The effects of a range of developmental photoperiods on adult dimorphism in Thyanta pallidovirens accerra were studied under laboratory conditions. Adults reared in photo- phases of 14L and higher had short pubescence and those in 12L and lower, long pu- bescence. No dimorphism in color was produced in these same photophases

McPherson, J. E

English

Valparaiso University

The Great Lakes Entomologist Volume 12 Number 2 - Summer 1979 Number 2 - Summer 1979 Article 5 June 1979 Effects of Various Photoperiods on Color and Pubescence in Thyanta Pallidovirens Accerra (Hemiptera: Pentatomidae) J. E. McPherson Southern Illinois University Follow this and additional works at: https://scholar.valpo.edu/tgle  Part of the Entomology Commons Recommended Citation McPherson, J. E. 1979. "Effects of Various Photoperiods on Color and Pubescence in Thyanta Pallidovirens Accerra (Hemiptera: Pentatomidae)," The Great Lakes Entomologist, vol 12 (2) Available at: https://scholar.valpo.edu/tgle/vol12/iss2/5 This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. For more information, please contact a ValpoScholar staff member at scholar@valpo.edu. 1W9 THE GREAT LAKES ENTOMOLOGIST EFFECTS OF VARIOUS PHOTOPERIODS ON COLOR AND PUBESCENCE IN THYANTA PALUDOVIRENS ACCERRA (HEMIPTERA: PENTATOMIDAE)' ABSTRACT The effects of a range of developmental photoperiods on adult dimorphism in Thyanta pallidovirens accerra were studied under laboratory conditions. Adults reared in photo- phases of 14L and higher had short pubescence and those in 12L and lower, long pu- bescence. No dimorphism in color was produced in these same photophases. Thyanta pallidovirens accerra McAtee ranges from New York south to Georgia, and west to Idaho, northeastern Utah, northeastern New Mexico, and Texas (Ruckes, 1957). Ruckes (1957) believed it, T. calceata (Say) and T. custator (Fabricius) had "an autumnal- vernal (overwintering) generation that differs in appearance from the summer brood. This seems to be a case of seasonal dimorphism. . ." The autumnal-vernal adults were brown with long seta-like hairs and summer adults, green with short hairs (less than diameter of tibia). McPherson (1977a) confirmed Ruckes' hypothesis that calceata is seasonally dimorphic, that (1977b. 1978a) the morphs result from developmental photoperiod influence, and that (1978b) a threshold photoperiod of about 12.5L: 11.5D (light: dark) is involved in the dimor- phic response. Animals reared in photophases above and below the threshold develop into green adults with short pubescence and brown adults with long pubescence, respectively. T. pallidovirens accerra, as noted above, is also apparently seasonally dimorphic; if so, it may also result from photoperiod influence. The results of an experiment to determine the role of photoperiod in producing adult dimorphism in this subspecies are presented here. METHODS AND MATERIALS A male and female ofpallidovirens accerra were collected during September, 1977, in Jackson County in Southern Illinois. From their offspring, 18 males and females were selected as parents and placed in an incubator (23.9 ? I  1.l0C) under an 18L:6D photoperiod. They were mantained in mason jars (nine of each sexljar) provided with cheesecloth as an oviposition site, filter paper and paper toweling strips, and fedgreen snap beans (Phseolus vulgaris L.) as described by McPherson (1W1). Each resulting egg cluster was placed in one of the following six photoperiods and the animals reared to adults as described by McPherson (1971): 8L:16D, 10L:14D, 12L:12D, 14L: 10D, 16L:8D, and 18L:6D. AU experiments were conducted at 23.9 + 1.loC during the light and dark phases, and about 130 ft-c during the light phases (Ken-Rad, 15W Daylight, F15T81D). Adult characters chosen for comparison were color (green or brown) and pubescence (longer or shorter than diameter of tibia). Adults were compared in sequential pairs of in- creasing photophase and the differences tested with the Fisher exact probability test. The 0.01 level of significance was chosen because of the variable and subjective nature of color. RESULTS AND DISCUSSION The success in rearing this subspecies on green beans was poor and thus, results from different photoperiods were combined to insure adequate numbers for statistical compari- '~inancial support was provided by the Ofice of Research Development and Administration, Southern Illinois University, Carbondale Graduate School. Project No. 2-1063 1. Z ~ e ~ a r t r n e n t  of Zoology, Southern Illinois University, Carbondale, IL 62901. 1McPherson: Effects of Various Photoperiods on Color and Pubescence in <i>ThyPublished by ValpoScholar, 197984 THE GREAT LAKES ENTOMOLOGIST Vol. 12, No. 2 sons. Since the threshold for the dimorphic response in calceata was near 12.5L:11.5D (McPherson, 1978b), I combined the results into the following three photoperiod groups: 8L: 16D and 10L: 14D; 12L: 12D; and 14L: ]OD, 16L:8D, and 18L:6D (Table 1). Photophases above 12.5L did not (unlike calceata) produce a significant number of green adult males and females; most were light to dark brown (males, 74.5-78.7%; females, 87.5%) as were those in the lower photophases (males, 72.2-95.8%; females, 63.6-94.7%) (Table 1). However, both sexes showed a significant switch between 12L:12D and 14L:lOD from long to short pubescence, similar to calceata. It is difficult to suggest, from the limited data, why this range of photoperiods did not produce adult color dimorphism in pallidovirens accerra as it did in calceata (McPherson, 1978b). It is possible that an additional variable is involved in adult color production in this subspecies (e.g., temperature, humidity), or that differential mortality occurred in which most potentially green adults died. Further studies should be conducted using a laboratory culture established with a larger field sample. LITERATURE CITED MePherson, J. E.  1971. Laboratory rearing of Euschistus tristigmus tristigmus. J .  Econ. Entomol. 64: 1339-1340. . 1977a. Notes on the biology of Thyanta calceata (Hemiptera: Pentatomidae) with information on adult seasonal dimorphism. Ann. Entomol. Soc. Amer. 70:370-372. . 1977b. Effects of developmental photoperiod on adult color and pubescence in Thyanta calceata (Hemiptera: Pentatomidae) with information on ability of adults to change color. Ann. Entomol. Soc. Amer. 70:373-376. , 1978a. Sensitivity of immature Thyanta calceata (Hemiptera: Pentatomidae) to photoperiod as reflected by adult color and pubescence. Great Lakes Entomol. 11:71-76. . 1978b. Effects of various photoperiods on color and pubescence in Thyanta calceata (Hemiptera: Pentatomidae). Great Lakes Entomol. 11:155-158. Ruckes, H. 1957. The taxonomic status and distribution of Thyanta custator (Fabricius) and Thyanta pallido-virens (Stsl) (Heteroptera: Pentatomidae). Arner. Mus. Novitates 1824:l- 23. Table 1. Comparison of color and pubescence between Thyanta pallidovirens accerra adults reared in various photoperiods. Color -- - - - Dorsal Ventral Pubescence Photoperiod Sex Brown Green Brown Green Short Long aFisher exact probability test. b 8 ~ :  16D + 10L: 14D. cl4L: IOD + 16L:gD + 18L:6D. 2The Great Lakes Entomologist, Vol. 12, No. 2 [1979], Art. 5https://scholar.valpo.edu/tgle/vol12/iss2/5

