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Oxygen uptake in male and female boll weevils, Anthonomus Grandis boheman (Coleoptera: Curculionidae) of the ebony strain fed a laboratory diet
C',~mp. l]i~'heln. Pll)~i
Iq7o. ~2l. 54.A. pp, 2 4 q to 251, Pcrffamt,tt I't,.,~,~, I'rimt,d itt (;rt'al Britain
O X Y G E N U P T A K E IN MALE A N D FEMALE BOLL WEEVILS, A N T H O N O M U S G R A N D I S B O H E M A N ( C O L E O P T E R A : C U R C U L I O N I D A E ) O F THE E B O N Y STRAIN F E D A L A B O R A T O R Y DIET GLENN WtYGUL ANt) NORMAN MtTLIN Boll Weevil Research Laboratory, USDA, Agricultural Research Service, Mississippi State, MS 39762, U,S.A,
(Receit,ed 7 August 1975) A b s t r a c t - - I . Oxygen uptake was measured in laboratory diet-fed 1- to 15-day old male and female boll weevils of the ebony strain. 2. O,~ uptake was found to be between 27.24 to 6.45 pl O2/mg wet wt per hr for males and between 26.37 and 5.64 pl O2/mg wet wt per hr for females. 3. Peak O , uptake for males was recorded when they were 4 and 12 days old. 4. Peak Oz uptake for females was recorded when they were 6, 10. and 14 days old.
INTRODUCTION THE NEED tO r e a r large n u m b e r s o f boll weevils for a sterile release p r o g r a m h a s c r e a t e d i n t e r e s t in t h e d e v e l o p m e n t o f tests t h a t c a n be used t o d e t e r m i n e t h e he~dth a n d v i g o r o f t h e s e insects. In a n e a r l i e r study, W i y g u l & H a y n e s , 1974 s h o w e d t h a t l o c o m o t o r a c t i v i t y c o u l d b e u s e d as a n i n d i c a t o r o f sterility in c h e m o s t e r i l i z e d b o l l weevils. In t h e p r e s e n t study, w e m e a s u r e d o x y g e n u p t a k e in 1- to 15-day o l d m a l e a n d f e m a l e a d u l t boll weevils t o e s t a b l i s h a b a s e l i n e for t h e p o s s i b l e d e v e l o p m e n t o f tests t o m e a s u r e hextlth a n d vigor.
51ATERIALS AND METitODS G r o u p s of about I00 newly emerged male and female ebony boll weevils (Bartlett, 1967) reared by the methods of G a s t (1966) were placed in separate plastic containers. The insects were fed the adult diet, a cottonseed meats puree (Lindig & Malone, 1973), except that the dry ingredients were diluted 25°,;~ with corn c o b grits. They were maintained at 24~C with 50~)-~r.h. and a 16 hr photophase. Oxygen uptake was measured on one insect at a time by using a Yellow Springs Instrument Co. Model 53 oxygen m o n i t o r confiected to a record.=r. A plastic Nalgene ® c o n t a i n e r with a volume of ct:. 4-5 ml was used to hold the insect and oxygen probe. T h e probe was attached to the container by using a serum septum that was placed in a water bath maintained at 30-5°C. The oxygen c o n s u m p t i o n was measured for 3 hr in each test. The first h o u r was used as an equilibrium period, and data were obtained from the results of the next 2 hr. Tests were conducted each day t h r o u g h 15 days and each test was replicated 6 times. Boll weevils listed as l-day old had emerged as adults during the previous 15 hr. The results were calculated on the basis o f / t l O2/mg wet wt per hr (Keister & Buck, 1974~ and also on the basis of td O2/insect per hr. Results were analyzed by using standard error
of tile mean, t-test, X z test, and linear regression (Steel & Torric, 1960).
