San Joaquin Valley California Citrus Peelminer Degree-Day Accumulations

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Biofix: 1st male flight  
Lower developmental threshold:
55
oF (12.9oC)
Degree-Days to Complete a Generation: 580 dd F (320 dd C)  Every 580 degree days, the peelminer completes a generation.  There are 7 flights potential flights in the San Joaquin Valley and 9 potential flights in the Coachella valley.  Hot summer temperatures tend to stop development of the peelminer in the summertime. 

2009 Tulare County Peelminer Observations

Date

Observations of peelminer larvae

April 7 1st flight of moths: in non-citrus host plants
May 26

2nd flight of moths: 1st larval generation in walnut stems

June 29

3rd flight of moths:  1st generation of larvae in pummelos and
2nd generation of larvae in walnut stems

July 20

4th flight of moths: 2nd generation of larvae in pummelos

August 10

5th flight of moths: possible 3rd generation larvae in pummelos and
1st generation of larvae in susceptible orange varieties

September 7 (predicted) 6th flight of moths:
7th flight of moths:

Click here for graphs of the current accumulation of degree day units.  The table shown below left is for Tulare County and the Foothill Region of the Central Valley. 
Kern County is approximately one week ahead of these figures, Fresno County is approximately one week behind.   

Predicted Peelminer Flight

DD As Of

      Tulare County

2009

2008

30 Yr

03/31

  48 0

04/07

0 73 7

04/14

36 164 78

04/21

112 147 150

04/28

176 269 244

05/05

227 335 341

05/12

348 386 444

05/19

460 528 556

05/26

607 624 679

06/02

740 690 806

06/09

853 784 938

06/16

957 933 1082

06/23

1088 1130 1240

06/30

1256 1292 1406

07/07

1432 1433 1583

07/14

1604 1677 1761

07/21

1814 1841 1928

07/28

2015 2020 2112

08/04

2215 2190 2315

08/11

2361 2386 2515

08/18

2550 2558 2697

08/25

2706 2754 2873

09/01

2925 2928 3043

09/08

3033 3070 3207

09/15

  3235 3354

09/22

  3354 3504

09/29

  3503 3646

10/06

  3616 3763

10/13

  3672 3858

10/20

  3754 3941

10/27

  3840 4003
11/03   3916  
       

DD As Of

      Coachella Valley

2009

2008

30 Yr

03/31

100 121 0

04/07

193 205 13

04/14

292 303 112

04/21

408 394 216

04/28

563 515 333

05/05

648 617 461

05/12

883 670 602

05/19

1010 818 749

05/26

1238 989 910

06/02

1418 1127 1086

06/09

1574 1323 1276

06/19

1753 1530 1481

06/26

1966 1937 1703

07/03

2189 2190 1939

07/10

2441 2443 2178

07/17

2695 2684 2425

07/24

2973 2925 2672

07/31

3252 3171 2929

08/07

3698 3431 3188

08/14

3905 3674 3439

08/21

4178 3910 3675

08/28

4442 4158 3917

09/04

4708 4395 4161

09/11

  4632 4394

09/18

  4857 4606

09/25

  5067 4799

10/02

  5280 4984

10/09

    5154

10/16

    5300

10/23

    5425

10/30

    5530