LIFE HISTORY

The Apple Maggot is a common pest in Eastern Canada, attacking apples, plums, cherries, pears, peaches and apricots. The insect usually has one generation per year, but on early maturing apple varieties there may be two generations in some years.

The Apple Maggot over-winters in the soil as a pupa, which develops into an adult fly as the soil temperature rises. The adult emerges from the soil from late June to mid-September, with peak emergence activity occurring in early August.

The adult is about the same size as a housefly and has characteristic red eyes and distinctive wing markings. While wing markings are similar to those of the Cherry Fruit Fly, the end of the Apple Maggot's wing usually has a clear unmarked zone and there are 3(male) or 4(female) white bands on the abdomen.

Within a week or so of emergence, the apple maggot flies become sexually active. After mating, the female deposits between 300-500 eggs singly under the skin of the fruit. Within 3-7 days the larvae emerge from the egg and burrow through the pulp of the fruit, leaving a winding brown trail through the flesh.

The period of larval development in the fruit usually lasts for 3-5 weeks, with the infested apples finally falling to the ground. The larvae then leave the fallen fruit, and enter the soil to a depth of 2-5 cm where they pupate. Some pupae may remain in the soil for up to 5 years before hatching out as adult flies.

TRAP PLACEMENT

Two types of trap are used against the apple maggot adult flies. The first of these is a Yellow AM or Yellow Sticky Trap, which is only attractive to the adults for the first few days after their emergence, while they are feeding and beginning to mature sexually. The second and more important type of trap is the sticky Red Ball Trap. The ball trap attracts sexually mature females looking for a place to deposit their eggs, and when they do so, they become trapped on the sticky coating of the trap. In order to further enhance the attractiveness of the red ball trap, it is strongly recommended that Apple Essence lures also be placed in the orchard.

Although the Apple Maggot fly may hatch out in the orchard, it will tend to move into the hedgerows to find wild host trees before returning to the orchard. As the insect returns to the orchard, it encounters suitable egg-laying areas along the orchard perimeter, which explains in part why 'edge' damage is often more severe. It is important to recognize this fact when using monitoring traps, since the first 'line of defence' should be either on the outer edge of the orchard or even in the adjacent hedgerows.

Hang one Red Ball trap every 10 - 20 metres around the perimeter of the orchard. If severe damage has been encountered in the past, place additional traps in the central part of the orchard. If using the Red Ball trap in an organic farming operation, attach 3 or more Red Ball traps per standard tree, and at least one ball trap per dwarf or semi-dwarf tree. Hang the ball traps at eye level and clean away foliage for about 1/2 metre around the trap to make it clearly visible to the Apple Maggot fly.

The Apple Essence Lure greatly enhances the effectiveness of the Red Ball trap when placed at 10 metre intervals near the trap. The Apple Essence lure will remain effective for the entire season, and will not need replacing until the following year. The Red Ball trap is re-usable and will give many years of service. If the trap becomes covered with flies or debris it should be washed off with mineral spirits and re-coated with the non-drying adhesive. Sometimes the application of two thin coats of adhesive is preferable to one single coating.

The yellow traps are best placed along the outside edge of the orchard or in adjoining hedgerows, since they catch the early emerging insects on or before their return to the orchard.

Traps should be inspected twice a week, and the captured flies scraped off the trap each time. Keep a record of the trap catch for each location and mark this information on your orchard map in order to pinpoint areas of high insect populations.

The guideline for insecticide application is 7-10 days after the first catches on the yellow traps or immediately after the first catch on the Red Ball trap. If using the Apple Essence Lure, the Red Ball trap catch will be about 5 times greater so the spray decision can be based on a trap catch of 5 flies rather than one.

These guidelines are only general in nature, since different locations will determine different courses of action.

LIFE HISTORY

Information can often be found indicating that the life cycle of an insect depends on particular temperatures or humidity or that there is exact period of time in which each stage occurs. In reality it doesn't always occur that way, since different foodstuffs consumed by the insect may result in different development times and different mortality rates. Probably the best information about an insect is that which is gathered over a period of time, at the location being monitored.

