Lilac/Ash (or Ash/lilac) Borer(Podosesia syringae)Latin Name: Podosesia syringae
Common Name: Lilac/Ash (or Ash/lilac) Borer
Appearance:
The ash borer, Podosesia syringae, is sometimes known as the lilac borer; however, serious damage to young ash trees is more prevalent in Iowa than lilac bushes. This bug will eat private and mountain ash as well.
The ash/lilac borer adult is uncommon in that it is a day-flying moth that looks like a typical paper wasp in color, size, form, and flight patterns.
Because the moth lacks the characteristic scales found in other moths, it is called a “clearwing” moth.
The forewings are smoky brown with a black border, whereas the hind wings are transparent with a dark border.
The overall length of the wings is 1 to 1 1/2 inches. When fully developed, the larvae are creamy-white with a brown head, have three pairs of segmented legs and multiple pairs of fleshy prolegs, and are one inch long.
Larvae are around 1 inch (2.5 cm) long and have a brown head.
Host plants:
The main hosts are lilac (Syringa spp. ), ash (Fraxinus spp. ), mountain ash (Sorbus), and privet (Ligustrum spp. ); however other members of the olive family (Oleaceae) may also be used on occasion.
Territory:
It is found throughout North America
Damage caused by Lilac/Ash Borer:
Borer infestations are most common in the lowest third of the host, from the soil level to 3 feet high. When ash trees are young, they are frequently attacked, and infections in trees larger than 6 inches in diameter are uncommon. Borers inflict structural damage to trees, causing them to shatter during storms. Trees that are small and heavily assaulted may be killed altogether. Larger lilac stems are preyed upon. Swollen, unattractive regions indicate borer activity on stems.
Life history and Habits:
The larvae of ash/lilac borers overwinter on afflicted trees and shrubs. Pupation takes place in the spring. Moth emergence typically begins in mid-to-late-April, peaks in May, dwindles in mid-to-late-June, and concludes in the first week of July. The moth has transparent wings and has the appearance of a wasp. It measures roughly 1″ in length and has a wingspan of 112 inches. Moths lay their eggs in bark cracks and fissures. It takes about 10 to 14 days for them to hatch. Frass builds up around holes. Repeated infestations are accompanied by swelling and cracking of the bark, and branches may be severely damaged at feeding locations. Terminal branches of affected plants perish during dry spells in late summer. Every year, there is a new generation.