R ESU LI'S Figures I and 2 indicate the oxygen consumption o f 1- t o 15-day o l d m a l e a n d f e m a l e boll weevils, re~ spectively, M a l e s h a d t w o m a j o r p e a k s o f o x y g e n c o n s u m p t i o n , the first a n d m o s t p r o n o u n c e d w h e n t h e y were 4 d a y s old a n d t h e s e c o n d at d a y 12. A m i n o r p e a k o c c u r r e d at d a y 9. F e m a l e s h a d p e a k 0 2 u p t a k e at d a y s 6, t 0 a n d 14, in o t h e r w o r d s , 4 d a y s a p a r t . A n a l y s i s b y t-test ( S t u d e n t ' s t) s h o w e d differences b e t w e e n m a l e a n d f e m a l e O z u p t a k e at d a y s 4 a n d 5 ( P < 0 . 0 1 ) a n d a t d a y s 10, 12, a n d 13 ( P < 0 . 0 5 ) . I n b o t h m a l e s a n d females, t h e r e s u l t s o n a pl O 2 / m g w e t w t p e r h r a n d o n a /A O 2 / i n s e c t p e r h r b a s i s w e r e p a r a l l e l ( P > 0-05 b y Zz test).
35
300 30
;Zb
20
tI
250
2OO
150
15
~
c 10
100
5
5O
Age
,n
~
Ocv~t
Fig. 1. pl O z uptake/mg wet vet per hr represented by O, a n d pl 0 2 uptake/insect per hr, represented by G , of lthrough 15-day old male boll weevils. Vertical bars represent S.E.
* Mention of a proprietary product in this paper does not constitute an endorsement of this product by the U.S. D e p a r t m e n t of Agriculture. 249
( i I . I N N V V h t l t ; I . A N P N(}~,~,IAN M r r I . I N
250
22
T f
tf ! ti
t
300
2:0 ~8
l
2~0
16
14 12 I0 8
o
t
½
,~o .~
6 4 2
Age
,n
O~rfs
Fig. 4. Weights of I- to 15-day old female boll weevils. Vertic~fl lines represent S.E. AG!
t~
O~vs
Fig. 2. /tl 02 l_lplake/rllg wet wE p~r hr represented by @, zmd id Oe uptake/insect per hr represented by [3, of lthrt)ugh 15-d:iy old female boll weevils. Vertical bars represent S.E.
Body wei~lht am/respiration The weights of the male and female boll weevils used in the test are presented in Figs. 3 and 4, respectively. From Fig. 3, the weight of nmlc boll weevils was cyclic over the tS-day lest period. A negative correlation (1' < 0'05) wits indicated for weight of the tultlcs vs 0 2 uptake/rag wet wt l~cr hr. The female weights (Fig. 4) were also cyclic but over approximate 4-day intervals: the peak periods occurred at days 3, 7, 11 and 14. These weights increased in almost linear fashion and then d r o p p e d suddenly so the low points of the cycles occurred the day after the peaks. There wits no linear correlation between female weights and O~ uptake/rag wet wt per hr. Analysis by t-test indicated that male and female weights were different from each other on days l, 9 and 15 (P < 0-01). Positive correlations were indicated for male (P < 0.05) and female (P < 0.01) weights vs O2 uptake/insect per hr over the 15-day period. T/acre were also positive correlations (P < 0.01) between both male and female weights vs ages through t5 days, indicating that even though the weights were cyclic, both sexes gained weight as they aged. DISCUSSION
When the 0 2 uptake d a t a for males and females arc compared, the periods of peak uptake for males 22
20 18 1G la
f
,
10 8
preceded by 2 days the periods of peak uptake for females except on the middle cycle when it preceded that of the female by 1 day. Slama (1964) reported that tile cycles of oxygen uptake of female Pyrrhocoris apterus L. (Hemiptera) were connected with cycles of reproduction and oviposition. Likewise, Calabrese & Stoffolano (1974) attributed periods of high oxygen uptake in male Phormh~ reqina (Meigen) (Diptera) to mating activity. Conceivably the same is true of boll weevils: however, i n f o r m a t i o n is lacking concerning mating and egg-laying cycles in this insect. Brazzel & Newsom (1959) reported that non-diapausing boll weevils had respiratory rates approx 3-times greater than those o f diapatising insects, Hayes et al. (1968) reported 0 2 uptake in diapausing boll weevils nmintained at 26.6~'C. Their insects t o o k up at least 10-times less oxygen than did those used in the present study, but Hayes (personal c o m m u n i c a tion) reported that their insects were older than those we used. There is evidence that older insects use less oxygen than younger ones and Tribe (1966) found this difference in the blowfly, t_~dliphora erthrocephala (Meigen). The authors have not found other examples in the literature of negative correlations between weight and oxygen uptake (as we found irt male bolt weevils). Nevertheless, weight loss because of increased .energy d e m a n d and resultant increased 0 2 uptake could be one explanation for such a correlation. This explanation was not valid for the female boll weevils because n o correlation could be found between weight and O2 uptake. Examination o f Figs. 2 and 4 reveal, however, that the low points of their weight cycles did c o r r e s p o n d with low points of the. 0 2 uptake cycles. Although we have no d a t a to verify a cyclic egg-laying pattern in female boll weevi!s, such a pattern c o u l d exist in view of the'weight oaildup and loss. Slarna (1964); G u e r r a & Cochran (1970) reported ihat the weight of female Pyrrhocoris apterus and Musca aut,mnalis D e Geer, respectively, increased early in life. T h e latter authors reported no d r a m a t i c changes in adult male weights, SUMMARY
Age
In
Day~
Fig. 3. Weights of 1- to 15-day old male boll weevils. Vertiall lines represent S.E.
