INTERESTING INSECTS

By N A Martin (2017)

Astelia lacebug

This endemic lacebug is found on both main Islands and some off-shore islands on its host plants, Astelia species (Asteliaceae). Both the nymphs and adults feed on the leaves. It has only been found in native ecosystems.

Conservation status: Widespread, not threatened.

After discovering the first host plant of the Astelia lacebug, Brenda May, a DSIR entomologist, studied its biology. Both males and females were on plants in January and February. Numbers of adults declined through late summer and Autumn. A few females survived the winter. Egg laying occurred mainly from January to July. Eggs hatching started in mid-September. Nymphs were on plants during spring and early summer. They took 5-6 weeks from egg hatch to becoming adults. Captive females laid about one egg per week, but wild females may lay more eggs per week when living on healthier leaves. There is only one generation per year.

Adults

The adults are small, about 3.2 mm long and 2.1 mm wide. They have clear gauzy wings held horizontally over a dark abdomen. The head and thorax, middle part of the body, are also dark brown. There are two long antennae and three pairs of legs. The wings and upper side of the body are covered in elaborate sculpting. The head for example has five pale forward pointing spines. There is a rostrum on the underside of the head that holds the stylets (rods) used for feeding. When it is not being used, it is held in a groove between the legs.

Eggs and Nymphs

The female lacebug inserts eggs into Astelia leaves. The yellowish egg is approximately cylindrical, about 0.5 mm long, and has a flat top, operculum. A small pale nymph emerges by pushing the operculum off the top of the egg with the aid of an 'egg burster'. There are four nymphal stages, each is called an instar. Nymphs go from one stage to the next by moulting (changing their skin). During moulting, the skin on the dorsal side splits and the next stage pulls itself out of the old skin. Like the adult, the nymphs have three pairs of legs, a pair of antennae and a rostrum with the stylets for feeding, but no wings. The older nymphs have wing buds. The bodies of the nymphs are covered by a variety of special seta (hairs), spines and growths. The second, third and fourth instars are covered with white stellate hairs. When the fourth instar nymph is fully grown, it moults into an adult. The tip of the underside of the fourth instar nymph is different in males and females.

Walking and flying

Nymphs and adults have three pairs of legs. Adults have two pairs of wings. The adults are reluctant to fly, but flying is how they disperse to new host plants.

Feeding

Like other Hemiptera, the Asterlia lacebug has piercing and sucking mouth parts. The long stylets, special shaped rods, are held in the rostrum. When it wishes to feed the bug moves the tip of the rostrum to a suitable part of the plant. The stylets are then gradually pushed into the plant. The stylets form two tubes, one through which saliva is injected into the plant and a second through which plant juices are sucked up into the insect. Astelia lacebug feeding has not been studied, but the damage to leaves show that they feed on the cells in the leaf. They probably use their saliva to digest the plant cells.

Adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9H]

Upper side of an adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9E]

Underside of an adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9B]

Upper side of an adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9D]

Underside of an adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9C]

Side view of an adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9F]

Drawing of an egg of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) containing a pre-emergent wasp parasitoid (Hymenoptera: Mymaridae). Creator: Brenda May. © Drawing published in Journal of the Royal Society of New Zealand. 7: 303-312, Fig. 11. [Image: 2IA0]

Drawing of a first instar (stage) nymph of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Brenda May. © Drawing published in Journal of the Royal Society of New Zealand. 7: 303-312, Fig. 5. [Image: 2I9Y]

Drawings of a second and third instar (stage) nymph of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) Creator: Brenda May. © Drawing published in Journal of the Royal Society of New Zealand. 7: 303-312, Figs. 6 & 7. [Image: 2I9Z]

Photographs of fourth instar (stage) nymph of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: DSIR Photographers. © Photographs published in Journal of the Royal Society of New Zealand. 7: 303-312, Figs. 4 a-d. [Image: 2I9X]

Nymphs of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf: first instar (stage) (left), 1st instar moulted skin (centre), second instar (right). Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9L]

Nymphs of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf: first and second instars (stages) (left), third instar (centre and right). Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9P]

Moulted skin of a second instar (stage) nymph of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Nicholas A. Martin. © Landcare Research. [Image: 2I9U]

Moulted skin of a third instar (stage) nymph of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Nicholas A. Martin. © Landcare Research. [Image: 2I9V]

Fourth instar (stage) nymphs of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9Q]

Fourth instar (stage) nymphs of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf: note the 'facial' protruberances. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9T]

A recently moulted adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf. Creator: Darren Snaith. © Plant & Food Research. [Image: 2I9R]

Leaf of Astelia trinervia (Asteliaceae) with yellow spots from feeding by Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2I98]

There are only three species of Tingidae in New Zealand. The Rhododendron lacebug, Stephanitis rhododendri Horváth, 1905, was brought to New Zealand accidentally with Rhododenron plants, while the Woolly nightshade lacebug, Gargaphia decoris Drake, 1931, was deliberately released to help control Woolly nightshade, Solanum mauritianum (Solanaceae). The Astelia lacebug is the only native species of the Family in New Zealand and only breeds on leaves of some species of Astelia (Asteliaceae).

