

(min)

48 0.982 0.956 +/- 0.059 -0.011 +/- 0.001 64.5 75.4

50 0.885 0.832 +/- 0.145 -0.077 +/- 0.020 7.9 9.5

52 0.925 0.964 +/- 0.140 -0.506 +/- 0.102 1.5 1.7

Intercept+/- SE

Slope+/- SE

Lethal times estimated from kinetic model for late instar RFB

42 44 46 48 50 52 54

Temperature (C)

Tim

e (m

in)

NOWIMMRFBLinear (RFB)Linear (NOW)Linear (IMM)

0.1

10

100

Comparison of TDT curves for target species

Temp

(°C) RFB NOW IMM

48 64.5 40.9 7.6

50 7.9 13.5 2.2

52 1.5 4.3 0.9

48 75.4 46.8 8.8

50 9.5 15.3 2.5

52 1.7 5.0 1.0

LT95

LT99

Target Species

Comparison of lethal times for target species