138

P. Srinivas et al.

spring. Some of the butterflies in this group will be the members of first generation,

capable of travelling 130 km in a day. Monarchs use polarized skylight pattern for

navigation. The day length decreases for migration towards south and day length

increases during the movement towards north [11, 12]. Kuester et al. [13] reported

the migration of boll weevil depending upon population genetic strategies.

Johnston [14] on Bumblebees discussed the new record by flying at a high altitude

of about 9000 m above the height of Himalayas (8,848 m). Generally, bumblebees

are considered to be the finest flyers, even at low pressures on high altitudes (i.e.,

death zones above 8,000 m) they are able to fly with low muscle temperatures and

are maintaining a thoracic temperature of 44 °C even at that height. Locust has been

reported to migrate at a height of 6000 ft at a very low temperature range up to −

30 °C (Table 10.1).

Table 10.1 Variation of atmospheric pressure, density and temperature with altitude

S No

Geometric height, h

M

Pressure,

p

Pa

Density,

ρ

kg/m³

Temp

T

K

1

−250

104,365

1.2547

289.775

2

0

101,325

1.2250

288.150

3

250

98357.6

1.1959

286.525

4

500

95461.2

1.1673

284.900

5

750

92634.6

1.1392

283.276

6

1000

89876.2

1.1117

281.651

7

1500

84559.6

1.0581

278.402

8

2000

79501.4

1.0066

275.154

9

2500

74691.7

0.95695

271.906

10

3000

70121.1

0.90925

268.659

11

3500

65780.3

0.86340

265.413

12

4000

61660.4

0.81935

262.166

13

5000

54048.2

0.73643

255.676

14

6000

47217.6

0.66011

249.187

15

7000

41105.2

0.59002

242.700

16

8000

35651.6

0.52579

236.215

17

9000

30800.7

0.46706

229.733

18

10,000

26499.9

0.41351

223.252

Source Atmosphere [15]