Sanehdeep Kaur ¹, Harminder Preet Kaur ¹, Kirandeep Kaur ¹, Amarjit Kaur ²

Affiliations
1 Department of Zoology, Guru Nanak Dev Universiy, Amritsar (punjab) 143001, IN
2 Department of Microbiology, Guru Nanak Dev University, Arnritsar I43 001, Punjab, IN

Abstract

Beauveria bassiana one of the most common and ubiquitous entomopathogens, is known to be a highly potential bioagent for the control of insects belonging to various orders. The cellular immune response was examined in Spodoptera litura larvae infected with B. bassiana. Third instar larvae were treated with a fungal suspension @ 2.03x10⁸ spores ml^-1. Haemolymph of treated and untreated larvae were taken after 2, 12, 24,48,72, 96 and 120 hours after inoculation. Plasmatocytes and granulocytes swelled 2 hours after inoculation (HAI) followed by lysis of plasma membrane. Within 24 HAI, apposition was observed. The encapsulation process started after 48 hours and continued for up to 72 hours. After 96 hours of inoculation the granulocytes and plasmatocytes were observed to form nodules. With increasing inoculation time, the size of clump increased, forming multiple layers at 120 HAI. However, despite these insect defense responses, growth of fungal hyphae was observed after 120 hours of inoculation which ultimately resulted in the death of the host.

Keywords

Beauveria bassiana, Spodoptera litura, Cellular Immune Response, Encapsulation, Immunity, Hemolymph, Hemocytes.

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Kirandeep Kaur ¹, Rabinder Kaur ¹

Affiliations
1 Department of Entomology, Punjab Agricultural University, Ludhiana - 141 004, Punjab, IN

Abstract

Experiments were conducted to find out the influence of two acaricides (Propargite and Ethion) on survivability of an anthocorid predator, Blaptostethus pallescens (Poppius) when exposed at different time intervals under laboratory conditions. In present investigation, the second instar nymphs of B. pallescens were exposed to propargite @ 300 ml/acre and ethion @ 450 ml/acre for different time intervals using two methods of treatment viz; leaf disc and foliar spray method. Both the acaricides had adverse effect on the survival of the predator but the effect of ethion was faster as compared to propargite. When exposure time for ethion treatment was increased from one to six hours, the mortality of second instar nymphs increased from 0.10 to 86.00 per cent. On the other hand, in case of propargite, the mortality was 0.10 per cent at 1 hour interval and gradually increased with increase in exposure time, up to 20 per cent at 48 hours of exposure. Second instar nymphs were released on potted plants showed higher rate of mortality after the foliar spray of acaricides as compared to those in leaf disc where corrected per cent mortality of ethion treated nymphs was 10.96 per cent at one hour of exposure and it became almost 100 per cent at six hours of exposure or above. Similar trend was followed in case of propargite where mortality was 6.97 to 75.5 per cent, when exposure time increased from one hour to 12 hours. Thus both acaricides were found to be unsafe to B. pallescens.

Keywords

Acaricides, Blaptostethus pallescens (Poppius), Ethion, Mortality, Propargite.

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Kirandeep Kaur ¹, Rabinder Kaur ¹

Affiliations
1 Department of Entomology, Punjab Agricultural University, Ludhiana - 141004, Punjab, IN

Abstract

Blaptostethus pallescens (Poppius) (Hemiptera: Anthocoridae) is a subtropical species and is reported to be a potential predator of sucking pests. Development of this predator was investigated at six different temperatures (15, 20, 25, 30, 35 and 40°C) in the laboratory. Temperature range of 20-30°C was found optimum. Rearing the bug at temperatures lower or higher than this range resulted in the mortality of both adults and pre-imaginal stages. The development of the bug showed a linear relationship with temperature within this range. Maximum fecundity (59 eggs) was recorded at 25 ± 5°C and it was best temperature for mass multiplication of this predatory bug.

Keywords

Biology, Biocontrol, Blaptostethus pallescens (Poppius), Development, Temperature.

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