0 2 uptake was measured in 1- to 15-day old adult male a n d female ebony boll weevils fed a laboratory diet. It was found to range between 27-24 /tl O2/mg wet wt per hr and 6-45 pl O 2 / m g wet wt per hr for
Oxygen uptake in male and female boll weevils male~ and between 26.37 ILl O_,/mg wet wt per hr and 5.64 itl Oz/mg wet wt per hr for females. The peak periods of consumption for males preceded the females peak periods of consumption for by 24--48 hr. Peak male consumption occurred when they were 4 and 13 days old; a minor peak at 9 days. Peak female consumption occurred at 6, 10 and 14 days. A cyclic pattern was demonstrated for mate weights over the test period. This pattern showed a negative linear correlation with O2 uptake. The cyclic weight pattern for females was also demonstrated with peaks occurring at days 3, 7, I l and 14, but no linear correlation with O : uptake could be demonstrated. REFERENCES BARTLI:'TTA. C. (1967) Genetic markers in boll weevils. d. Hered. 58, 159-63. BRAZZr~t. J. R. & Nrwsor~l L. D. (1959) Diapause in Anthot)omus (irandis Boh. d. econ. Ent. 52, 603-1 l. CAtaBIU~E E. J. & STOF):OtaNOJ. G.. Jr~. 11974) The infl;aence of age and diet on respiration in adult male and female blowflit~, Phormia rt¥1#la. J. Insect PhysioL 20, 383-93.
251
G^s'r R. T. (1966) Oviposition and fecundity of boll weevils in mass rearing cultures. J. econ. E))t. 59, 173-6. GUEt~KAA. A. & COCHRAND. G. (1970) Respiration during the life cycle of the face fly, 3. econ. Ent. 63, 918-21. HAYIk~;D. K., SCHI:-Clm'RM. S., MENSING E. & HORTON J. (1968) Oxygen uptake of single insects determined with a poklrographic oxygen electrode. AnaIj't, Biochem. 26. 51-60. KI!ISrl..RM. & Bt)cl~ J, (1974) In The Physioloqy of Insects. Edited by ROCRST~tN, M. 2nd Edn. Vol. VI. Academic Press, New York. LINom O. H. & MALONI~O. L, (1973) Oviposition of boll weevils fed diets containing germinated cottonseed puree or cottonseed meats puree, d. econ. Ent. 66, 566--7. SLAI~tAK. (1964) Hormonal control of respiratory metabolism during growth, reproduction, and diapause in female adults of Pyrrhoccoris apterus L. (Hemiptera). J. Insect Physiol. 10, 283-303. S'rEI~LR. G. D. & TolUtll.'.J. H. (1960)'Principles and Procedul'es of Statistics, McGraw-Hill, New York. Tame M. A. (1966) Some physiological studies in relation to age in the blowfly, Catliphora erthrocephah~ (Meigen). J. Insect Physiol. 12, 1577-93. WZVGUt, G. & H^vs~s J. W. (t974) A locomotor test for the prediction of sterility in boll weevils. Entomolo.qia exp. cUll)l, 17, 452-53.
