|Cherry Lace Bug – Corythucha pruni |
Order Hemiptera / Suborder Heteroptera / Family Tingidae
Bugs Main | Bugs Index | Assassin Bugs | Plant Bugs | Ambush Bugs
Live adult bugs photographed in the wild at Allegheny Nat’l Forest, Pennsylvania, USA.
This adult lace bug is 4mm (1/8 inch) long with an elaborately sculptured PFE (Posterior flattened evagination of the pronotum) which, along with the forewings, have tiny clear cells that form a lacelike covering, hence the name “lace bugs.” Many lace bugs are multicolored with a distinctive, species-specific pattern of a dark, pale, and clear areas. The wingless nymphs are smaller, oval, and commonly have body spines. Adults and nymphs occur together in groups on the underside of leaves .
Both nymphs and adults live on the lower surface of leaves and suck juices through slender, piercing mouthparts. This produces yellow or whitish spots on the upper surface of the leaf. As the insects feed, they deposit a hard, varnish-like excrement onto the leaf surface. These are called tar spots or resin spots .
Lace bugs feed on many plants, but each species feeds on a very limited variety of hosts 
Image courtesy PLoS 
Many treehoppers can be indentified by their distinctive prototum, which often manifests spines, bulbs, “thorns” and other bizarre structures. A spectacular hypothesis was published recently in the Journal Nature, asserting the â€œhelmetâ€ (a dorsal thoracic sclerite) of treehoppers is connected to the 1st thoracic segment (T1; prothorax) via a jointed articulation and therefore was a true appendage . Furthermore, the helmet was interpreted to share multiple characteristics with wings, which in extant pterygote insects are present only on the 2nd (T2) and 3rd (T3) thoracic segments. In this context, the helmet could be considered an evolutionary novelty .
Although multiple lines of morphological evidence putatively supported the helmet-wing homology, the relationship of the helmet to other thoracic sclerites and muscles remained unclear. Observations of exemplar thoraces of 10 hemipteran families (table 1) reveal multiple misinterpretations relevant to the helmet-wing homology hypothesis as originally conceived: 1) the helmet actually represents T1 (excluding the fore legs); 2) the â€œT1 tergumâ€ is actually the anterior dorsal area of T2; 3) the putative articulation between the â€œhelmetâ€ and T1 is actually the articulation between T1 and T2 .
The researchers concluded that there is no dorsal, articulated appendage on the membracid T1. Although the posterior, flattened, cuticular evagination (*PFE) of the membracid T1 does share structural and genetic attributes with wings, the PFE is actually widely distributed across Hemiptera. Hence, the presence of this structure in Membracidae is not an evolutionary novelty for this clade .
*PFE = Posterior flattened evagination of the pronotum
The presence of the T1 “wing” in treehoppers is discussed as an evolutionary novelty that appeared very early during the evolution of Membracidae. Although non-articulated T1 cuticular outgrowths, which resemble wings of T2 and T3 structurally, are present in numerous non-membracid hemipterans (e.g., Tingidae right), a detailed morphological examination of the Heteroptera pronotum has never been published. Since these cuticular outgrowths were considered as possible precursors of the treehoppers’ â€œhelmetâ€ a detailed examination of the Heteroptera pronotum is critical for accurate interpretation and contextualization of the results .
CLSM = Confocal laser scanning microscopy
PFE in lace bugs (Tingidae) – More images at PLoS
Lace bugs can be divided into two groups – those that attack deciduous trees and shrubs and those that attack evergreen shrubs. Lace bugs that attack deciduous plants spend the winter in the adult stage by hibernating on the plant under bark or near the plant in leaf litter. Lace bugs that attack evergreens overwinter in the egg stage attached to the leaves.
The hawthorn lace bug is one type that attacks deciduous plants. The adults hibernate under loose bark of their host plants as well as among leaf litter. They become active in early to mid-May and return to the new leaves. The females soon begin to lay eggs along the larger veins on the lower leaf surface. The females may lay eggs for a considerable time, often extending into June. The eggs hatch in a couple of weeks and the nymphs cluster together and feed. Each nymph sheds its skin (molts) five times before the adult stage is reached. Growth to the adult stage usually takes three to four weeks. Peak numbers of this pest are usually present in July. Only one generation occurs per year. Related species of lace bugs such as the oak, sycamore and hackberry lace bugs have two and occasionally three generations in a summer.
The azalea lace bug (an example of a lace bug that attacks evergreens) overwinters in the egg stage. The eggs are partially inserted into the leaf tissues along the midvein and are covered with the resin-like excrement of the female. The nymphs hatch in the spring, usually mid-May, after the danger of frost is over. They feed in small groups on the under surface of leaves and molt five times before becoming adults. The adults mate and lay eggs for a second generation by mid to late-July. Often there is a third generation in the late summer and early fall. The Andromeda and rhododendron lace bugs have similar life cycles .
Order Hemiptera: True Bugs number almost 5,000 species in North America, and 40,000 worldwide. They have mouthparts formed into a beak, adapted for sucking plant juices or the liquefied insides of their animal prey.
Suborder Auchenorrhyncha – Cicadas & Planthoppers
Suborder Sternorrhyncha – Aphids, scales, mealybugs, jumping plant lice.