The Astelia lacebug adults and nymphs are usually found on the underside of leaves, but their presence on a plants is usually revealed by yellow spotting on the upper side of leaves. The adults have a black body under distinctive gauzy wings. There are four distinctive nymphal stages, instars.

Leaves of Astelia banksii (Asteliaceae) with yellow spots from feeding by Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2I99]

Leaf of Astelia banksii (Asteliaceae) with yellow spots from feeding by Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2I9A]

Adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on the underside of an Astelia (Asteliaceae) leaf. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9J]

Adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on the underside of an Astelia (Asteliaceae) leaf: note the pale spines on the head. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9K]

Side view of an adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae): note the pale spines on the head. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9G]

Drawing of a first instar (stage) nymph of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Brenda May. © Drawing published in Journal of the Royal Society of New Zealand. 7: 303-312, Fig. 5. [Image: 2I9Y]

Drawings of a second and third instar (stage) nymph of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) Creator: Brenda May. © Drawing published in Journal of the Royal Society of New Zealand. 7: 303-312, Figs. 6 & 7. [Image: 2I9Z]

Photographs of fourth instar (stage) nymph of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: DSIR Photographers. © Photographs published in Journal of the Royal Society of New Zealand. 7: 303-312, Figs. 4 a-d. [Image: 2I9X]

Nymphs of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf: first and second instars (stages) (left), third instar (centre and right). Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9P]

Two fifth instar (stage) nymphs of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9N]

Moulted skins of first and second instar (stage) nmphs of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on underside of an Astelia (Asteliaceae) leaf. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9M]

One egg parasitoid has been found, a tiny wasp in the family Mymaridae. Adults and nymphs of the Astelia lacebug are likely to be eaten by birds, spiders and predatory insects.

Drawing of an egg of Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) containing a pre-emergent wasp parasitoid (Hymenoptera: Mymaridae). Creator: Brenda May. © Drawing published in Journal of the Royal Society of New Zealand. 7: 303-312, Fig. 11. [Image: 2IA0]

The Astelia lacebug only feeds on leaves of Astelia species (Asteliaceae). Brenda May, a DSIR entomologist was the first person to find a host plant. She only found it feeding and breeding on Coastal astelia, Astelia banksii. It has since been found on two other species.

Feeding

Like other Hemiptera, the Asterlia lacebug has piercing and sucking mouth parts. The long stylets, special shaped rods, are held in the rostrum. When it wishes to feed the bug moves the tip of the rostrum to a suitable part of the plant. The stylets are then gradually pushed into the plant. The stylets form two tubes, one through which saliva is injected into the plant and a second through which plant juices are sucked up into the insect. Astelia lacebug feeding has not been studied, but the damage to leaves show that they feed on the cells in the leaf. They probably use their saliva to digest the plant cells.

Leaf of Astelia trinervia (Asteliaceae) with yellow spots from feeding by Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2I98]

Leaves of Astelia banksii (Asteliaceae) with yellow spots from feeding by Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2I99]

Leaf of Astelia banksii (Asteliaceae) with yellow spots from feeding by Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2I9A]

Adult Astelia lacebug, Tanybyrsa cumberi (Hemiptera: Tingidae) on an Astelia (Asteliaceae) leaf. Creator: Tim Holmes. © Plant & Food Research. [Image: 2I9I]

Drake,C.J. 1959: A new tingid from New Zealand (Hemiptera). Transactions of the Royal Society of New Zealand: 87(1-2):67-68.

May BM. 1977. The immature stages and biology of the lacebug Tanybyrsa cumberi. Journal of the Royal Society of New Zealand. 7 (3): 303-312.

Plant-SyNZ: Invertebrate herbivore-host plant association database. plant-synz.landcareresearch.co.nz/.

The New Zealand Plant & Food Research Institute Limited (Plant & Food Research) for permission to use photographs.

Landcare Research New Zealand Limited (Landcare Research) for permission to use photographs.

1 December 2018. NA Martin. Changed symbol used for apostrophes.