Abstract: Chilli (Capsicum annum L.) an important commercial vegetable crop is ravaged by a number of insect-pests during both vegetative and reproductive phase resulting into significant crop loss.Thrips, Scirtothripsdorsalis, mite, Polyphagotarsonemuslatus and whitefly, Bemisiatabaci are the key sap feeding insects, their infestation leads to leaf curl, stunted growth and yield loss.During flowering and fruit formation stage, gall midge fly, Asphondyliacapparis (Rubsaaman) infesting flower buds and young fruits andHelicoverpaarmigera (Hubner) feeding on matured green fruits are the important insect pests causing significant crop loss.The pest is known to infest both flower buds and young fruits resulting into malformation of flower buds and twisting of fruits.In order to manage these insect-pests a combi product consisting of imidacloprid and betacyfluthrin (Soloman 300 OD) was evaluated for its bio-efficacy, phytotoxicity and effect on predator activity.Imidacloprid, a systemic insecticide belonging to neo-nicotinoid group, is effective against insect pests such as aphids, whiteflies (sap feeders) and other insectsviz., termites and soil insects.Beta-Cyfluthrin is an insecticide of synthetic pyrethroid group which acts by contact action and ingestion. It acts on the insects' nervous system as sodium channel blocker consequently a disorder of the nervous system occurs leading finally to the death. The field experiments were taken up during 2015 and 2016 at the Main Agricultural Research Station of University of Agricultural Sciences, Dharwad, Karnataka, India.The trials were laid out in a Randomized Block Design (RBD) with three replications using popular land race of Byadagi crop variety.Results indicated that the product at 21.6 + 50.4% gai/ha (240 ml/ha) and 27.9 + 65% gai/ha (310 ml/ha) was found quite effective in controlling thrips (0.00 to 0.66 thrips per six leaves) as against the standard check insecticide recommended for thrips by the University of Agricultural Sciences, Dharwad wherein the density of thrips recorded was significantly higher (1.00 to 2.00 Nos./6 leaves). Similarly, the test insecticide was quite effective against other target insects, whiteflies, fruit borer and gall midge fly as indicated by lower insect population observed in the treatments as compared to standard insecticidal control. The predatory beetle activity was found to be normal in all experimental plots. Highest green fruit yield of 5100-5500 kg/ha was recorded in Soloman 300 OD applied crop at 310 ml/ha rate as compared to 4750 to 5050 kg/ha recorded in check. At present 6-8 sprays of insecticides are recommended for management of these insect-pests on the crop. If combi-products are used in pest management programmes, it is possible to reduce insecticide usages in crop ecosystem.
Abstract: Effect of biopesticide from wood vinegar and
extracted substances from 3 medicinal plants such as: non taai yak
(Stemona tuberosa Lour), boraphet (Tinospora crispa Mier) and
derris (Derris elliptica Roxb) were tested on the age five years of
pomelo. The selected pomelo was carried out for insects’ pest control
and its quality. The experimental site was located at farmer’s orchard
in Phichit Province, Thailand. This study was undertaken during the
drought season (December to March). The extracted from plants and
wood vinegar were evaluated in 6 treatments: 1) water as control; 2)
wood vinegar; 3) S. tuberosa Lour; 4) T. crispa Mier; 5) D. elliptica
Roxb; 6) mixed (wood vinegar + S. tuberosa Lour + T. crispa Mier +
D. elliptica Roxb). The experiment was RCB with 6 treatments and 3
replications per treatment. The results showed that T. crispa Mier was
the highest effectiveness for reduction population of thrips
(Scirtothrips dorsalis Hood) and citrus leaf miner (Phyllocnistis
citrella Stainton) at 14.10 and 15.37 respectively, followed by
treatment of mixed, D. elliptica Roxb, S. tuberosa Lour and wood
vinegar with significance different. Additionally, T. crispa Mier
promoted the high quality of harvested pomelo in term of thickness
of skin at 12.45 mm and S. tuberosa Lour gave the high quality of the
pomelo in term of firmness (276.5 kg/cm2) and brix (11.0%).
Abstract: Scolothrips longicornis Priesner is one of the
important predators of tetranychid mites with a wide distribution
throughout Iran. Life table and population growth parameters of S.
longicornis feeding on two-spotted spider mite, Tetranychus
turkestani Ugarov & Nikolski were investigated under laboratory
condition (26±1ºC, 65±5% R.H. and 16L: 8D). To carry of these
experiments, S. longicornis collections reared on cowpea infested
with T. turkestani were prepared. The eggs with less than 24 hours
old were selected and reared. The emerged larvae feeding directly on
cowpea leaf discs which were infested with T. turkestani. Thirty
females of S. longicornis with 24 hours age were selected and
released on infested leaf discs. They replaced daily to a new leaf disc
and the laying eggs have counted. The experiment continued till the
last thrips had died. The result showed that the mean age mortality of
the adult female thrips were between 21-25 days which is nearly
equal life expectancy (ex) at the time of adult eclosion. Parameters
related to reproductive table including gross reproductive rate, net
reproductive rate, intrinsic rate of natural increase and finite rate of
increase were 48.91, 37.63, 0.26 and 2.3, respectively. Mean age per
female/day, mean fertile egg per female/day, gross hatch rate, mean
net age fertility, mean net age fecundity, net fertility rate and net
fecundity rate were 2.23, 1.76, 0.87, 13.87, 14.26, 69.1 and 78.5,
respectively. Sex ratio of offspring also recorded daily. The highest
sex ratio for females was 0.88 in first day of oviposition. The sex
ratio decreased gradually and reached under 0.46 after the day 26 and
the oviposition rate declined. Then it seems that maintenance of
rearing culture of predatory thrips for mass rearing later than 26 days
after egg-laying commence is not profitable.