Leptoglossus occidentalis (western conifer seed bug)
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Leptoglossus occidentalis Common name: western conifer seed bug Family: Coreidae Host plants: conifers & angiosperms Adult size: 0.65 – 0.8 inch (16-20 mm) |
| Life Cycle: one generation per year (see Special Notes below) adult – overwinter egg – 10 days nymph – 5 instar stages lasting about 8 weeks
Description: Adults emerge from their overwintering spots in mid-May to early June. A few days later, females start to lay their eggs in small groups on conifer needles and leaf stems of garden plants. Eggs hatch in 10 days. The young nymphs go through 5 instar stages as they feed on conifer needles and the tender tissue of cone scales. During the latter instar stages, when the nymphs have developed their piercing and sucking mouth parts, they will feed on developing conifer seeds. The final moult into adults occurs by mid-August. Adults are varying shades of brown and look quite similar to assassin bugs and shield bugs. Their abdomen, which is revealed when they fly, is yellow or orange in colour with five black lines clearly defined and running horizontally across the body. This is a true bug. They belong to a small group of insects called the leaf-footed bugs. This name comes from the flat, leaf-like expansions on their hind legs.
Special Notes: First identified in its native range of California, Oregon and Nevada in 1910. Species began to expand its range eastwards and northwards in the 1950s…reaching into Canada in 1985 and the eastern seaboard by 1987. Discovered in northern Italy in 1999, it then began traveling throughout Europe (France, Spain, Switzerland, Austria, Belgium, Germany, Hungary, Poland, Czech Republic, Slovenia and Croatia). By 2008, it was found in Tokyo, Japan and in 2009, Istanbul, Turkey. It is also making its way through England as well as Mexico…and possibly other tropical regions. Because of its expanded range, the life cycle of this bug varies. In its native warm, temperate regions there is only one generation per year. This holds true for other regions of similar weather patterns. However, in some parts of Europe there are two generations per year…and in Mexico and other tropical areas, there are three generations per year. Status: I have listed this bug under “Beneficial” as it has a purpose in Nature’s grand scheme of things. However, it can become a bit of a pest to conifer plantations where it can cause damage to the developing seed cones through feeding on the sap. They can also be a nuisance for their propensity of over-wintering in our homes, whenever and wherever they can find an opening to squeeze through. They are perfectly harmless, however, except when they are startled or touched. They will then emit an unpleasant pungent, acrid odour.
Posted on September 12, 2014 |
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Malacosoma californicum pluviale (northern tent caterpillar)
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Malacosoma californicum pluviale Class: Insecta Host plants: broad-leaved deciduous hardwood trees Adult size: moth wingspan = 1-1.5 in (2.5-3.8cm) |
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Life cycle: one generation per year
Description & Life Cycle: Young larvae emerge in spring coinciding with the leaves unfurling on hardwood trees. Timing is dependant on regional weather. Just an eighth of an inch long (3mm) and dark in colour, they are distinguishable by the white hairs covering their length. For the next 6 weeks, the larvae eat their way through 5 to 6 instar stages, moulting out of their skin as they outgrow it. With each successive shedding, their distinguishable markings become visible. Down the centre of their back is a network of uniform orange patches, in the centre of which and corresponding to each body segment, is an elliptical light blue-grey patch outlined in dark brownish-black. There are two blue-grey dots in each body segment running down both sides beneath which runs a narrow orange strip. (Note: There can be variations in the markings.) By the end of the 5th or 6th instar stage, the caterpillars measure about 1.75 – 2.2 inches (4.5 – 5.5cm) long. When they are ready to pupate at the end of the 6 weeks, the caterpillars spin cocoons of pale silk, covered in a yellow powdery dust, attached in a sheltered area of a tree or shrub. However, they will also use any convenient, out-of-the-way spot including up under the eave of the house or tool shed. The pupa is dark reddish-brown colour and measures 0.6 – 0.75 inches (1.5 – 2.0cm) long. In 14 – 21 days the adult moth emerges. Stout-bodied adult moths vary in colour from buff yellow to a dark reddish-brown. Forewing is marked with a dark line running at a right angle from the body. Two paler lines run parallel to the outer wing edge and neatly divide the forewing into three equal segments. Wingspan ranges from 1.0 – 1.5 inches (2.5 – 3.8cm). The moths do not feed and only live one to fourteen days. Their sole purpose is to mate. Once a female is fertilized, she lays 150 to 250 eggs in a sixth of an inch (1.5cm) long mass on a small diameter twig. She then encases them in spumaline – a frothy, glue-like substance which hardens and turns a glossy, dark brown colour. This protects the eggs from small predatory insects. Within three weeks, the embryos have developed into phalate larvae. At this stage, they will diapause through the winter inside the eggs.
