Immature stages of the gallerDiplolepis triforma(Hymenoptera: Cynipidae) with comments on the role of its prepupa

Abstract

Sections of stem galls induced by Diplolepis triforma Shorthouse and Ritchie obtained by plant histological techniques were used to examine anatomical features of immature stages of the insect found in situ. First-instar larvae feed over the entire surface of larval chambers, whereas maturing larvae feed only at one end of the chambers. Last-instar larvae undergo two phases of development: feeding occurs in the first phase, whereas in the second, or prepupal phase, feeding has ceased, the mid- and hind-guts become joined, contents of the gut are voided, and compound eyes, gonads, and internal ovipositional apparatus begin to differentiate. The prepupal phase also consists of two phases: the first occurs in the fall and winter, and the second occurs in the spring prior to pupation. The spring phase exhibits external adult features within the integument of the last-instar and moults to the pupa. Sections of some maturing larvae contained endoparasitoid larvae of the genus Orthopelma Taschenberg (Hymenoptera: Ichneumonidae).

Development of stem galls induced byDiplolepis triforma(Hymenoptera: Cynipidae) onRosa acicularis(Rosaceae)

“…Each new generation of D. triforma begins in the early spring, when the overwintering prepupae pupate and adults emerge within their chambers and chew an exit channel to the outside (Shorthouse and Leggo 2002). Adult cynipids are unusual among insects in that they possess active mandibles for chewing plant tissues but do not eat.…”

“…Adults emerge from pupae in the spring (Shorthouse and Leggo 2002) and chew a tunnel to the outside. The appearance of adults is synchronized with the presence of host tissues at a stage suitable for oviposition.…”

Galls induced by cynipid wasps of the genus Diplolepis (Hymenoptera: Cynipidae) on the roses of Canada's grasslands

“…Both larvae and galls are mature by mid-August when the larvae enter an overwintering pre-pupa stage (Shorthouse and Leggo 2002). The pre-pupa is a transition stage between a larva and a pupa in which eyes ( Fig.…”

“…The pre-pupa is a transition stage between a larva and a pupa in which eyes ( Fig. 13) and reproductive organs begin to form (Shorthouse and Leggo 2002). The pre-pupae turn into white pupae (Fig.…”

The community members associated with rose gall wasp Diplolepis fructuum (Rübsaamen, 1895) (Hymenoptera: Cynipidae) in Tokat Province of Turkey

“…The galls of Diplolepis mature in mid-August and the larvae enter the overwintering prepupal stage (Shorthouse and Leggo, 2002). Collected galls are supposed to be mature in order to let the larvae feed and grow into adults; therefore, spring and autumn are proper seasons for collecting (Shorthouse, 2010).…”