Chrysopa oculata



     The Chrysopa oculata have an annual reproductive cycle, which is complete with metamorphosis (egg, larva, pupa, and adult stages).The eggs may be laid in the water, soil, or on plants. Eggs may or may not have stalks. The larvae are predaceous. Pupation occurs in silken cocoons. Adults emerge one or two weeks later (Dunn 1996). The reproductive behavior of Chrysopa oculata females displays a dependence on diet. Females remain unmated when maintained on a regimen of sugar and water. Comparatively, females mate and produce fertile eggs when given pea aphids prior to pairing. Males do not require a specialized diet around mating season and can keep a diet of sugar and water in order to produce fertile matings. The survival of the eggs of the Chrysopa oculata is determined by factors such as cannibalism and predation. One way in which it does this is by laying eggs with stalks (Tauber and Tauber 1973). The first instar larvae of Chrysopa oculata cannibalize more eggs without stalks than those with. In an experiment, unfed males and females of C. oculata avoided feeding on eggs with stalks, but readily cannibalized those without. The degree of cannibalism is similar in both sexes. Although predation of eggs with and without stalks by hungry adult coccinellids (beetles) is high, the stalks protect the eggs to some extent. The vulnerability of singly laid chrysopid eggs appears to be reduced mainly by their camouflage color and long hyaline stems. Females seem to be able to recognize conspecific eggs by slowly moving their palps along the stalk. Apart from the protective function against predation, stalks may provide some degree of protection against mechanical injury and overheating (Ruzicka 1997).

This is a series of pictures depicting stages of development in Chrysopa oculata.

 Use with permission from This is a photo of an egg on a stalk

Used with permission from larva pulling free from stalked egg

Use with permission from Predacious hatchling

Use with permission from Larvae molting (clockwise from top left)

Use with permission from Fully-developed larvae spinning silk cocoon

Use with permission from Some larvae pupated without having completed their cocoons. The tan-colored, freshly molted pupa gradually turns green. (left-to-right and top-to-bottom)

Use with permission from The mobile pupa in the first image had located a suitable perch. The exuvium is visible in the next image as the thin film over the abdomen. (left-to-right, top-to-bottom)

Use with permission from The legs are pulled free, followed in by the wings, antennae, and abdomen.

Use with permission from gradual expansion of the wings

Use with permission from Adult Chrysopa oculata, ready to fly, feed, and search for a mate to continue the life cycle




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