Iq7o. ~2l. 54.A. pp, 2 4 q to 251, Pcrffamt,tt I't,.,~,~, I'rimt,d itt (;rt'al Britain
O X Y G E N U P T A K E IN MALE A N D FEMALE BOLL WEEVILS, A N T H O N O M U S G R A N D I S B O H E M A N ( C O L E O P T E R A : C U R C U L I O N I D A E ) O F THE E B O N Y STRAIN F E D A L A B O R A T O R Y DIET GLENN WtYGUL ANt) NORMAN MtTLIN Boll Weevil Research Laboratory, USDA, Agricultural Research Service, Mississippi State, MS 39762, U,S.A,
(Receit,ed 7 August 1975) A b s t r a c t - - I . Oxygen uptake was measured in laboratory diet-fed 1- to 15-day old male and female boll weevils of the ebony strain. 2. O,~ uptake was found to be between 27.24 to 6.45 pl O2/mg wet wt per hr for males and between 26.37 and 5.64 pl O2/mg wet wt per hr for females. 3. Peak O , uptake for males was recorded when they were 4 and 12 days old. 4. Peak Oz uptake for females was recorded when they were 6, 10. and 14 days old.
INTRODUCTION THE NEED tO r e a r large n u m b e r s o f boll weevils for a sterile release p r o g r a m h a s c r e a t e d i n t e r e s t in t h e d e v e l o p m e n t o f tests t h a t c a n be used t o d e t e r m i n e t h e he~dth a n d v i g o r o f t h e s e insects. In a n e a r l i e r study, W i y g u l & H a y n e s , 1974 s h o w e d t h a t l o c o m o t o r a c t i v i t y c o u l d b e u s e d as a n i n d i c a t o r o f sterility in c h e m o s t e r i l i z e d b o l l weevils. In t h e p r e s e n t study, w e m e a s u r e d o x y g e n u p t a k e in 1- to 15-day o l d m a l e a n d f e m a l e a d u l t boll weevils t o e s t a b l i s h a b a s e l i n e for t h e p o s s i b l e d e v e l o p m e n t o f tests t o m e a s u r e hextlth a n d vigor.
51ATERIALS AND METitODS G r o u p s of about I00 newly emerged male and female ebony boll weevils (Bartlett, 1967) reared by the methods of G a s t (1966) were placed in separate plastic containers. The insects were fed the adult diet, a cottonseed meats puree (Lindig & Malone, 1973), except that the dry ingredients were diluted 25°,;~ with corn c o b grits. They were maintained at 24~C with 50~)-~r.h. and a 16 hr photophase. Oxygen uptake was measured on one insect at a time by using a Yellow Springs Instrument Co. Model 53 oxygen m o n i t o r confiected to a record.=r. A plastic Nalgene ® c o n t a i n e r with a volume of ct:. 4-5 ml was used to hold the insect and oxygen probe. T h e probe was attached to the container by using a serum septum that was placed in a water bath maintained at 30-5°C. The oxygen c o n s u m p t i o n was measured for 3 hr in each test. The first h o u r was used as an equilibrium period, and data were obtained from the results of the next 2 hr. Tests were conducted each day t h r o u g h 15 days and each test was replicated 6 times. Boll weevils listed as l-day old had emerged as adults during the previous 15 hr. The results were calculated on the basis o f / t l O2/mg wet wt per hr (Keister & Buck, 1974~ and also on the basis of td O2/insect per hr. Results were analyzed by using standard error
of tile mean, t-test, X z test, and linear regression (Steel & Torric, 1960).
