Wing polymorphism in Nysius huttoni White (Hemiptera: Orsillidae)

Figures & data

Table 1  The proportion of each wing form of N. huttoni adults collected from the field in three years, 1995–1998.

		Macropterous						Sub-brachypterous						Brachypterous
		No.			%			No.			%			No.			%
Year (n)^1	^2Total no adults collected	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂
1995–1996 (15)	3884 (1:1.18)**	1582	1971	3553 (1:1.25)**	40.7	50.7	91.5	196	134	330 (1:0.68)**	5.0	3.5	8.5	1	0	1 (1:0.00)	0.0	0.0	0.0
1996–1997 (19)	6492 (1:1.07)**	2900	3194	6094 (1:1.10)**	44.7	49.2	93.9	213	156	369 (1:0.73)**	3.3	2.4	5.7	18	11	29 (1:0.61)	0.3	0.2	0.4
1997–1998 (22)	3869 (1:1.08)*	1801	1950	3751 (1:1.08)*	46.5	50.4	97.0	46	44	90 (1:0.96)	1.2	1.1	2.3	12	16	28 (1:1.33)	0.3	0.4	0.7
Total (56)	14245 (1:1.10)**	6283	7115	13398 (1:1.13)**	44.1	49.9	94.1	455	334	789 (1:0.73)**	3.2	2.3	5.5	31	27	58 (1:0.87)	0.2	0.2	0.4
^1n=number of samples collected. ^2Ratio within round brackets indicates sex ratio expressed as ♀:♂=1:x, *P<0.05, **P<0.01 (χ^2 test).

Figure 1  The proportions of macropterous (M) and sub-brachypterous (Sb) forms of N. huttoni adults collected from the field over three years: A, 1995–1996. B, 1996–1997. C, 1997–1998. In 1995 no collections were made between the beginning of September and the fourth week in December so data for overwintered adults and some first generation adults are absent. The last sampling date varies among years in response to variation in the date that the adults of the third generation disappeared for overwintering. The brachypterous form is not shown because of its low proportion (see Table 1).

Table 2  The proportion of different wing form combinations found in copula in the field during 1995–1996 and 1996–1997.

		M×Sb*						M×B*						Sb×B
		M*×M		♀M×♂Sb		♂M×♀Sb		♀M×♂B		♂M×♀B		Sb×Sb		♀Sb×♂B		♂Sb×♀B		B×B
Sampling date	No. pairs in copula sampled	No.	%	No.	%	No.	%	No.	%	No.	%	No.	%	No.	%	No.	%	No.	%	Generation
1995–1996
1995-12-24	42	30	71.4	3	7.1	9	21.4	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	1
1996-1-24	48	43	89.6	0	0.0	5	10.4	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	2
1996-2-2	127	73	57.5	3	2.4	43	33.9	0	0.0	0	0.0	8	6.3	0	0.0	0	0.0	0	0.0	2
1996-2-10	139	102	73.4	0	0.0	31	22.3	0	0.0	0	0.0	6	4.3	0	0.0	0	0.0	0	0.0	2
1996-2-14	99	89	89.9	1	1.0	9	9.1	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	2
1996-2-24	51	49	90.7	0	0.0	2	3.9	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	2
Total	506	386	76.3	7	1.4	99	19.6	0	0.0	0	0.0	14	2.8	0	0.0	0	0.0	0	0.0	—
1996–1997
1996-9-24	98	69	70.4	4	4.1	22	22.4	0	0.0	1	1.0	2	2.0	0	0.0	0	0.0	0	0.0	Overwintered
1996-9-25	101	71	70.3	5	5.0	20	19.8	0	0.0	0	0.0	5	5.0	0	0.0	0	0.0	0	0.0	Overwintered
1996-10-5	100	59	59.0	9	9.0	20	20.0	0	0.0	7	7.0	5	5.0	0	0.0	0	0.0	0	0.0	Overwintered
1996-12-1	209	197	94.3	2	1.0	10	4.8	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	1
1996-12-22	100	90	90.0	3	3.0	7	7.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	1
1997-1-8	100	80	80.0	3	3.0	14	14.0	0	0.0	1	1.0	1	1.0	0	0.0	1	1.0	0	0.0	1+2
1997-1-20	100	98	98.0	1	1.0	1	1.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	2+1
1997-1-27	100	98	98.0	0	0.0	2	2.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	2
Total	908	762	83.9	27	3.0	96	10.6	0	0.0	9	1.0	13	1.4	0	0.0	1	0.1	0	0.0	—
*M— Macropterous; Sb— Sub-brachypterous; B— Brachypterous.

