All about potatoes.pdf - Vegetableipmasia.org

8.
MAJOR NATURAL ENEMIES OF POTATO PESTS
8.1.8 Other predators
Other predators found in potato fields are dragonflies, crickets and red ants. These
insects are highly abundant on potato crops that have not been sprayed with
insecticides, and are suitably effective at controlling insect pest numbers. Predatory
ability depends on the species and development stage of the predator and its prey.
8.2 Parasitoids
8.2.1 Parasitoids of leafminer fly
A. Hemiptarsenus varicornis
Adult insects are a kind of parasitic wasp. They have blue-green
metallic bodies measuring 1.3-1.2 mm in length and have two
pairs of wings. These parasitoids are commonly found on potato
crops. This parasitoid specifically parasitizes leafminer flies
when they are still in their larval form. The wasp lays eggs on
the leafminer larva. After hatching, the parasitoid larva lives on
the leafminer fly larva by sucking its body fluids. Host larvae
growth is stunted and they often die. On potato crops, rates of
parasitism can reach 70%, albeit mostly too late in the season
after a lot of damage has already been done. This parasitoid is
not that effective at controlling quantities of leafminer flies by
itself, but is complementary in a diverse natural enemy complex
in the potato field.
Male
Female
B. Opius sp.
Adult Opius wasps have black bodies, two pairs of wings
and jointed antennae. Although it is not so common, this
parasitoid is generally more effective than Hemiptarsenus.
It also parasitizes flies in their larval and pupal stages. The
larva and cocoons of this parasitoid live inside leafminer fly
larvae and pupae. Parasitized larvae and pupae will die.
Intensive use of insecticides on potato crops will cause
very low levels of parasitism.
C. Gronotoma sp.
Adult insects have black bodies and jointed antennae that look
like beads. This insect solely parasitizes leafminer fly larvae.
Parasitoid larvae live inside the bodies of leafminer fly larvae.
Parasitized leafminer larvae can pupate, but will not develop
into adult flies.
8.2.2 Parasitoids of other potato pests
Other parasitoids are found not only on leafminer flies,
but also on other insect pests, such as aphids, cluster
caterpillars, potato tuber moth larvae or cabbage looper
larvae. The appearance of mummified aphids is a clear
indication of the presence of the common parasitoid,
Dieretella spp. Another way to determine whether
parasitoids are present is to remove insect pest larvae
A HANDBOOK TO THE ECOLOGY AND INTEGRATED MANAGEMENT OF POTATO 51