R ESU LI'S Figures I and 2 indicate the oxygen consumption o f 1- t o 15-day o l d m a l e a n d f e m a l e boll weevils, re~ spectively, M a l e s h a d t w o m a j o r p e a k s o f o x y g e n c o n s u m p t i o n , the first a n d m o s t p r o n o u n c e d w h e n t h e y were 4 d a y s old a n d t h e s e c o n d at d a y 12. A m i n o r p e a k o c c u r r e d at d a y 9. F e m a l e s h a d p e a k 0 2 u p t a k e at d a y s 6, t 0 a n d 14, in o t h e r w o r d s , 4 d a y s a p a r t . A n a l y s i s b y t-test ( S t u d e n t ' s t) s h o w e d differences b e t w e e n m a l e a n d f e m a l e O z u p t a k e at d a y s 4 a n d 5 ( P < 0 . 0 1 ) a n d a t d a y s 10, 12, a n d 13 ( P < 0 . 0 5 ) . I n b o t h m a l e s a n d females, t h e r e s u l t s o n a pl O 2 / m g w e t w t p e r h r a n d o n a /A O 2 / i n s e c t p e r h r b a s i s w e r e p a r a l l e l ( P > 0-05 b y Zz test).
35
300 30
;Zb
20
tI
250
2OO
150
15
~
c 10
100
5
5O
Age
,n
~
Ocv~t
Fig. 1. pl O z uptake/mg wet vet per hr represented by O, a n d pl 0 2 uptake/insect per hr, represented by G , of lthrough 15-day old male boll weevils. Vertical bars represent S.E.
* Mention of a proprietary product in this paper does not constitute an endorsement of this product by the U.S. D e p a r t m e n t of Agriculture. 249
( i I . I N N V V h t l t ; I . A N P N(}~,~,IAN M r r I . I N
250
22
T f
tf ! ti
t
300
2:0 ~8
l
2~0
16
14 12 I0 8
o
t
½
,~o .~
6 4 2
Age
,n
O~rfs
Fig. 4. Weights of I- to 15-day old female boll weevils. Vertic~fl lines represent S.E. AG!
t~
O~vs
Fig. 2. /tl 02 l_lplake/rllg wet wE p~r hr represented by @, zmd id Oe uptake/insect per hr represented by [3, of lthrt)ugh 15-d:iy old female boll weevils. Vertical bars represent S.E.
Body wei~lht am/respiration The weights of the male and female boll weevils used in the test are presented in Figs. 3 and 4, respectively. From Fig. 3, the weight of nmlc boll weevils was cyclic over the tS-day lest period. A negative correlation (1' < 0'05) wits indicated for weight of the tultlcs vs 0 2 uptake/rag wet wt l~cr hr. The female weights (Fig. 4) were also cyclic but over approximate 4-day intervals: the peak periods occurred at days 3, 7, 11 and 14. These weights increased in almost linear fashion and then d r o p p e d suddenly so the low points of the cycles occurred the day after the peaks. There wits no linear correlation between female weights and O~ uptake/rag wet wt per hr. Analysis by t-test indicated that male and female weights were different from each other on days l, 9 and 15 (P < 0-01). Positive correlations were indicated for male (P < 0.05) and female (P < 0.01) weights vs O2 uptake/insect per hr over the 15-day period. T/acre were also positive correlations (P < 0.01) between both male and female weights vs ages through t5 days, indicating that even though the weights were cyclic, both sexes gained weight as they aged. DISCUSSION
When the 0 2 uptake d a t a for males and females arc compared, the periods of peak uptake for males 22
20 18 1G la
f
,
10 8
preceded by 2 days the periods of peak uptake for females except on the middle cycle when it preceded that of the female by 1 day. Slama (1964) reported that tile cycles of oxygen uptake of female Pyrrhocoris apterus L. (Hemiptera) were connected with cycles of reproduction and oviposition. Likewise, Calabrese & Stoffolano (1974) attributed periods of high oxygen uptake in male Phormh~ reqina (Meigen) (Diptera) to mating activity. Conceivably the same is true of boll weevils: however, i n f o r m a t i o n is lacking concerning mating and egg-laying cycles in this insect. Brazzel & Newsom (1959) reported that non-diapausing boll weevils had respiratory rates approx 3-times greater than those o f diapatising insects, Hayes et al. (1968) reported 0 2 uptake in diapausing boll weevils nmintained at 26.6~'C. Their insects t o o k up at least 10-times less oxygen than did those used in the present study, but Hayes (personal c o m m u n i c a tion) reported that their insects were older than those we used. There is evidence that older insects use less oxygen than younger ones and Tribe (1966) found this difference in the blowfly, t_~dliphora erthrocephala (Meigen). The authors have not found other examples in the literature of negative correlations between weight and oxygen uptake (as we found irt male bolt weevils). Nevertheless, weight loss because of increased .energy d e m a n d and resultant increased 0 2 uptake could be one explanation for such a correlation. This explanation was not valid for the female boll weevils because n o correlation could be found between weight and O2 uptake. Examination o f Figs. 2 and 4 reveal, however, that the low points of their weight cycles did c o r r e s p o n d with low points of the. 0 2 uptake cycles. Although we have no d a t a to verify a cyclic egg-laying pattern in female boll weevi!s, such a pattern c o u l d exist in view of the'weight oaildup and loss. Slarna (1964); G u e r r a & Cochran (1970) reported ihat the weight of female Pyrrhocoris apterus and Musca aut,mnalis D e Geer, respectively, increased early in life. T h e latter authors reported no d r a m a t i c changes in adult male weights, SUMMARY
Age
In
Day~
Fig. 3. Weights of 1- to 15-day old male boll weevils. Vertiall lines represent S.E.
