Brief SummaryRead full entry
Ant lions are found worldwide, in tropical and subtropical regions in Africa, Asia, Australia, and the Americas (Resh and Cardé 2003). They live in arid and semiarid areas of open woodlands, scrub grasses, and dry sandy areas (Resh and Cardé 2003). They are more abundant in lower rainfall areas since the larvae require dry and loose soil (McClure 1983). However, the larvae can also be found in areas protected from rain in regions with higher rainfall (McClure 1983).
Ant lions are holometabolus, which means that they undergo complete metamorphosis, and larvae are morphologically very different from adults. Morphologically, adults are similar to damselflies, but they have a few differences. Adult ant lions have softer bodies, pointed wing tips, different wing venation, and long, clubbed antennae (Borror and White 1970, McClure 1983). Adults are 5-6 cm in length and thin-bodied, and they have broad pronotums and prominent compound eyes (McClure 1983). Eggs are unstalked, relatively large, and covered with an adhesive glandular secretion (Resh and Cardé 2003). They are laid singly in dry, loose soil in open areas or under shelter (McClure 1983, Resh and Cardé 2003).
Larvae are rough, squat, and wedge-shaped (McClure 1983). They have long, sickle-like jaws, posteriorly tapered abdomens, flat heads, metathoracic legs (with fused tibia and tarsus), enlarged, forward-directed claws, and forward-directed bristles on their bodies (Borror and White 1970, McClure 1983). Larval development can occur over several years depending on prey availability, and while the average time spent as a larva is two years, it can last longer than three years (McClure 1983). This variability results in large ranges of sizes of larvae that hatched around the same size in a given location (Resh and Cardé 2003, McClure 1983). Larvae have three instars, and fully-grown larvae are 10-12 mm in length (McClure 1983, Resh and Cardé 2003). Cocoons are spherical, single-walled, 10-15 mm in diameter, and are made of sand and silk (McClure 1983, Resh and Cardé 2003).
When a larva hatches, it moves backwards in an irregular pattern to find a suitable location for a pit (McClure 1983). The larva then digs a conical pit by plowing backwards in a circle and flicking sand upwards with its head (McClure 1983). Pits are 1-4 cm in diameter (McClure 1983). The larva remains concealed at the bottom of its pit and waits for prey (McClure 1983). Many studies have been conducted on ant lion larvae, especially on pits and competition (Burgess 2009, Scharf et al. 2008, Swenson et al. 2007).
Both larvae and adult ant lions are predaceous (McClure 1983). Larvae eat ants and other small arthropods that fall into their pits (Resh and Cardé 2003). A larva feeds by using its piercing mandibles to grab the fallen prey, and it injects digestive enzymes into the prey (McClure 1983, Resh and Cardé 2003). After a few minutes, the larva sucks the liquids out, and finally, it flicks the remains out of the pit with its head (Resh and Cardé 2003, McClure 1983). Adults are also predaceous on small arthropods, and they are crepuscular or nocturnal (McClure 1983).
Lastly, adult males use extrusions of hair pencils and abdominal glands/sacs for sexual communication (Resh and Cardé 2003). Male and female adults can also release volatile substances from thoracic glands (Resh and Cardé 2003).