Hypsipyla grandella, the Meliaceae shoot borer, is one of the most important forestry plague in the Neotropics. It attacks cryptically the apical meristem of species of Meliaceae, as Cedrela, Swietenia and Carapa. Its damages forks the trees and the most valuable log, with subsequent financial losses in forestry projects, reaching up to 100% trees of a forest plantation, making it unfeasible high-density plantations. Its distribution matches that of its hosts (^{Newton et al., 1993}).

^{Newton et al. (1993)} reported cases where full control of H. grandella was accomplished with cultural practices, shading effects, fertilization and growth improvement; however, the mechanisms were not well understood. Integrated pest management (IPM) practices for H. grandella requires further knowledge on its biology, including interaction with its hosts and natural enemies. Some studies regarding the control of H. grandella were carried out in South America. In Colombia M. hypsipylaphagous Herrera-Florez was described and recorded as parasitoid of pupae of H. grandella (^{Herrera-Florez et al., 2017}). ^{Sands & Murphy (2001)} reported some natural enemies of H. grandella. It is register for the first time Zethus schadei as a predator of pupae and larvae of H. grandella.

Terminal shoots of Cedrela odorata bored by H. grandella were collected in a plantation established in a protective forest reserve called “Reserva Forestal Protectora Regional La Montaña” (06°28’48.18”N, 074°39’28.80” W) managed by Corpoica, Research Center “El Nus”, San Roque (Antioquia, Colombia), located in a humid tropical forest at 850 m.a.s.l. The mean multiannual precipitation is 2,223.32 mm, and temperature is 23 °C. Cedrela odorata was planted without shade with at 6 x 6 m. Shoots were collected on February 15^th 2016 and 25 individuals of H. grandella (larvae and pupae) were obtained. Specimens were left inside the shoots in 15 x 2.5 cm glass Petri dishes at room temperature; various shoots were placed in the same dish. Larvae turned into pupae in few days (7 days), obtaining 15 adults of H. grandella and one adult-female of Z. schadei. The same process was repeated on October 10^th and on November 15^th 2016. Six H. grandella larvae and one Z. schadei adult-female were obtained on October; and four H. grandella larvae and one Z. schadei adult-female on November.

Voucher specimens are deposited in Museo Entomológico Francisco Luis Gallego. H. grandella specimens were identified with the description of ^{Heinrich (1956)} (catalogs number 27911 to 27924); Z. schadei specimens (Figure 1) were identified with the taxonomic keys by ^{Bohart & Stange (1965)} (catalogs number 36533 and 36534).

Figure 1 Zethus schadei^{Bohart & Stange 1965}. 

Figure 2 Zethus schadei^{Bohart & Stange 1965} pupa at the bottom of a Cedrela odorata shoot bored by Hypsipyla grandella. A membrane in the upper side of Z. schadei was present. 

Little is known about the reared insects. One pupae of Z. schadei were found at the bottom of the shoots burrowed by H. grandella, with a membrane on its upper side (Figure 2). Zethus wasps are predators, mostly solitary, some subsocial. Females collect small caterpillars to take to their nests to feed their larvae. They are attracted by Compositae flowers; some species build extremely specialized nest with mud and masticated and salivated vegetal material, other species build their nest inside twigs, wood or in the ground. Zethus is mainly distributed in tropical areas. Z. schadei has been reported in Peru and Paraguay (^{Bohart & Stange, 1965}; ^{Hermes, 2012}). This is the first report of Z. schadei for Colombia.

Few days after H. grandella lays its eggs, the larvae hatch and start looking for a place to bore, usually the terminal shoot of the tree that later dies. Attacked terminal shoots and new ones must be pruned to ensure one leading terminal shoot in order to obtain the first log in good quality. When attacked branches are cut, usually its inhabitants die, i.e. H. grandella and its natural enemies. The presence in the forest of the natural enemies here reported indicates that the H. grandella population is being controlled, decreasing future attacks and the need for pruning; knowledge of its bionomics will provide information important to add to current IPM schemes.