emergence, and thus the optimum period for 
sandpiper breeding, differed by 10 days between 
1971 and 1972. Norton et al. (this volume) 
showed that avian breeding was delayed some- 
what in 1972, thus preventing severe dis- 
synchrony between predator and prey; however, 
it is possible that large, year-to-year differences 
in sandpiper breeding success relate to differ- 
ences in the timing of cranefly and other insect 
emergence. The short summer season that char- 
acterizes arctic tundra makes timing or phenol- 
ogical relationships especially important; this 
may be one area in which the tundra is particu- 
larly sensitive to small disruptions. 
The total number of captures in any plot 
provides an index of abundance that can be used 
for between-plot and between-year comparisons. 
The delayed melt-off and prolonged flooding of 
the lake basin (plots 4 and 5) in 1972 produced 
no major decline in insect abundance. In fact, 
Tipulidae and Dolichopodidae (Fig. 3) increased 
in abundance from 1971 to 1972. Only the 
parasitic Hymenoptera (Fig. 6) declined from 
1971 to 1972, and this occurred on all plots. 
Captures of leafhoppers (Cicadellidae) were 
concentrated on the drier plots (Fig. 7). On 
Diptera: Dolichopodidae 
Plot N 
97 ey 170 
972 |__—_—_sees —$—$—{ 544 
(0 — SSS 630 
a 
972 $$ 799 
97 aS SS 274 
= 972 {$s $$ 272 
Tx f —| 42\ 
4 
972 $e $$$ 6 | 2 
5 971 —t + +— 375 
972 eer 
6 1972 TS 
7 1972 EER 
(as eS | ! ! cee 
10 20 30 10 20 30 10 20 29 
June July August 
Fig. 3. Seasonal distribution of “sticky-board” 
captures of long-legged flies (Diptera: 
Dolichopodidae) in 1971 and 1972. 
WA 
Diptera: Small Nematocera 
Plot N 
1971 SS 2547 
1972 |—__ $n 
SA et t }——————————-__ 4565 
2 1972 oe 
1978—§ +4 2578 
3 
1972 _—___/ 
1971 ——4 { ee 
3 1972 —_——_ $9455 
el = t OOS 
> 1972 —_—— pe 7763 
6 1972 | $$. 478| 
7 1972 |_— n —_— 4533 
— a a Ee ee) 
@ 2 30. [oO 2 sO" IO eo 2S 
June July August 
Fig. 4. Seasonal distribution of “sticky-board” 
captures of other species of Diptera, suborder 
Nematocera in 1971 and 1972. 
Diptera: Brachycera & Cyclorrhapha 
Plot N 
ed 0 — 221 
1972 | $n 3 
1978—§ YX 
2 520 
1972 —_—__—_—_—_—_ 
a 387 
3 
1972 a 198 
i — eS 
4 716 
1972 | Un 
5 1971 ——+t t ———————} 704 
1972 a 421 
6 1972 I 
7 1972 _ ore 
aa a i 1 1 asi 1 J 
[O} ee cOMNESOM IONS 2On 50 10 20 29 
June July Auaust 
Fig. 5. Seasonal distribution of "'sticky-board" 
captures of "higher"’ flies (suborders Diptera, 
Brachycera and Cyclorrhapha) in 1971 and 
1972. 
