Research at UAF - Exploring biological activities of citrus limonoids: A multidisciplinary approach for controlling insects
Name of P.I: Dr. Waseem Akram
Phone: 041-9200161/3804
Fax: 041-9200764
areeba14@yahoo.com
Name of Co-P.I: Dr. Muhammad Asghar Bajwa
Phone: 041-9200161
Fax: 041-9200764
Duration: 36 Months
Cost: (Rs. Million) 1.402456
Funding agency: HEC

Progress Reports

Abstract
The present study has been carried out to test the efficacy of different varieties of citrus against Aedes albopictus larvae. Oils from citrus peel and seeds were extracted by hydraulic press and soxhlet apparatus. The varieties tested indicate a strong base for the success of these oils against mosquito larvae.  The study also provides a complete update of the most widely distributed species of mosquitoes in Punjab. The research is in progress and final observations regarding its absorption in the body are under way.


Problem statement
Minimize the use of pesticide in our environment
Objectives

  • Identification of economically important insects (Mosquitoes)
  • Isolation and purification of limonoids from citrus varieties
  • Mechanism involved in the killing of insect (THIRD YEAR)

Methodology

  • Collection of all stages  through recommended techniques
  • Extraction of oil from seed and peel of citrus varieties
  • HPLC analysis for estimation of limonoids in the oils
  • Bioassay tests for larvicide, adulticide and repellent

Results
Data collected from May 2006 to March 2009 on seasonal distribution and species composition of mosquitoes revealed that for 14 of the total 17 months of collection, the population of mosquitoes was high during different times of the year. Our findings are similar to those of Rifaat et al. (1970) and Alten et al.(2000), who reported that the daytime biting mosquito species captured throughout the study period were most abundant in late summer. Overall, the population of Aedes was high from May to September, with peaks between mid-June to end-September, followed by a decline to December that persisted to March of the next year. A downward population trend was recorded between 45 to 50 ° C with relative humidity of 45%, however, in the shady areas even during June to July high populations of Aedes were recorded. For most of the mosquito species, more individuals were collected during the “high season” months (March to October) than in the “low season” months (January to Mid February). Average population counts for Anopheles, Culex and Aedes were in the ratio to 50 : 90 : 18. The population that was increasing revealed Culex (36.8%), Anopheles (32.1%) and Aedes (26.3%) in greater numbers in August with temperature more or less in the range of 40 ± 2° C.
We collected data on mosquito distribution which was statistically analyised using SPSS 13.0. Results obtained from the analysis have been presented in tables and graphs. On the whole 12 species of mosquitoes including 4 genera were captured:
Cross-tabulation was performed to show the association between different habitats and collected mosquitoes species from rural areas. p-values of the cross-tabulation. Association of Aedes albopictus and nursery and park, Armigeres obturbans and park, Cx. fuscanus and tap catch basin, Cx. pseudovishnui and rice area, livestock farm and roadside pool, Cx. vishnui and near agricultural field and tap catch basin was highly significant.


Conclusions
Clear water, mud (bottom), exposed shady (light) had a significant relationship and maximum population of mosquitoes was collected from these abiotic factors.  Aedes  albopictus maximum number of samples were collected and found associated with grass (plantation), buffalo (animals), crow (birds) and water beetle (predators) because these biotic factors had  highly significant association with larval population of mosquitoes.
Recommendations

  • Citrus limonoids have greater potential for controlling insects. Therefore it is recommended that they can be a part of effective mosquito control program.
  • Oils from citrus varieties are effective as repellents for the adults and insecticides for the larvae. Pakistan has big cirus production therefore the availability of raw materials is not an issue.

The most commonly and widely distributed species is Aedes albopictus which is active during two seasons and therefore well planned short and long term management is required for its control in order to minimize dengue spread.
One to two photographs of the project