Predators

 [Home ] [ Introduction ] [ The Crop ] [ The Problems ] [ Glossary ] [ Credits ] [ Contact Us ]

Common Predators

Ladybird beetles
 

larva (E.  Vasquez)	adult (E. Vasquez)
M. sexmaculatus
larva (E. Vasquez)	adult (E. Vasquez)
C. inequalis

 

Description

Adults are hemispherical-shaped beetles, typically coloured red or orange with black spots. Several species exist with variable spotting. Adults are usually 4- 6 mm. Larvae are elongate flattened grubs. Adults and larvae are actively moving around the plant and often live in aphid colonies. Adults are often confused with ladybugs such as chrysomellid beetles.

Prey

Adults and larvae feed on aphids and other small insects.

Syrphid flies
 

larva (E. Vasquez) adult (E. Vasquez) Ischiodon scutellaris Description   Adults are attractive black and yellow flies which resemble bees. They can easily be distinguished from bees since flies only have two wings and bees have four. They commonly hover around flowers. These flies do not sting or bite. Size ranges 14-19 mm. Larvae are green maggots found on leaf surfaces where aphid colonies are found.   Prey   Larvae feed on aphids. Adults feed on nectar from flowers and aid in pollination in the process.

Lacewings
 

egg (CIP) nymph (CIP) adult (CIP) Description Adults have four glossy net-like wings folded like a tent over the body. Larvae are called aphislions, generally elongate, flattened and wider at the middle with large hooked mandibles for catching and consuming prey. Small white eggs are laid on stalks. Prey Adults and larvae feed on aphids and other small-soft bodied insects.

Predatory earwigs

Earwig is a predator of sweetpotato weevil (E. Vasquez). Description Any of various insects of the order Dermaptera. They vary in size from 1- 2.5 cm length and brown to black in colour. They may be winged or wingless with a few species as good fliers. They have an elongate body that terminates in a pair of pincer-like appendages or forceps, their most distinctive characteristic, protruding from the rear of the abdomen. These forceps are used in capturing prey and mating. Earwigs hide in the soil or plant parts preferring moist shady places during the day and become active during the night when they look for eggs, larvae or nymphs of smaller insects to prey on. Prey Earwigs feed on sweetpotato weevil larvae and other smaller soft-bodied insects.

Description

Adults have elongate, stick-like body with long legs. Front legs are enlarged and come together to hold prey. The body is usually green but may be brown. Adults have wings which are normally folded over the abdomen. All stages are difficult to see in the field because they blend with their surroundings. Size reaches up to 8-10 cm.

Prey

Mantids feed on a variety of insects including grasshoppers, caterpillars, flies and bees. While the mantid chews on the prey, it holds it with his forelegs. Prey is captured by a rapid thrust as it moves by. The mantids hunt by waiting or very slow stalking.

Spiders

lynx spider (E. Vasquez). crab spider (D. Amalin). Description Spiders are eight legged creatures with two body regions, characteristics that distinguish them from insects. Almost all spiders form some webbings that help in catching their preys and as defense against other predators. Prey All spiders are general predators. They feed on several small insect species. Many are quite effective at reducing pest population.

Predatory bugs (pentatomid and assassin bugs) 

pentatomid bug (E. Vasquez) Description   The predatory pentatomid, shield or stink bugs, have well-developed 5-segmented antennae and characteristically shield-like shape with well developed triangular scutellum (part on the top-side of the thorax). Assassin bugs have slender body, long legs, a long narrow head, and an extended, 3-segmented, needle-like beak. They are often brightly coloured and may often be blackish, reddish, or brown.  Prey Caterpillars and probably other insects are attacked. Body fluids are extracted from the prey by sucking.

Predatory ants

P. megacephala (H. van den Berg). big headed ants (B. Kusuma). Description The big headed ant, Pheidole megacephala (Fabricius) have a relatively large head compared to their bodies. Two sizes (major and minor) of workers will be found in a colony. They have 12-segmented antennae with a three-segmented club. Prey Eggs of sweetpotato weevil and other insects.

Predatory mites (Phytoseiid mites)

eggs adults Amblyseius longispinosus (E. Vasquez). Description Mites are more closely related to spiders than they are to insects. They do not have antennae like insects do, nor segmented bodies nor wings. They are usually very small and often go unnoticed. Most mites have an egg stage, a six-legged larval stage, and two eight-legged stages before becoming an adult. Phytoseiid mites are the major group of natural enemies that attack certain kinds of pest spider mites. Most predaceous mites are somewhat pear-shaped and shiny, with noticeably long legs. They may be bright red, yellow, or green depending on what they eat or may appear transparent. Predaceous mite eggs are usually oblong instead of spherical like the eggs of pest mite species. Predaceous mites are also much more active and mobile than pest mite species. Prey Red spider mites, false spider mites and other phytophagous mite species.

Dole, U. 1991. Beneficial insects of British Columbia cranberry bogs. http://www.direct.ca/pestpage/ben3.html. 28 September 2002.

Shepard, B.M., G.R. Carner, A.T. Barrion, P.A.C. Ooi and H. van den Berg. 1999. Insects and their Natural Enemies Associated with Vegetables and Soybean in Southeast Asia. Quality Pronting Co. SC. USA. 108 pp.

Amalin, D.M. and E.A. Vasquez. 1993. A Handbook on Philippine Sweet Potato Arthropod Pests and their Natural Enemies. International Potato Center, Los Baños, Laguna, Philippines. 82 pp.

Bajwa, W. I. 2001. Insect-pathogenic bacteria. http://www.ippc.orst.edu/biocontrol/biopesticides/papers/bacteria-ent-pathogens.html Integrated Plant Protection Center (IPPC) Oregon State University, Corvallis. 26 September, 2002.

Contributed by: Erlinda Vasquez and Vilma Amante

Ladybird beetles

Syrphid flies

Lacewings

Earwigs

Mantids

Spiders

Predatory bugs

Predatory ants

Predatory mites

Parasitoids

Pathogens

Insect and mite pests

Insect pest image gallery