The females usually lay about 100 eggs, which hatch into larvae after about 6 - 10 days. This larval stage lasts for 3-4 weeks before the larvae pupate and emerge a week later as new adults. The entire life cycle can take about 120 days at 20o C, but less than a month at higher temperatures. Development usually ceases at temperatures of around 17o C and adults are usually killed after a week at 4oC. Short exposure to cold-storage conditions (-20o C) will also kill the insect.

Lasioderma serricorne is generally found in warmer parts of the world and that means a wide range of foodstuffs can be damaged, including tobacco leaf, cigarettes, oilseeds, pulses, dried fruits, cereal products, spices and some animal products. As international trade develops, we begin to see possible insect 'strains' developing in different areas, often with dietary preferences. A strange example of this was seen when an infestation of Lasioderma beetles ate their way through a shipment of brassieres on their way from Hong Kong to Holland.

TRAP PLACEMENT

The Cigarette beetle is a strong flier and therefore the placement height of the traps is of less importance to the insect than it is to the person monitoring them. Traps should be placed where they will not obstruct normal warehouse traffic. For example, temperatures near the roof may be higher and therefore encourage more insect activity, however these areas are difficult to monitor.

Due to the many variables present in a warehouse, it is preferable to start with traps evenly dispersed throughout the target area, at intervals of 10 and 20 metres. Based on the trap catch, this spacing can be changed to concentrate traps in areas of greater catch, and to reduce those in areas of no catch.

In order to keep a constant attraction pressure on the insects, each trap lure should be replaced every 6 weeks, since after this period the rate of release of pheromone from the lure slows down. Pheromone traps are the usual tool for monitoring, but light traps are also used in some warehouses.

WHAT DOES THE TRAP INFORMATION TELL YOU?

By plotting the catch as a graph, you will see the periods of maximum insect activity and from this it will be possible to identify which areas within the building are showing more activity than others. Subsequent searching in those 'hot-spot' areas can usually lead you to the cause of the problem.

The causes of these problems may be poor sanitation, broken packaging, poor stock rotation or a recent arrival of contaminated product. From this point, good detective work is needed to identify the actual source of the problem. In order to tie in recent events that could have caused the problem, it is very important that the trap information is collected on a regular basis or else it will be difficult to identify those causes.

Over a period of time it will be possible to fine tune the placement of the traps in areas that are most vulnerable, but the main advantage is that the information gained will lead to better hygiene, sanitation and management practices - which in turn will lead to less insect product damage.

TRAP PLACEMENT

• Select which windows you need to trap, and clean an area at the lower edge of the glass pane where you will attach the trap (usually a corner).
• Hold the trap in a horizontal position, with the sealed entrance slot on the upper side. Shake it sideways and lightly tap the sides to get the powder level inside the trap.
• Remove the protective paper from the 2-sided tape on the back of the trap and firmly attach the trap to the glass.
• Very slowly remove the foam pad from the slot on the upper side of the trap

Note: Because the powder in the trap is exceptionally light, it will create a dust if disturbed or spilled. Although the powder is non-toxic, it can make a mess if the trap is tampered with or pulled off the window roughly. Avoid vacuuming near the slot, since this may suck out the powder contents.

The use of powder in an insect trap is a newly patented concept that makes the 'Cluster Buster' a good example of an IPM tool that not only complements, but also monitors the effectiveness of other treatments. The 'Cluster Buster' is made entirely from recycled materials, and is an excellent choice for use in residential and commercial building.

LIFE HISTORY

The Codling Moth is one of the most common pests of apples worldwide, but also attacks pear, crabapple, quince, walnut and certain other fruits. The insect produces 1-2 generations during the season (depending on locality) and overwinters as a late stage larva under the rough bark of the tree trunk, or even in and around apple packing sheds. These overwintering larvae have good low temperature tolerance and those that are found under the tree bark are often 30-60cm above the ground.

Between mid to late April, the larvae pupate within their protective cocoon, and form a hard brownish pupa which hatches into an adult moth between 2-4 weeks later, depending on temperature.