0 2 uptake was measured in 1- to 15-day old adult male a n d female ebony boll weevils fed a laboratory diet. It was found to range between 27-24 /tl O2/mg wet wt per hr and 6-45 pl O 2 / m g wet wt per hr for
Oxygen uptake in male and female boll weevils male~ and between 26.37 ILl O_,/mg wet wt per hr and 5.64 itl Oz/mg wet wt per hr for females. The peak periods of consumption for males preceded the females peak periods of consumption for by 24--48 hr. Peak male consumption occurred when they were 4 and 13 days old; a minor peak at 9 days. Peak female consumption occurred at 6, 10 and 14 days. A cyclic pattern was demonstrated for mate weights over the test period. This pattern showed a negative linear correlation with O2 uptake. The cyclic weight pattern for females was also demonstrated with peaks occurring at days 3, 7, I l and 14, but no linear correlation with O : uptake could be demonstrated. REFERENCES BARTLI:'TTA. C. (1967) Genetic markers in boll weevils. d. Hered. 58, 159-63. BRAZZr~t. J. R. & Nrwsor~l L. D. (1959) Diapause in Anthot)omus (irandis Boh. d. econ. Ent. 52, 603-1 l. CAtaBIU~E E. J. & STOF):OtaNOJ. G.. Jr~. 11974) The infl;aence of age and diet on respiration in adult male and female blowflit~, Phormia rt¥1#la. J. Insect PhysioL 20, 383-93.
251
G^s'r R. T. (1966) Oviposition and fecundity of boll weevils in mass rearing cultures. J. econ. E))t. 59, 173-6. GUEt~KAA. A. & COCHRAND. G. (1970) Respiration during the life cycle of the face fly, 3. econ. Ent. 63, 918-21. HAYIk~;D. K., SCHI:-Clm'RM. S., MENSING E. & HORTON J. (1968) Oxygen uptake of single insects determined with a poklrographic oxygen electrode. AnaIj't, Biochem. 26. 51-60. KI!ISrl..RM. & Bt)cl~ J, (1974) In The Physioloqy of Insects. Edited by ROCRST~tN, M. 2nd Edn. Vol. VI. Academic Press, New York. LINom O. H. & MALONI~O. L, (1973) Oviposition of boll weevils fed diets containing germinated cottonseed puree or cottonseed meats puree, d. econ. Ent. 66, 566--7. SLAI~tAK. (1964) Hormonal control of respiratory metabolism during growth, reproduction, and diapause in female adults of Pyrrhoccoris apterus L. (Hemiptera). J. Insect Physiol. 10, 283-303. S'rEI~LR. G. D. & TolUtll.'.J. H. (1960)'Principles and Procedul'es of Statistics, McGraw-Hill, New York. Tame M. A. (1966) Some physiological studies in relation to age in the blowfly, Catliphora erthrocephah~ (Meigen). J. Insect Physiol. 12, 1577-93. WZVGUt, G. & H^vs~s J. W. (t974) A locomotor test for the prediction of sterility in boll weevils. Entomolo.qia exp. cUll)l, 17, 452-53.