Informatics Publishing Limited

V. Charles ¹, P. Puneeth ¹, V. A. Vijayan ¹, S. K. Jalali ²

Affiliations
1 Vector Biology Research Lab., Department of Zoology, University of Mysore, Manasagangothri, Mysore, 574005, Karnataka, IN
2 National Bureau of Agriculturally Important Insects, Hebbal, Bangalore, 560024, Karnataka, IN

Abstract

Trichogramma genus is one of the most important groups of biotic agents employed for the control of several lepidopterous pests. However, these parasitoids are also subjected to environmental stress such as insecticides, temperature etc. in the agricultural field. Selection of parasitoids tolerant to insecticides has been recognized as a potent method for enhancing their performance. In this regard, the present study was carried out to know insecticide tolerance level and the kind of inheritance in Trichogramma chilonis Ishii., strains on commonly used insecticides in the agricultural fields. Endosulfan, spinosad and lamda cyhalothrin tolerant strains along with a susceptible one were selected to carryout the crossing experiments. The LC₅₀ values of endosulfan, spinosad and lamda cyhalothrin tolerant strains were found to be 278.03, 9.84 and 6.23 ppm respectively. This is in contrast to the respective susceptible strains to these insecticides which have exhibited LC₅₀ values of 106.03, 4.78 and 3.45 ppm respectively. The endosulfan tolerance appeared to be recessive for the cross involving tolerant male parent and semi dominant for the tolerant female parent. The spinosad tolerance was found to be semi dominant for crosses involving both male and female tolerant parents. In contrast, the lamda cyhalothrin tolerance was completely dominant for crosses with the tolerant male and female parents.

Keywords

Trichogramma chilonis, Pesticide Tolerance, Degree of Dominance.

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V. Charles ¹, V. A. Vijayan ¹, A. Ali Ashraf ¹, S. P. Hosmani ²

Affiliations
1 Vector Biology Research Lab, Department of Zoology, University of Mysore, Manasagangothri, Mysore-570 005, Karnataka, IN
2 Department of Biotechnology, SBRR Mahajana First Grade college, Jayalakshmipuram, Mysore-570 012, Karnataka, IN

Abstract

Algae are important food sources for aquatic insects including mosquitoes. Eight mosquito species were collected in and around Mysore city in order to examine the gut contents of the larvae. A total of sixty five species of algae were identified from different larval habitats of mosquito larvae, out of which 55 were encountered in the larval guts. From these algal species identified in the larval gut, 21 (38.18%) belonged to Bacillariophyceae, 12 (21.8%) to Chlorophyceae, 9 (16.36%) to Cyanophyceae, 7 (12.72%) to Desmidaceae and 6 (10.9%) to Euglenophyceae. From the larval breeding sources, out of the 65 identified species, 26 (40%) belonged to Bacillariophyceae, 16 (24.6%) to Chlorophyceae, 10 (15.3%) to Cyanophyceae, 7 (10.76%) to Desmidaceae and 6 (9.2%) to Euglenophyceae. Identification of food sources and their importance to larval development and survival is particularly relevant to the development of novel vector control methods, especially in the study area where malaria, chikungunya and dengue are endemic.

Keywords

Algae, Mosquito Larvae, Feeding Habitats, Larval Gut, Larval Breeding Source.

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