Table 3  The observed and expected proportions of mating pairs collected from the field during 1995–1996 and 1996–1997.

		M×Sb*		M×B*			Sb×B
	M*×M	♀M×♂Sb	♂M×♀Sb	♀M×♂B	♂M×♀B	Sb×Sb	♀Sb×♂B	♂Sb×♀B	B×B
Observed (%)	81.2	2.4	13.8	0.0	0.6	1.9	0.0	0.1	0.0
Expected (%)	86.3	4.8	7.8	0.2	0.4	0.4	0.0	0.0	0.0
*M— Macropterous; Sb—Sub-brachypterous; B— Brachypterous. Observed and expected values were compared and none was significantly different (P > 0.05, χ^2 test).

Table 4  Effect of temperature on wing development of N. huttoni in the laboratory.

		Macropterous						Sub-brachypterous						Brachypterous
		No.			%			No.			%			No.			%
Temperature (°C)	Total no. adults	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂
15	19	0	0	0	0.0	0.0	0.0	6	3	9 (1:0.50)	31.6	15.8	47.4	4	6	10 (1:1.50)	21.1	31.6	52.6
20	81	31	26	57 (1:0.84)	38.3	32.1	70.4	2	15	17 (1:7.50)**	2.5	18.5	21.0	2	5	7 (1:2.50)	2.5	6.2	8.6
25	47	17	20	37 (1:1.18)	36.2	42.6	78.7	4	6	10 (1:1.50)	8.5	12.8	21.3	0	0	0	0.0	0.0	0.0
30	111	41	30	71 (1:0.73)	36.9	27.0	64.0	15	20	35 (1:1.33)	13.5	18.0	31.5	1	4	5 (1:4.00)	0.9	3.6	4.5
35	212	61	95	156 (1:1.56)**	28.8	44.8	73.6	26	9	35 (1:0.35)**	12.3	4.3	16.5	16	5	21 (1:0.31)*	7.5	2.4	9.9
A-T	120	52	42	94 (1:0.81)	43.3	35.0	78.3	11	15	26 (1:1.36)	9.2	12.5	21.7	0	0	0	0.0	0.0	0.0
^1A-T: Ambient temperature with mean 20.3°C (12.5–29.5°C). ^2Ratio within round brackets indicates sex ratio expressed as ♀:♂=1:x, *P<0.05,**P<0.01 (χ^2 test).

Table 5  Effect of photoperiod on wing development of N. huttoni in the laboratory.

			Macropterous						Sub-brachypterous						Brachypterous
			No.			%			No.			%			No.			%
Temperature (°C)	Photoperiod (L:D)	Total no. adults	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂	♀	♂	♀+♂
20	16:8	71	42	27	69 (1:0.64)	59.2	38.0	97.2	0	2	2	0.0	2.8	2.8	0	0	0	0.0	0.0	0.0
	12:12	81	31	26	57 (1:0.84)	38.3	32.1	70.4	2	15	17 (1:7.50)**	2.5	18.5	21.0	2	5	7 (1:2.50)	2.5	6.2	8.6
	8:16	40	12	18	30 (1:1.50)	30.0	45.0	75.0	2	4	6 (1:2.00)	5.0	10.0	15.0	0	4	4	0.0	10.0	10.0
27.5	16:8	104	49	50	99 (1:1.02)	47.1	48.1	95.2	1	0	1 (1:0.00)	1.0	0.0	1.0	0	4	4	0.0	3.8	3.8
	12:12	112	41	71	112 (1:1.73)**	36.6	63.4	100.0	0	0	0	0.0	0.0	0.0	0	0	0	0.0	0.0	0.0
	8:16	92	46	43	89 (1:0.93)	50.0	46.7	96.7	0	2	2	0.0	2.2	2.2	0	1	1	0.0	1.1	1.1
^1Ratio within round brackets indicates sex ratio expressed as ♀:♂=1:x, *P<0.05, **P<0.01 (χ^2 test).