Ezzat (1956) and Green (1922) described I. insignis (as Orthezia insignis) in detail. Body of adult female is about 1.5 mm long and 1.3 mm wide (excluding the ovisac), brownish olive green;dorsum mostly bare of wax except for two narrow logitudinal rows of 12 small white wax processes, these rows situated on either side of the mid-line;the dorsal wax processes fairly short, the longest and most curled occurring towards the posterior end. Venter with white waxy areas around mouthparts and limb bases, and the white ovisac of sculpted wax arising from just posterior of the hind leg coxae and from a submarginal belt around the abdomen. Ovisac 1.5 - 3.5 mm long, of brittle wax plates, nearly parallel-sided, curving slightly upwards posteriorly, ending in a dorsal opening. Unlike most Coccoidea, I. insignis carries the ovisac attached to the body, rather than attaching it to the substrate. Antennae are 8-segmented, brownish, about 0.9 mm long, terminal segment longest. Eyes each situated on a conical projection just posterior to each antenna base.
Immature females lack any development of the ovisac but otherwise resemble smaller versions of the adult;first instar with body 0.3 mm long, antennae each 6-segmented, lacking ventral waxy areas and without bare area between dorsal rows of wax plates;second instar similar but larger;third instar larger again, with 7-segmented antennae and ventral waxy areas present.
Males are seldom produced (Green (1922) observed them produced at approximately four-year intervals in Sri Lanka). Adult male with body (excluding terminal wax filaments) 2.0 mm long;the single pair of wings appears greyish white with powdery wax;a pair of halteres present;antennae each 9-segmented, significantly longer than body, covered with short hairs;a pair of compound eyes present, each associated with a single ocellus;mouthparts absent;legs long and slender;abdomen terminates in a caudal tuft of white wax filaments arising from the antepenultimate segment.
Examine shrubs or trees closely for signs of sooty mould or sticky honeydew on leaves and stems, or ants running about. Look for I. insignis on twigs and stems (and sometimes on the underside of leaf midribs);the white ovisacs of the adult females are easily seen, especially when they walk about and the moving ovisacs catch the light. Good light conditions are essential for examination;in poor light, a powerful flashlight is helpful.
Related invasive species
- Insignorthezia insignis
Related Farm Practice
- Pests
- Hosts
- Movement
- Development
- Windbreaks
I. insignis extracts large quantities of sap, causing general host debilitation, but not death (Green, 1922). Build-up of sticky honeydew deposits occurs on nearby surfaces, which may attract attendant ants. Unsightly sooty moulds grow on the sugary deposits (Green, 1922), and badly fouled leaves may be dropped prematurely and the quality of fruits may be reduced. The older females are easy to see on young stems, especially when they walk about and the movement of the white ovisacs catches the light.
I. insignis is polyphagous, usually preferring woody hosts, occurring mainly on the shoots and twigs. Ben-Dov et al. (1998) list hosts from 34 plant families. It is most often found on trees and shrubs of the Verbenaceae (especially Lantana, Clerodendron and Duranta species), Solanaceae (especially Capsicum and Solanum), Acanthaceae, Compositae (especially Eupatorium and other ornamentals) and Rubiaceae (including Coffea). Green (1922) remarked that, while I. insignis damages numerous ornamental plants in Sri Lanka, it was not a pest on tea or coffee. Ezzat (1956) successfully reared I. insignis on sprouting potato tubers in Egypt, where he recorded the pest damaging a wide range of crops and utility plants such as sugarcane, Citrus, potatoes, tomatoes, chrysanthemums, shade trees such as Jacaranda, and windbreaks such as Casuarina.