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600<br />
4 week moving means<br />
Weekly t o t a l s<br />
Deep V e r t i s o l<br />
30<br />
400<br />
20<br />
200<br />
A l f i s o l<br />
10<br />
Oct N o v Dec Jan Oct N o v Dec Jan<br />
20<br />
c v H y - 3 A<br />
A l f i s o l<br />
Eggs<br />
L a r v a e<br />
c v H y - 3 A<br />
Deep Vertisol<br />
Oct Nov Dec Jan<br />
Oct Nov Dec Jan<br />
60<br />
40<br />
20<br />
cv H y - 2<br />
A l f i s o l<br />
Eggs<br />
L a r v a e<br />
cv H y - 2<br />
Deep V e r t i s o l<br />
Oct N o v Dec Jan Oct Nov Dec ' Jan<br />
The terminal is distal 25-cm portion of the pigeonpea branch.<br />
Figure 75. Heliothis armigera (Hubner) eggs and larvae per 100 terminals on intercropped pigeonpea (cv<br />
HY-2 and HY-3A) and moths trapped at two locations, ICRISAT Center, 1976-1977.<br />
percent in Vertisols. This was associated with<br />
slow initial growth of seedlings in Alfisols. Heavier<br />
attacks were also obtained on sorghum due to<br />
slow growth in some Vertisol areas sown after<br />
unweeded fallow. Orius sp., a predatory bug, and<br />
earhead bugs, Calocoris angustatus Leth., were<br />
present in higher numbers on Alfisols than on<br />
Vertisols (S3 compared with 25 per 40 earheads<br />
and 16.5 compared with 3 per 40 earheads,<br />
respectively). Predatory spiders were found in<br />
greater numbers on sorghum earheads on A l -<br />
fisols, while thrips were more numerous on<br />
Vertisols (21 compared with 15 per 40 heads).<br />
Light-trap studies and insect fauna at ICRISAT<br />
Center. A third light trap at a Vertisol watershed<br />
was commissioned in April 1977. Three<br />
years of regular light-trap monitoring of more<br />
than 50 important pests of the SAT on legumes<br />
and cereals is revealing basic information on<br />
seasonal variations in pest species.<br />
Four-week moving means during 1974-1977<br />
for H. armigera moths recorded from Trap 1 are<br />
shown in Figure 76. The first and the third peaks<br />
were further displaced during this year, but the<br />
second appeared in the same week as observed<br />
during 1974-1975. A fourth peak at the end of<br />
April this year was from a summer cowpea crop<br />
at ICRISAT Center.<br />
The most significant pests and beneficial fauna<br />
to date on the range of crops were authenticated.<br />
A list of parasites, predators, and hyperparasites,<br />
along with a detailed list of pests and insects, has<br />
been compiled.<br />
166
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