Invasive Species Compendium

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Abstract

Insects on Corn and Teosinte in Guatemala.

Abstract

Among sou.e 180 mseets- collected in Guatemala in late summer in 1951 and 1952 on maize or tuosinte (Euchlatna mexicana), which is native to the region and the w 1d plant most nearly related to maize, only 93 could be identified to specx's 66 from maize, 12 from teosinte and 15 from both. A systematic list ot these is given, with notes on the circumstances in which they were obtained and in some cases on their bionomics and importance. The insects that were most destructive to the growing maize were species of Diabrotica and related genera, Diatraea lineolata (Wlk.) and D. saccharalis (F.), Euxesta major Wulp, and Laphygma frugiperda[Spodoptera frugiperda] (S. & A.), which was by far the most conspicuous pest of all.
D. saccharalis was more abundant than D. lineolata in most areas. The eggs of both species were laid in masses, and the larvae skeletonised the leaves in the whorl, tunnelled in the stems and attacked the pith, but rarely the kernels, in the ears, leading to rotting. Oviposition also occurred on teosinte. Eggs collected on maize at one place were heavily parasitized, possibly by Trichogramma minutum R il., cocoons of Apanteles diatraeae Mues, were common in the larval burrows, and an unidentified Muscoid fly was apparently parasitic on the larvae. A. diatraeae was itself parasitized by Horismenus floridanus (Ashm.), and the puparia of the Muscoid by Trichopria sp. Paratheresia claripalpis (Wulp), which is known to parasitize species of Diatraea, was present in several areas. The predators observed included the Carabid, Leptotrachclus testaceus puncticollis Bates, and probably the pseudoscorpion, Lustrochernes rcimoseri Beier, and the earwig, Doru lineare (Esch.), both of which were observed breeding in Diatraea burrows.
Young larvae of Laphygma frugiperda[Spodoptera frugiperda] fed in the whorl and on the developing tassel, and older ones burrowed in the stem and ear shoots and fed on the kernels in the developing ears. The females are known to lay up to 5, 000 eggs each in groups of 40 or more 011 the upper part of the stem, and the larvae pupate in the soil or under débris. The Tachinid, Achaetoneura archippivora (Will.), was reared from the larvae in considerable numbers, and the Carabid, Onypterygia faminii Solier, was observed attacking them. The corn earworm, Heliothis zea[Helicoverpa zea] (Boddie) (armígera, auct., umbrosa Grote [cf. R.A.E., A 42 421]) was in general not numerous on maize.
Larvae of E. major were observed in the bases and tips of the oars as well as in the buds, and also attacked teosinte. Frankliniella williamsi Hood, which caused severe damage to seedlings of maize and teosinte, was controlled by sprays of 4 1b. DDT or 4 o/ aldrin or dieldrin per 100 U.S. gals.