Red spider mites are insect pests that feed on strawberry plants. They can be controlled by natural predators such as predatory mites and lacewing larvae.
Draw a food chain showing the relationship between strawberry plants, red spider mites, and predatory mites.
A grower wanted to compare the effectiveness of these two different biological control agents to manage red spider mites. Predatory mites were released on day 0 into one polytunnel (Polytunnel A), and lacewing larvae were released into a different polytunnel (Polytunnel B).
The table below shows the results:
Time\multicolumn2c∣Polytunnel A\multicolumn2cPolytunnel B\cline2−5(days)Spider mites per m2Predatory mites per m2Spider mites per m2Lacewing larvae per m20800208202057804561011010740952202501545021015180205038084025035014003003304800\begin{array}{c|c|c|c|c} \hline \textbf{Time} & \multicolumn{2}{c|}{\textbf{Polytunnel A}} & \multicolumn{2}{c}{\textbf{Polytunnel B}} \\ \cline{2-5} \textbf{(days)} & \textbf{Spider mites per } \text{m}^2 & \textbf{Predatory mites per } \text{m}^2 & \textbf{Spider mites per } \text{m}^2 & \textbf{Lacewing larvae per } \text{m}^2 \\ \hline 0 & 800 & 20 & 820 & 20 \\ 5 & 780 & 45 & 610 & 110 \\ 10 & 740 & 95 & 220 & 250 \\ 15 & 450 & 210 & 15 & 180 \\ 20 & 50 & 380 & 8 & 40 \\ 25 & 0 & 350 & 140 & 0 \\ 30 & 0 & 330 & 480 & 0 \\ \hline \end{array}Time\cline2−5(days)051015202530\multicolumn2c∣Polytunnel ASpider mites per m28007807404505000\multicolumn2cPolytunnel BPredatory mites per m2204595210380350330Spider mites per m2820610220158140480Lacewing larvae per m2201102501804000Use the information in the table to answer the following:
Suggest two reasons why predatory mites might be a better biological control agent to use than lacewing larvae.
Suggest one reason why lacewing larvae might be a better biological control agent than predatory mites.
Other than predation, name two biotic (living) factors that may affect red spider mite numbers.
Name two abiotic (non-living) factors that may affect red spider mite numbers.
