Prodenia litura (Fabricius)

Swezey, O. H., 1946, Lepidoptera, Geometridae, Arctiidae, Agrotidae, and Pyralidae of Guam, Insects of Guam II, Honolulu, Hawaii: Bernice P. Bishop Museum Bulletin 189, pp. 163-185 : 166-167

4. Prodenia litura (Fabricius) .

Noctua litura Fabricius, Syst. Ent., 601, 1775.

Prodenia litura, Hampson, Cat. Lep. Phalaenae 8: 245, 1909.

,Although caterpillars or their work were found in every garden we visited in the different districts of the island, the moths of our collection were obtained mostly at Agana and Piti as follows: Agana swamp, May 4, reared from caterpillars on taro, Swezey ; Machanao , June 2, reared from caterpillars on tobacco, Swezey ; Piti , Aug. 13 , Sept. 3, at light, Swezey ; Piti , Oct. 25 , Nov. 24, reared from caterpillars on banana, Swezey .

This is called the cotton moth in Egypt. It is a pest in the tropics around the world. It does not yet occur in Hawaii, but is known in most islands of the Pacific. It was collected by Fullaway in 1911 but not recorded at the time. It was first recorded there in 1927 as a pest on taro. In 1936, caterpillars were found on a large variety of host plants, taro, banana, tobacco, tomato, onion, bean, cabbage, corn, and amaranth. More were found on banana and taro than on other plants, but they were not numerous enough to cause extensive injury. In cages, caterpillars fed and thrived on morning-glory, pumpkin, and papaya leaves, but none were found on these plants in the open. The eggs are laid in large clusters of one layer on the under side of the leaves. One cluster contained "1,224 eggs, but the usual number was 200 to 400. On hatching, the larvae feed gregariously for a time, but eventually scatter. While small, they eat only the surface of the leaf, but when larger consume the whole substance of the leaf blade.

The full-grown caterpillar is about 35 to 40 mm., of a general mottled fuscous coloration with two dorsal lines of segmental black marks, wide apart, and the marks usually have yellow on their ventral edge. The spiracles are black and situated in the ventral edge of fuscous spots, a whitish dot is situated above and a little behind each. Apparently very few of the caterpillars reached maturity, as large-sized caterpillars were never found in proportionate abundance to the number of young hatching from the egg clusters. It is likely that the abundant Polistes and Icaria wasps were preying on them while still of small size, though we did not observe them doing this. These· wasps were in such abundance as to require quantities of caterpillars as food for their young, and young Prodenia caterpillars would furnish the most ready supply for them.

While we were in Guam a supply of the egg-parasite Telenomus nawai was sent from the Experiment Station, Hawaiian Sugar Planters' Association, Honolulu. These parasites readily bred on Prodenia eggs, and were reared for distribution at the Agricultural School until they became well established.