Effects of Various Photoperiods on Color and Pubescence in \u3ci\u3eThyanta Pallidovirens Accerra\u3c/i\u3e (Hemiptera: Pentatomidae)

ValpoScholar

The Great Lakes Entomologist 
Volume 12 
Number 2 - Summer 1979 Number 2 - Summer 
1979 
Article 5 
June 1979 
Effects of Various Photoperiods on Color and Pubescence in 
Thyanta Pallidovirens Accerra (Hemiptera: Pentatomidae) 
J. E. McPherson 
Southern Illinois University 
Follow this and additional works at: https://scholar.valpo.edu/tgle 
 Part of the Entomology Commons 
Recommended Citation 
McPherson, J. E. 1979. "Effects of Various Photoperiods on Color and Pubescence in Thyanta 
Pallidovirens Accerra (Hemiptera: Pentatomidae)," The Great Lakes Entomologist, vol 12 (2) 
Available at: https://scholar.valpo.edu/tgle/vol12/iss2/5 
This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. 
It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. 
For more information, please contact a ValpoScholar staff member at scholar@valpo.edu. 
1W9 THE GREAT LAKES ENTOMOLOGIST 
EFFECTS OF VARIOUS PHOTOPERIODS ON COLOR AND 
PUBESCENCE IN THYANTA PALUDOVIRENS ACCERRA 
(HEMIPTERA: PENTATOMIDAE)' 
ABSTRACT 
The effects of a range of developmental photoperiods on adult dimorphism in Thyanta 
pallidovirens accerra were studied under laboratory conditions. Adults reared in photo- 
phases of 14L and higher had short pubescence and those in 12L and lower, long pu- 
bescence. No dimorphism in color was produced in these same photophases. 
Thyanta pallidovirens accerra McAtee ranges from New York south to Georgia, and 
west to Idaho, northeastern Utah, northeastern New Mexico, and Texas (Ruckes, 1957). 
Ruckes (1957) believed it, T. calceata (Say) and T. custator (Fabricius) had "an autumnal- 
vernal (overwintering) generation that differs in appearance from the summer brood. This 
seems to be a case of seasonal dimorphism. . ." The autumnal-vernal adults were brown 
with long seta-like hairs and summer adults, green with short hairs (less than diameter of 
tibia). 
McPherson (1977a) confirmed Ruckes' hypothesis that calceata is seasonally dimorphic, 
that (1977b. 1978a) the morphs result from developmental photoperiod influence, and that 
(1978b) a threshold photoperiod of about 12.5L: 11.5D (light: dark) is involved in the dimor- 
phic response. Animals reared in photophases above and below the threshold develop into 
green adults with short pubescence and brown adults with long pubescence, respectively. 
T. pallidovirens accerra, as noted above, is also apparently seasonally dimorphic; if so, it 
may also result from photoperiod influence. The results of an experiment to determine the 
role of photoperiod in producing adult dimorphism in this subspecies are presented here. 
METHODS AND MATERIALS 
A male and female ofpallidovirens accerra were collected during September, 1977, in Jackson 
County in Southern Illinois. From their offspring, 18 males and females were selected as 
parents and placed in an incubator (23.9 ? I  1.l0C) under an 18L:6D photoperiod. They were 
mantained in mason jars (nine of each sexljar) provided with cheesecloth as an oviposition 
site, filter paper and paper toweling strips, and fedgreen snap beans (Phseolus vulgaris L.) as 
described by McPherson (1W1). 
Each resulting egg cluster was placed in one of the following six photoperiods and the 
animals reared to adults as described by McPherson (1971): 8L:16D, 10L:14D, 12L:12D, 
14L: 10D, 16L:8D, and 18L:6D. AU experiments were conducted at 23.9 + 1.loC during the 
light and dark phases, and about 130 ft-c during the light phases (Ken-Rad, 15W Daylight, 
F15T81D). 
Adult characters chosen for comparison were color (green or brown) and pubescence 
