Objectives Identify common greenhouse insects by
visual observation Determine the correct beneficial
biological control for each damaging insect
AphidsAn even more amazing feature of life cycles of most aphid species is that reproduction is accomplished without the help of male aphids! In the picture above you can see that some aphids are much smaller than the others. Those small ones have no fathers. They were born from the larger females without the benefit of
sexual reproduction
AphidsWingless adult female aphids can produce 50 to 100 offspring. A newly born aphid becomes a reproducing adult within about a week and then can produce up to 5 offspring per day for up to 30 days!
MealybugsMealybug females feed on plant sap. They attach themselves to the plant and secrete a powdery wax layer (therefore the name mealybug) used for protection while they suck the plant juices. The males on the other hand, are short-lived as they do not feed at all as adults and only live to fertilize the females.
Spider MitesIt lays its eggs on the leaves, and it poses a threat to host
plants by sucking cell contents from the leaves cell by cell, leaving very tiny, pale spots or scars where the green epidermal cells have been destroyed. Although the individual lesions are very small, commensurate with the small size of the mites, the frequently-observed attack of hundreds or thousands of spider mites can cause thousands of lesions and thus can significantly reduce the photosynthetic capability of plants, greatly reducing their production of nutrients, sometimes even killing the plants.
ThripsThrips feed on the tender plant foliage. The eggs are laid on plant tissue or may be inserted into slits. Average time to complete life cycle is two weeks. This results in several generations per year.
Thrips*Fruit will show signs of a “zipper” or “railroad tracks”
*Leaves margins turn brownish and silvering on the underside
Whiteflies
Longevity depends on temperature, at high temperatures the female lives 10-15 days, at lower temperatures they can live up to 2 months. Adults can live for an extensive time even without host plants in an empty greenhouse, however, they cannot survive temperatures below freezing.
Whiteflies
Females lay eggs on the undersides of new leaves.
After 1 or 2 days, the eggs turn brown to black.
The larvae emerge after 7 to 10 days.
Whiteflies
The pupa is dirty white, and surrounded
by much wax and honeydew. The adult whitefly emerges from the
pupa and begins to eat.
Whiteflies
Adults are 1mm long with two pairs of white wings and a light yellow body.
They are generally found at the top of the plant. Females start laying eggs
within 1 to 2 days, and may lay up to 500 eggs in a lifetime.
1.To design a program for controlling diseases in the greenhouse.
2.To design a program for controlling insects in the greenhouse.