The grayish moths are moderately large (with a wingspan of about 18mm) and appear around the end of May or early June. They can be recognized by bronze chocolate-brown patches on the tips of the front wings, and faint wavy crossbands of brown on the rest of the wings. Mating activity takes place as the evening temperatures increase to about 16°C. The female can lay 300 eggs or more, often singly, on the fruit or leaf surfaces. Eggs hatch out after about 2 weeks (less in very hot weather) and the emerging larvae attack the fruits. At first the larvae may feed on the fruit surface, but eventually they will tunnel into the centre of the fruit and eat the seeds. About 3 weeks later the mature larvae exit the fruit, drop to the ground and make their way to a suitably well-protected place on the bark. Here they spin a protective cocoon. The second generation of adult moths emerge from these cocoons about 2 weeks later (early August) and the life cycle is repeated.

TRAP PLACEMENT

Traps should be placed in the orchard before the first moths emerge (mid-late May). Hang the traps at head height in the trees and space them 30 metres apart.

Monitor regularly (twice a week), record the catch and scrape out the moths each time so that you don't count the same moths next time. Plot the average number of moths caught from all the traps onto your graph to determine the peak population - usually the end of May and again in mid-August. The timing for the first generation spray should be 10-14 days after this peak is reached, and in the second generation, 3-4 days after the peak, since development is often faster. Keep annual records and monitor on the same regular 3 or 4-day cycle all season.

Replace the pheromone lure after 6 weeks. Keep lures in the freezer until ready for use.

LIFE HISTORY

The Tribolium spp. have one of the highest rates of population increase in storage product areas, with the females laying between 2-11 eggs per day for 2 months. The larval stage lasts 2 - 3 weeks and after a short pupation period, the emerging adults feed continuously and mate frequently for the following 6 months.

TRAP PLACEMENT

The adults are winged and can fly well, so initial trapping should be fairly intensive in suspected food storage and processing areas, with traps placed every 5 - 10 metres. These traps can be of various types and can be baited with a pheromone lure or a food attractant, but regular inspections must be made to record the trapcatch. (See monitoring guide #1902-20 'An Overview of Traps and Attractants for Storage and Grain Beetles')

Cannibalism is a factor that helps to control the levels of these two Tribolium insects, and there is often competition between them, and although T. confusum thrives better under cooler conditions, it is usually less successful than T. castaneum.

The aggregation pheromone should be replaced in the traps every 6 weeks to ensure a constant rate of attraction.

Monitoring should continue throughout the year once infestations are found in a storage building, but improved hygiene and sanitation are essential in order to keep the populations under control.

LIFE HISTORY

Grape Berry Moth (GBM) is the major insect pest of grapes in Southern Ontario, accounting for at least 5% and often significantly higher crop damage. In the Niagara region, the insect emerges from it s over wintering pupal stage around the 6th 12th May each year and because there is still very little foliage protection in the vineyard at this time, it seeks shelter in adjacent hedgerows and other sheltered areas. Female GBM s begin releasing their pheromones towards the end of the month, signalling the beginning of mating activity and the commencement of the first of three consecutive generations of this insect. Mated females immediately start depositing their eggs on the flower clusters of the developing grapes. These eggs hatch into larvae about 4 5 days later and the larvae start feeding on the flower clusters for the next 3 4 weeks. During this time of feeding activity, the larvae continue to grow and change colour from near transparent, to white, to greenish and then finally to a brownish colour. The flower cluster will be covered in fine white webbing that easily identifies where this damage is occurring.

Once the larvae reach maturity, they roll themselves up in a segment of the grape leaf and drop to the ground - this is known as the pupal stage. About 4-5 days later a new adult moth emerges from this pupa, thus completing the first generation and launching into the second generation.

In the Niagara region, the adult moths emerge in late-May, early July and midAugust, and in the second and third generations the eggs are laid on the berry clusters. The eggs laid on the berry clusters hatch out into larvae after 2 5 days, and these larvae remain on the surface of a berry for 1-2 days, before eating their way into the flesh of the berry, often eating the pit before moving into the next berry. When inspecting for larval damage, the tiny entrance tunnel into the berry is easy to see, along with the resulting purplish discolouration. After 3 - 4 weeks of feeding, the larva pupates and falls to the ground.

Some grape varieties produce secondary grape clusters that are immature at harvest and may remain on the vine. These green clusters are often full of larvae, and should be destroyed or removed from the vineyard to prevent insect carry-over to the next year.