(longer or shorter than diameter of tibia). Adults were compared in sequential pairs of in- 
creasing photophase and the differences tested with the Fisher exact probability test. The 
0.01 level of significance was chosen because of the variable and subjective nature of color. 
RESULTS AND DISCUSSION 
The success in rearing this subspecies on green beans was poor and thus, results from 
different photoperiods were combined to insure adequate numbers for statistical compari- 
'~inancial support was provided by the Ofice of Research Development and Administration, Southern 
Illinois University, Carbondale Graduate School. Project No. 2-1063 1. 
Z ~ e ~ a r t r n e n t  of Zoology, Southern Illinois University, Carbondale, IL 62901. 
1
McPherson: Effects of Various Photoperiods on Color and Pubescence in <i>Thy
Published by ValpoScholar, 1979
84 THE GREAT LAKES ENTOMOLOGIST Vol. 12, No. 2 
sons. Since the threshold for the dimorphic response in calceata was near 12.5L:11.5D 
(McPherson, 1978b), I combined the results into the following three photoperiod groups: 
8L: 16D and 10L: 14D; 12L: 12D; and 14L: ]OD, 16L:8D, and 18L:6D (Table 1). 
Photophases above 12.5L did not (unlike calceata) produce a significant number of green 
adult males and females; most were light to dark brown (males, 74.5-78.7%; females, 87.5%) 
as were those in the lower photophases (males, 72.2-95.8%; females, 63.6-94.7%) (Table 1). 
However, both sexes showed a significant switch between 12L:12D and 14L:lOD from long 
to short pubescence, similar to calceata. 
It is difficult to suggest, from the limited data, why this range of photoperiods did not 
produce adult color dimorphism in pallidovirens accerra as it did in calceata (McPherson, 
1978b). It is possible that an additional variable is involved in adult color production in this 
subspecies (e.g., temperature, humidity), or that differential mortality occurred in which 
most potentially green adults died. Further studies should be conducted using a laboratory 
culture established with a larger field sample. 
LITERATURE CITED 
MePherson, J. E.  1971. Laboratory rearing of Euschistus tristigmus tristigmus. J .  Econ. 
Entomol. 64: 1339-1340. 
. 1977a. Notes on the biology of Thyanta calceata (Hemiptera: Pentatomidae) 
with information on adult seasonal dimorphism. Ann. Entomol. Soc. Amer. 70:370-372. 
. 1977b. Effects of developmental photoperiod on adult color and pubescence 
in Thyanta calceata (Hemiptera: Pentatomidae) with information on ability of adults to 
change color. Ann. Entomol. Soc. Amer. 70:373-376. 
, 1978a. Sensitivity of immature Thyanta calceata (Hemiptera: Pentatomidae) 
to photoperiod as reflected by adult color and pubescence. Great Lakes Entomol. 11:71-76. 
. 1978b. Effects of various photoperiods on color and pubescence in Thyanta 
calceata (Hemiptera: Pentatomidae). Great Lakes Entomol. 11:155-158. 
Ruckes, H. 1957. The taxonomic status and distribution of Thyanta custator (Fabricius) and 
Thyanta pallido-virens (Stsl) (Heteroptera: Pentatomidae). Arner. Mus. Novitates 1824:l- 
23. 
Table 1. Comparison of color and pubescence between Thyanta pallidovirens accerra adults 
reared in various photoperiods. 
Color 
-- - - - 
Dorsal Ventral Pubescence 
Photoperiod Sex Brown Green Brown Green Short Long 
aFisher exact probability test. 
b 8 ~ :  16D + 10L: 14D. 
cl4L: IOD + 16L:gD + 18L:6D. 
2
The Great Lakes Entomologist, Vol. 12, No. 2 [1979], Art. 5
https://scholar.valpo.edu/tgle/vol12/iss2/5


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Effects of Various Photoperiods on Color and Pubescence in \u3ci\u3eThyanta Pallidovirens Accerra\u3c/i\u3e (Hemiptera: Pentatomidae)

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