Integrated Orchard Safeguard

Overview

Current method of applying entomogenous fungal pesticides is large-scaled spraying fungal spore solution. However, deployment of genetically engineered fungal pesticides using contemporary methods puts the local eco-system at risk of disruption by the residual fungi. Our project is divided into two main focuses to neutralize these risks. While our team members in wet lab aim to design a killing switch circuit to decrease the environmental risk of genetically engineered fungus from within the organism. Our prototype team attempt introduce an alternative to large-scaled spraying of genetically modified biopesticide by designing and building an Integrated Orchard Safeguard system centered around our prototype bait trap.

In modern bait traps, the bait only attract B. dorsalis. However, it is female flies that is responsible for the species' high reproductiveness and destructiveness. This is why we designed the bait trap to attract, infect, and release male flies to allow M. anisopliae infection of female flies via copulation. The IR counter, another feature of our prototype, record and provide information including pest population size and meteorological data, such as temperature and humidity. Furthermore, farmers can monitor their orchards with a smartphone app that receives data from the IR counter.

We present the Integrated Orchard Safeguard, a informative defense system that links our bait trap, IR counter, and smartphone app.

Bait Trap

After the bait trap receives the population size of oriental fruit fly from the IR counter, it will then automatically regulate the frequency of the spray of fungal spore solution and the opening duration of the door.

Design

1. The First Layer – Microcontroller, Power

The Arduino UNO in our design has combined with Appsduino's product, AppsBee Shield and Appsduino Shield. (The web site of Appsduino: http://appsduino.com/)

2. The Second Layer – Motor

We use the string attached to a ULN2003 stepper motor driver to open and close the door.

3. Drawer – Entrance, Atomization Device

Since flying up is one of the behaviors of B. dorsalis, we set the entrance at the bottom of the trap to hinder the escape of trapped flies. The grower can pull out the drawer to refill the methyl eugenol(a pheromone precursor) to maintain the trap's attraction to male flies. The atomization device in the drawer sprays fungal spore solution to infect the trapped male flies.

Features

1. Specificity - Methyl Eugenol

Methyl Eugenol is the pheromone precursor of B. dorsalis. It only attracts male flies. The male flies will fly away once they have consumed enough Methyl Eugenol.

2. Target main Problem – Female B. dorsalis

female B. dorsalis poses more threat than males.

3. Regulation – IR Counter, Trap, Phone App

Automatically regulation of the spray frequency and door open duration depends on the data collected by the IR counter and phone APP.

4. Eco-Friendly – Recycle

Replacing the indissoluble plastic material (distributed by the government) with recyclable wood chips, which can reduce environmental pollution.

Mechanism

Functionality Display Video

IR Counter & APP

IR counter records and provides real-time information of the orchard : pest group size, meteorological data including temperature and humidity. With a smartphone app, the bait traps are able to inform the grower of these important information.

Design

Functional Test

"Diameter of the tunnel that allows passage to one B. dorsalis" & IR counter

To improve the accuracy of counter, we tried to find the proper tunnel diameter allows only one-by-one passage of B. dorsalis. We prepared different size of straws to connect two centrifuge tubes. One contained male B. dorsalis, and the other contained the bait, methyl eugenol.

Result

The results indicate that when the tunnel diameter is above 0.8 cm, the flies can pass through.

Twin Infection Rate experiments

"Infecting B. dorsalis with non-designed M. anisopliae" and "infecting female B. dorsalis by copulation with infected male B. dorsalis" experiments link to each other; they not only confirm the fact that M. anisopliae successfully invaded and eventually caused the death of B. dorsalis also show the NEW way of bio-control through the interaction from the male to the FEMALE.
The concentration that efficiently and sufficiently causing the death of B. dorsalis is 1.6 × 10⁶ (conidia/ ml).

The death rate of female B. dorsalis infected by M. anisopliae via copulation with infected males is 80%.

The moment we change the day and night to the B. dorsalis during the infection rate experiment.

Efficiency Model

A population size model of B. dorsalis was constructed to simulate a comparison of B. dorsalis population size between an IOS-protected orchard and a normal orchard. The results show a significant decrease of 35% in B. dorsalis population in an IOS-protected orchard compared to one without IOS.
Link to modeling

Population size without IOS

Population size with IOS

Expenditure Analysis

Based on our experimental deployment of counters and traps in an orchard one-hectare in size. The estimated total cost of IOS is listed below:

It is estimated that orchard without any B. dorsalis treatment may incur lost up to 30% of fruit(1). A few calculation was done based on the data from government, and it shows that the saving of fruit value due to our IOS is much greater than the cost of IOS, suggesting our IOS is really worthwhile to be implemented.

(cost of IOS only in low ratio compared to the total profit)

(figure showing the great savings from IOS)

Reference: