Functional Dimensions of Mirid Bug, Creontiades biseratense (Distant) (Miridae : Hemiptera) Population Dynamics in Bt Cotton
Loading...
Date
2011
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
UAS, Dharwad
Abstract
A season long fixed plot survey was conducted across 13 locations in Haveri
district. On Kanaka Bt BG-II, the average population across the district was 128.3 +
18.2 mirids/100 squares with highest (284.5 + 60.2) in November first fortnight and
least (14.5 + 3.4) in February. The population was high in Rattihalli (190.4 + 115.6)
followed by Aladakatti (164.5 + 108.3) and least in Bisanahalli (87.8 + 70.2). Mirid
menance was severe in Hirekerur and Haveri and least in Shiggaon taluk. There was
significant positive correlation noticed between mirid incidence and squares on cotton
plants.
Mirid bug population had negative association with maximum and minimum
temperature and positive association with morning and evening relative humidity and
rainfall. The important predators viz., Spiders Chrysoperla carnea, Coccinellids and
Nabis spp. showed positive correlation with mirid bug population. The species of
mirid bug found to infest the cultivated crops viz., pigeonpea, maize, sunflower,
safflower, sorghum, amaranths and castor. A total of 65.48 and 28.90 early and late
instar mirid bugs were consumed by single C. carnea grub during its developmental
period. However, third instar C. carnea was predominant predator with daily
consumption of 8.04 and 3.40 mirid bug early and late instar nymphs. The feeding
potentiality of Lynx spider, Oxyopes biramanicus was 5.39 nymphs and 2.36 adult
mirid bugs per day.
The EIL and ETL worked out appeared to be 6.50 and 5.00 nymphs/plant,
respectively. Based on molecular study, it was evident that C. biseratense (Distant)
occurring in different locations viz., Dharwad, Belgaum, Haveri, Raichur and
Gulbarga on Bt cotton, pigeonpea and maize belonged to same species despite colour
morphs.
Description
Keywords
Agricultural Entomology