Mosquito Larvae/Pupae Counter

Mosquito Larvae/Pupae Counter

The mosquito larvae counter (MLC) is an automated system, designed and developed by Radiation General Ltd, Budapest, Hungary. The device counts different immature stages of the mosquitoes, from L1up to different pupae stages using optical sensing.

Description and operating principle of the mosquito larval counter

The MLC-CH1 (Figure 1) consists of three major parts:

1. an input larvae container (LC) or a funnel into which the sample is poured, a supporting frame and an optional stirrer unit,

2. the counting unit (ECU),

3. the PC and the Larvae controlling program.

A specially designed sensor head (Fig. 1G) is connected to an electronic fibre optic sensor unit (MLC-FO-01, Radiation General Ltd.) by optical fibres. One optical fibre is connected to the light source output; another fibre is connected to the sensor input of the fibre optic sensor unit. The light beam in the sensor head passes perpendicularly through the water path. Objects suspended in water passing by gravity at a controlled rate through the sensor head partially occlude the light beam, which is converted by the fibre optic sensor unit to a voltage pulse, which is proportional in amplitude to the particle size. If the decrease of the light intensity is greater than an adjustable threshold, the passing object (e.g. larvae) is counted by a data acquisition module. A pinch valve (Fig 1H) controls the water flow and can be set to stop the flow at a set count. Result can be directly viewed in the software and the program records the measurement results (total number and time elapsed since start) in a log file.

Figure 1:

The automated mosquito larvae counter. General view of the counter (A); general display of the electronic counting unit and the input container (B); funnel as input container (C); stirrer unit (D); electronic counting unit (E); electrical connections (F); optical sensorhead (G); pinch valve (H).

Specification of the system

  • The type of larvae: L1-L4
  • Input: One barbed tube adapter diam. 6mm
  • Output: one barbed tube adapter diam. 6mm
  • Output: about 1 litres – 5.000 larvae – in about 1…3 minutes
  • Maximum input: 5.000 larvae in 1 litre pure water
  • The volume of the output can be simply diluted according to the breeding system
  • The accuracy of the measurement is below ±10%
  • The larvae solution should be free of “pollution”
  • The water is considered clean when the “count” without larvae - during the actual measuring time and at the actual size threshold - is less than 5% of the count with larvae
  • The measurements are carried out in normal laboratory environment
  • Human Machine Interface is on the connected PC
  • The MLC is powered by 90-260VAC mains supply
  • The container for the input and the supporting frame are optional
  • The supporting frame of the input larvae container the Electronic Counting Unit should be constructed and made locally based on our recommendations
  • The MLC does not damage the larvae

 

The software resides on a PC computer (desktop or laptop). The minimum configuration of the PC is the following:

  • Microsoft Windows 10 operating system,
  • .NET 4.5 or newer,
  • Display resolution minimum of 1280*1024 pixels. If the screen resolution is different, the runtime screens will differ from those in this document: parts can be clipped.
  • 4 GB RAM,
  • 500 GB Fixed disk or equivalent SSD,
  • Keyboard, mouse,
  • 1 USB port 2.0 to connect the hardware module(s),
  • Special A to B type USB cable (shipped with module system).