Special Notes: Malacosoma californicum pluviale are native to North America, more commonly found in the southern half of British Columbia as far east as Quebec and in Newfoundland. Their range also reaches south into the United States, typically west of the Cascade Mountains in Washington and Oregon states. But populations have also been found in the northern parts of Montana, Idaho and several northeastern states. Young northern tent caterpillar larvae form a silky tent in the crotch of a tree branch, usually at the outer reaches of the tree crown…and there can be larvae from more than one egg mass within one tent. As the larvae grow in size, they increase the size of their silky tent. Once they reach the last instar stage, the caterpillars begin to separate from the mass and start to search out suitable pupating spots. Large outbreaks of northern tent caterpillars typically happen roughly every ten to twelve years and can last anywhere from three to six years in a row. The adult moths are nocturnal and highly attracted to lights.
Natural Controls: Predators include frogs, small mammals and a large number of different bird species. There are also a large number of insect predators including bees, wasps, flies, ants, beetles and earwigs that will prey on the northern tent caterpillar throughout various stages of its life span. During large outbreaks numerous diseases are known to develop amongst colonies of Malacosoma species which can be directly attributed to controlling their numbers. One such disease is the nuclear polyhedrus virus, also known as nucleopolyhedrosis virus, or NPV. Often, an infected dead caterpillar will be seen hanging in place from a branch by its mid-section…its body forming an inverted V-shape.
Caution: The yellow powdery dust on the cocoon can cause an allergic reaction in some people.
However, it is not unusual to see the odd mature northern tent caterpillar intermingling with a mass of forest tent caterpillars as they search for a suitable spot to pupate.
Posted on May 31, 2013
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Malacosoma disstria (forest tent caterpillar)
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Malacosoma disstria Common name: forest tent caterpillar Class: Insecta Host plants: broad-leaved deciduous hardwood trees Adult size: moth wing span = 1-1.75 in (2.5-4.5cm) |
| Life cycle: one generation per year egg – overwinter larva – 5 instar stages lasting a total of 5-6 weeks pupation – 10 to 14 days adult – 1 to 10 days
Description & Life Cycle: Young larvae emerge in spring coinciding with the leaves unfurling on hardwood trees. Timing is dependant on regional weather. Just an eighth of an inch long (3mm) and almost completely black, they are distinguishable by the hairs covering their length.
When they are ready to pupate at the end of the 5 or 6 weeks, the caterpillars spin cocoons of pale silk covered in a yellow powdery dust, usually curling up leaf. But they will use any convenient, out-of-the-way spot including up under the eave of the house or tool shed. In 10 – 14 days the adult moth emerges. |
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Contarinia quinquenotata (hemerocallis gall midge)
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Contarinia quinquenotata |
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Class: Insecta Description: The Hemerocallis gall midge is a tiny fly about 0.08 inch (2 mm) in size and greyish-brown in colour with translucent pink wings. Very difficult to see with the naked eye. They emerge from the soil in late April or early May to begin mating. The female has a retractable ovipositor with which she can pierce newly forming daylily flower buds to deposit her eggs inside.
The maggots get to about 0.12 inch (3 mm) long and drop to the ground in July where they spin their silk cocoons in the soil and pupate over the winter. Adults emerge the following spring in late April or early May. There is one generation per year.
Additional information re Hemerocallis gall midge Jump ahead a few years and observation of the gall midge pest has provided some more useful information. Of particular note is the fact that most of the gall midge damage appears to be on the early flowering hemerocallis plants. And yellow seems to be the predominant flower colour under attack, although other colours of daylily flowers can suffer bud damage too. Thank goodness for the good plants people and scientists at the Royal Horticultural Society’s (RHS) Garden at Wisley. There is a large Hemerocallis collection at this garden which came under attack of Contarinia quinquenotata in the 1990s. Meticulous records were kept for a number of years on everything to do with daylilies and the gall midge. One of the results: they were able to assemble an admirable list of daylilies species and cultivars which are able to provide a worthwhile floral display in the garden after the gall midge attacks run their course in late July. Symbols explained: Daylilies:
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