Hoverflies are medium-sized insects. They have a characteristic, wasp resembling, yellow-black marking. Hoverflies can be distinguished by their typical “hovering” way of flying. Hoverflies do not sting. Adults of episyrphus balteatus feed themselves with nectar and pollen. The hoverfly larvae are 10 to 20 mm. in length, have a soft, transparent body and resemble slugs.
Life cycle and relative effectiveness
Until the episyrphus larva pupates in one to two weeks, it can consume between 400 and 700 aphids. During the hunt they move forward swinging their upper part of the body, looking for their prey, which they subsequently latch with their saliva and suck out. The larvae become active at a temperature of 8 ºC. A humidity above 60% has a favourable influence on the effectiveness of the episyrphus larvae. Hoverflies are highly susceptible to the use of chemicals. Therefore, during a minimum of six weeks prior to introduction of episyrphus, no chemicals can be applied.
Application and dose
Episyrphus can be used against all kinds of aphids on crop with a smooth leaf surface. It is also possible to use hoverflies outside greenhouses, for example in cultivation of roses. After arrival, episyrphus balteatus must be plotted as soon as possible. The larvae must be plotted on the affected plants, closely to the aphid colonies. To increase the effectiveness of episyrphus, the crop has to be moisture. As a result, the material will adhere to the leaf surface.
Storage and handling
Episyrphus balteatus supplied in bottles (100 ml.) containing 50 pupae. Keep the bottles horizontally, in darkness, at a temperature between 8°C – 10°C. Maximum storage time of two days.