TRAP PLACEMENT

Every vineyard is different, so there is no exact application rate for monitoring traps, however, in the early stages of gathering information about a vineyard a larger number of traps are often used. On fields of 2 4 hectares at least 6 traps are recommended. These should be evenly spaced, with at least 4 of the traps placed 10 metres in from the edge of the crop and the other 2 traps placed more centrally. If there is adjoining scrub, woodland or buildings that would offer protection to the insects, traps should be put in those areas too. If there are known areas that have shown higher damage these should also be trapped.

The traps themselves are easy to assemble and should be hung on a middle trellis wire, with a marker ribbon at the end of each row that a trap is hung in. Put the traps out in the first week of May and place the lure on the sticky floor of the trap. Number the trap and record the date that it was set up.

CHECKING THE TRAPS

This is the most important part of monitoring. Plan to check traps on a regular basis from May to harvest, at least once but ideally twice a week, otherwise the resulting information can be very misleading. Each time that you inspect a trap, count and scrape out the GBM caught on the trap. Average out the catch for the vineyard and plot it on a graph.

WHAT DOES A GRAPH TELL YOU?

As the adult GBM mating activity increases, so does the trapcatch. The numbers will peak and then quickly fall off, indicating that mating is complete and the females are no longer releasing their sex pheromone but are now laying eggs. Some egg laying will also have occurred by the time the graph peaks, which means that any spray application should be made as soon as you recognize the peak, since at this point some of the first laid eggs will be hatching into larvae. And they will be most vulnerable before they bore into the grapes.

For the next 3 - 4 weeks you cannot expect to see any catch in the traps, since the insect will either be in the larval stage or have died off. At this point you should try to establish a threshold for determining whether or not to spray, but this is not easy to do before you have accumulated some vineyard history. As a suggestion, you could decide to spray only if the average trapcatch for the vineyard at the peak is greater than 2 insects per trap otherwise a border  spray is probably adequate. Towards the end of each larval period, and before the next generation of adult moths emerges, replace the lure in the trap with a new one (it may not be necessary to change the trap).

SAMPLING FOR LARVAL DAMAGE

If you have decided to spray, check the success of the chemical application by sampling for berry damage after the safe re-entry period. For the first generation, there will be no berries, therefore a count should be made of the percentage of clusters that show webbing damage. Remember that the majority of damage will be in the outside 15 metres of the crop and that there will be pockets of damage known from previous years. For this reason biased sampling is preferable to totally random sampling, so long as large areas of the vineyard are not ignored.

At the same time that you would normally check your traps (which will now be catching nothing) select one or two sampling blocks, each made up of 3 vines x 3 rows. Inspect 10 clusters on each vine by looking for the holes and the purplish discolouration. Record the number of berries that you find damaged in those 90 clusters. (This is a visual non-destructive count, so you will leave the clusters intact on the vine)

CALCULATING THE DAMAGE

Since different varieties of grape will have different sized clusters, you will need to establish an average number of berries per cluster for the variety in that vineyard. You can do this at the onset of sampling by counting a number of bunches.

For Example: If you find 72 damaged berries in your sample block of 90 clusters vines (10clusters on 9 vines), and the average number of berries per cluster for that variety is 80, you can calculate the percentage damage as follows:

In Ontario there is no official threshold figure set for damage, but Vinifera growers should aim for a damage level less than 0.5% (the New York standard for Labrusca varieties is 2%). If on the first larval inspection the damage level exceeds 5%, check your application equipment and rates. It is possible that an immediate re-spray could still be effective, however as the larvae burrow deeper into the grapes they become less vulnerable to the spray treatment, so speed is important

SUMMARY

Over time you will build up a blueprint for GBM activity in each of your vineyards, but be prepared for differences from other vineyards, even though they may be in the same general area. What you will see is a repetition of the same pattern of insect activity every year (not necessarily at the same intensity), but it will enable you to stay on top of the problem by reminding you when and where you should look for problems. In due course it is possible that you will decide to change to a biological control system rather than a chemical one. If this happens, the monitoring information that you have established will be vital in making that successful.